Deprecated: The each() function is deprecated. This message will be suppressed on further calls in /customers/c/9/b/ on line 66 Warning: Cannot modify header information - headers already sent by (output started at /customers/c/9/b/ in /customers/c/9/b/ on line 316 Warning: Use of undefined constant SIMPLEPIE_FILE_SOURCE_NONE - assumed 'SIMPLEPIE_FILE_SOURCE_NONE' (this will throw an Error in a future version of PHP) in /customers/c/9/b/ on line 28 Warning: Use of undefined constant SIMPLEPIE_FILE_SOURCE_NONE - assumed 'SIMPLEPIE_FILE_SOURCE_NONE' (this will throw an Error in a future version of PHP) in /customers/c/9/b/ on line 28 Warning: Cannot modify header information - headers already sent by (output started at /customers/c/9/b/ in /customers/c/9/b/ on line 89 Hacker News Links for the intellectually curious, ranked by readers. Start Your Own ISP <p>This site is dedicated to helping you start your own Internet Service Provider. Specifically this guide is about building a Wireless ISP (<a href="">WISP</a>).</p> <p>This guide is focused on the very earliest stages of starting a WISP - determining feasibility up through connecting the first few customers. There are many challenges that will come up at 100, 1,000 or 10,000 customers that are not (yet) covered in this guide.</p> <p>If you’d like personalized assistance with a project feel free to <a href="">book some time</a> with me.</p> <p><a href=""><strong>Join the discussion!</strong></a> Chat with me (the author) and others interested in this kind of thing here: <a href=""></a>.</p> <p><a href=""><strong>Follow Along</strong></a> on Twitter <a href="">@syoisp</a></p> <h2 id="getting-started">Getting Started</h2> <p><a href=""><strong>What is a WISP?</strong></a> And why might you want to build one? Also defines some terminology.</p> <p><a href=""><strong>Costs</strong></a> What does it cost to build a wireless Internet Service Provider? (Link to a Google Sheet that you can copy and customize.)</p> <p><a href=""><strong>About Me</strong></a> Who am I? Why am I doing this?</p> <h2 id="step-by-step-guide">Step by Step Guide</h2> <p><a href=""><strong>Step 1: Evaluate an Area</strong></a>: Make sure your area is a good candidate for a Wireless Internet network.</p> <p><a href=""><strong>Step 2: Find a Fiber Provider</strong></a>: Find a building where you can purchase a fiber connection and use the rooftop to start your wireless network.</p> <p><a href=""><strong>Step 3: Find Relay Sites</strong></a>: Extend your network wirelessly toward your customers.</p> <p><a href=""><strong>Step 4: Pick a Hardware Platform</strong></a>: Evaluate available options for wireless hardware.</p> <p><a href=""><strong>Step 5: Billing and Customer Management</strong></a>: Make sure you’re able to get paid and support your customers.</p> <p><a href=""><strong>Step 6: Network Topology</strong></a>: Design your network topology to make your network reliable and scalable. Routers, switches, IP addresses, VLANs, etc.</p> <p><a href=""><strong>Step 7: Build your Infrastructure</strong></a>: Install hardware for your fiber connection and your relay sites.</p> <p><a href=""><strong>Step 8: Install a Customer</strong></a>: Get your first customer online!</p> <p><a href=""><strong>Step 9: Marketing</strong></a>: Let people know about your service so they can experience a better Internet connection!</p> <p><a href=""><strong>Step 10: Maintenance</strong></a>: Keep your network running smoothly, even in bad weather.</p> <h2 id="miscellaneous">Miscellaneous</h2> <p><a href=""><strong>Form 477: How to prepare and file with the FCC</strong></a> Form 477 is used by the FCC to determine which providers are servicing which areas. ISPs must file this form twice a year.</p> <p><a href=""><strong>Tools you’ll want to have</strong></a> A list of the tools you’ll need to install relays sites and customers.</p> <p><a href=""><strong>Aim a Backhaul</strong></a> A guide describing the proper techniques for aiming backhauls. Designed to be printed out and taken to the site for reference.</p> <p><a href=""><strong>Backhaul List</strong></a> If you just need to get a solid wireless connection from Point A to Point B then use this list to pick the right equipment and get it set up.</p> <p><a href=""><strong>RF Basics and Channel Planning</strong></a> Avoid self interference by carefully choosing channels for your access points and backhauls.</p> <p><a href=""><strong>MDUs (Multiple Dwelling Units)</strong></a> Best practices for providing service to apartment buildings, condos, attached townhomes, etc.</p> <p><a href=""><strong>Guide to Google Earth</strong></a> Some tips and tricks for using Google Earth to plan and build your network.</p> <p><a href=""><strong>Roof and Ladder Safety</strong></a> Stay safe out there!</p> <aside class="copyright" role="note"><center> Sponsored by <a href="">BroadbandNow</a>.<br/>Looking to donate? <a href="">Patreon</a> or BTC 1JKa1Kdrp3r4xPSXBRJ6nPC6YYdLcqQ4Bp. Many thanks! <br/>© 2019 – Documentation built with <a href="" target="_blank">Hugo</a> using the <a href="" target="_blank">Material</a> theme. </center> </aside> Sat, 17 Aug 2019 22:43:37 +0000 GNU Parallel 2018 <h4>Zenodo DOI Badge</h4> <h4> <small>DOI</small> </h4> <h4> <pre>10.5281/zenodo.1146014</pre> </h4> <h4> <small>Markdown</small> </h4> <h4 readability="-2"> <pre>[![DOI](](</pre> </h4> <h4> <small>reStructedText</small> </h4> <h4 readability="-2"> <pre>.. image:: :target:</pre> </h4> <h4> <small>HTML</small> </h4> <h4 readability="-2"> <pre>&lt;a href=""&gt;&lt;img src="" alt="DOI"&gt;&lt;/a&gt;</pre> </h4> <h4> <small>Image URL</small> </h4> <h4 readability="-3"> <pre></pre> </h4> <h4> <small>Target URL</small> </h4> <h4 readability="-3"> <pre></pre> </h4> Sat, 17 Aug 2019 21:49:42 +0000 The Completely Reasonable Reason People Are Flying with Mini Horses <div readability="40.821895424837"><div class="css-53u6y8" readability="27.542483660131"><p class="css-exrw3m evys1bk0">Last week, after months of deliberation, the Department of Transportation released <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">formal guidance</a> regarding animals on planes. The 28-page document makes it clear that three types of service animals should be prioritized for travel: cats, dogs and miniature horses.</p><p class="css-exrw3m evys1bk0">Yes, miniature horses. The document repeatedly includes mini horses in a trio of “the most commonly recognized service animals” and the “most commonly used service animals.”</p><p class="css-exrw3m evys1bk0">Shortly after the guidelines’ release, a photo of a small ginger horse, squeezed in front <!-- -->of a woman’s knees, circulated on the internet. It appeared atop numerous articles, without any sort of caption, <!-- -->only adding to the questions raised by the travel document: If flying horses are so common, how come I’ve never rolled my carry-on past one? How could that photo be real? And even if it is, why would you ever want to squeeze a horse in front of a seat like that?</p></div><aside class="css-o6xoe7"/></div><div readability="33.401442307692"><div class="css-53u6y8" readability="14.314903846154"><h2 class="css-ani50b eoo0vm40" id="link-50aebf64">So, is that picture real?</h2><p class="css-exrw3m evys1bk0">Yes. Compared with cats and dogs, miniature horses are still a rare sight on planes. But the horse in the photo, <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">Confetti</a>, is far from the only miniature to have ever flown. According to <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">the website</a> of a ranch that was involved in raising Confetti, the picture — which shows the horse pressed <!-- -->against her owner<!-- --> — was taken on a Delta flight in 2004, somewhere between Atlanta and Boston.</p></div><aside class="css-o6xoe7"/></div><div readability="44.505439005439"><div class="css-53u6y8" readability="38.540792540793"><h2 class="css-ani50b eoo0vm40" id="link-409e3e76">Why a mini horse?</h2><p class="css-exrw3m evys1bk0">There are many<a class="css-1g7m0tk" href="" title=""> reasons</a> someone would fly with a miniature horse, disability experts say. Although a growing number of <a class="css-1g7m0tk" href="" title="">emotional support</a> <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">animals</a> have emerged in recent years, in the case of miniature horses, their function as service animal is primarily physical, said Kenneth Shiotani, a senior staff lawyer at the National Disability Rights Network. </p><p class="css-exrw3m evys1bk0">For some blind people, such as <!-- -->Confetti’s owner,<!-- --> guide horses serve as a compelling alternative to guide dogs.The animals are mild-mannered and fast learners, with nearly 360-degree vision. They may also offer balance support to individuals with physical disabilities. </p><p class="css-exrw3m evys1bk0">Mona Ramouni, who has more experience traveling with a miniature horse than perhaps anyone else in America, pointed out that training <!-- -->a <!-- -->service animal takes thousands of hours. “With a dog you’ll get eight to 10 years if you are lucky,” she said, adding that “with a horse you get 35, 40 years.” Ms. Ramouni’s own horse, Cali, is 14. “She’s just getting to middle age<!-- -->,” she said.</p><h2 class="css-ani50b eoo0vm40" id="link-21dbdb65">How do you get a horse to the airport?</h2><p class="css-exrw3m evys1bk0">True miniature horses, which are not to be confused with <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">ponies</a>, are <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">less than 34 inches</a> in height. They were bred to be pets for European nobility in the 1600s, <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">according to the International Museum of the Horse</a>.</p></div><aside class="css-o6xoe7"/></div><div readability="33"><div class="css-53u6y8" readability="11"><p class="css-exrw3m evys1bk0">Their compact size makes them capable of fitting into the back of a hatchback, which is how Ms. Ramouni and her husband typically get Cali to the airport. “She’ll jump into the back of the car,” Ms. Ramouni said.</p></div><aside class="css-o6xoe7"/></div><div readability="48.5"><div class="css-53u6y8" readability="42"><h2 class="css-ani50b eoo0vm40" id="link-14f9b500">How do you get the horse on the plane?</h2><p class="css-exrw3m evys1bk0">Ms. Ramouni usually buys flights on short notice, calling the airline the day before to give a heads up that she will be traveling with a horse. Occasionally airlines have told her that they did not have room, she said, but she is hopeful that the new guidelines will discourage such behavior.</p><p class="css-exrw3m evys1bk0">Going through security with Cali ten<!-- -->ds to prompt giggles and declarations <!-- -->from workers<!-- --> that “I’ve never checked a horse before.” <!-- -->Airport officials will sometimes ask for Cali’s <!-- -->official “horse <!-- -->ID,” Ms. Ramouni said. Unaware of any organization that offers such a thing, she and a friend eventually made a card themselves. </p><p class="css-exrw3m evys1bk0">Before going to the gate, Ms. Ramouni will ask someone to lead them to the women’s restroom.“My horse has been trained to go potty in a plastic bag,” she said. “I would just give her the command to go potty, then I flush it down the toilet.”</p><p class="css-exrw3m evys1bk0">Seeing a horse in an airport restroom tends to spark questions like, “Is that real?” She enjoys indulging the question, she said, but on one occasion, she relished responding to a drunken woman with, “I don’t know what you are talking about.”</p><h2 class="css-ani50b eoo0vm40" id="link-59bde6b2">How do you fit a horse in front of your seat?</h2><p class="css-exrw3m evys1bk0">It does not seem strange that miniature horses are among the most commonly “recognized” service animals because there is a long history of evidence that they are helpful to people with disabilities, said Jennifer Mathis, director of policy and legal advocacy at the Bazelon Center for Mental Health Law.</p></div><aside class="css-o6xoe7"/></div><div readability="51.31497005988"><div class="css-53u6y8" readability="48.354491017964"><p class="css-exrw3m evys1bk0">But though they may technically be among the “most commonly used” service animals according to The Department of Transportation, they are still rare. Ms. Ramouni said she knew a couple of other blind people who had flown, but “it’s kind of uncharted territory.”</p><p class="css-exrw3m evys1bk0">Airlines that have engaged with miniature horses before typically put Ms. Ramouni and Cali in the bulkhead row, which has more legroom and no seats in front. T<!-- -->hroughout the flight<!-- --> Cali stands at Ms. Ramouni’s feet<!-- -->.</p><p class="css-exrw3m evys1bk0">For many people, their most memorable encounter with a miniature horse might have been seeing <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">Li’l Sebastian</a> on the TV show “Parks and Recreation” or visiting a petting zoo. As a sort of mini horse ambassador, Ms. Ramouni feels pressure to ensure Cali doesn’t stink up a plane.</p><p class="css-exrw3m evys1bk0">“I don’t want my accidents to be someone’s first impression,” she said. Cali is used to going for long stretches without urinating, but Ms. Ramouni has created a tidy defecation setup for long flights: When she senses that Cali needs to go, she signals<!-- --> the horse, who then<!-- --> goes into a deodorized bag.</p><p class="css-exrw3m evys1bk0">On the way down, Ms. Ramouni gives Cali ice to chew for the pressure. She doesn’t like to fly too often — or for too long — because she knows that flying is hard on <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">horses</a>, small and large.</p><p class="css-exrw3m evys1bk0">It works out best when she has a friend or family member pick up the other end. Onetime, she said, she tried to hail a cab with Cali. No one stopped.</p><p class="css-exrw3m evys1bk0">Ms. Ramouni said she was hopeful that the new regulations would encourage other people to fly with their guide horses and, in doing so, would help make a case for guide horses over guide dogs. The next frontier, she said, is international travel.</p></div><aside class="css-o6xoe7"/></div> Sat, 17 Aug 2019 22:24:13 +0000 São Paulo Uncovered by Outdoor Advertising Ban <p>When São Paulo introduced its Clean City Law (<a href="">Lei Cidade Limpa</a>) a decade ago, over 15,000 marketing billboards were taken down. An additional 300,000 ostentatious business signs, hanging over streets or painted in large letters on facades, were also subject to a hefty fine if they were not removed promptly. Bus, taxi, and poster advertisements had to go as well. Even handing out pamphlets on the street was prohibited. While this legislation helped clean up the largest city in Brazil, it also revealed surprises hiding behind ad-covered urban signs and surfaces.</p> <figure id="attachment_12153" aria-describedby="caption-attachment-12153" class="wp-caption alignnone"><a href="" class="media-img"><img class="wp-image-12153 size-full" src="" alt="signage before after" width="1259" height="408" srcset=" 1259w, 300w, 600w, 728w" sizes="(max-width: 1259px) 100vw, 1259px"/></a><figcaption id="caption-attachment-12153" class="wp-caption-text">Before and after images by Marcelo Palinkas of the São Paulo City Council</figcaption></figure><p>The move to ban ads in this giant metropolis was controversial, in part due to its substantial estimated impact on the local economy. The law was (predictably) fought at all stages by business groups with a vested commercial interest in buying and selling prime public ad space.</p> <p>Some arguments from the business community were framed as selfless. A lack of ads, according to one such argument, would lead to less lighting (of billboards and walls) and thus more dangerous streets. Other arguments were more blatantly self-interested. <a href="">Clear Channel Outdoor</a>, one of the world’s biggest outdoor-advertising companies, went so far as to <a href="">sue the city</a>, claiming the ban was unconstitutional.</p> <p>In the end, the law went into effect on January 1st, 2007, and businesses were given 90 days to comply or pay the price.</p> <figure id="attachment_12152" aria-describedby="caption-attachment-12152" class="wp-caption alignnone"><a href="" class="media-img"><img class="wp-image-12152 size-full" src="" alt="street before after" width="1259" height="463" srcset=" 1259w, 300w, 600w, 728w" sizes="(max-width: 1259px) 100vw, 1259px"/></a><figcaption id="caption-attachment-12152" class="wp-caption-text">Before and after images by Marcelo Palinkas of the São Paulo City Council</figcaption></figure><p>Most citizens were fans of the initiative, including local reporter <a href="">Vinicius Galvao</a>, who writes for the <a href="">Folha de São Paulo</a>, Brazil’s largest newspaper. He notes that his hometown is “a very vertical city,” but before the law “you couldn’t even [see] the architecture of the old buildings, because they were just covered with billboards and logos and propaganda. And there was no criteria [to restrict them].”</p> <figure id="attachment_12154" aria-describedby="caption-attachment-12154" class="wp-caption alignnone"><a href="" class="media-img"><img class="wp-image-12154 size-full" src="" alt="clean city signs billboards" width="1209" height="806" srcset=" 1209w, 300w, 600w, 728w" sizes="(max-width: 1209px) 100vw, 1209px"/></a><figcaption id="caption-attachment-12154" class="wp-caption-text">Signs, billboards and building walls shortly after the Clean City law was passed, images by <a href="">Tony de Marco</a></figcaption></figure><p>While the law had broad public support, some residents were worried for financial, pragmatic, and aesthetic reasons. For starters, the city would not only <a href="">lose revenue</a> from absent ads, but would have to actively spend money taking down the resulting <a href="">ghost town</a> of empty billboards. Further: signs, no matter how corporate, can be <a href="">wayfinding devices</a>, and stripping them could make familiar routes harder to follow. Other critics were nervous that without the colorful veneer of advertisements the urban environment might look worse rather than better, unmasked as a gloomy concrete cityscape. Passing the Clean City Law did uncover a number of things no one expected, for better and worse.</p> <figure id="attachment_12170" aria-describedby="caption-attachment-12170" class="wp-caption alignnone"><a href="" class="media-img"><img class="wp-image-12170 size-medium" src="" alt="favela example" width="600" height="399" srcset=" 600w, 300w, 728w" sizes="(max-width: 600px) 100vw, 600px"/></a><figcaption id="caption-attachment-12170" class="wp-caption-text"><a href="">Rocinha</a>, the largest favela in Brazil (located in Rio de Janeiro), image by <a href="">chensiyuan, GFDL</a></figcaption></figure><p>As it turned out, advertisements were quite literally covering up problems with the city that needed to be addressed. Removing billboards revealed, for instance, the presence of <a href=";sl=pt&amp;u=;prev=search">certain smaller shanty towns</a> (known as favelas) that few knew existed, hidden as they were behind a vertical landscape of giant signs. As facade-spanning ads were pulled down from the sides of buildings, immigrants living inside of the same factories in which they worked (often in poor conditions) were discovered. Crumbling civic infrastructure was also cast into the spotlight, made more visible in the absence of distracting ads.</p> <figure id="attachment_12147" aria-describedby="caption-attachment-12147" class="wp-caption alignnone"><a href="" class="media-img"><img class="wp-image-12147 size-medium" src="" alt="bright building mural" width="600" height="338" srcset=" 600w, 300w, 728w, 1280w" sizes="(max-width: 600px) 100vw, 600px"/></a><figcaption id="caption-attachment-12147" class="wp-caption-text">Vertical building mural stands out against the lack of street advertising</figcaption></figure><p>Cleaning up ads from the sides of buildings also inadvertently freed up more space for street artists to work with, and helped make new and existing artworks stand out against the urban environment.</p> <p>Enthusiastic city workers, however, took things a step further than people expected when it first came to enforcing the law. Certain public murals were wiped clean, causing concern among citizens. The <a href=";sid=ar4OrAXUisPQ&amp;refer=latin_america">removal of one 2,000-foot-long work</a> in particular sparked local outrage as well as global press coverage. Eventually, with public support, the city created an official registry to protect key extant and future pieces of street art, now more visible than ever.</p> <figure id="attachment_12153" aria-describedby="caption-attachment-12153" class="wp-caption alignnone"><a href="" class="media-img"><img class="wp-image-12153 size-medium" src="" alt="signage before after" width="600" height="194" srcset=" 600w, 300w, 728w, 1259w" sizes="(max-width: 600px) 100vw, 600px"/></a><figcaption id="caption-attachment-12153" class="wp-caption-text">Before and after images by Marcelo Palinkas of the São Paulo City Council</figcaption></figure><p>The Clean City law also forced building owners and businesses to confront unpainted and unattractive architecture, reconsidering their visual presence in shared civic spaces. For businesses forced to remove their prominent signs and logos, painting structures in distinctive colors became a way to help people identify and distinguish between them.</p> <figure id="attachment_12156" aria-describedby="caption-attachment-12156" class="wp-caption alignnone"><a href="" class="media-img"><img class="wp-image-12156 size-full" src="" alt="london before after ads" width="600" height="600" srcset=" 600w, 300w, 400w" sizes="(max-width: 600px) 100vw, 600px"/></a><figcaption id="caption-attachment-12156" class="wp-caption-text">Historical, recent and contemporary images of the London Trocadero via <a href="">Torchwar</a></figcaption></figure><p>This move to reduce advertising in public spaces is not unique to São Paulo, though other cities rarely take it so far. Above, the <a href="">London Trocadero</a> is shown first in its original condition, then during its prime marketing career and, finally, after the advertisements were removed once again. Several states in the US prohibit billboard advertising, including Alaska, Hawaii, Maine and Vermont. In Beijing, the mayor <a href="">banned public ads for luxury apartments</a> for encouraging self-centered and over-indulgent lifestyles. Paris has recently <a href="">reduced public ad space by a third</a>, while Tehran temporarily <a href="">replaced its 1,500 advertising billboards with art</a> for 10 days in 2015.</p> <figure id="attachment_12173" aria-describedby="caption-attachment-12173" class="wp-caption alignnone"><a href="" class="media-img"><img class="wp-image-12173 size-medium" src="" alt="Downtown São Paulo at night by Júlio Boaro" width="600" height="337" srcset=" 600w, 300w, 728w" sizes="(max-width: 600px) 100vw, 600px"/></a><figcaption id="caption-attachment-12173" class="wp-caption-text">Downtown São Paulo at night by <a href="">Júlio Boaro</a></figcaption></figure><p>Today, some ads are being reintroduced in São Paulo, but in a much more controlled fashion than before. An interactive search engine ad at bus stops, for instance, helpfully allows residents to look up weather conditions for their destinations, providing a useful service.</p> <p>Starting from scratch has its advantages, like letting the community drive decisions about what to allow and what to prohibit. As São Paulo’s approach illustrates, such a sweeping initial act of removing ads can reveal both secret weaknesses but also hidden strengths of a city.</p> Sat, 17 Aug 2019 18:18:11 +0000 Kurt Kohlstedt Software architects should be involved in earliest system engineering activities <div readability="62.488529014845"> <p class="Body"><i>Suzanne Miller, Bill Nichols, Don Firesmith, and Mike Phillips contributed to this post.</i></p> <p class="Body">Today's major defense systems rely heavily on software-enabled capabilities. However, many defense programs acquiring new systems first determine the physical items to develop, assuming the contractors for those items will provide all needed software for the capability. But software by its nature spans physical items: it provides the inter-system communications that have a direct influence on most capabilities, and thus must be architected intelligently, especially when pieces are built by different contractors. If this architecture step is not done properly, a software-reliant project can be set up to fail from the first architectural decision.</p> <p class="Body"><i>Example: </i><a href=""><i>The Global Positioning System (GPS)</i></a><i>) was divided into ground, user, and satellite segments, and the government issued different contracts for each segment. Many interaction and schedule problems resulted, partly because the segments had different schedules. For example: a satellite was due to launch with new software, so the existing ground segment software was not designed to work with it, but the new ground segment software was not complete.</i></p> <p class="Body">If, instead, system acquirers ensure that systems engineers address software concerns at the same time as the physical solution is conceptualized, acquirers can opt for a slightly different physical system, whose software architecture is tuned to optimize the provided capabilities.</p> </div><div readability="269.57545750815"> <p class="Body"><b>Acquisition of Defense Systems</b></p> <p class="Body"><a href="">The 2018 National Defense Strategy</a> proposed a set of challenges needing solutions. Challenges like a "complex and volatile security environment" and a call for a "more lethal, resilient, and rapidly innovating Joint Force, combined with a robust constellation of allies and partners" can be addressed only by a complex combination of capabilities created from a large number of individual systems.</p> <p class="Body">To start creating capabilities, the Department of Defense (DoD) identifies specific capability gaps and creates an <a href="">Initial Capabilities Document (ICD)</a> that describes why non-materiel changes alone have been inadequate. Subsequent DoD analysis leads to one or more <a href="">Capabilities Development Documents (CDDs)</a>. A CDD describes requirements for an acquirable system that will provide a specified contribution to the <a href="">system-of-systems (SoS)</a> capability. The acquirable system's requirements describe "a militarily useful increment of capability" that is feasible to contract out for delivery.</p> <p class="Body">Commandment 4 of the <a href="">Defense Innovation Board's Ten Commandments of Software</a> (<i>Adopt a <a href="">DevOps</a> culture for software systems</i>) notes that "Software is never 'finished' but must be constantly updated to maintain capability, address ongoing security issues and potentially add or increase performance." For this reason, the evolvability of software has become a large part of the <a href="">sustainability</a> of a system. If the software architecture is not modifiable, the system as a whole may not be sustainable.</p> <p class="Body">Figure 1 shows an identified problem leading to a notional solution architecture.</p> <p class="Body"><img alt="figure1_08122019_sheard.png" src="" class="mt-image-center" width="974" height="377"/></p> <p><em>Figure 1. Earliest system engineering converts the problem to the notional solution architecture</em>.</p> <p class="Body">Today's complex capability needs lead to complex capability requirements that can often only be provided by a <a href="">system of systems</a>. To create the SoS, the program must identify a set of constituent systems that together provide the needed capability and individually are small enough that a single contractor can build each one. Early government analyses (including <a href="!13">analysis of alternatives (AoA)</a>, performance analysis, and individual technical analyses such as pointing analyses) determine which set of smaller systems will provide an SoS capability that will meet the need. Because SoSs evolve with every added or modified system, the initial system might only provide some of the desired capabilities, but capability deficits can be addressed with subsequent acquisitions.</p> <p class="Body"><b>Historical Division of Contracts along Physical Lines</b></p> <p class="Body">It is easy to imagine that the SoS creation process outlined above would lead to a separation of contractor responsibilities along the lines of physical systems. A satellite might be built by one contractor, the ground system by another, and user handheld equipment by a third. Back when the interfaces among these systems, such as analog radio channels, were fairly simple and well understood, the desired capabilities existed primarily within the systems contracted out to single contractors. Communication between the systems was fairly easily defined.</p> <p class="Body">In our satellite example, the government could have sought contractors to build each of the three systems and assumed that they would include everything needed to make the systems work, including inter-system communications. This thinking aligns with the 1960-1980 version of satellites that assumed software existed <i>internal</i> to a system, which is described in <a href="">a previous blog post</a>. In contrast, more recent thinking acknowledges that software drives communication and control paths among all the different physical pieces of a system, making its role in providing SoS capability more critical.</p> <p class="Body"><b>Problems with Separating Along Physical Lines</b></p> <p class="Body">Especially today, breaking contracts along strictly physical lines is a recipe for integration problems. Software architectures determine <a href="">software quality attributes</a>. The quality attributes of SoSs are likewise determined to a large degree by the software architecture of the constituent systems and their compatibility with each other. Making a small decision on a simple system can seem minor, but if it breaks the compatibility with other systems, there can be big problems at the SoS level. Today's decisions influence tomorrow's software modifiability, and thus tomorrow's <a href="">sustainment cost</a>.</p> <p class="Body">In today's software-intensive systems, the <i>software</i> architecture also greatly influences <i>system</i> quality attributes, even when no such connection is apparent to the system designers. This connection is one reason designers must pay attention to the relationship of the needed software to the system-level decomposition: the decomposition creates a structure that constrains the software architecture, which, in turn, affects the system's quality attributes. If the software architecture is incorrectly constrained by the system-level decomposition to physical pieces, this constraint can reduce the functionality that the software provides.</p> <p class="Body"><b>Strong Software-Software Communication Today</b></p> <p class="Body">With <a href="">the ubiquity of digital data</a> that has developed in the last decade, communication among systems is a strong contributor to the rapidly expanding capabilities of systems of systems. Today, much more information is communicated from system to system, in many different formats and along different paths, with different critical constraints including timing, privacy, and security. Determination of system and sensor status and sending of commands that achieve control require communication, which is thus a prime contributor to system quality attributes such as quality, safety, and security.</p> <p class="Body">Figure 2 highlights the software that allows the communication to occur, relative to the notional solution architecture. This drawing also shows communication to entities external to the system, such as existing legacy systems and stakeholders, and other systems that may be created in the future. Leaving the requirements for all these kinds of software undetermined often makes the integration and realization of future capability more difficult.</p> <p class="Body"><img alt="figure2_sheard_08122019.png" src="" class="mt-image-center" width="974" height="364"/></p> <p><em>Figure 2. Software provides capability for internal and external communication.</em></p> <p class="Body"><b>Decisions Needing Software Architects</b></p> <p class="Body">Rather than focusing on the physical items and ignoring the communication paths, it is now more important than ever that government analysts consider the tradeoffs involved when cutting a system into acquirable pieces. Early systems engineering teams must include people with the background knowledge and the expertise to identify problems that will need further study before tradeoffs can be finalized.</p> <p class="Body"><i>Example: Consider an unmanned aerial vehicle system (a drone, or remotely piloted aircraft) in a battle theater. This drone takes photographs and sends the data back to tactical decision makers. What kind of security should this drone system have? Should the data be encrypted? If so, how will the military have to staff the battle areas to ensure cryptographically qualified workers are available? Should data be processed on the aircraft, leading to heavier aircraft with lower communication bandwidth, or should it be sent raw, with the opposite effects? </i></p> <p class="Body">Such questions arise in today's SoSs when acquirers are determining the initial capabilities to develop. Without the expertise of systems architects on the government team, the implications of all these decisions to the system architecture--including software cost--are unclear. The initial system's impact is unclear, but even more unclear is the manner in which these decisions will affect later versions of the evolving SoS.</p> <p class="Body">Another integration issue that occurs in complex SoSs is that holders of the various contracts make different assumptions about the software and data. If one contractor has defined 1/360<sup>th</sup> of a year as a day in their sensor calculations, but this is unclear to an engineer developing the sensor processing algorithm, then the software will produce wrong results. If each contributor to a massive calculation does a <a href="">Fourier transform</a> from time to frequency or vice-versa, the software may not meet its required timing. Software architects must be aware of the assumptions and of the effect that incorrect assumptions may have on the results. Software architects should define known assumptions and specify how future conflicts in assumptions should be resolved.</p> <p class="Body"><b>Balancing Is a Systems Engineering Job</b></p> <p class="Body">The <a href=",%20revised%2022%20Feb%202017.pdf">Defense Acquisition University's Joint Capabilities Integration and Development System (JCIDS) Primer</a> defines the requirements environment as finding the balance between near-term and long-range requirements, system versatility and optimization, growing demands and fiscal constraints, ambition and achievability, and quantity and quality. Such balancing is part of the <a href="">defense systems engineering discipline</a>. System engineers ask and attempt to answer questions such as the following:</p> <ul><li><i>Should the individual systems be more powerful at the cost of slower communication, which would delay the signal across the SoS? </i></li> <li><i>Would the security issues created by transmitting raw data, rather than processed and encrypted data, overwhelm the advantages of having all the processing done on the ground as opposed to in the air or in-orbit? </i></li> <li><i>Would building a partial system quickly get more needed capability to the field than a slower system with integrated capability? </i></li> </ul><p class="Body">To answer these questions, the systems engineering team must have a clear idea of the system and software architectural challenges and of modern ways to address such challenges. Such considerations demand either that a software architect with considerable experience in the domain be part of all such early systems engineering teams or that the systems engineers have significant strength in software architecture. The latter is problematic: systems engineers must excel in a broad set of engineering topics and understand the operational domain, while software architects must understand very detailed aspects about software and keep continuously up to date. It is difficult for any one person to master all this information, and <a href="">the two aspects may be generally suited to different kinds of people</a>: a systems engineer's job is easier if they like interacting with the many people who are needed to provide the broad system overview (For more on this see <a href=""><i>Development of Systems Engineering Expertise</i></a> by James R. Armstrong), while software engineers often need to think through a number of complex concepts during a quiet time with a closed door. It is usually best to add a capable, experienced software architect to the systems engineering team.</p> <p class="Body"><b>Systems Engineers Use Trade Studies to Ensure Balance</b></p> <p class="Body">To achieve this necessary balance across disciplines and over the lifecycle, with recent emphasis on ensuring evolvability due to recognition of high sustainment costs [see <a href="">here</a> and <a href="">here</a>], systems engineers perform trade studies. Early trade studies look at multiple ways of meeting the highest-level customer need. During these trades, systems engineers--including those in the acquirer organization--identify a number of options (i.e., architectures) for breaking an early system concept into pieces that are small enough for individual contractors to develop.</p> <p class="Body">Because software fulfills more system capability today than in previous decades, because system solutions tend to be SoSs, and because evolvability is an increasingly important quality attribute, today's systems engineers working in the earliest phases should pay special attention to potential integration issues. They must look at multiple options and conduct trade studies documenting how well each option meets the various success criteria.</p> <p class="Body">Software architects must also be available to look at each potential solution and identify its likelihood of meeting software quality attributes. These architects should be skilled in understanding the implications of various architectures on different kinds of performance. They should also be willing to estimate relative risk across the options given as well as recommend architectural tweaks that could improve the score of any particular option.</p> <p class="Body">The DoD has tried a number of ways to get systems engineers to learn enough about software to make such decisions, including education and experience. However, software is so deep and dynamic that it is difficult to remain knowledgeable about it while also maintaining the broad knowledge systems engineers need.</p> <p class="Body">Hardware engineers will also be expected to provide estimates and implications for each option: estimating cost, schedule, performance, and risk. But both systems engineers and hardware engineers have been included in early efforts for a number of decades, whereas trade-study activities that include software engineers and architects are less common. For example, a <a href="">2004 document</a> showed the Navy's mature process at that time for creating trade study data and presenting it to decision makers. The document specifically mentions utility curves as showing how well different options meet the trade study criteria. The word <i>software</i> is not found in the document, thus only the systems engineers considered it relevant.</p> <p class="Body"><b>Solution: Include Software Architects in Early Systems Engineering Efforts</b></p> <p class="Body">Figure 3 shows how the early design process could look with early involvement of software architects. When trade studies are performed, the software architect helps to identify constraints, risks, performance issues, cost issues, and schedule issues that relate to the software-enabled capabilities of the SoS.</p> <p class="Body"><img alt="figure3_earlydesignprocess_08122019.png" src="" class="mt-image-center" width="974" height="462"/></p> <p><em>Figure 3. Early Design Process</em></p> <p class="Body">To make effective use of the software architect on the team, the system engineer should ask the following questions. This paper featuring this list was presented at the <a href="">29<sup>th</sup> Annual INCOSE International Symposium</a>. The answers will be folded into system trade studies.</p> <ul><li><i>What major software architectural decisions are going to be needed? What impact will the various options have at the system level?</i></li> <li><i>What decisions must be made to ensure that software is not unreasonably constrained, so developers will be able to create the software economically, and it will serve the operational needs correctly, including adaptation, reconfiguration, and graceful degradation? </i></li> <li><i>What approaches reduce risk of cyberattack, and how might they change?</i></li> <li><i>What makes development difficult? Would some options be easier to develop than others?</i></li> <li><i>What software risks could become system risks? </i></li> <li><i>Will this change be a small change? Or might it become a huge problem?</i></li> </ul><p class="Body">Not every software engineer will provide the right skills to the systems engineering team. Many programmers will wait until a detailed specification is presented to them to start work. Software engineers may not look for future compatibility and tradeoffs. Generally, good software architects are good systems engineers of software, who may lack knowledge about and experience with non-software pieces of systems. The goal is to include software architects who can reason about the software as a whole in the early stages, are familiar with the domain, and are keeping up as software and cybersecurity best practices evolve.</p> <p class="Body"><b>Looking Ahead </b></p> <p class="Body">In today's systems, which are often implemented as components of SoSs, it is critical that we recognize the importance of software to provide the necessary capabilities to the customer and user. Splitting the system along physical lines makes software engineering difficult, introduces many risks, and endangers cost, schedule, and system performance goals.</p> <p class="Body">Today and into the future the best way to ensure that a new system's software architecture supports needed capabilities and also system evolvability is to involve software-knowledgeable personnel--specifically software architects--in the early system decisions about breaking up a system into acquirable parts. At this early stage, many software problems are either caused or avoided, and software architects are needed to ensure the latter.</p> <p class="Body"><b>Additional Resources</b></p> <p class="Body">Read other <a href="">blog posts by Sarah Sheard</a>.</p> </div> Sat, 17 Aug 2019 17:53:33 +0000 Microsoft Has First Major Impact on Chrome <p><img class="alignnone size-full wp-image-205514" src="" alt="" width="1066" height="600" srcset=" 1066w, 450w, 768w, 1024w, 800w, 310w, 500w, 600w" sizes="(max-width: 1066px) 100vw, 1066px"/></p> <p>Thanks to the open-source nature of Chromium, Microsoft has had its first major and positive impact on Chrome, Google’s web browser. Thanks to a feature request from Microsoft, Google will issue a change to Chromium, the open-source project by which Google makes Chrome, that significantly improves battery life.</p> <p>“Today, media content is cached to disk during acquisition and playback,” Microsoft’s Shawn Pickett <a href="">explains</a> in his change suggestion for Chromium. “Keeping the disk active during this process increases power consumption in general, and [it] can also prevent certain lower-power modes from being engaged in the operating system. Since media consumption is a high-usage scenario, this extra power usage has a negative impact on battery life. This change will prevent the caching of certain media content to disk for the purpose of improving device battery life for users.”</p> <p>And Microsoft knows battery life. Aside from being the makers of the most popular desktop operating system on which Chrome and other Chromium-based browsers are run, it also spent several years optimizing battery life in its previous versions of Microsoft Edge. And then it would publicize the results, in which classic Edge routinely outperformed the battery life in Chrome and other browsers.</p> <p>And Google’s on board. For now, the change is being tested as an experimental feature in Chrome Canary—the nightly builds of Chrome 78—which needs to be enabled by default: Just open chrome://flags and search for “Turn off caching of streaming media to disk.” (This works in Chrome for Windows, Mac, Linux, Chrome OS, and Android.)</p> <p>And if all goes as well as expected, it will be implemented and enabled by default in the browser.</p> <p>Tagged with <a href="" rel="tag">Chromium</a></p> Sat, 17 Aug 2019 20:37:55 +0000 Circle Show HN: Saag as a Service – macronutrient-portioned Indian spinach curry <img src="" alt="feature" class="img-fluid feature-img"/><!-- Empty Space --> <!--/ End Empty Space --> <h4 class="subtabove">Saag Paneer</h4> <h3 class="title">Classic <span class="badge badge-info">High Fat</span></h3> <!-- Empty Space --> <!--/ End Empty Space --> <p class="lead saagvariantdes">&#13; Our <strong>keto-friendly</strong> Saag Paneer features Indian farm cheese in a delectable, perfectly spiced spinach sauce.&#13; </p> <table class="table d-md-none"><tbody><tr class="table-info"><td>500 cals</td>&#13; <td>21g protein</td>&#13; <td>43g fat</td>&#13; <td>6g carbs</td>&#13; </tr></tbody></table> Sat, 17 Aug 2019 17:59:15 +0000 You May Be Better Off Picking Stocks at Random, Study Finds <p><strong>VANCOUVER, British Columbia — </strong>Looking to take a stab at the stock markets, but aren’t sure where to begin? Try not to put too much stock in deciding what to buy. An interesting new study finds that novice investors are actually better off choosing stocks completely at random instead of making their own decisions.</p> <p>Thanks to the emergence of free, easy to use stock trading platforms, more consumers than ever before are trying their hand in the stock market. These platforms allow users to avoid high financial management fees, all while controlling their own stock portfolio. While these developments have certainly made it easier for the average person to start trading stocks, the study, conducted at the University of British Columbia, finds that many of these <a href="" target="_blank" rel="noopener noreferrer">less-experienced investors</a> are failing to diversify and could be putting themselves at great financial risk.</p> <p>For the study, researchers asked study participants to create investment portfolios using tables of previous financial asset returns, then assessed their level of <a href="" target="_blank" rel="noopener noreferrer">financial literacy</a>. The research team found that investors with poor financial literacy usually chose positively correlated assets, such as stocks in oil and forestry, that tend to fluctuate in value together.</p> <p>“An amateur investor might buy stocks in lumber, mining, oil and banks, and believe they are diversifying because they’re investing in different companies and sectors,” explains study co-author David Hardisty in a media <a href="" target="_blank" rel="noopener noreferrer">release</a>. “But because all of those equities tend to move in unison, it can be quite risky, because all the assets can potentially plunge at the same time.”</p> <p class="p1"><a href=""><b>CLICK HERE TO SUBSCRIBE TO OUR WEEKLY NEWSLETTER &amp; GET THE LATEST STUDIES FROM STUDYFINDS.ORG BY EMAIL!</b></a></p> <p>More experienced investors in the study, on the other hand, hedged their bets by always including negatively correlated, or uncorrelated, assets. Negatively correlated assets move up while the other moves down, and uncorrelated assets move up and down independently of each other. This more experienced approach to <a href="" target="_blank" rel="noopener noreferrer">stock investing</a> is a much better strategy to protect against potential financial losses.</p> <p>Hardisty and his team also found that the average amateur investor preferred correlated assets because they seemed less complicated and more predictable.</p> <p>“If it seems predictable, it seems safer and easier to track,” comments Hardisty. “Whereas if you have a combination of assets that all go in different directions, it seems chaotic, unpredictable and riskier.”</p> <p>Rather ironically, novice investors actually made safer, more diversified decisions when they were encouraged to make <a href="" target="_blank" rel="noopener noreferrer">riskier choices</a> by researchers.</p> <p>“This shows that amateur investors rely on a definition of risk that greatly differs from the objective definition of portfolio risk,” says Yann Cornil, another co-author on the study. “This can lead them to make objectively low-risk investments when they intend to take risk, or to make high-risk investments when they intend to reduce risk.”</p> <p>On the bright side, researchers say that the less experienced investors were able to see and acknowledge the errors in their approach after being encouraged to view their portfolios as a whole, instead of just focusing on each asset separately.</p> <p>The study’s authors encourage everyone thinking about dabbling in the stock market to do the proper amount of research before diving in, and to always take advantage of the diversification tools and education opportunities that many platforms offer to new investors.</p> <p>The <a href="" target="_blank" rel="noopener noreferrer">study</a> is published in the journal <em>Organizational Behavior and Human Decision Processes</em>.</p> <p><a class="fb-follow-link" href="" target="_blank"><svg xmlns="" width="48" height="48" viewbox="0 0 48 48"><path fill-rule="evenodd" d="M27.3303691,44 L18.4419742,44 L18.4419742,25.1116052 L14,25.1116052 L14,17.8350378 L18.4419742,17.8350378 L18.4419742,13.4664295 C18.4419742,7.53268119 20.9497554,4 28.0729213,4 L34.0066696,4 L34.0066696,11.2787906 L30.300578,11.2787906 C27.5260116,11.2787906 27.3414851,12.2970209 27.3414851,14.1934193 L27.3303691,17.8350378 L34.0489106,17.8350378 L33.2618942,25.1116052 L27.3303691,25.1116052 L27.3303691,44 Z"/></svg> Like studies? Follow us on Facebook!</a></p> Sat, 17 Aug 2019 14:58:03 +0000 Show HN: ClojureScript pixel game engine with Blender live-reloading <p>Aug. 17, 2019</p><div readability="61.195704057279"> <p>Recently I've been hacking on a game engine for <a href="">infinitelives</a> called <a href="">px3d</a>.</p> <p><img alt="around.gif" src=""/></p> <p>It's built on top of <a href="">ClojureScript</a>, <a href="">Blender</a>, and <a href="">Three.js</a> and it runs in the browser.</p> <p>One feature I'm particularly happy with is the live-reloading of Blender assets into the game. You hit "save" in Blender and the updates appear in the running game a second later - no need to re-compile or re-load the game.</p> <p><img alt="live-reloading.gif" src=""/></p> <p>The way this works is with a background script which watches the <code>assets.blend</code> file. It re-builds the <code>assets.glb</code> whenever it is modified, and writes the hash of the file into <code>assets.cljs</code>. Figwheel pushes changes to the compiled cljs files whenever they change, and there is another bit of code which tells three.js to re-load <code>assets.glb</code> if the hash has changed.</p> <p><a href="">Infinitelives</a> is the vehicle me and my buddy Crispin use to make games and tooling, mostly for gamejams. The gamejam format is great because it is time-boxed, which means we can periodically do this self-indulgent thing we enjoy without taking too much family or work time.</p> <p>Gamejams are typically only 48 hours long and so we have learned some good techniques for shipping working code under extreme constraints. A hardcore economy of time, resources, and scope is required.</p> <p><a href="">ClojureScript</a> &amp; <a href="">Figwheel</a> are perfect for this with their hot-loading of modified code. I built the tight Blender re-load integration for the same reason. Hand drawn graphics consume a lot of time during jams and this should help us really level up on the content side of things.</p> <p><img alt="cda02a53bdeea5ee13ac8d943761a42b.png" src=""/></p> <p>If you'd like to find out when we release games and new tools you can sign up to our release notifications on the <a href="">infinitelives home page</a> or <a href="">follow us on Twitter</a>.</p> </div> Sat, 17 Aug 2019 11:09:09 +0000 With friends like these... <h4>C-o-rr-a-ll-i-n-g<tt> </tt>d-i-tt-o-e-d<tt> </tt>l-e-tt-e-r-s</h4> <p>I was going to focus this week on the first task of the <a href="">20th Perl Weekly Challenge</a>...but what can I say? The task was a break a string specified on the command-line into runs of identical characters:</p> <pre><code class="prettyprint"> "toolless" → t oo ll e ss "subbookkeeper" → s u bb oo kk ee p e r "committee" → c o mm i tt ee </code></pre> <p>But that’s utterly trivial in Perl 6:</p> <pre><code class="prettyprint"> use v6.d; sub MAIN (\str) { .say for str.comb: /(.) $0*/ } </code></pre> <p>And almost as easy in Perl 5:</p> <p><code class="prettyprint"> use v5.30;</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> my $str = $ARGV[0]</code><br /><code class="prettyprint"> </code><tt>//</tt><code class="prettyprint"> die "Usage:\n $0 &lt;str&gt;\n";</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> say $&amp; while $str =~ /(.) \1*/gx;</code><br /></p> <p>In both cases, the regex simply matches any character (<code class="prettyprint">(.)</code>) and then rematches exactly<br />the same character (<code class="prettyprint">$0</code> or <code class="prettyprint">\1</code>) zero-or-more times (<code class="prettyprint">*</code>). Both match operations (<code class="prettyprint">str.comb</code><br />and <code class="prettyprint">$str =~</code>) produce a list of the matched strings, each of which we then output<br />(<code class="prettyprint">.say for...</code> or <code class="prettyprint">say $&amp; while...</code>).</p> <p>As there’s not much more to say in either case, I instead turned my attention to the second task: to locate and print the first pair of <a href="">amicable numbers</a>.</p> <h4>The friend of my friend is my enemy</h4> <p>Amicable numbers are pairs of integers, each of which has a set of proper divisors<br />(<em>i.e.</em> every smaller number by which it is evenly divisible) that happen to add up to<br />the other number.</p> <p>For example, the number 1184 is divisible by 1, 2, 4, 8, 16, 32, 37, 74, 148, 296, and 592; and the sum of 1+2+4+8+16+32+37+74+148+296+592 is 1210. Meanwhile, the number 1210 is divisible by 1, 2, 5, 10, 11, 22, 55, 110, 121, 242, and 605; and the sum of 1+2+5+10+11+22+55+110+121+242+605 guessed it...1184.</p> <p>Such pairs of numbers are uncommon. There are only five among the first 10 thousand integers, only thirteen below 100 thousand, only forty-one under 1 million. And the further we go, the scarcer they become: there only 7554 such pairs less than 1 trillion. Asymptotically, their average density amongst the positive integers converges on <a href="">zero</a>.</p> <p>There is no known universal formula for finding amicable numbers, though the 9th century Islamic scholar <a href="" title="Al-Ṣābiʾ Thābit ibn Qurrah al-Ḥarrānī">ثابت بن قره</a> did discover <a href="">a partial formula</a>, which Euler <em>(of course!)</em> subsequently <a href="">improved upon</a> 900 years later.</p> <p>So they’re rare, and they’re unpredictable...but they’re not especially hard to find.</p> <p>In number theory, the function giving the sum of all proper divisors of <em>N</em><br />(known as the <em>“restricted divisor function”</em>) is denoted by <big>𝑠</big>(<em>N</em>):</p> <p><code class="prettyprint"> sub <big>𝑠</big> (\N) { sum divisors(N) :proper }</code></p> <p>That trailing <code class="prettyprint">:proper</code> is an “adverbial modifier” being applied to the call to <code class="prettyprint">divisors(N)</code>,<br />telling the function to return only <em>proper</em> divisors (<em>i.e.</em> to exclude <code class="prettyprint">N</code> itself from the list).<br />And, yeah, that’s a Unicode italic <big><code class="prettyprint">𝑠</code></big> we’re using as the function name. Because we can.</p> <p>Once we have the restricted divisor function defined, we could simply iterate through each integer <em>i</em> from 1 to infinity, finding <big>𝑠</big><em>(i)</em>, then checking to see if the sum-of-divisors of <em>that</em> number (<em>i.e.</em> <big>𝑠</big><em>(<big>𝑠</big>(i)) </em>) is identical to the original number. If we only need to find the first pair of amicable numbers, that’s just:</p> <p><code class="prettyprint"> for 1..∞ -&gt; \number {</code><br /><code class="prettyprint"> my \</code><tt>friend</tt><code class="prettyprint"> = <big>𝑠</big>(number);</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> say (number, </code><tt>friend</tt><code class="prettyprint">) and exit</code><br /><code class="prettyprint"> if number != </code><tt>friend</tt><code class="prettyprint"> &amp;&amp; <big>𝑠</big>(</code><tt>friend</tt><code class="prettyprint">) == number;</code><br /><code class="prettyprint"> }</code></p> <p>Which outputs:</p> <pre><code class="prettyprint"> (220, 284) </code></pre> <p>But why stop at one result? When it’s no harder to find <em>all</em> the amicable numbers:</p> <p><code class="prettyprint"> for 1..∞ -&gt; \number {</code><br /><code class="prettyprint"> my \</code><tt>friend</tt><code class="prettyprint"> = <big>𝑠</big>(number);</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> say (number, </code><tt>friend</tt><code class="prettyprint">)</code><br /><code class="prettyprint"> if number &lt; </code><tt>friend</tt><code class="prettyprint"> &amp;&amp; <big>𝑠</big>(</code><tt>friend</tt><code class="prettyprint">) == number;</code><br /><code class="prettyprint"> }</code></p> <p>Note that, because the <em>amicable</em> relationship between numbers is (by definition) symmetrical,<br />we changed the <code class="prettyprint">number != </code><tt>friend</tt> test to <code class="prettyprint">number &lt; </code><tt>friend</tt><br /> prevent the loop from printing each pair twice:</p> <p><code class="prettyprint"> (220, 284)</code><br /><code class="prettyprint"> (284, 220)</code><br /><code class="prettyprint"> (1184 1210)</code><br /><code class="prettyprint"> (1210 1184)</code><br /><code class="prettyprint"> (2620 2924)</code><br /><code class="prettyprint"> (2924 2620)</code><br /><code class="prettyprint"> <em>(et cetera)</em></code><br /><code class="prettyprint"> <em>(cetera et)</em></code><br /><code class="prettyprint"></code><br /></p> <h4>The missing built-in</h4> <p>That would be the end of this story, except for one small problem: somewhat surprisingly,<br />Perl 6 doesn’t <em>have</em> the <code class="prettyprint">divisors</code> builtin we need to implement the <big><code class="prettyprint">𝑠</code></big> function. So we’re going to have to build one ourselves. In fact, we’re going to build quite a few of them...</p> <p>The divisors of a whole number are all the integers by which it can be divided leaving no remainder. This includes the number itself, and the integer 1. The <em>“proper divisors”</em> of a number are all of its divisors <em>except</em> itself. The <em>“non-trivial divisors”</em> of a number are all of its divisors except itself or 1. That is:</p> <pre><code class="prettyprint"> say divisors(12); # (1 2 3 4 5 6 12) say divisors(12) :proper; # (1 2 3 4 5 6) say divisors(12) :non-trivial; # (2 3 4 5 6) </code></pre> <p>The second and third alternatives above, with the funky adverbial modifiers, are really just <a id="syntactic-honey" href="" title="Like syntactic sugar, but good for you!">syntactic honey</a> for a normal call to <code class="prettyprint">divisors</code> but with an additional named argument:</p> <pre><code class="prettyprint"> say divisors(12); # (1 2 3 4 5 6 12) say divisors(12, :proper); # (1 2 3 4 5 6) say divisors(12, :non-trivial); # (2 3 4 5 6) </code></pre> <p>In Perl 6 it’s easiest to implement those kinds of <em>“adverbed”</em> functions using multiple dispatch, where each special case has a unique required named argument:</p> <p><code class="prettyprint"> multi divisors (\N, <strong>:$proper!</strong>) { divisors(N).grep(1..^N) }</code><br /><code class="prettyprint"> multi divisors (\N, <strong>:$non-trivial!</strong>) { divisors(N).grep(1^..^N) }</code><br /></p> <p>Within the body of each of these special cases of <code class="prettyprint">divisors</code>, we just call the regular variant of the function (<em>i.e.</em> <code class="prettyprint">divisors(N)</code>) and then <code class="prettyprint">grep</code> out the unwanted endpoint(s).<br />The <a href="^"><code class="prettyprint">..^</code> operator</a> generates a range that excludes its own upper limit,<br />while the <code class="prettyprint">^..^</code> operator generates a range that excludes both its bounds.<br /><em>(Yes, there’s also a <code class="prettyprint">^..</code> variant to exclude just the lower bound)</em>.</p> <p>So, when the <code class="prettyprint">:proper</code> option is specified, we filter the full list returned by <code class="prettyprint">divisors(N)</code><br />to omit the number itself (<code class="prettyprint">.grep(1..^N</code>). Likewise, we exclude <em>both</em> extremal values when the <code class="prettyprint">:non-trivial</code> option is included (<code class="prettyprint">.grep(1^..^N</code>).</p> <p>But what about the original unfiltered list of divisors?<br />How do we get that in the first place?</p> <p>The naïve way to generate the full list of divisors of a number <em>N</em>, known as <em>“trial division”</em>,<br />is to simply to walk through all the numbers from 1 to <em>N</em>, keeping all those that divide <em>N</em><br />with no remainder...which is easy to test, as Perl 6 has the <code class="prettyprint">%%</code> <em>is-divisible-by</em> operator:</p> <pre><code class="prettyprint"> multi divisors (\N) { # Track all divisors found so far... my \divisors = []; # For every potential divisor... for 1..N -&gt; \i { # Skip if it's not an actual divisor... next unless N %% i; # Otherwise, add it to the list... divisors.push: i; } # Deliver the results... return divisors; } </code></pre> <p>Except that we’re not cave dwellers and we don't need to rub sticks together like that, nor do number theory by counting on our toes. We can get the same result <strong><em>far</em></strong> more elegantly:</p> <pre><code class="prettyprint"> multi divisors (\N) { (1..N).grep(N %% *) } </code></pre> <p>Here we simply filter the list of potential divisors (<code class="prettyprint">1..N</code>), keeping only those that evenly divide <em>N</em> (<code class="prettyprint">.grep(N %% *)</code>). The <code class="prettyprint">N %% *</code> test is a shorthand for creating a <code class="prettyprint">Code</code> object that takes one argument (represented by the <code class="prettyprint">*</code>) and returns <code class="prettyprint">N %%</code> that argument. In other words, it creates a one-argument function by pre-binding the first operand of the infix <code class="prettyprint">%%</code> operator to <code class="prettyprint">N</code>. If that’s a little too syntactically mellifluous for you, we could also have written it as an <a href="">explicit pre-binding</a> of the <code class="prettyprint">%%</code> operator:</p> <p><code class="prettyprint"> (1..N).grep( <strong>&amp;infix:&lt;%%&gt;.assuming(N)</strong> )</code><br /></p> <p>...or as a lambda:</p> <p><code class="prettyprint"> (1..N).grep( <strong>-&gt; \i { N %% i }</strong> )</code><br /></p> <p>...or as an anonymous subroutine:</p> <p><code class="prettyprint"> (1..N).grep( <strong>sub (\i) { N %% i }</strong> )</code><br /></p> <p>...or as a named subroutine:</p> <p><code class="prettyprint"> my sub divisors-of-N (\i) { N %% i }</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> (1..N).grep( <strong>&amp;divisors-of-N</strong> )</code><br /></p> <p>Perl 6 aims to let us express ourselves in whichever notation we find most convenient, comfortable, and comprehensible.</p> <h4>Getting to the root of the problem</h4> <p>It’s hard to imagine a simpler solution to the problem of finding divisors than:</p> <pre><code class="prettyprint"> multi divisors (\N) { (1..N).grep(N %% *) } </code></pre> <p>But it’s also hard to imagine a less efficient one. For example, in order to find the eight divisors of the number 2001, we have to check all 2001 potential divisors, which is 99.6% wasted effort. Even for a number like 2100—which has thirty-six divisors—we’re still throwing away over 98% of the <code class="prettyprint">1..N</code> sequence. And the bigger the number,<br />the smaller its relative number of divisors, and the longer it takes to find them.<br />There must be a better way.</p> <p>And, of course, there is. The simplest improvement we can make was first published back in 1202 by Fibonacci in his magnum opus <a href=""><em>Liber Abbaci</em></a>. We start by observing that the divisors of a number always come in <em>complementary pairs</em>; pairs that multiply together to produce the number itself. For example, the divisors of 99 are:</p> <pre><code class="prettyprint"> 1 3 9 99 33 11 </code></pre> <p>...while the divisors of 100 are:</p> <pre><code class="prettyprint"> 1 2 4 5 10 100 50 25 20 10 </code></pre> <p>...and the divisors of 101 are:</p> <pre><code class="prettyprint"> 1 101 </code></pre> <p>Notice that, in each case, the top row of divisors always contains “small” integers no greater than the square-root of the original number. And the bottom row consists entirely of <em>N</em> divided by the corresponding top-row divisor. So we could find half the divisors by searching the range <code class="prettyprint">1..sqrt N</code> (in just O(<em>√N</em>) steps), and then find the other half by subtracting each element of that list from <code class="prettyprint">N</code> (also in just O(<em>√N</em>) steps). In Perl 6 that look like this:</p> <pre><code class="prettyprint"> multi divisors (\N) { my \small-divisors = (1..sqrt N).grep(N %% *); my \big-divisors = N «div« small-divisors; return unique flat small-divisors, big-divisors; } </code></pre> <p>The <code class="prettyprint">div</code> operator is integer division, and putting the double angles around it makes it<br />a <a href="">vector operator</a> that divides <code class="prettyprint">N</code> by each element of the list of <code class="prettyprint">small-divisors</code>.<br />The <code class="prettyprint">flat</code> is needed because the two list objects in <code class="prettyprint">small-divisors</code> and<br /><code class="prettyprint">big-divisors</code> are not automatically “flattened” into a single list in Perl 6.<br />The <code class="prettyprint">unique</code> is needed because if <code class="prettyprint">N</code> is a perfect square, we would otherwise get two copies of its square-root (as in the above example of 10/10 among the divisor-pairs of 100).</p> <h4>Thinking big</h4> <p>It’s great that we were able to improve our O(<em>N</em>) algorithm to O(√<em>N</em>) so easily,<br />but even that only gets us so far. The performance of the <code class="prettyprint">divisors</code> function up to <code class="prettyprint">divisors(10⁹)</code> is entirely acceptable at under 0.1 seconds,<br />but starts to fall off rapidly after that point:</p> <p><img src="" width="630" height="246" alt="Graph showing exponential increase in computation time for divisors by trial division, with the elbow of the graph around N = 100 trillion." class="mt-image-center" /></p> <p>If we want our function to be usable for very large numbers, we need a better algorithm.<br />And, happily, the world of cryptography (which is <em>obsessed</em> with factoring numbers)<br />provides <a href="">plenty of alternative techniques</a>, ranging from the merely very complex<br />to the positively eldritch.</p> <p>One of the easier approaches to understand (and code!) is <a href="">Pollard’s <big>𝜌</big> algorithm</a>, which I explained briefly as part of a <a href="">Perl Conference keynote</a> few years ago. And which Stephen Schulze subsequently made available as the <code class="prettyprint">prime-factors</code> function in a Perl 6 module named <code class="prettyprint">Prime::Factor</code>.</p> <p>I don’t plan to explain the <big>𝜌</big> algorithm here, or even discuss Stephen’s excellent implementation of it...though it’s definitely worth exploring <a href="">the module’s code</a>, especially the sublime shortcut that uses <code class="prettyprint">$n gcd 6541380665835015</code> to instantly detect if the number has a prime factor less than 44.</p> <p>Suffice it to say that the module finds all the prime factors of very large numbers<br />very quickly. For example, whereas our previous implementation of <code class="prettyprint">divisors</code> would take<br />around five seconds to find the divisors of 1 trillion, the <code class="prettyprint">prime-factors</code> function finds<br />the prime factors of that number in less than 0.002 seconds.</p> <p>The only problem is: the <em>prime factors</em> of a number <strong>aren’t</strong> the same as its <em>divisors</em>.<br />The divisors of 1 trillion are all the numbers by which it is evenly divisible. Namely:</p> <p><code class="prettyprint"> 1, 2, 4, 5, 8, 10, 16, 20, 25, 32, 40, 50, 64, 80, 100,</code><br /><code class="prettyprint"> 125, 128, 160, 200, 250, 256, 320, 400, 500, 512, 625,</code><br /><code class="prettyprint"> 640, 800, 1000, 1024, 1250, 1280, 1600, 2000, 2048, 2500,</code><br /><code class="prettyprint"> <em>[...218 more integers here...]</em></code><br /><code class="prettyprint"> 10000000000, 12500000000, 15625000000, 20000000000,</code><br /><code class="prettyprint"> 25000000000, 31250000000, 40000000000, 50000000000,</code><br /><code class="prettyprint"> 62500000000, 100000000000, 125000000000, 200000000000,</code><br /><code class="prettyprint"> 250000000000, 500000000000, 1000000000000</code></p> <p>In contrast, the <em>prime factors</em> of a number is the unique set of (usually repeated) primes which can be multiplied together to reconstitute the original number. For the number<br />1 trillion, that unique set of primes is:</p> <pre><code class="prettyprint"> 2,2,2,2,2,2,2,2,2,2,2,2,5,5,5,5,5,5,5,5,5,5,5,5 </code></pre> <p>...because:</p> <pre><code class="prettyprint"> 2×2×2×2×2×2×2×2×2×2×2×2×5×5×5×5×5×5×5×5×5×5×5×5 → 1000000000000 </code></pre> <p>To find amicable pairs we need <em>divisors</em>, nor <em>prime factors</em>. Fortunately, it’s not too hard to extract one from the other. Multiplying the complete list of prime factors produces the original number, but if we select various subsets of the prime factors instead:</p> <pre><code class="prettyprint"> 2×2×2×2×5×5×5 → 2000 2×2×2×2×2×2×2×2 → 256 2×5×5×5×5 → 1250 </code></pre> <p>...then we get some of the actual divisors. And if we select the <a href=""><em>power set</em></a> of the prime factors (<em>i.e.</em> every possible subset), then we get <em>every possible</em> divisor.</p> <p>So all we need to do is to take the complete list of prime factors produced by<br /><code class="prettyprint">prime-factors</code>, generate every possible combination of the elements of that list,<br />multiply the elements of each combination together, and keep only the unique results.<br />Which, in Perl 6, is just:</p> <pre><code class="prettyprint"> use Prime::Factor; multi divisors (\N) { prime-factors(N).combinations».reduce( &amp;[×] ).unique; } </code></pre> <p>The <code class="prettyprint">.combinations</code> method produces a list of lists, where each inner list is one possible combination of some unique subset of the original list of prime factors. Something like:</p> <pre><code class="prettyprint"> (2), (5), (2,2), (2,5), (2,2,2), (2,2,5), (2,5,5), ... </code></pre> <p>The <code class="prettyprint">».reduce</code> method call is a vector form of the <a href="">“fold” operation</a>, which inserts<br />the specified operator between every element of the list of lists on which it’s called.<br />In this case, we’re inserting infix multiplication via the <code class="prettyprint">&amp;infix:&lt;×&gt;</code> operator<br />...which we can abbreviate to: <code class="prettyprint">&amp;[×]</code></p> <p>So we get something like:</p> <pre><code class="prettyprint"> (2), (5), (2×2), (2×5), (2×2×2), (2×2×5), (2×5×5), ... </code></pre> <p>Then we just cull any duplicate results with a final call to <code class="prettyprint">.unique</code>.</p> <h4>As simple as possible...but no simpler!</h4> <p>And then we test our shiny new prime-factor based algorithm. And weep to discover that it is <strong><em>catastrophically</em></strong> slower than our original trial division approach:</p> <p><img src="" width="630" height="246" alt="Graph showing performance of prime-factors approach vs trial division. The new approach has a similar exponential increase in computation time, but with the elbow of the graph even earlier, at around N = 100 trillion." class="mt-image-center" /></p> <p>The problem here is that the use of the <code class="prettyprint">.combinations</code> method is leading to a <a href="">combinatorial explosion</a> in some cases. We found the complete set of divisors by taking all possible subsets of the prime factors:</p> <pre><code class="prettyprint"> 2×2×2×2×2×2×2×2×2×2×2×2×5×5×5×5×5×5×5×5×5×5×5×5 → 1000000000000 2×2×2×2×5×5×5 → 2000 2×2×2×2×2×2×2×2 → 256 2×5×5×5×5 → 1250 </code></pre> <p>But that also means that we took subsets like this:</p> <pre><code class="prettyprint"> 2×2×2 → 8 2×2×2 → 8 2×2×2 → 8 2 ×2 ×2 → 8 </code></pre> <p>In fact, we took 220 distinct <code class="prettyprint">2×2×2</code> subsets. Not to mention 495 <code class="prettyprint">2×2×2×2</code> subsets,<br />792 <code class="prettyprint">2×2×2×2×2</code> subsets, and so on. In total, the 24 prime factors of 1 trillion produce<br />a power set of 2<sup>24</sup> distinct subsets, which we then whittle down to just 168 distinct divisors.<br />In other words, <code class="prettyprint">.combinations</code> has to build and return a list of those 16777216 subsets,<br />each of which <code class="prettyprint">».reduce</code> then has to process, after which <code class="prettyprint">.unique</code> immediately throws away 99.999% of them. Clearly, we need a <strong><em>much</em></strong> better way of combining the factors into divisors.</p> <p>And, happily, there is one. We can rewrite the multiplication:</p> <pre><code class="prettyprint"> 2×2×2×2×2×2×2×2×2×2×2×2×5×5×5×5×5×5×5×5×5×5×5×5 → 1000000000000 </code></pre> <p> a much more compact:</p> <p><code class="prettyprint"> 2<sup>12</sup> × 5<sup>12</sup> → 1000000000000</code></p> <p>We then observe that we can get all the unique subsets simply by varying the exponents of the two primes, from zero up to the maximum allowed value (12 in each case):</p> <pre><code class="prettyprint"> 2⁰×5⁰ → 1 2¹×5⁰ → 2 2²×5⁰ → 4 2³×5⁰ → 8 ⋯ 2⁰×5¹ → 5 2¹×5¹ → 10 2²×5¹ → 20 2³×5¹ → 40 ⋯ 2⁰×5² → 25 2¹×5² → 50 2²×5² → 100 2³×5² → 200 ⋯ 2⁰×5³ → 125 2¹×5³ → 250 2²×5³ → 500 2³×5³ → 1000 ⋯ 2⁰×5⁴ → 625 2¹×5⁴ → 1250 2²×5⁴ → 2500 2³×5⁴ → 5000 ⋯ ⋮ ⋮ ⋮ ⋮ ⋱ </code></pre> <p>In general, if a number has prime factors <em>p<sub>ℓ</sub><sup>𝐼</sup> × p<sub>m</sub><sup>J</sup> × p<sub>n</sub><sup>K</sup></em>, then its complete set of divisors is given by <em>p<sub>ℓ</sub><sup>(0..𝐼)</sup> × p<sub>m</sub><sup>(0..J)</sup> × p<sub>n</sub><sup>(0..K)</sup></em>.</p> <p>Which means we can find them like so:</p> <pre><code class="prettyprint"> multi divisors (\N) { # Find and count prime factors of N (as before)... my \factors = bag prime-factors(N); # Short-cut if N is prime... return (1,N) if == 1; # Extract list of unique prime factors... my \pₗpₘpₙ = factors.keys xx ∞; # Build all unique combinations of exponents... my \ᴵᴶᴷ = [X] (0 .. .value for factors); # Each divisor is pₗᴵ × pₘᴶ × pₙᴷ... return ([×] .list for pₗpₘpₙ «**« ᴵᴶᴷ); } </code></pre> <p>We get the list of prime factors as in the previous version (<code class="prettyprint">prime-factors(N)</code>), but now we put them straight into a <code class="prettyprint">Bag</code> data structure (<code class="prettyprint">bag prime-factors(N)</code>). A “bag” is an <a href="">integer-weighted set</a>: a special kind of hash in which the keys are the original elements of the list and the values are the counts of how many times each distinct value appears (<em>i.e.</em> its “weight” in the list).</p> <p>For example, the prime factors of 9876543210 are <code class="prettyprint">(2, 3, 3, 5, 17, 17, 379721)</code>.<br />If we put that list into a bag, we get the equivalent of:</p> <pre><code class="prettyprint"> { 2=&gt;1, 3=&gt;2, 5=&gt;1, 17=&gt;2, 379721=&gt;1 } </code></pre> <p>So converting the list of prime factors to a bag gives us an easy and efficient way of determining the unique primes involved, and the powers to which each prime must be raised.</p> <p>However, if there is only one prime key in the resulting bag, and its corresponding count is 1,<br />then the original number must itself have been that prime (raised to the power of 1).<br />In which case, we know the divisors can only be that original number and 1,<br />so we can immediately return them:</p> <pre><code class="prettyprint"> return (1,N) if == 1; </code></pre> <p>The <code class="prettyprint">.total</code> method simply sums up all the integer weights in the bag.<br />If the total is 1, there can have been only one element, with the weight 1.</p> <p>Otherwise, the one or more keys of the bag (<code class="prettyprint">factors.keys</code>) are the list of prime factors of the original number <em>(pₗ, pₘ, pₙ, ...)</em>, which we extract and store in an appropriate Unicode-named variable: <code class="prettyprint">pₗpₘpₙ</code>. Note that we need multiple identical copies of these prime-factor lists: one for every possible combination of exponents. As we don’t know (yet) how many such combinations there will be, to ensure we’ll have enough we simply make the list infinitely long: <code class="prettyprint">factors.keys xx ∞</code>. In our example, that would produce the list of factor lists like this:</p> <pre><code class="prettyprint"> ((1,3,5,17,379721), (1,3,5,17,379721), (1,3,5,17,379721), ...) </code></pre> <p>To get the list of exponent sets, we need every combination of possible exponents (<em>I</em>,<em>J</em>,<em>K</em>,...), from zero up to the maximum count for each prime. That is, for our example:</p> <p><code class="prettyprint"> { 2=&gt;<strong>1</strong>, 3=&gt;<strong>2</strong>, 5=&gt;<strong>1</strong>, 17=&gt;<strong>2</strong>, 379721=&gt;<strong>1</strong> }</code></p> <p>we need:</p> <pre> ( (0,0,0,0,0), (0,0,0,0,1), (0,0,0,1,0), (0,0,0,1,1), (0,0,0,2,0), (0,0,0,2,1), (0,0,1,0,0), (0,0,1,0,1), (0,0,1,1,0), (0,0,1,1,1), (0,0,1,2,0), (0,0,1,2,1), (0,1,0,0,0), (0,1,0,0,1), (0,1,0,1,0), (0,1,0,1,1), (0,1,0,2,0), (0,1,0,2,1), (0,1,1,0,0), (0,1,1,0,1), (0,1,1,1,0), (0,1,1,1,1), (0,1,1,2,0), (0,1,1,2,1), (0,2,0,0,0), (0,2,0,0,1), (0,2,0,1,0), (0,2,0,1,1), (0,2,0,2,0), (0,2,0,2,1), (0,2,1,0,0), (0,2,1,0,1), (0,2,1,1,0), (0,2,1,1,1), (0,2,1,2,0), (0,2,1,2,1), (1,0,0,0,0), (1,0,0,0,1), (1,0,0,1,0), (1,0,0,1,1), (1,0,0,2,0), (1,0,0,2,1), (1,0,1,0,0), (1,0,1,0,1), (1,0,1,1,0), (1,0,1,1,1), (1,0,1,2,0), (1,0,1,2,1), (1,1,0,0,0), (1,1,0,0,1), (1,1,0,1,0), (1,1,0,1,1), (1,1,0,2,0), (1,1,0,2,1), (1,1,1,0,0), (1,1,1,0,1), (1,1,1,1,0), (1,1,1,1,1), (1,1,1,2,0), (1,1,1,2,1), (1,2,0,0,0), (1,2,0,0,1), (1,2,0,1,0), (1,2,0,1,1), (1,2,0,2,0), (1,2,0,2,1), (1,2,1,0,0), (1,2,1,0,1), (1,2,1,1,0), (1,2,1,1,1), (1,2,1,2,0) (1,2,1,2,1) ) </pre> <p>Or, to be express it more concisely, we need the cross-product (<em>i.e.</em> the <code class="prettyprint">X</code> operator)<br />of the valid ranges of each exponent:</p> <pre><code class="prettyprint"> # 2 3 5 17 379721 (0..1) X (0..2) X (0..1) X (0..2) X (0..1) </code></pre> <p>The maximal exponents are just the values from the bag of prime factors (<code class="prettyprint">factors.values</code>), so we can get a list of the required exponent ranges by converting each “prime count” value to a 0..<em>count</em> range: <code class="prettyprint">(0 .. .value for factors)</code></p> <p>Note that, in Perl 6, a loop within parentheses produces a list of the final values<br />of each iteration of that loop. Or you can think of this construct as a <a href="">list comprehension</a>,<br />as in Python: <code class="prettyprint">[range(0,value) for value in factors.values()]</code> <em>(but less prosy)</em><br />or in Haskell: <code class="prettyprint">[ [0..value] | value &lt;- elems factors ]</code> <em>(but with less line noise).</em></p> <p>Then we just take the resulting list of ranges and compute the n-ary cross-product<br />by reducing the list over the <code class="prettyprint">X</code> operator: <strong><code class="prettyprint">[X]</code></strong><code class="prettyprint">(0 .. .value for factors)</code><br />and store the resulting list of <em>I,J,K</em> exponent lists in a suitably named variable: <code class="prettyprint">ᴵᴶᴷ</code><br /><em>(Yes, superscript letters are perfectly valid Unicode alphabetics, so we can certainly<br />use them as an identifier.)</em></p> <p>At this point almost all the hard work is done. We have a list of the prime factors (<code class="prettyprint">pₗpₘpₙ</code>),<br />and a list of the unique combinations of exponents that will produce distinct divisors (<code class="prettyprint">ᴵᴶᴷ</code>),<br />so all we need to do now is raise each set of numbers in the first list to the various sets<br />of exponents in the second list using a vector exponentiation operator (<code class="prettyprint">pₗpₘpₙ «**« ᴵᴶᴷ</code>)<br />and then multiply the list of values produced by each exponentiation (<code class="prettyprint">[×] .list for …</code>)<br />in another list comprehension, to produce the list of divisors.</p> <p>And that’s it. It’s five lines instead of one:</p> <pre><code class="prettyprint"> multi divisors (\N) { my \factors = bag prime-factors(N); return (1,N) if == 1; my \pₗpₘpₙ = factors.keys xx ∞; my \ᴵᴶᴷ = [X] (0 .. .value for factors); return ([×] .list for pₗpₘpₙ «**« ᴵᴶᴷ); } </code></pre> <p>...but with no combinatorial explosives lurking inside them. Instead of building O(<em>2ᴺ</em>) subsets of the factors directly, we build O(<em>N</em>) subsets of their respective exponents.</p> <p>And then we test our shinier newer <code class="prettyprint">divisors</code> implementation. And weep tears<br />...of relief when we find that it scales <strong><em>ridiculously</em></strong> better than the previous one.<br />And also vastly better than the original trial division solution:</p> <p><img src="" width="630" height="246" alt="Graph showing exponential computation-time behaviour of original two divisor functions, and linear performance of the new algorithm all the way to ten-to-the-100." class="mt-image-center" /></p> <p>Mission accomplished!</p> <h4>The best of both worlds</h4> <p>Except that, if we zoom in on the start of the graph:</p> <p><img src="" width="630" height="246" alt="Graph showing the trial division algorithm outperforming the prime-factors approach on numbers less than 10 thousand." class="mt-image-center" /></p> <p>...we see that our new algorithm’s performance is only <strong><em>eventually</em></strong> better.<br />Due to the relatively high computational overheads of the Pollard’s <big>𝜌</big> algorithm<br />at its heart, and to the need to build, exponentiate, and multiply together the power set<br />of prime factors, the performance of this version of <code class="prettyprint">divisors</code> is marginally <em>worse</em><br />than simple trial least on numbers less than <em>N</em>=10000.</p> <p>Ideally, we could somehow employ <em>both</em> algorithms: use trial division for the “small” numbers, and prime factoring for everything bigger. And that too is trivially easy in Perl 6.<br />No, not by muddling them together in some kind of Frankenstein function:</p> <pre><code class="prettyprint"> multi divisors (\N) { if N &lt; 10⁴ { my \small-divisors = (1..sqrt N).grep(N %% *); my \big-divisors = N «div« small-divisors; return unique flat small-divisors, big-divisors; } else { my \factors = bag prime-factors(N); return (1,N) if == 1; my \pₘpₙpₒ = factors.keys xx ∞; my \ᴵᴶᴷ = [X] (0 .. .value for factors); return ([×] .list for pₘpₙpₒ «**« ᴵᴶᴷ); } } </code></pre> <p>Instead, we just implement both approaches independently in separate multis,<br />as we did previously, then modify their signatures to tell the compiler<br />the range of <em>N</em> values to which they should each be applied:</p> <p><code class="prettyprint"> <strong>constant SMALL = 1 ..^ 10⁴;</strong></code><br /><code class="prettyprint"> <strong>constant BIG = 10⁴ .. ∞;</strong></code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> multi divisors (\N <strong>where BIG</strong>) {</code><br /><code class="prettyprint"> my \factors = bag prime-factors(N);</code><br /><code class="prettyprint"> return (1,N) if == 1;</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> my \pₘpₙpₒ = factors.keys xx ∞;</code><br /><code class="prettyprint"> my \ᴵᴶᴷ = [X] (0 .. .value for factors);</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> return ([×] .list for pₘpₙpₒ «**« ᴵᴶᴷ);</code><br /><code class="prettyprint"> }</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> multi divisors (\N <strong>where SMALL</strong>) {</code><br /><code class="prettyprint"> my \small-divisors = (1..sqrt N).grep(N %% *);</code><br /><code class="prettyprint"> my \big-divisors = N «div« small-divisors;</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> return unique flat small-divisors, big-divisors;</code><br /><code class="prettyprint"> }</code></p> <p>The actual improvement in this particular case is only slight; perhaps too slight to be worth the bother of maintaining two variants of the same function. But the principle being demonstrated here is important. The Perl 6 multiple dispatch mechanism makes it very easy to inject special-case optimizations into an existing function...without making the function’s original source code any more complex, any slower, or any less maintainable.</p> <h4>Meanwhile, in a parallel universe...</h4> <p>Now that we have an efficient way to find the proper divisors of any number, we can start locating amicable pairs using the code shown earlier:</p> <p><code class="prettyprint"> for 1..∞ -&gt; \number {</code><br /><code class="prettyprint"> my \</code><tt>friend</tt><code class="prettyprint"> = <big>𝑠</big>(number);</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> say (number, </code><tt>friend</tt><code class="prettyprint">)</code><br /><code class="prettyprint"> if number &lt; </code><tt>friend</tt><code class="prettyprint"> &amp;&amp; <big>𝑠</big>(</code><tt>friend</tt><code class="prettyprint">) == number;</code><br /><code class="prettyprint"> }</code></p> <p>When we do, we find that the first few pairs are printed out very quickly but, after that, things start to slow down noticeably. So we might start looking for yet another way to accelerate the search.</p> <p>We might, for example, notice that each iteration of the <code class="prettyprint">for</code> loop is entirely independent of any other. No outside information is required to test a particular amicable pair, and no persistent state need be passed from iteration to iteration. And that, we would quickly realize, means that this is a perfect opportunity to introduce a little <a href="">concurrency</a>.</p> <p>In many languages, converting our simple linear <code class="prettyprint">for</code> loop into some kind of concurrent search would require a shambling mound of extra code: to schedule, create, orchestrate, manage, coordinate, synchronize, and terminate a collection of threads or thread objects.</p> <p>In Perl 6, though, it just means we need to add a single five-letter modifier<br />to our existing <code class="prettyprint">for</code> loop:</p> <p><code class="prettyprint"> <strong>hyper</strong> for 1..∞ -&gt; \number {</code><br /><code class="prettyprint"> my \</code><tt>friend</tt><code class="prettyprint"> = <big>𝑠</big>(number);</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> say (number, </code><tt>friend</tt><code class="prettyprint">)</code><br /><code class="prettyprint"> if number &lt; </code><tt>friend</tt><code class="prettyprint"> &amp;&amp; <big>𝑠</big>(</code><tt>friend</tt><code class="prettyprint">) == number;</code><br /><code class="prettyprint"> }</code><br /></p> <p>The <code class="prettyprint">hyper</code> prefix tells the compiler that this particular <code class="prettyprint">for</code> loop does not need to iterate sequentially; that each of its iterations can be executed with whatever degree of concurrency the compiler deems appropriate <em>(by default, in four parallel threads, though there are <a href="">extra parameters</a> that allow you to tune the degree of concurrency to match the capacities of your hardware)</em>.</p> <p>The <code class="prettyprint">hyper</code> prefix is really just a shorthand for adding a call to the <a href=""><code class="prettyprint">.hyper</code> method</a> to the list being iterated. That method converts the iterator of the object to one that can iterate concurrently. So we could also write our concurrent loop like this:</p> <p><code class="prettyprint"> for (1..∞)<strong>.hyper</strong> -&gt; \number {</code><br /><code class="prettyprint"> my \</code><tt>friend</tt><code class="prettyprint"> = <big>𝑠</big>(number);</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> say (number, </code><tt>friend</tt><code class="prettyprint">)</code><br /><code class="prettyprint"> if number &lt; </code><tt>friend</tt><code class="prettyprint"> &amp;&amp; <big>𝑠</big>(</code><tt>friend</tt><code class="prettyprint">) == number;</code><br /><code class="prettyprint"> }</code><br /></p> <p>Note that, whichever way we write this parallel <code class="prettyprint">for</code> loop, with multiple iterations happening in parallel, the results are no longer guaranteed to be printed out in strictly increasing order. In practice, however, the low density of amicable pairs amongst the integers makes this extremely likely anyway.</p> <p>When we convert the previous <code class="prettyprint">for</code> loop to a <code class="prettyprint">hyper for</code>, the performance of the loop doubles. For example, the regular loop can find every amicable pair up to 1 million in a little over an hour; the <code class="prettyprint">hyper</code> loop does the same in under 25 minutes.</p> <h4>To infinity and beyond</h4> <p>Finally, having constructed and optimized all the components of our finder of lost amities,<br />we can begin our search in earnest. Not just for the first amicable pair, but for the first amicable pair over one thousand, over one million, over one billion, over one trillion,<br /><em>et cetera:</em></p> <p><code class="prettyprint"> # Convert 1 → "10⁰", 10 → "10¹", 100 → "10²", 1000 → "10³", ...</code><br /><code class="prettyprint"> sub order (\N where /^ 10* $/) {</code><br /><code class="prettyprint"> 10 ~ N.chars.pred.trans: '0123456789' =&gt; '⁰¹²³⁴⁵⁶⁷⁸⁹'</code><br /><code class="prettyprint"> }</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> # For every power of 1000...</code><br /><code class="prettyprint"> for 1, 10³, 10⁶ ... ∞ -&gt; \min {</code><br /><code class="prettyprint"> # Concurrently find the first amicable pair in that range...</code><br /><code class="prettyprint"> for (min..∞).hyper -&gt; \number {</code><br /><code class="prettyprint"> my \</code><tt>friend</tt><code class="prettyprint"> = <big>𝑠</big>(number);</code><br /><code class="prettyprint"> next if number &gt;= </code><tt>friend</tt><code class="prettyprint"> || <big>𝑠</big>(</code><tt>friend</tt><code class="prettyprint">) != number;</code><br /><code class="prettyprint"></code><br /><code class="prettyprint"> # Report it and go on to the next power of 1000...</code><br /><code class="prettyprint"> say "First amicable pair over &amp;order(min):",</code><br /><code class="prettyprint"> "\t({number}, {</code><tt>friend</tt><code class="prettyprint">})";</code><br /><code class="prettyprint"> last;</code><br /><code class="prettyprint"> }</code><br /><code class="prettyprint"> }</code></p> <p>Which reveals:</p> <p><code class="prettyprint"> </code><tt>First amicable pair over 10⁰:</tt><code class="prettyprint"> </code><tt>(220, 284)</tt><br /><code class="prettyprint"> </code><tt>First amicable pair over 10³:</tt><code class="prettyprint"> </code><tt>(1184, 1210)</tt><br /><code class="prettyprint"> </code><tt>First amicable pair over 10⁶:</tt><code class="prettyprint"> </code><tt>(1077890, 1099390)</tt><br /><code class="prettyprint"> </code><tt>First amicable pair over 10⁹:</tt><code class="prettyprint"> </code><tt>(1000233608, 1001668568)</tt><br /><code class="prettyprint"> </code><tt>First amicable pair over 10¹²:</tt><code class="prettyprint"> </code><tt>(1000302285872, 1000452085744)</tt><br /><code class="prettyprint"> </code><tt><em>et cetera</em></tt></p> <p>Well, reveals them...<em>eventually!</em></p> <p>Damian</p> Sat, 17 Aug 2019 08:06:11 +0000 Plastic recycling is a myth: What happens to your rubbish? <p><span class="drop-cap"><span class="drop-cap__inner">A</span></span>n alarm sounds, the blockage is cleared, and the line at Green Recycling in Maldon, Essex, rumbles back into life. A momentous river of garbage rolls down the conveyor: cardboard boxes, splintered skirting board, plastic bottles, crisp packets, DVD cases, printer cartridges, countless newspapers, including this one. Odd bits of junk catch the eye, conjuring little vignettes: a single discarded glove. A crushed Tupperware container, the meal inside uneaten. A photograph of a smiling child on an adult’s shoulders. But they are gone in a moment. The line at Green <a href="" data-link-name="auto-linked-tag" data-component="auto-linked-tag" class="u-underline in-body-link--immersive">Recycling</a> handles up to 12 tonnes of waste an hour.</p> <p>“We produce 200 to 300 tonnes a day,” says Jamie Smith, Green Recycling’s general manager, above the din. We are standing three storeys up on the green health-and-safety gangway, looking down the line. On the tipping floor, an excavator is grabbing clawfuls of trash from heaps and piling it into a spinning drum, which spreads it evenly across the conveyor. Along the belt, human workers pick and channel what is valuable (bottles, cardboard, aluminium cans) into sorting chutes.</p> <p>“Our main products are paper, cardboard, plastic bottles, mixed plastics, and wood,” says Smith, 40. “We’re seeing a significant rise in boxes, thanks to Amazon.” By the end of the line, the torrent has become a trickle. The waste stands stacked neatly in bales, ready to be loaded on to trucks. From there, it will go – well, that is when it gets complicated.</p> <p>You drink a Coca-Cola, throw the bottle into the recycling, put the bins out on collection day and forget about it. But it doesn’t disappear. Everything you own will one day become the property of this, the waste industry, a <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">£250bn global enterprise</a> determined to extract every last penny of value from what remains. It starts with materials recovery facilities (MRFs) such as this one, which sort waste into its constituent parts. From there, the materials enter a labyrinthine network of brokers and traders. Some of that happens in the UK, but much of it – about half of all paper and cardboard, and two-thirds of plastics – will be loaded on to container ships to be sent to Europe or Asia for recycling. Paper and cardboard goes to mills; glass is washed and re-used or smashed and melted, like metal and plastic. Food, and anything else, is burned or sent to landfill.</p> <p>Or, at least, that’s how it used to work. Then, on the first day of 2018, China, the world’s largest market for recycled waste, essentially shut its doors. Under its National Sword policy, <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">China prohibited 24 types of waste from entering the country</a>, arguing that what was coming in was too contaminated. The policy shift was partly attributed to the impact of a documentary,<a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive"> Plastic China</a>, which went viral before censors erased it from China’s internet. The film follows a family working in the country’s recycling industry, where humans pick through vast dunes of western waste, shredding and melting salvageable plastic into pellets that can be sold to manufacturers. It is filthy, polluting work – and badly paid. The remainder is often burned in the open air. The family lives alongside the sorting machine, their 11-year-old daughter playing with a Barbie pulled from the rubbish.</p> <aside class="element element-pullquote element--supporting" readability="1.5"><span class="inline-garnett-quote inline-icon "> <svg width="70" height="49" viewbox="0 0 35 25" class="inline-garnett-quote__svg inline-icon__svg"><path d="M69.587.9c-1.842 15.556-3.89 31.316-4.708 48.1H37.043c3.07-16.784 8.391-32.544 17.602-48.1h14.942zM32.949.9c-2.047 15.556-4.094 31.316-4.912 48.1H.2C3.066 32.216 8.592 16.456 17.598.9h15.35z"/></svg></span> <blockquote readability="6"> <p class="pullquote-paragraph">Westminster council sent 82% of all household waste – including that put in recycling bins – for incineration in 2017/18</p> </blockquote> </aside><p>For recyclers such as Smith, National Sword was a huge blow. “The price of cardboard has probably halved in the last 12 months,” he says. “The price of plastics has plummeted to the extent that it isn’t worth recycling. If China doesn’t take plastic, we can’t sell it.” Still, that waste has to go somewhere. The UK, like most developed nations, produces more waste than it can process at home: <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">230m tonnes a year</a><a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive"> – </a><a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">about 1.1kg per person per day</a>. (The US, the world’s most wasteful nation, produces 2kg per person per day.) Quickly, the market began flooding any country that would take the trash: Thailand, Indonesia, Vietnam, countries with some of the world’s highest rates of what researchers call “waste mismanagement” – rubbish left or burned in open landfills, illegal sites or facilities with inadequate reporting, making its final fate difficult to trace.</p> <p>The present dumping ground of choice is Malaysia. In October last year, a <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">Greenpeace Unearthed investigation</a> found mountains of British and European waste in illegal dumps there: Tesco crisp packets, Flora tubs and recycling collection bags from three London councils. As in China, the waste is often burned or abandoned, eventually finding its way into rivers and oceans. In May, the Malaysian government began turning back container ships, citing public health concerns. Thailand and India have announced bans on the import of foreign plastic waste. But still the rubbish flows.</p> <figure itemprop="associatedMedia image" itemscope="" itemtype="" data-component="image" class="element element-image img--landscape fig--narrow-caption fig--has-shares " data-media-id="1681dc08d17c1159ba61f43753e72b5a32a934d3" id="img-2"><meta itemprop="url" content=";quality=85&amp;auto=format&amp;fit=max&amp;s=1641faf723ab34446b86b12683c0f799"/><meta itemprop="width" content="5238"/><meta itemprop="height" content="3143"/><a href="" class="article__img-container js-gallerythumbs in-body-link--immersive" data-link-name="Launch Article Lightbox" data-is-ajax=""> <span class="inline-expand-image inline-icon centered-icon rounded-icon article__fullscreen modern-visible"> <svg width="22" height="22" viewbox="0 0 22 22" class="centered-icon__svg rounded-icon__svg article__fullscreen__svg modern-visible__svg inline-expand-image__svg inline-icon__svg"><path d="M3.4 20.2L9 14.5 7.5 13l-5.7 5.6L1 14H0v7.5l.5.5H8v-1l-4.6-.8M18.7 1.9L13 7.6 14.4 9l5.7-5.7.5 4.7h1.2V.6l-.5-.5H14v1.2l4.7.6"/></svg></span> </a> <figcaption class="caption caption--img caption caption--img" itemprop="description"><span class="inline-triangle inline-icon "> <svg width="11" height="10" viewbox="0 0 11 10" class="inline-triangle__svg inline-icon__svg"><path fill-rule="evenodd" d="M5.5 0L11 10H0z"/></svg></span> Plastic waste ready for inspection before being sent to Malaysia; the UK produces more refuse than it can process at home – about 1.1kg per person per day. Photograph: AFP/Getty Images </figcaption></figure><p>We want our waste hidden. Green Recycling is tucked away at the end of an industrial estate, surrounded by sound-deflecting metal boards. Outside, a machine called an Air Spectrum masks the acrid odour with the smell of cotton bedsheets. But, all of a sudden, the industry is under intense scrutiny. In the UK, recycling rates have stagnated in recent years, while National Sword and funding cuts have led to more waste being burned in incinerators and energy-from-waste plants. (Incineration, while often criticised for being polluting and an inefficient source of energy, is today preferred to landfill, which emits methane and can leach toxic chemicals.) Westminster council sent 82% of all household waste – including that put in recycling bins – for incineration in 2017/18. Some councils have debated giving up recycling altogether. And yet the UK is a successful recycling nation: 45.7% of all household waste is classed as recycled (although that number indicates only that it is sent for recycling, not where it ends up.) In the US, that figure is 25.8%.</p> <aside class="element element-pullquote element--supporting" readability="2"><span class="inline-garnett-quote inline-icon "> <svg width="70" height="49" viewbox="0 0 35 25" class="inline-garnett-quote__svg inline-icon__svg"><path d="M69.587.9c-1.842 15.556-3.89 31.316-4.708 48.1H37.043c3.07-16.784 8.391-32.544 17.602-48.1h14.942zM32.949.9c-2.047 15.556-4.094 31.316-4.912 48.1H.2C3.066 32.216 8.592 16.456 17.598.9h15.35z"/></svg></span> <blockquote readability="7"> <p class="pullquote-paragraph">One of the UK’s largest waste companies, attempted to ship used nappies abroad in consignments marked as waste paper</p> </blockquote> </aside><p>If you look at plastics, the picture is even bleaker. Of the 8.3bn tonnes of virgin plastic produced worldwide, only 9% has been recycled, according to a <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">2017 Science Advances paper</a> entitled Production, Use And Fate Of All Plastics Ever Made. “I think the best global estimate is maybe we’re at 20% [per year] globally right now,” says Roland Geyer, its lead author, a professor of industrial ecology at the University of California, Santa Barbara. Academics and NGOs doubt those numbers, due to the uncertain fate of our waste exports. In June, one of the UK’s largest waste companies, Biffa, was <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">found guilty of attempting to ship </a><a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">used nappies, sanitary towels and clothing</a> abroad in consignments marked as waste paper. “I think there’s a lot of creative accounting going on to push the numbers up,” Geyer says.</p> <p>“It’s really a complete myth when people say that we’re recycling our plastics,” says Jim Puckett, the executive director of the Seattle-based <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">Basel Action Network</a>, which campaigns against the illegal waste trade. “It all sounded good. ‘It’s going to be recycled in China!’ I hate to break it to everyone, but these places are routinely dumping massive amounts of [that] plastic and burning it on open fires.”</p> <p>***</p> <p>Recycling is as old as thrift. The Japanese were recycling paper in the 11th century; medieval blacksmiths made armour from scrap metal. During the second world war, scrap metal was made into tanks and women’s nylons into parachutes. “The trouble started when, in the late 70s, we began trying to recycle household waste,” says Geyer. This was contaminated with all sorts of undesirables: non-recyclable materials, food waste, oils and liquids that rot and spoil the bales.</p> <p>At the same time, the packaging industry flooded our homes with cheap plastic: tubs, films, bottles, individually shrink-wrapped vegetables. Plastic is where recycling gets most controversial. Recycling aluminium, say, is straightforward, profitable and environmentally sound: making a can from recycled aluminium reduces its carbon footprint by up to 95%. But with plastic, it is not that simple. While virtually all plastics can be recycled, many aren’t because the process is expensive, complicated and the resulting product is of lower quality than what you put in. The carbon-reduction benefits are also less clear. “You ship it around, then you have to wash it, then you have to chop it up, then you have to re-melt it, so the collection and recycling itself has its own environmental impact,” says Geyer.</p> <figure itemprop="associatedMedia image" itemscope="" itemtype="" data-component="image" class="element element-image img--landscape fig--narrow-caption fig--has-shares " data-media-id="dc5ac761808be733f32db6cfae600ca614cc2f6e" id="img-3"><meta itemprop="url" content=";quality=85&amp;auto=format&amp;fit=max&amp;s=8aecd8a9e5de65dfa2d0a82230c1c3e3"/><meta itemprop="width" content="4080"/><meta itemprop="height" content="2448"/><a href="" class="article__img-container js-gallerythumbs in-body-link--immersive" data-link-name="Launch Article Lightbox" data-is-ajax=""> <span class="inline-expand-image inline-icon centered-icon rounded-icon article__fullscreen modern-visible"> <svg width="22" height="22" viewbox="0 0 22 22" class="centered-icon__svg rounded-icon__svg article__fullscreen__svg modern-visible__svg inline-expand-image__svg inline-icon__svg"><path d="M3.4 20.2L9 14.5 7.5 13l-5.7 5.6L1 14H0v7.5l.5.5H8v-1l-4.6-.8M18.7 1.9L13 7.6 14.4 9l5.7-5.7.5 4.7h1.2V.6l-.5-.5H14v1.2l4.7.6"/></svg></span> </a> <figcaption class="caption caption--img caption caption--img" itemprop="description"><span class="inline-triangle inline-icon "> <svg width="11" height="10" viewbox="0 0 11 10" class="inline-triangle__svg inline-icon__svg"><path fill-rule="evenodd" d="M5.5 0L11 10H0z"/></svg></span> A materials recovery facility in Milton Keynes where waste is sorted. In the UK, there are 28 different recycling labels that can appear on packaging. Photograph: Alamy </figcaption></figure><p>Household recycling requires sorting at a vast scale. This is why most developed countries have colour-coded bins: to keep the end product as pure as possible. In the UK, <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">Recycle Now</a> lists 28 different recycling labels that can appear on packaging. There is the mobius loop (three twisted arrows), which indicates a product can technically be recycled; sometimes that symbol contains a number between one and seven, indicating the plastic resin from which the object is made. There is the green dot (two green arrows embracing), which indicates that the producer has contributed to a European recycling scheme. There are labels that say “Widely Recycled” (acceptable by 75% of local councils) and “Check Local Recycling” (between 20% and 75% of councils).</p> <p>Since National Sword, sorting has become even more crucial, as overseas markets demand higher-quality material. “They don’t want to be the world’s dumping ground, quite rightly,” Smith says, as we walk along the Green Recycling line. About halfway, four women in hi-vis and caps pull out large chunks of cardboard and plastic films, which machines struggle with. There is a low rumble in the air and a thick layer of dust on the gangway. Green Recycling is a commercial MRF: it takes waste from schools, colleges and local businesses. That means lower volume, but better margins, as the company can charge clients directly and maintain control over what it collects. “The business is all about turning straw into gold,” says Smith, referencing Rumpelstiltskin. “But it’s hard – and it’s become a lot harder.”</p> <p>Towards the end of the line is the machine that Smith hopes will change that. Last year, Green Recycling became the first MRF in the UK to invest in Max, <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">a US-made, artificially intelligent sorting machine</a>. Inside a large clear box over the conveyor, a robotic suction arm marked FlexPickerTM is zipping back and forth over the belt, picking tirelessly. “He’s looking for plastic bottles first,” Smith says. “He does 60 picks a minute. Humans will pick between 20 and 40, on a good day.” A camera system identifies the waste rolling by, displaying a detailed breakdown on a nearby screen. The machine is intended not to replace humans, but to augment them. “He’s picking three tonnes of waste a day that otherwise our human guys would have to leave,” Smith says. In fact, the robot has created a new human job to maintain it: this is done by Danielle, whom the crew refer to as “Max’s mum”. The benefits of automation, Smith says, are twofold: more material to sell and less waste that the company needs to pay to have burned afterwards. Margins are thin and landfill tax is £91 a tonne.</p> <p>***</p> <p>Smith is not alone in putting his faith in technology. With consumers and the government outraged at the plastics crisis, the waste industry is scrambling to solve the problem. One great hope is chemical recycling: turning problem plastics into oil or gas through industrial processes. “It recycles the kind of plastics that mechanical recycling can’t look at: the pouches, the sachets, the black plastics,” says Adrian Griffiths, the founder of Swindon-based Recycling Technologies. The idea found its way to Griffiths, a former management consultant, by accident, after a mistake in a Warwick University press release. “They said they could turn any old plastic back into a monomer. At the time, they couldn’t,” Griffiths says. Intrigued, Griffiths got in touch. He ended up partnering with the researchers to launch a company that could do this.</p> <aside class="element element-pullquote element--supporting" readability="1.5"><span class="inline-garnett-quote inline-icon "> <svg width="70" height="49" viewbox="0 0 35 25" class="inline-garnett-quote__svg inline-icon__svg"><path d="M69.587.9c-1.842 15.556-3.89 31.316-4.708 48.1H37.043c3.07-16.784 8.391-32.544 17.602-48.1h14.942zM32.949.9c-2.047 15.556-4.094 31.316-4.912 48.1H.2C3.066 32.216 8.592 16.456 17.598.9h15.35z"/></svg></span> <blockquote readability="6"> <p class="pullquote-paragraph">By moving from disposable to reusable, you unlock epic design opportunities</p> </blockquote> </aside><p>At Recycling Technologies’ pilot plant in Swindon, plastic (Griffiths says it can process any type) is fed into a towering steel cracking chamber, where it is separated at extremely high temperatures into gas and an oil, <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">plaxx</a>, which can be used as a fuel or feedstock for new plastic. While the global mood has turned against plastic, Griffiths is a rare defender of it. “Plastic packaging has actually done an incredible service for the world, because it has reduced the amount of glass, metal and paper that we were using,” he says. “The thing that worries me more than the plastic problem is global warming. If you use more glass, more metal, those materials have a much higher carbon footprint.” The company recently launched a trial scheme with Tesco and is already working on a second facility, in Scotland. Eventually, Griffiths hopes to sell the machines to recycling facilities worldwide. “We need to stop shipping recycling abroad,” he says. “No civilised society should be getting rid of its waste to a developing country.”</p> <p>There is cause for optimism: in December 2018, the UK government published <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">a comprehensive new waste strategy</a>, partly in response to National Sword. Among its proposals: a tax on plastic packaging containing less than 30% recycled material; a simplified labelling system; and means to force companies to take responsibility for the plastic packaging they produce. They hope to force the industry to invest in recycling infrastructure at home. </p> <p>Meanwhile, the industry is being forced to adapt: in May, 186 countries passed measures to track and control the export of plastic waste to developing countries, while more than 350 companies have signed a global commitment to eliminate the use of single-use plastics by 2025.</p> <p>Yet such is the torrent of humanity’s refuse that these efforts may not be enough. Recycling rates in the west are stalling and packaging use is set to soar in developing countries, where recycling rates are low. If National Sword has shown us anything, it is that recycling – while needed – simply isn’t enough to solve our waste crisis.</p> <p>***</p> <p>Perhaps there is an alternative. Since <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">Blue Planet II</a> brought the plastic crisis to our attention, a dying trade is having a resurgence in Britain: <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">the milkman</a>. More of us are choosing to have milk bottles delivered, collected and re-used. Similar models are springing up: <a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">zero-waste shops that require you to bring your own containers</a>; the boom in refillable cups and bottles. It is as if we have remembered that the old environmental slogan “Reduce, re-use, recycle” wasn’t only catchy, but listed in order of preference.</p> <p>Tom Szaky wants to apply the milkman model to almost everything you buy. The bearded, shaggy-haired Hungarian-Canadian is a veteran of the waste industry: he founded his first recycling startup as a student at Princeton, selling worm-based fertiliser out of re-used bottles. That company, TerraCycle, is now a recycling giant, with operations in 21 countries. In 2017, TerraCycle worked with Head &amp; Shoulders on a shampoo bottle made from recycled ocean plastics. The product launched at the World Economic Forum in Davos and was an immediate hit. Proctor &amp; Gamble, which makes Head &amp; Shoulders, was keen to know what was next, so Szaky pitched something far more ambitious.</p> <p><a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">The result </a><a href="" title="" data-link-name="in body link" class="u-underline in-body-link--immersive">is Loop</a>, which launched trials in France and the US this spring and will arrive in Britain this winter. It offers a variety of household products – from manufacturers including P&amp;G, Unilever, Nestlé and Coca-Cola – in reusable packaging. The items are available online or through exclusive retailers. Customers pay a small deposit, and the used containers are eventually collected by a courier or dropped off in store (Walgreens in the US, Tesco in the UK), washed, and sent back to the producer to be refilled. “Loop is a not a product company; it’s a waste management company,” says Szaky. “We’re just looking at waste before it begins.”</p> <p>Many of the Loop designs are familiar: refillable glass bottles of Coca-Cola and Tropicana; aluminium bottles of Pantene. But others are being rethought entirely. “By moving from disposable to reusable, you unlock epic design opportunities,” says Szaky. For example: Unilever is working on toothpaste tablets that dissolve into paste under running water; Häagen-Dazs ice-cream comes in a stainless steel tub that stays cold long enough for picnics. Even the deliveries come in a specially designed insulated bag, to cut down on cardboard.</p> <figure itemprop="associatedMedia image" itemscope="" itemtype="" data-component="image" class="element element-image img--landscape fig--narrow-caption fig--has-shares " data-media-id="6930479e5ebf068e96c8f6921b4ec3455ec3bb6d" id="img-4"><meta itemprop="url" content=";quality=85&amp;auto=format&amp;fit=max&amp;s=be5b4167dd0cd97226648dcf1e3ef0f3"/><meta itemprop="width" content="1920"/><meta itemprop="height" content="1152"/><a href="" class="article__img-container js-gallerythumbs in-body-link--immersive" data-link-name="Launch Article Lightbox" data-is-ajax=""> <span class="inline-expand-image inline-icon centered-icon rounded-icon article__fullscreen modern-visible"> <svg width="22" height="22" viewbox="0 0 22 22" class="centered-icon__svg rounded-icon__svg article__fullscreen__svg modern-visible__svg inline-expand-image__svg inline-icon__svg"><path d="M3.4 20.2L9 14.5 7.5 13l-5.7 5.6L1 14H0v7.5l.5.5H8v-1l-4.6-.8M18.7 1.9L13 7.6 14.4 9l5.7-5.7.5 4.7h1.2V.6l-.5-.5H14v1.2l4.7.6"/></svg></span> </a> <figcaption class="caption caption--img caption caption--img" itemprop="description"><span class="inline-triangle inline-icon "> <svg width="11" height="10" viewbox="0 0 11 10" class="inline-triangle__svg inline-icon__svg"><path fill-rule="evenodd" d="M5.5 0L11 10H0z"/></svg></span> At Recycling Technologies in Swindon, nearly all plastics can be turned into plaxx, an oil that can be used to make new plastic. Photograph: Recycling Technologies Ltd </figcaption></figure><p>Tina Hill, a Paris-based copywriter, signed up to Loop soon after its launch in France. “It’s super-easy,” she says. “It’s a small deposit, €3 [per container]. What I like about it is that they have things I already use: olive oil, washing pods.” Hill describes herself as “pretty green: we recycle anything that can be recycled, we buy organic”. By combining Loop with shopping at local zero-waste stores, Hills has helped her family radically reduce its reliance on single-use packaging. “The only downside is that the prices can be a little high. We don’t mind spending a little bit more to support the things that you believe in, but on some things, like pasta, it’s prohibitive.”</p> <p>A major advantage to Loop’s business model, Szaky says, is that it forces packaging designers to prioritise durability over disposability. In future, Szaky anticipates that Loop will be able to email users warnings for expiry dates and other advice to reduce their waste footprint. The milkman model is about more than just the bottle: it makes us think about what we consume and what we throw away. “Garbage is something that we want out of sight and mind – it’s dirty, it’s gross, it smells bad,” says Szaky.</p> <p>That is what needs to change. It is tempting to see plastic piled up in Malaysian landfills and assume recycling is a waste of time, but that isn’t true. In the UK, recycling is largely a success story, and the alternatives – burning our waste or burying it – are worse. Instead of giving up on recycling, Szaky says, we should all use less, re-use what we can and treat our waste like the waste industry sees it: as a resource. Not the ending of something, but the beginning of something else.</p> <p>“We don’t call it waste; we call it materials,” says Green Recycling’s Smith, back in Maldon. Down in the yard, a haulage truck is being loaded with 35 bales of sorted cardboard. From here, Smith will send it to a mill in Kent for pulping. It will be new cardboard boxes within the fortnight – and someone else’s rubbish soon after.</p> <p><span class="bullet">•</span> If you would like a comment on this piece to be considered for inclusion on Weekend magazine’s letters page in print, please email <a href="mailto:" data-link-name="in body link" class="u-underline in-body-link--immersive"></a>, including your name and address (not for publication).</p> Sat, 17 Aug 2019 22:00:59 +0000 The first solar road has turned out to be a disappointing failure <p>In July, the French daily newspaper <em>Le Monde</em> <a href="">reported</a> that the 0.6-mile (1 kilometre) solar road was a fiasco.</p><p>In December 2016, when the trial road was unveiled, the French Ministry of the Environment called it <a href="">"unprecedented"</a>. French officials said the road, made of photovoltaic panels, would generate electricity to power streetlights in Tourouvre, a local town.</p> <p>But less than three years later, a report published by Global Construction Review says <a href="">France's road dream may be over</a>. Cracks have appeared, and in 2018, part of the road had to be demolished due to damage from wear and tear.</p><p>Even at its peak, the road was only producing half of the expected energy, because engineers didn't take into consideration rotting leaves falling on the road.</p><p>Here what the road looked like in all of its former glory, and how it got to this point.</p><p><span class=" wf_caption"><img src="" alt="(Benoit Tessier / Reuters)" width="700"/><span>(Benoit Tessier/Reuters)</span></span></p><p>It was all smiles and high hopes in 2016, when the world's first solar panel road, called Wattway, opened. France spent US$5.2 million on 0.6 miles (1 kilometre) of road, and 30,000 square feet (3,000 square metres) of solar panels. It was hailed as the longest solar road in the world.</p><p>Media gathered around to take a walk down what was thought to be the road of the future. The French minister for energy said she wanted to have solar panels on one mile of road every 621 miles in the country within the next five years.</p><p>Despite grey skies on the day of the inauguration, France was leading the world for solar transportation.</p><p>But the brake was never removed, and the wheels never started rolling - so to speak.</p><p>It was a bold move beginning a solar panel trial in Normandy, France, since the region doesn't have the most sunshine. Caen, a city in Normandy, only has 44 days of strong sunshine in a year. Thunderstorms also reportedly broke solar panels on the road.</p><p>The trial road was meant to produce about 150,000 kWh a year, which is enough power to provide light for up to 5,000 people, every day. Instead, it was making just under 80,000 in 2018, and fewer than 40,000 by July 2019.</p><p>Colas, the company that built the road, said in 2016 that the solar panels were covered with resin containing sheets of silicon to make them capable of withstanding all traffic. But since the opening, panels have come loose or broken into little pieces.</p><p>In May 2018, 300 feet (90 metres) of the road had to be demolished since it wasn't salvageable.</p><p><span class=" wf_caption"><img src="" alt="(Fabrizio Bensch / Reuters)" width="700"/><span>(Fabrizio Bensch/Reuters)</span></span></p><p>The engineers also didn't take into account the effects of leaves, which caused damage and limited the amount of electricity the panels could produce. They also didn't think about the pressure and weight from tractors, two locals told <em>Le Monde</em>.</p><p>And now the trial looks like it's all over. Wattway's managing director Etienne Gaudin told <em>Le Monde</em> that it would not be going to market.</p><p>"Our system is not mature on long distance traffic," he said. The company would focus on creating electricity for smaller things, like CCTV cameras and lighting bus shelters.</p><p><strong>This article was originally published by <a href="">Business Insider</a>.</strong></p><p><strong>More from Business Insider:</strong></p> Sat, 17 Aug 2019 19:46:46 +0000 Announcing New AMD EPYC-based Azure Virtual Machines <p>Microsoft is committed to giving our customers industry-leading performance for all their workloads. After being the first global cloud provider to announce the <a href="" target="_blank">deployment of AMD EPYC™ based Azure Virtual Machines</a> in 2017, we’ve been working together to continue bringing the latest innovation to enterprises.</p> <p>Today, we are announcing our second-generation HB-series Azure Virtual Machines, HBv2, which features the latest AMD <a href="" target="_blank">EPYC 7002 processor</a>. Customers will be able to increase HPC performance and scalability to run materially larger workloads on Azure. We’ll also be bringing the AMD 7002 processors and Radeon Instinct GPUs to our family of cloud-based virtual desktops. Finally, our new Dav3 and Eav3-series Azure Virtual Machines, in preview today, provide more customer choice to meet a broad range of requirements for general purpose workloads using the new AMD EPYC™ 7452 processor.</p> <h2>Our growing Azure HPC offerings</h2> <p>Customers are choosing our Azure HPC offerings (HB-series) incorporating first generation AMD EPYC Naples for their performance and scalability. We’ve seen a 33 percent memory bandwidth advantage with EPYC, and that’s a key factor for many of our customers’ HPC workloads. For example, fluid dynamics is one workload in which this advantage is valuable. Azure has an increasing number of customers for whom this is a core part of their R&amp;D and even production activities. On ANSYS Fluent, a widely used fluid dynamics application, we have measured EPYC-powered HB instances delivering a 54x performance improvement by scaling across nearly 6,000 processor cores. And this is 24 percent faster than a leading bare-metal solution with an identical InfiniBand network. Additionally, earlier this year, Azure became the first cloud to scale a tightly coupled HPC application to 10,000 cores. This is 10x higher than what had been previously possible on any other cloud provider. Azure customers will be among the first to take advantage of this capability to tackle the toughest challenges and innovate with purpose.</p> <h2>New HPC, general purpose, and memory optimized Azure Virtual Machines</h2> <p>Azure is continuing to increase its HPC capabilities, thanks in part to our collaboration with AMD. In preliminary benchmarking, HBv2 VMs featuring 120 CPUs from the second generation EPYC processor are demonstrating performance gains of over 100 percent on HPC workloads like fluid dynamics and automotive crash test analysis. HBv2 scalability limits are also increasing with the cloud’s first deployment of 200 Gigabit InfiniBand, thanks to the second generation EPYC processor’s PCIe 4.0 capability. HBv2 virtual machines (VMs) will support up to 36,000 cores for MPI workloads in a single virtual machine scale set, and up to 80,000 cores for our largest customers.</p> <p>We’ll also be bringing AMD EPYC 7002 processor to our family of cloud-based remote desktops, pairing with the Radeon MI25 GPU for customers running Windows-based environments. The new series offers unprecedented GPU resourcing flexibility, giving customers more choice than ever before to size virtual machines all the way from 1/8th of a single GPU up to a whole GPU.</p> <p>Finally, we are also announcing new Azure Virtual Machines as part of the Dv3 and Ev3-series—optimized for general purpose and memory intensive workloads. These new VM sizes feature AMD’s EPYC™ 7452 processor. The new general purpose Da_v3 and Das_v3 Azure Virtual Machines provide up to 64 vCPUs, 256 GiBs of RAM, and 1,600 GiBs of SSD-based temporary storage. Additionally, the new memory optimized Ea_v3 and Eas_v3 Azure Virtual Machines provide up to 64 vCPUs, 432 GiBs of RAM, and 1,600 GiBs of SSD-based temporary storage. Both VM series support Premium SSD disk storage. The new VMs are currently in preview in the East US Azure region and with availability coming soon to other regions.</p> <p>Da_v3 and Das_v3 virtual machines can be used for a broad range of general-purpose applications. Example use cases include most enterprise-grade applications, relational databases, in-memory caching, and analytics. Applications that demand faster CPUs, better local disk performance or higher memories can also benefit from these new VMs. Additionally, the Ea_v3 and Eas_v3 VM series are optimized for other large in-memory business critical workloads.</p> <h2>Taking advantage of these new offerings</h2> Sat, 17 Aug 2019 20:05:45 +0000 Girish Bablani Deep Operation <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> <div id="contentSub"/> <a class="mw-jump-link" href="">Jump to navigation</a> <a class="mw-jump-link" href="">Jump to search</a> <div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><div class="mw-parser-output"><p class="mw-empty-elt"> </p> <p><b>Deep operation</b> (<a href="" title="Russian language">Russian</a>: <span lang="ru">Глубокая операция</span>, <i>glubokaya operatsiya</i>), also known as <b>Soviet Deep Battle</b>, was a <a href="" title="Military theory">military theory</a> developed by the <a href="" title="Soviet Union">Soviet Union</a> for its <a href="" title="Soviet Armed Forces">armed forces</a> during the 1920s and 1930s. It was a <a href="" class="extiw" title="wikt:tenet">tenet</a> that emphasized destroying, suppressing or disorganizing enemy forces not only at the line of contact, but throughout the depth of the battlefield. </p><p>The term comes from <a href="" title="Vladimir Triandafillov">Vladimir Triandafillov</a>, an influential military writer, who worked with others to create a military strategy with its own specialized <a href="" class="mw-redirect" title="Operational art">operational art</a> and <a href="" title="Military tactics">tactics</a>. The concept of deep operations was a national strategy, tailored to the <a href="" class="mw-redirect" title="Economic">economic</a>, <a href="" class="mw-redirect" title="Cultural">cultural</a> and <a href="" title="Geopolitics">geopolitical</a> position of the Soviet Union. In the aftermath of several failures or defeats in the <a href="" title="Russo-Japanese War">Russo-Japanese War</a>, <a href="" class="mw-redirect" title="First World War">First World War</a> and <a href="–Soviet_War" title="Polish–Soviet War">Polish–Soviet War</a>, the Soviet High Command (<i><a href="" title="Stavka">Stavka</a></i>) focused on developing new methods for the conduct of war. This new approach considered military strategy and tactics, but also introduced a new intermediate level of military art: <a href="" title="Operational level of war">operations</a>. The Soviet Union was the first country to officially distinguish the third level of military thinking which occupied the position between <a href="" title="Strategy">strategy</a> and <a href="" title="Military tactics">tactics</a>.<sup id="cite_ref-1" class="reference"><a href="">[1]</a></sup></p><p>Using these templates, the Soviets developed the concept of deep battle and by 1936 it had become part of the <a href="" title="Red Army">Red Army</a> Field Regulations. Deep operations had two phases: the <b>tactical deep battle</b>, followed by the exploitation of tactical success, known as the conduct of <b>deep battle operations</b>. Deep battle envisaged the breaking of the enemy's forward defenses, or tactical zones, through <a href="" title="Combined arms">combined arms</a> assaults, which would be followed up by fresh uncommitted mobile operational reserves sent to exploit the <a href="" title="Strategic depth">strategic depth</a> of an enemy <a href="" title="Front (military)">front</a>. The goal of a deep operation was to inflict a decisive strategic defeat on the enemy's <a href="" title="Military logistics">logistical</a> abilities and render the defence of their front more difficult, impossible—or, indeed, irrelevant. Unlike most other doctrines, deep battle stressed combined arms cooperation at <i>all</i> levels: strategic, operational, and tactical. </p> <style data-mw-deduplicate="TemplateStyles:r886046785"><![CDATA[.mw-parser-output .toclimit-2 .toclevel-1 ul,.mw-parser-output .toclimit-3 .toclevel-2 ul,.mw-parser-output .toclimit-4 .toclevel-3 ul,.mw-parser-output .toclimit-5 .toclevel-4 ul,.mw-parser-output .toclimit-6 .toclevel-5 ul,.mw-parser-output .toclimit-7 .toclevel-6 ul{display:none}]]></style><div class="toclimit-3"><div id="toc" class="toc"><div class="toctitle" lang="en" dir="ltr"><h2>Contents</h2><span class="toctogglespan"><label class="toctogglelabel" for="toctogglecheckbox"/></span></div> <ul><li class="toclevel-1 tocsection-1"><a href=""><span class="tocnumber">1</span> <span class="toctext">History</span></a> <ul><li class="toclevel-2 tocsection-2"><a href=""><span class="tocnumber">1.1</span> <span class="toctext">Before deep battle</span></a></li> <li class="toclevel-2 tocsection-3"><a href=""><span class="tocnumber">1.2</span> <span class="toctext">Roots of deep battle</span></a></li> </ul></li> <li class="toclevel-1 tocsection-4"><a href=""><span class="tocnumber">2</span> <span class="toctext">Principles</span></a> <ul><li class="toclevel-2 tocsection-5"><a href=""><span class="tocnumber">2.1</span> <span class="toctext">Doctrine</span></a></li> <li class="toclevel-2 tocsection-6"><a href=""><span class="tocnumber">2.2</span> <span class="toctext">Tukhachevsky legacy</span></a></li> <li class="toclevel-2 tocsection-7"><a href=";_the_factor_of_depth"><span class="tocnumber">2.3</span> <span class="toctext">Isserson; the factor of depth</span></a></li> <li class="toclevel-2 tocsection-8"><a href=""><span class="tocnumber">2.4</span> <span class="toctext">Tactical deep battle</span></a></li> <li class="toclevel-2 tocsection-9"><a href=""><span class="tocnumber">2.5</span> <span class="toctext">Deep operation</span></a></li> <li class="toclevel-2 tocsection-10"><a href=""><span class="tocnumber">2.6</span> <span class="toctext">Varfolomeev and the composition of deep operations</span></a></li> <li class="toclevel-2 tocsection-11"><a href=""><span class="tocnumber">2.7</span> <span class="toctext">Deep operations engagement</span></a></li> <li class="toclevel-2 tocsection-12"><a href=""><span class="tocnumber">2.8</span> <span class="toctext">Logistics</span></a></li> </ul></li> <li class="toclevel-1 tocsection-13"><a href=";_differences_with_other_methodologies"><span class="tocnumber">3</span> <span class="toctext">Intended outcomes; differences with other methodologies</span></a></li> <li class="toclevel-1 tocsection-14"><a href=""><span class="tocnumber">4</span> <span class="toctext">The impact of the purges</span></a></li> <li class="toclevel-1 tocsection-15"><a href=""><span class="tocnumber">5</span> <span class="toctext">Deep operations during World War II</span></a> <ul><li class="toclevel-2 tocsection-16"><a href=""><span class="tocnumber">5.1</span> <span class="toctext">Moscow counter offensive</span></a> <ul><li class="toclevel-3 tocsection-17"><a href=""><span class="tocnumber">5.1.1</span> <span class="toctext">Deep battle plan</span></a></li> <li class="toclevel-3 tocsection-18"><a href=""><span class="tocnumber">5.1.2</span> <span class="toctext">Outcome</span></a></li> </ul></li> <li class="toclevel-2 tocsection-19"><a href="–Vyazma_offensive"><span class="tocnumber">5.2</span> <span class="toctext">Rzhev–Vyazma offensive</span></a> <ul><li class="toclevel-3 tocsection-20"><a href=""><span class="tocnumber">5.2.1</span> <span class="toctext">Deep battle plan</span></a></li> <li class="toclevel-3 tocsection-21"><a href=""><span class="tocnumber">5.2.2</span> <span class="toctext">Outcome</span></a></li> </ul></li> <li class="toclevel-2 tocsection-22"><a href=""><span class="tocnumber">5.3</span> <span class="toctext">Operation Uranus and Third Kharkov</span></a> <ul><li class="toclevel-3 tocsection-23"><a href=""><span class="tocnumber">5.3.1</span> <span class="toctext">Deep battle plan</span></a></li> <li class="toclevel-3 tocsection-24"><a href=""><span class="tocnumber">5.3.2</span> <span class="toctext">Outcome</span></a></li> </ul></li> <li class="toclevel-2 tocsection-25"><a href=""><span class="tocnumber">5.4</span> <span class="toctext">Kursk</span></a> <ul><li class="toclevel-3 tocsection-26"><a href=""><span class="tocnumber">5.4.1</span> <span class="toctext">Deep battle plan</span></a></li> <li class="toclevel-3 tocsection-27"><a href=""><span class="tocnumber">5.4.2</span> <span class="toctext">Outcome</span></a></li> </ul></li> <li class="toclevel-2 tocsection-28"><a href=""><span class="tocnumber">5.5</span> <span class="toctext">Other campaigns</span></a></li> </ul></li> <li class="toclevel-1 tocsection-29"><a href=""><span class="tocnumber">6</span> <span class="toctext">Cold War</span></a> <ul><li class="toclevel-2 tocsection-30"><a href=""><span class="tocnumber">6.1</span> <span class="toctext">Central Europe</span></a></li> <li class="toclevel-2 tocsection-31"><a href=""><span class="tocnumber">6.2</span> <span class="toctext">Asia</span></a></li> </ul></li> <li class="toclevel-1 tocsection-32"><a href=""><span class="tocnumber">7</span> <span class="toctext">Major proponents</span></a></li> <li class="toclevel-1 tocsection-33"><a href=""><span class="tocnumber">8</span> <span class="toctext">See also</span></a></li> <li class="toclevel-1 tocsection-34"><a href=""><span class="tocnumber">9</span> <span class="toctext">References</span></a> <ul><li class="toclevel-2 tocsection-35"><a href=""><span class="tocnumber">9.1</span> <span class="toctext">Citations</span></a></li> <li class="toclevel-2 tocsection-36"><a href=""><span class="tocnumber">9.2</span> <span class="toctext">Bibliography</span></a></li> </ul></li> <li class="toclevel-1 tocsection-37"><a href=""><span class="tocnumber">10</span> <span class="toctext">External links</span></a></li> </ul></div> </div> <h2><span class="mw-headline" id="History">History</span></h2> <h3><span class="mw-headline" id="Before_deep_battle">Before deep battle</span></h3> <p>Russian military thinking had changed little over the course of three centuries prior to the 1920s. The <a href="" title="Russian Empire">Russian Empire</a> had kept pace with its enemies and allies and performed well in its major conflicts in the run-up to the 19th century. However, despite some notable victories in the <a href="" title="Napoleonic Wars">Napoleonic Wars</a> (1803–1815) and in various <a href="" class="mw-redirect" title="Russo-Turkish Wars">Russo-Turkish Wars</a>, Russian defeats in the <a href="" title="Crimean War">Crimean War</a> (1853–1856), <a href="" title="Russo-Japanese War">Russo-Japanese War</a> (1904–1905) and <a href="" class="mw-redirect" title="First World War">First World War</a> (1914–1918), together with a series of Soviet defeats at the hands of <a href="" title="Poland">Poland</a> in the <a href="–Soviet_War" title="Polish–Soviet War">Polish–Soviet War</a> (1919–1921), highlighted the inferiority of Russian methodology in organisation and training.<sup id="cite_ref-2" class="reference"><a href="">[2]</a></sup><sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="" title="Wikipedia:Verifiability"><span title="Quotation needed from source to verify. (August 2017)">need quotation to verify</span></a></i>]</sup></p><p>After the <a href="" class="mw-redirect" title="Russian Revolution (1917)">Russian Revolution</a> of 1917, the new <a href="" class="mw-redirect" title="Bolshevik">Bolshevik</a> regime sought to establish an entirely new military system that reflected the Bolshevik revolutionary spirit. The new <a href="" title="Red Army">Red Army</a> (founded in 1918) combined the old and new methods. It still relied on the country's enormous manpower reserves; however, the Soviet program to develop heavy industry, which <a href="" title="First five-year plan">began in 1929</a>, also raised the technical standards of Soviet arms industries to the level of other European nations. Once this had been achieved,<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="" title="Wikipedia:Manual of Style/Dates and numbers"><span title="The time period mentioned near this tag is ambiguous. (August 2017)">when?</span></a></i>]</sup> the Soviets turned their attention to solving the problem of military <a href="" class="mw-redirect" title="Operational mobility">operational mobility</a>.<sup id="cite_ref-3" class="reference"><a href="">[3]</a></sup><sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="" title="Wikipedia:Verifiability"><span title="Quotation needed from source to verify. (August 2017)">need quotation to verify</span></a></i>]</sup></p><p>Primary advocates of this development included <a href="" title="Alexander Andreyevich Svechin">Alexander Svechin</a> (1878–1938), <a href="" title="Mikhail Frunze">Mikhail Frunze</a> (1885–1925), and <a href="" title="Mikhail Tukhachevsky">Mikhail Tukhachevsky</a> (1893–1937). They promoted the development of military scientific societies and they identified groups of talented officers. Many of these officers entered the <a href="" class="mw-redirect" title="Frunze Military Academy">Soviet Military Academy</a> during Tukhachevsky's tenure as its commandant in 1921–1922. Others came later, particularly <a href="" title="Nikolai Efimovich Varfolomeev">Nikolai Varfolomeev</a> (1890–1939) and <a href="" title="Vladimir Triandafillov">Vladimir Triandafillov</a> (1894–1931), who made significant contributions to the use of technology in deep offensive operations.<sup id="cite_ref-4" class="reference"><a href="">[4]</a></sup></p> <h3><span class="mw-headline" id="Roots_of_deep_battle">Roots of deep battle</span></h3> <p>In the aftermath of the wars with <a href="" title="Empire of Japan">Japan</a> and <a href="" title="Second Polish Republic">Poland</a> several senior Soviet Commanders called for a unified military doctrine. The most prominent was Mikhail Frunze.<sup id="cite_ref-5" class="reference"><a href="">[5]</a></sup> The call prompted opposition by <a href="" title="Leon Trotsky">Leon Trotsky</a>. Frunze' position eventually found favour with the officer elements that had experienced the poor command and control of Soviet forces in the conflict with Poland during the Polish-Soviet War. This turn of events prompted Trotsky's replacement by Frunze in January 1925. </p> <div class="thumb tright"><div class="thumbinner" style="width:155px;"><a href="" class="image"><img alt="" src="" decoding="async" width="153" height="251" class="thumbimage" data-file-width="153" data-file-height="251"/></a> <div class="thumbcaption"><a href="" title="Mikhail Tukhachevsky">Mikhail Tukhachevsky</a></div></div></div> <p>The nature of this new doctrine was to be political. The Soviets were to fuse the military with the Bolshevik ideal. This would define the nature of war for the Soviet Union. The Soviets believed their most likely enemy would be the capitalist states of the west they had to defend themselves against before and that such a conflict was unavoidable. The nature of this war raised four major questions:<sup id="cite_ref-Harrison_2001,_p._126._6-0" class="reference"><a href=",_p._126.-6">[6]</a></sup></p> <ul><li>Would the next war be won in one decisive campaign or would it be a long struggle of attrition?</li> <li>Should the Red Army be primarily offensive or defensive?</li> <li>Would the nature of battle be fluid or static?</li> <li>Would mechanized or infantry forces be more important?</li></ul><p>The discussion evolved into debate between those, like <a href="" title="Alexander Andreyevich Svechin">Alexander Svechin</a>, who advocated a <a href="" title="Attrition warfare">strategy of attrition</a>, and others, like Tukhachevsky, who thought that a strategy of decisive destruction of the enemy forces was needed. The latter opinion was motivated in part by the condition of the Soviet Union's economy: the country was still not industrialized and thus was economically too weak to fight a long war of attrition.<sup id="cite_ref-7" class="reference"><a href="">[7]</a></sup> By 1928 Tukhachevsky's ideas had changed: he considered that, given the nature and lessons of the <a href="" class="mw-redirect" title="First World War">First World War</a>, the next major war would almost certainly be one of attrition. He determined, however, that the vast size of the Soviet Union ensured that some mobility was still possible. Svechin accepted this and allowed for the first offensives to be fast and fluid; but ultimately he decided that it would come down to a war of position and attrition. This would require a strong economy and a loyal and politically indoctrinated population in order to outlast the enemy.<sup id="cite_ref-Harrison_2001,_p._126._6-1" class="reference"><a href=",_p._126.-6">[6]</a></sup></p><p>The doctrine pursued by the Soviets was offensively oriented. Tukhachevsky's neglect of defense pushed the Red Army toward the decisive battle and <a href="" title="Cult of the offensive">cult of the offensive</a> mentality, which along with other events, caused enormous problems in 1941.<sup id="cite_ref-Harrison_2001,_p._140._8-0" class="reference"><a href=",_p._140.-8">[8]</a></sup></p><p>Unlike Tukhachevsky, Svechin determined the next war could only be won by attrition, not by a single or several decisive battles. Svechin also argued that a theory of alternating defensive and offensive action was needed. Within this framework, Svechin also recognised the theoretical distinction of operational art that lay between tactics and strategy. In his opinion the role of the operation was to group and direct tactical battles toward a series of simultaneous operational objectives along a wide frontage, either directly or indirectly, in order to achieve the <i>stavka's</i> ultimate strategic target(s).<sup id="cite_ref-Harrison_2001,_p._140._8-1" class="reference"><a href=",_p._140.-8">[8]</a></sup> This became the blueprint for Soviet deep battle. </p><p>In 1929 <a href="" title="Vladimir Triandafillov">Vladimir Triandafillov</a> and Tukhachevsky formed a partnership to create a coherent system of principles from the concept formed by Svechin. Tukhachevsky was to elaborate the principles of the tactical and operational phases of deep battle.<sup id="cite_ref-9" class="reference"><a href="">[9]</a></sup> In response to his efforts and in acceptance of the methodology, the Red Army produced the <i>Provisional Instructions for Organizing the Deep Battle</i> manual in 1933. This was the first time that "deep battle" was mentioned in official Red Army literature.<sup id="cite_ref-10" class="reference"><a href="">[10]</a></sup></p> <h2><span class="mw-headline" id="Principles">Principles</span></h2> <h3><span class="mw-headline" id="Doctrine">Doctrine</span></h3> <p>Deep battle encompassed manoeuvre by multiple <a href="" class="mw-redirect" title="Front (Soviet Army)">Soviet Army front</a>-size formations simultaneously. It was not meant to deliver a victory in a single operation; instead, multiple operations, which might be conducted in parallel or successively, would induce a catastrophic failure in the enemy's defensive system. </p><p>Each operation served to divert enemy attention and keep the defender guessing about where the main effort, and main objective, lay. In doing so, it prevented the enemy from dispatching powerful mobile reserves to this area. The Army could then overrun vast regions before the defender could recover. The diversion operations also frustrated an opponent trying to conduct an <a href="" class="mw-redirect" title="Elastic defence">elastic defence</a>. The supporting operations had significant strategic objectives themselves and supporting units were to continue their offensive actions until they were unable to progress any further. However, they were still subordinated to the main/decisive strategic objective determined by the <i>Stavka</i>.<sup id="cite_ref-11" class="reference"><a href="">[11]</a></sup></p><p>Each of the operations along the front would have secondary strategic goals, and one of those operations would usually be aimed towards the primary objective. </p><p>The strategic objective, or mission, was to secure the primary strategic target. The primary target usually consisted of a geographical objective and the destruction of a proportion of the enemy armed forces. Usually the strategic missions of each operation were carried out by a <a href="" class="mw-redirect" title="Front (Soviet Army)">Soviet front</a>. The front itself usually had several shock armies attached to it, which were to converge on the target and encircle or assault it. The means of securing it was the job of the <a href="" title="Division (military)">division</a> and its tactical components, which Soviet deep battle termed the tactical mission. </p><p>Terminology, force allocation and mission table.<sup id="cite_ref-12" class="reference"><a href="">[12]</a></sup></p> <table class="wikitable sortable" style="font-size: 9pt; text-align:center"><tbody><tr><th>Mission</th> <th>Territory</th> <th>Actions</th> <th>Force allocation </th></tr><tr><td>Strategic aim</td> <td>Theatre of operations</td> <td>Strategic operation</td> <td>Strategic unit (front) </td></tr><tr><td>Strategic mission</td> <td>Strategic direction</td> <td>Front operation</td> <td>Operational-strategic unit (front) </td></tr><tr><td>Operational Mission</td> <td>Operational direction</td> <td>Army-size operation battle</td> <td>Operational unit (shock army/corps) </td></tr><tr><td>Tactical mission</td> <td>Battlefield</td> <td>Battle</td> <td>Operational-tactical unit (shock army/corps/army division) </td></tr></tbody></table><p>The concept of deep battle was not just offensive. The theory took into account all forms of warfare, and decided both the offensive and defensive should be studied and incorporated into deep battle. The defensive phase of deep battle involved identifying crucial strategic targets and securing them against attack from all directions. As with the offensive methods of deep battle, the target area would be identified and dissected into operational and tactical zones. In defence, the tactical zones, forward of the objective would be fortified with <a href="" title="Artillery">artillery</a> and infantry forces. The outer and forwardmost defences would be heavily mined, making a very strong static defence position. The tactical zones would have <a href="" title="Defence in depth">several defence lines, one after the other</a>, usually 12 kilometres from the main objective. In the zone some 1–3 kilometres from the main objective, shock forces, which contained the bulk of the Soviet combat formations, would be positioned.<sup id="cite_ref-Harrison_2001,_p._193._13-0" class="reference"><a href=",_p._193.-13">[13]</a></sup></p><p>The goal of the defence in depth concept was to blunt the elite enemy forces, which would be first to breach the Soviet lines, several times, causing them to exhaust themselves. Once the enemy had become bogged down in Soviet defences, the operational reserves came into play. Being positioned behind the tactical zones, the fresh mobile forces consisting of <a href="" title="Mechanized infantry">mechanized infantry</a>, foot infantry, <a href="" title="Tank corps (Soviet Union)">armored forces</a>, and powerful tactical air support would engage the worn down enemy in a <a href="" title="Counter-offensive">counter-offensive</a>, either destroying it by attacking its flank, or driving it out of the Soviet tactical zone and into enemy held territory as far as possible.<sup id="cite_ref-Harrison_2001,_p._193._13-1" class="reference"><a href=",_p._193.-13">[13]</a></sup></p> <h3><span class="mw-headline" id="Tukhachevsky_legacy">Tukhachevsky legacy</span></h3> <p>There are three standard doctrine about military to understand Deep Battle, as adopted by the <a href="" title="United States Army">United States Army</a> and <a href="" title="United States Marine Corps">United States Marine Corps</a>: </p><p><b>1. Tactic</b> </p><p>The lower level is tactic, an aspect of individual skill and corps size. </p><p><b>2. Strategy</b> </p><p>The highest level, an aspect of <a href="" title="Theater (warfare)">theater</a> operation and the leadership of organization of a government. </p><p><b>3. Operational</b> </p><p>Operational is the bridge between tactics and strategy. </p><p>According to Col McPadden (US Army) the most precious legacy of Tukhachevsky are his concepts about all operations theory including the "operational art". Mikhail Tukhachevsky is the first who made operational as a systematic concept. According to Col. McPadden the main skill of military commander is dependent on Tukhachevsky's Theory, which is the ability to integrate tactic and strategy. The meaning is, the capability of commander on "the use of military forces to achieve strategic goals through the design, organization, integration and conduct of theater strategies, campaigns, major operations and battles".<sup id="cite_ref-14" class="reference"><a href="">[14]</a></sup><sup id="cite_ref-15" class="reference"><a href="">[15]</a></sup></p> <h3><span id="Isserson.3B_the_factor_of_depth"/><span class="mw-headline" id="Isserson;_the_factor_of_depth">Isserson; the factor of depth</span></h3> <p>Georgii Samoilovich Isserson (1898–1976) was a prolific writer on military tactics and operations. Amongst his most important works on operational art were <i>The Evolution of Operational Art</i> (1932 and 1937) and <i>Fundamentals of the Deep Operation</i> (1933). The latter work remains classified to this day.<sup id="cite_ref-Harrison_2001,_p._204._16-0" class="reference"><a href=",_p._204.-16">[16]</a></sup></p><p>Isserson concentrated on depth and the role it played in operations and strategy. According to his view strategy had moved on from <a href="" title="Napoleonic era">Napoleonic</a> times and the strategy of a single point (the decisive battle) and the <a href="" title="Helmuth von Moltke the Younger">Moltke</a> era of linear strategy. The continuous front that developed in the First World War would not allow the flanking moves of the pre-1914 period. Isserson argued that the front had become devoid of open flanks and military art faced a challenge to develop new methods to break through a deeply echeloned defence. To this end he wrote, "we are at the dawn of a new epoch in military art, and must move from a linear strategy to a deep strategy".<sup id="cite_ref-Harrison_2001,_p._204._16-1" class="reference"><a href=",_p._204.-16">[16]</a></sup></p><p>Isserson calculated that the Red Army's attack echelon must be 100 to 120 kilometres long. He estimated that enemy tactical defences, in about two lines would be shallow in the first, stretching back some 5 to 6 kilometres. The second line would be formed behind and have 12 to 15 kilometres of depth. Beyond this lay the operational depth, this would be larger and more densely occupied than the first, embracing the railheads and supply stations to a depth of 50 to 60 kilometres. Here the main enemy forces were concentrated. The third zone, beyond the operational depth was known as the strategic depth. This zone served as the vital link between the country's manpower reservoirs and industrial power-supply sites and the area of military operations. In this zone lay the headquarters of the strategic forces, which included the <a href="" title="Army group">army group</a> level.<sup id="cite_ref-Harrison_2001,_p._204._16-2" class="reference"><a href=",_p._204.-16">[16]</a></sup></p><p>Isserson much like Varfolomeev divided his shock armies, one for the task of breaking the enemy forward (or front line defences) and the other to exploit the breakthrough and occupy the operational zone, while destroying enemy reserve concentrations as they attempted to counter the assault. The exploitation phase would be carried out by <a href="" title="Combined arms">combined arms</a> teams of mechanized <a href="" title="Airborne forces">airborne infantry</a> and motorised forces.<sup id="cite_ref-Harrison_2001,_p._205._17-0" class="reference"><a href=",_p._205.-17">[17]</a></sup></p><p>The breadth of the attack zone was an important factor in Soviet calculations. Isserson asserted an attack over a frontage of 70 to 80 kilometres would be best. Three or four <a href="" class="mw-redirect" title="Rifle corps (Soviet)">rifle corps</a> would make a breakthrough along a front of 30 kilometres. The breakthrough zone (only under favourable conditions) might be expanded to 48 to 50 kilometres with another rifle corps. Under these conditions, a rifle corps would attack along a 10 to 12 kilometre front, with each division in the corps' first echelon allocated a 6 kilometre frontage. A fifth supporting rifle corps would make diversionary attacks along the flanks of the main thrust to tie down counter responses, confuse the enemy as to the area of the main thrust and delay his reserves from arriving.<sup id="cite_ref-Harrison_2001,_p._205._17-1" class="reference"><a href=",_p._205.-17">[17]</a></sup></p> <h3><span class="mw-headline" id="Tactical_deep_battle">Tactical deep battle</span></h3> <p>Once the strategic objectives had been determined and operational preparation completed the Red Army would be tasked with assaulting the tactical zones of the enemy front in order to break through into its rear, allowing operationally mobile forces to invade the undefended enemy-held area to the rear. The <a href="" class="mw-redirect" title="Rifle corps (Soviet)">Soviet rifle corps</a> was essential to the tactical method. As the largest tactical unit it formed the central component of the tactical deep battle. The rifle corps usually formed part of a larger operational effort and would be reinforced with tanks, artillery and other weapons. Several corps would take part in the attack, some with defensive missions and others with offensive assignments. These were known as holding and shock groups respectively.<sup id="cite_ref-18" class="reference"><a href="">[18]</a></sup></p><p>The <a href="" title="Order of battle">order of battle</a> was to encompass three echelons. The first echelon, acting as the first layer of forces, would come into immediate contact with opposing forces to break the tactical zones. The follow on echelons would support the breakthrough and the reserve would exploit it operationally. The holding group would be positioned on either flank of the combat zone to tie down enemy reinforcements via means of diversion attacks or blocking defence. </p><p>Nevertheless, despite the diversion being a primary mission, the limited forces conducting holding actions would be assigned geographical objectives. Once the main thrust had defeated the enemy's main defence, the tactical holding forces were to merge with the main body of forces conducting the operations.<sup id="cite_ref-Harrison_2001,_p._190._19-0" class="reference"><a href=",_p._190.-19">[19]</a></sup></p><p>In defence, the same principles would apply. The holding group would be positioned forward of the <a href="" class="mw-redirect" title="Main Line of Resistance">main defensive lines</a>. The job of the holding echelons in this event was to weaken or halt the main enemy forces. Should this be achieved, the enemy would be weakened sufficiently to be caught and impaled on the main defence lines. If this failed, and the enemy succeeded in sweeping aside the holding forces and breaching the several main defence lines, mobile operational reserves, including tanks and <a href="" class="mw-redirect" title="Ground-attack aircraft">assault aviation</a>, would be committed. These forces would be allocated to holding and shock groups alike, and were often positioned behind the main defences to engage the battle worn enemy thrust.<sup id="cite_ref-Harrison_2001,_p._190._19-1" class="reference"><a href=",_p._190.-19">[19]</a></sup></p><p>The forces used to carry out the tactical assignments varied from 1933 to 1943. The number of shock armies, rifle corps, and divisions (mechanized and infantry) given to a strategic front constantly changed. By 1943, the year the Red Army began to practice deep battle properly, the order of battle for each tactical unit under the command of a front were: </p><p><b>Rifle army</b> </p> <ul><li>3 rifle corps <ul><li>7–12 rifle divisions</li></ul></li> <li>4 artillery <a href="" title="Regiment">regiments</a> <ul><li>One field artillery regiment</li> <li>One anti-tank gun regiment</li> <li>anti-aircraft artillery regiment</li> <li>One mortar regiment</li></ul></li> <li>One <a href="" class="mw-redirect" title="Signals (military)">signal regiment</a></li> <li>One communication <a href="" title="Battalion">battalion</a></li> <li>One <a href="" title="Telegraph troops">telegraph</a> <a href="" title="Company (military unit)">company</a></li> <li>One aviation communication <a href="" title="Troop">troop</a></li></ul><p><b>Stavka operational forces</b> </p> <ul><li>1–2 artillery divisions <ul><li>3 artillery regiments</li> <li>3 tank destroyer regiments</li></ul></li> <li>3–4 tank or <a href="" title="Self-propelled gun">self-propelled gun</a> brigades</li> <li>10 separate tank or self-propelled gun regiments</li> <li>2 anti-aircraft divisions</li> <li>1–2 <a href="" title="Mechanised corps (Soviet Union)">mechanized corps</a></li></ul><p>These forces numbered some 80,000–130,000 men, 1,500–2,000 guns and mortars, 48-497 rocket launchers, and 30-226 self-propelled guns.<sup id="cite_ref-Glantz_1991a,_p._124._20-0" class="reference"><a href=",_p._124.-20">[20]</a></sup></p><p><b>Rifle corps</b> </p> <ul><li>3 Rifle divisions</li> <li>One artillery regiment</li> <li>One signals battalion</li> <li>One <a href="" title="Sapper">sapper</a> battalion</li></ul><p><b>Rifle division</b> </p> <ul><li>3 Rifle regiments</li> <li>One artillery regiment</li> <li>One anti-tank battalion</li> <li>One sapper battalion</li> <li>One signal company</li> <li>One reconnaissance company</li></ul><p>The division numbered some 9,380 men (10,670 in a guards rifle division), 44 field guns, 160 mortars and 48 anti-tank guns.<sup id="cite_ref-Glantz_1991a,_p._124._20-1" class="reference"><a href=",_p._124.-20">[20]</a></sup></p> <h3><span class="mw-headline" id="Deep_operation">Deep operation</span></h3> <p>Soviet analysts recognised that it was not enough to break through the enemy tactical zone. Although it is the first step and crucial, tactical deep battle offered no solution about how a force could sustain an advance beyond it and into the operational and strategic depths of an enemy front. The success of tactical action counted for little in an operational defensive zone which extended dozens of kilometres and where the enemy held large reserves. Such enemy concentrations could prevent the exploitation of a tactical breakthrough and threaten the operational advance.<sup id="cite_ref-Harrison_2001,_p._194._21-0" class="reference"><a href=",_p._194.-21">[21]</a></sup></p> <div class="thumb tright"><div class="thumbinner" style="width:302px;"><a href="" class="image"><img alt="" src="" decoding="async" width="300" height="183" class="thumbimage" srcset="// 1.5x, // 2x" data-file-width="901" data-file-height="551"/></a> <div class="thumbcaption">The Deep Operation. The corps's forces breach the tactical front defences (in blue) and the fresh second echelon (mechanized operational exploitation forces) follows through the gap. Air strikes hit enemy reserves before the second echelon engages them. Other corps launch delaying and diversion assaults on either flank of the enemy tactical defence.</div></div></div> <p>This was demonstrated during the <a href="" class="mw-redirect" title="First World War">First World War</a>, when initial breakthroughs were rendered useless owing to exhaustion during the tactical effort, limited mobility, and a slow-paced advance and enemy reinforcements. The attacker was further unable to influence the fighting beyond the immediate battlefield, due to the limited range, speed and reliability in existing weapons. The attacker was often unable to exploit tactical success in even the most favourable circumstances as his infantry could not push into the breach rapidly enough. Enemy reinforcements could then seal off the break in their lines.<sup id="cite_ref-Harrison_2001,_p._194._21-1" class="reference"><a href=",_p._194.-21">[21]</a></sup></p><p>By the early 1930s, however, new weapons had come into circulation. Improvements in the speed and range of offensive weaponry matched those of its defensive counterparts. New tanks, aircraft and motorised vehicles were entering service in large numbers to form divisions and corps of air fleets, motorised and mechanized divisions. These trends prompted the <a href="" title="Red Army">Red Army</a> strategists to attempt to solve the problem of maintaining operational tempo with new technology.<sup id="cite_ref-Harrison_2001,_p._194._21-2" class="reference"><a href=",_p._194.-21">[21]</a></sup></p><p>The concept was termed "deep operations" (<i>glubokaya operatsiya</i>). It emerged in 1936 and placed within the context of deep battle in the 1936 Field Regulations. The deep operation was geared toward operations at the Army and or Front level and was larger, in terms of the forces engaged, than deep battle's tactical component, which used units not larger than corps size.<sup id="cite_ref-Harrison_2001,_p._194._21-3" class="reference"><a href=",_p._194.-21">[21]</a></sup></p><p>The forces used in the operational phase were much larger. The Red Army proposed to use the efforts of <a href="" title="Air force">air forces</a>, <a href="" title="Airborne forces">airborne forces</a> and ground forces to launch a "simultaneous blow throughout the entire depth of the enemy's operational defense" in order to delay his strongest forces positioned in the area of operations by defeating them in detail; to surround and destroy those units at the front (the tactical zone, by occupying the operational depth to its rear); and to continue the offensive into the defender's operational and strategic depth.<sup id="cite_ref-Harrison_2001,_p._195._22-0" class="reference"><a href=",_p._195.-22">[22]</a></sup></p> <div class="thumb tright"><div class="thumbinner" style="width:202px;"><a href="" class="image"><img alt="" src="" decoding="async" width="200" height="237" class="thumbimage" srcset="// 1.5x" data-file-width="291" data-file-height="345"/></a> <div class="thumbcaption"><a href="" title="Vladimir Triandafillov">Vladimir Triandafillov</a></div></div></div> <p>The central composition of the deep operation was the shock army, acting either in cooperation with each other or independently as part of a strategic front operation. Several shock armies would be subordinated to a strategic front. <a href="" title="Vladimir Triandafillov">Triandafilov</a> created this layout of force allocation for deep operations in his <i>Character of Operations of Modern Armies</i>, which retained its utility throughout the 1930s. Triandafilov assigned the shock army some 12–18 rifle divisions, in four to five corps. These units were supplemented with 16–20 artillery regiments and 8–12 tank battalions. By the time of his death in 1931, Triandafilov had submitted various strength proposals which included the assignment of aviation units to the front unit. This consisted of two or three aviation brigades of <a href="" title="Bomber">bomber</a> aircraft and six to eight squadrons of <a href="" title="Fighter aircraft">fighter aircraft</a>.<sup id="cite_ref-Harrison_2001,_p._195._22-1" class="reference"><a href=",_p._195.-22">[22]</a></sup></p><p>Triandafilov's successor, <a href="" title="Nikolai Efimovich Varfolomeev">Nikolai Efimovich Varfolomeev</a>, was less concerned with developing the quantitative indices of deep battle, but rather the mechanics of the shock army's mission. Varfolomeev termed this as "launching an uninterrupted, deep and shattering blow" along the main axis of advance. Varfolomeev believed the shock army needed both firepower and mobility to destroy both enemy tactical defences, operational reserves and seize geographical targets or positions in harmony with other operationally independent, but strategically collaborative, offensives.<sup id="cite_ref-Harrison_2001,_p._196._23-0" class="reference"><a href=",_p._196.-23">[23]</a></sup></p> <h3><span class="mw-headline" id="Varfolomeev_and_the_composition_of_deep_operations">Varfolomeev and the composition of deep operations</span></h3> <p>Varfolomeev noted that deep and echeloned tactical and operational defences should call for equal or similar counter responses from the attacker. This allowed the attacker to deliver a deep blow at the concentrating point. The new technological advances would allow the echelon forces to advance the penetration of the enemy tactical zones quickly, denying the enemy defender the time to establish a new defensive line and bring up reinforcements to seal the breach.<sup id="cite_ref-Harrison_2001,_p._197._24-0" class="reference"><a href=",_p._197.-24">[24]</a></sup></p><p>Varfolomeev sought to organise the shock armies into two echelon formations. The first was to be the tactical breakthrough echelon, composed of several rifle corps. These would be backed up by a series of second line divisions from the reserves to sustain the tempo of advance and to maintain momentum pressure upon the enemy. These forces would strike 15 to 20 kilometres into enemy tactical defences to engage his forward and reserve <i>tactical forces</i>. Once these had been defeated, the Red Army Front was ready to release its fresh, and uncommitted operational forces to pass through the conquered tactical zone and exploit the enemy operational zones.<sup id="cite_ref-Harrison_2001,_p._197._24-1" class="reference"><a href=",_p._197.-24">[24]</a></sup></p><p>The first echelon used raw firepower and mass to break the layered enemy defences, but the second echelon operational reserves combined firepower <i>and</i> mobility, something lacking in the former. Operational units were heavily formed from mechanized, motorised and Cavalry forces. These forces would now seek to envelope the enemy tactical forces as yet unengaged along the flanks of the breakthrough point. Other units would press on to occupy the operational zones and meet the enemy operational reserves as they moved through his rear to establish a new defence's line. While in the operational rear of the enemy, communications and supply depots were prime targets for the Soviet forces. With his tactical zones isolated from reinforcements, reinforcements blocked from relieving them, the front would be indefensible. Such a method would instigate operational paralysis for the defender.<sup id="cite_ref-Harrison_2001,_p._197._24-2" class="reference"><a href=",_p._197.-24">[24]</a></sup></p><p>In official literature Varfolomeev stated that the forces pursuing the enemy operational depth must advance between 20 and 25 kilometres a day. Forces operating against the flanks of enemy tactical forces must advance as much as 40–45 kilometres a day, to prevent the enemy from escaping.<sup id="cite_ref-Harrison_2001,_pp._197–198._25-0" class="reference"><a href=",_pp._197–198.-25">[25]</a></sup></p><p>According to a report by the Staff of the Urals Military district in 1936, a shock army would number 12 rifle divisions; a mechanized corps (from its <i>Stavka</i> operational reserve) and an independent mechanized brigade; three Cavalry divisions; a light-bomber brigade, two brigades of assault aviation, two squadrons of fighter and reconnaissance aircraft; six tank battalions; five artillery regiments; plus two heavy artillery battalions; two battalions of Chemical troops. The shock army would number some 300,000 men, 100,000 horses, 1,668 smaller-calibre and 1,550 medium and heavy calibre guns, 722 aircraft and 2,853 tanks.<sup id="cite_ref-Harrison_2001,_p._198._26-0" class="reference"><a href=",_p._198.-26">[26]</a></sup></p> <h3><span class="mw-headline" id="Deep_operations_engagement">Deep operations engagement</span></h3> <p>Having organized the operational forces and secured a tactical breakthrough into the operational rear of the enemy front, several issues took shape about how the Red Army would engage the main operational enemy forces. Attacking in echelon formation denied the Soviet forces the chance to bring all their units to bear. This might lead to the defeat of a shock army against a superior enemy force.<sup id="cite_ref-Harrison_2001,_p._199._27-0" class="reference"><a href=",_p._199.-27">[27]</a></sup></p><p>In order to avoid such a situation, echelon forces were to strike at the flanks of enemy concentrations for the first few days of the assault, while the main mobile forces caught up. The aim of this was to avoid a head-on clash and tie down enemy forces from reaching the tactical zones. The expected scope of the operation could be anywhere between 150 and 200 kilometres.<sup id="cite_ref-Harrison_2001,_p._200._28-0" class="reference"><a href=",_p._200.-28">[28]</a></sup></p><p>Should the attack prove successful at pinning the enemy in place and defeating its forces in battle, mechanized forces would break the flank and surround the enemy with infantry to consolidate the success. As the defender withdrew, mechanized cavalry and motorised forces would harass, cut off, and destroy his retreating columns which would also be assaulted by powerful aviation forces.<sup id="cite_ref-Harrison_2001,_p._200._28-1" class="reference"><a href=",_p._200.-28">[28]</a></sup></p><p>The pursuit would be pushed as far into the enemy depth as possible until exhaustion set in. With the tactical zones defeated, and the enemy operational forces either destroyed or incapable of further defence, the Soviet forces could push into the strategic depth.<sup id="cite_ref-Harrison_2001,_p._200._28-2" class="reference"><a href=",_p._200.-28">[28]</a></sup></p> <h3><span class="mw-headline" id="Logistics">Logistics</span></h3> <p>The development of Soviet operational logistics—that complex of rear service roles, missions, procedures, and resources intended to sustain military operations by army and front groupings—clearly occupied a prominent place within overall Soviet efforts to formulate or adapt warfighting approaches to new conditions. As Soviet military theorists and planners have long emphasised, logistic theory and practice are shaped by the same historical and technological developments that influence Soviet warfighting approaches at every level. In turn, they play a major role in defining directions and parameters for Soviet methods. </p><p>Soviet theory recognised the need for logistic theory and practice that were consistent with other components of strategy, operational art, and tactics. Despite the many changes in the political, economic, and military environment and the quickening pace of technological change, logistical doctrine was an important feature of Soviet thinking. </p> <h2><span id="Intended_outcomes.3B_differences_with_other_methodologies"/><span class="mw-headline" id="Intended_outcomes;_differences_with_other_methodologies">Intended outcomes; differences with other methodologies</span></h2> <p>During the 1930s, the resurgence of the German military in the era of the <i><a href="" class="mw-redirect" title="Third Reich">Third Reich</a></i> saw German innovations in the tactical arena. The methodology used by the Germans in the <a href="" class="mw-redirect" title="Second World War">Second World War</a> was named "<i><a href="" title="Blitzkrieg">Blitzkrieg</a></i>". There is a common misconception that <i>Blitzkrieg</i>, which is not accepted as a coherent military doctrine, was similar to Soviet deep operations. The only similarities of the two doctrines were an emphasis on mobile warfare and offensive posture. While the two similarities differentiate the doctrines from French and British doctrine at the time, the two were considerably different. While <i>Blitzkrieg</i> emphasized the importance of a single strike on a <a href="" class="mw-redirect" title="Schwerpunkt"><i>Schwerpunkt</i> (focal point)</a> as a means of rapidly defeating an enemy, Deep Battle emphasized the need for multiple breakthrough points and reserves to exploit the breach quickly. The difference in doctrine can be explained by the strategic circumstances for the USSR and Germany at the time. Germany had a smaller population but a better trained army whereas the Soviet Union had a larger population but a more poorly trained army. As a result, the <i>Blitzkrieg</i> emphasized narrow front attacks where quality could be decisive, while Deep Battle emphasized wider front attacks where quantity could be used effectively. </p><p>In principle, the Red Army would seek to destroy the enemy operational reserves, his operational depth and occupy as much of his strategic depth as possible. Within the Soviet concept of deep operations was the principle of strangulation if the situation demanded it, instead of physically encircling the enemy and destroying him immediately. Triandafillov stated in 1929: </p> <blockquote><p>The outcome in modern war will be attained not through the physical destruction of the opponent but rather through a succession of developing manoeuvres that will aim at inducing him to see his ability to comply further with his operational goals. The effect of this mental state leads to operational shock or system paralysis, and ultimately to the disintegration of his operational system. The success of the operational manoeuvre is attained through all-arms combat (<a href="" title="Combined arms">combined arms</a>) at the tactical level, and by combining a frontal holding force with a mobile column to penetrate the opponent's depth at the operational level. The element of depth is a dominant factor in the conduct of deep operations both in the offensive and defensive.<sup id="cite_ref-Watt_2008,_p._677_29-0" class="reference"><a href=",_p._677-29">[29]</a></sup></p></blockquote> <p>The theory moved away from the <a href="" title="Carl von Clausewitz">Clausewitzian</a> principle of battlefield destruction and the annihilation of enemy field forces, which obsessed the Germans. Instead deep operations stressed the ability to create conditions whereby the enemy loses the will to mount an operational defence.<sup id="cite_ref-30" class="reference"><a href="">[30]</a></sup> An example of this theory in practice is <a href="" title="Operation Uranus">Operation Uranus</a> in 1942. The Red Army in <a href="" class="mw-redirect" title="Stalingrad">Stalingrad</a> was allocated enough forces to hold the <a href="" title="6th Army (Wehrmacht)">German Sixth Army</a> in the city, causing attrition which would force it to weaken its flanks to secure its centre. Meanwhile, reserves were built up, which then struck at the weak flanks. The Soviets broke through the German flanks and exploited the operational depth, closing the pocket at <a href="" title="Kalach-na-Donu">Kalach-na-Donu</a>. </p><p>The operation left the German tactical zones largely intact. But by occupying the German operational depth and preventing their retreat the German Army forces were isolated. Instead of reducing the pocket immediately, the Soviets tightened their grip on the enemy forces, preferring to let the enemy weaken and surrender, starve him completely, or a combination of these methods before delivering a final destructive assault. In this way the Soviet tactical and operational method opted to <a href="" class="mw-redirect" title="Besiege">besiege</a> the enemy into submission, rather than destroy it physically and immediately. </p><p>In this sense, the Soviet deep battle, in the words of one historian, "was radically different to the nebulous 'blitzkrieg'" method, although it produced similar if more strategically impressive results.<sup id="cite_ref-31" class="reference"><a href="">[31]</a></sup></p> <h2><span class="mw-headline" id="The_impact_of_the_purges">The impact of the purges</span></h2> <p>Deep Operations were first formally expressed as a concept in the Red Army's "Field Regulations" of 1929, and more fully developed in the 1935 <i>Instructions on Deep Battle</i>. The concept was finally codified by the army in 1936 in the <i>Provisional Field Regulations</i> of 1936. By 1937, the Soviet Union had the largest mechanized army in the world and a sophisticated operational system to operate it. </p><p>However, the death of Triandafillov in an airplane crash and the "<a href="" title="Great Purge">Great Purge</a>" of 1937 to 1939 removed many of the leading officers of the Red Army, including Svechin, Varfolomeev and Tukhachevsky.<sup id="cite_ref-32" class="reference"><a href="">[32]</a></sup> The purge of the Soviet military liquidated the generation of officers who had given the Red Army the deep battle strategy, operations and tactics and who also had rebuilt the Soviet armed forces. Along with these personalities, their ideas were also dispensed with.<sup id="cite_ref-33" class="reference"><a href="">[33]</a></sup> Some 35,000 personnel, about 50 percent of the officer corps, three out of five marshals; 13 out of 15 army group commanders; 57 out of 85 corps commanders; 110 out of 195 division commanders; 220 out of 406 brigade commanders were executed, imprisoned or "discharged". Stalin thus destroyed the cream of the personnel with operational and tactical competence in the Red Army.<sup id="cite_ref-34" class="reference"><a href="">[34]</a></sup> Other sources state that 60 out of 67 corps commanders, 221 out of 397 brigade commanders, 79 percent of regimental commanders, 88 percent of regimental chiefs of staff, and 87 percent of all battalion commanders were excised from the army by various means.<sup id="cite_ref-35" class="reference"><a href="">[35]</a></sup></p><p>Soviet sources admitted in 1988: </p> <blockquote><p>In 1937–1938 ... all commanders of the armed forces, members of the military councils, and chiefs of the political departments of the military districts, the majority of the chiefs of the central administrations of the People's Commissariat of Defense, all corps commanders, almost all division and brigade commanders, about one-third of the regimental commissars, many teachers of higher or middle military and military-political schools were judged and destroyed.<sup id="cite_ref-36" class="reference"><a href="">[36]</a></sup></p></blockquote> <p>The deep operation concept was thrown out of Soviet military strategy as it was associated with the denounced figures that created it. </p> <h2><span class="mw-headline" id="Deep_operations_during_World_War_II">Deep operations during World War II</span></h2> <p>The abandonment of deep operations had a huge impact on Soviet military capability. Fully engaging in the Second World War (after Winter War) the <a href="" title="Operation Barbarossa">German invasion of the Soviet Union in June 1941</a>, the Soviets struggled to relearn it. The surprise German invasion (<a href="" title="Operation Barbarossa">Operation Barbarossa</a>) subjected the Red Army to six months of disasters. The Red Army was shattered during the first two months. Thereafter it faced the task of surviving, then reviving and maturing into an instrument that could compete with the <i>Wehrmacht</i> and achieve victory. </p><p>Soviet military analysts and historians divide the war into three periods. The Red Army was primarily on the strategic defensive during the first period of war (22 June 1941 – 19 November 1942). By late 1942 the Soviets had recovered sufficiently to put their concept into practice. The second period of war (19 November 1942 – 31 December 1943), which commenced with the Soviet strategic <a href="" title="Battle of Stalingrad">counteroffensive at Stalingrad</a>, was a transitional period marked by alternating attempts by both sides to secure strategic advantage. After that, deep battle was used to devastating effect, allowing the Red Army to destroy hundreds of <a href="" title="Axis powers">Axis</a> divisions. After the <a href="" title="Battle of Kursk">Battle of Kursk</a>, the Soviets had firmly secured the strategic initiative and advanced beyond the <a href="" class="mw-redirect" title="Dnepr River">Dnepr River</a>. The Red Army maintained the strategic initiative during the third and final period of war (1944–1945) and ultimately played a central role in the Allied victory in Europe.<sup id="cite_ref-37" class="reference"><a href="">[37]</a></sup></p> <h3><span class="mw-headline" id="Moscow_counter_offensive">Moscow counter offensive</span></h3> <h4><span class="mw-headline" id="Deep_battle_plan">Deep battle plan</span></h4> <p>Operation Barbarossa had inflicted a series of severe defeats on the Red Army. German <a href="" title="Army Group North">Army Group North</a> was besieging <a href="" class="mw-redirect" title="Leningrad">Leningrad</a>, <a href="" title="Army Group South">Army Group South</a> was occupying most of Ukraine and threatening <a href="" title="Rostov-on-Don">Rostov-on-Don</a>, the key to the <a href="" title="Caucasus">Caucasus</a>, and <a href="" title="Army Group Centre">Army Group Centre</a> had launched <a href="" class="mw-redirect" title="Operation Typhoon">Operation Typhoon</a> and was closing in on <a href="" title="Moscow">Moscow</a>. The <i>Stavka</i> was able to halt the Northern and Southern Army Groups but was confronted with the German forces approaching the Soviet capital. The Soviet strategy at this point was the defence of the capital and if possible, the defeat and destruction of Army Group Centre. By late November the German pincers either side of the capital had stalled. The <i>Stavka</i> decided to launch a counter offensive. The operational goals were to strike into the enemy operational rear and envelop or destroy the German armies spearheading the attack on Moscow. It was hoped a thrust deeper into the German rear would induce a collapse of Army Group Centre. </p> <h4><span class="mw-headline" id="Outcome">Outcome</span></h4> <p>Soviet rifle forces penetrated German tactical defenses and pursued into the operational depths on foot at slow speed. They were, however, deficient in staying power. Soon, growing infantry casualties brought every advance to an abrupt end. Soviet cavalry corps reinforced by rifle and tank brigades also penetrated into the German operational rear. Once there and reinforced by airborne or air-landed forces, they ruled the countryside, forests, and swamps but were unable to drive the more mobile Germans from the main communications arteries and villages. At best, they could force limited German withdrawals, but only if in concert with pressure from forces along the front. At worst, these mobile forces were themselves encircled, only to be destroyed or driven from the German rear area when summer arrived. </p><p>No encirclements ensued, and German forces halted the Soviet advance at the Mius River defenses. South of Moscow, the Red Army penetrated into the rear of the <a href="" title="2nd Panzer Army">Second Panzer Army</a> and advanced 100 kilometers deep into the Kaluga region. During the second phase of the Moscow counter offensive in January 1942, the 11th, 2nd Guards, and 1st Guards Cavalry Corps penetrated deep into the German rear area in an attempt to encircle German Army Group Center. Despite the commitment into combat of the entire 4th Airborne Corps, the cavalry corps failed to link up and became encircled in the German rear area. The ambitious Soviet operation failed to achieve its ultimate strategic aim, due largely to the fragile nature of Soviet operational mobile forces. </p> <h3><span id="Rzhev.E2.80.93Vyazma_offensive"/><span class="mw-headline" id="Rzhev–Vyazma_offensive">Rzhev–Vyazma offensive</span></h3> <h4><span class="mw-headline" id="Deep_battle_plan_2">Deep battle plan</span></h4> <p>The Stavka correctly judged that these operations had failed because of the Red Army's lack of large, coherent, mechanized, and armored formations capable of performing sustained operational maneuver. To remedy the problem, in April 1942 the Soviets fielded new tank corps consisting of three tank brigades and one motorized rifle brigade, totaling 168 tanks each. The Stavka placed these corps at the disposal of army and front commanders for use as mobile groups operating in tandem with older cavalry corps, which by now had also received a new complement of armour. The Stavka employed these new tank corps in an offensive role for the first time in early 1942. </p><p>During this time, the Germans launched <a href="" title="Operation Kremlin">Operation Kremlin</a>, a deception campaign to mislead the Stavka into believing that the main German attack in the summer would be aimed at Moscow. The Stavka were convinced that the offensive would involve Army Group South as a southern pincer against the Central Front protecting Moscow. To preempt the German assault, the Red Army launched two offensive operations, the <a href="" title="Battles of Rzhev">Rzhev–Vyazma strategic offensive operation</a> against <a href="" title="Army Group Centre">Army Group Centre</a>, and the Kharkov offensive operation (known officially as the Barvenkovo-Lozovaia offensive)<sup id="cite_ref-38" class="reference"><a href="">[38]</a></sup> against <a href="" title="Army Group South">Army Group South</a>. Both were directly linked as a spoiling offensives to break up and exhaust German formations before they could launch <a href="" class="mw-redirect" title="Operation Blue">Operation Blue</a>.<sup id="cite_ref-39" class="reference"><a href="">[39]</a></sup> The Kharkov operation was designed to attack the northern flank of German forces around Kharkov, to seize bridgeheads across the Donets River north east of the city. A southern attack would be made from bridgeheads seized by the winter-counter offensive in 1941. The operation was to encircle the <a href="" class="mw-redirect" title="Fourth Panzer Army">Fourth Panzer Army</a> and <a href="" title="6th Army (Wehrmacht)">German Sixth Army</a> as they advanced towards the <a href="" class="mw-redirect" title="Dnepr river">Dnepr river</a>.<sup id="cite_ref-40" class="reference"><a href="">[40]</a></sup> The operation led to the <a href="" title="Second Battle of Kharkov">Second Battle of Kharkov</a>. </p><p>The battlefield plan involved the Soviet South Western Front. The South Western Front was to attack out of bridgeheads across the Northern Donets River north and south of Kharkov. The Soviets intended to exploit with a cavalry corps (the 3rd Guards) in the north and two secretly formed and redeployed tank corps (the 21st and 23rd) and a cavalry corps (the 6th) in the south. Ultimately the two mobile groups were to link up west of Kharkov and entrap the German Sixth Army. Once this was achieved, a sustained offensive into the Ukraine would enable the recovery of industrial regions. </p> <h4><span class="mw-headline" id="Outcome_2">Outcome</span></h4> <p>In fact, primarily due to Stalin's overriding his subordinates' suggestions, the Stavka fell for the German ruse. Instead of attacking the southern pincer of the suspected Moscow operation, they ran into heavy concentrations of German forces that were to strike southward to the Soviet oilfields in the <a href="" title="Caucasus">Caucasus</a>, the actual aim of Operation Blue. </p><p>Although the offensive surprised the <i>Wehrmacht</i>, the Soviets mishandled their mobile forces. Soviet infantry penetrated German defences to the consternation of the German commanders, but the Soviets procrastinated and failed to commit the two tank corps for six days. The corps finally went into action on 17 May simultaneously with a massive surprise attack by <a href="" title="1st Panzer Army">First Panzer Army</a> against the southern flank of the Soviet salient. Over the next two days, the two tank corps disengaged, retraced their path, and engaged the new threat. But it was too late. The German counterattack encircled and destroyed the better part of three Soviet armies, the two tank corps and two cavalry corps, totaling more than 250,000 men.<sup id="cite_ref-41" class="reference"><a href="">[41]</a></sup></p><p>The Kharkov debacle demonstrated to Stalin and Soviet planners that they not only had to create larger armoured units, but they also had to learn to employ them properly. </p> <h3><span class="mw-headline" id="Operation_Uranus_and_Third_Kharkov">Operation Uranus and Third Kharkov</span></h3> <h4><span class="mw-headline" id="Deep_battle_plan_3">Deep battle plan</span></h4> <div class="thumb tright"><div class="thumbinner" style="width:302px;"><a href="" class="image"><img alt="" src="" decoding="async" width="300" height="230" class="thumbimage" srcset="// 1.5x, // 2x" data-file-width="1201" data-file-height="921"/></a> <div class="thumbcaption">Operation Uranus, which achieved great success in its initial stages</div></div></div> <p>The <a href="" title="Battle of Stalingrad">Battle of Stalingrad</a>, by October 1942, was allowing the Soviets an ever tighter grip on the course of events. Soviet strategy was simple: elimination of the <a href="" title="6th Army (Wehrmacht)">enemy field army</a> and the collapse of <a href="" title="Army Group South">Army Group South</a>. </p><p>In operational terms, by drawing the German Army into the city of Stalingrad, they denied them the chance to practice their greater experience in mobile warfare. The Red Army was able to force its enemy to fight in a limited area, hampered by the city landscape, unable to use its mobility or firepower as effectively as in the open country. The <a href="" title="6th Army (Wehrmacht)">German Sixth Army</a> was forced to endure severe losses, which forced the OKW to strip its flanks to secure its centre. This left its poorly equipped Axis allies to defend its centre of gravity—its operational depth. When Soviet intelligence had reason to believe the Axis front was at its weakest, it would strike at the flanks and encircle the German Army (<a href="" title="Operation Uranus">Operation Uranus</a>). The mission of the Red Army, then, was to create a formidable barrier between the cut off German army and any relief forces. The aim of the Soviets was to allow the German army to weaken in the winter conditions and inflict attrition on any attempt by the enemy to relieve the pocket. When it was judged the enemy had weakened sufficiently, a strong offensive would finish the enemy field army off. These siege tactics would remove enemy forces to their rear.<sup id="cite_ref-Watt_2008,_p._677_29-1" class="reference"><a href=",_p._677-29">[29]</a></sup></p><p>Having practised the deep battle phase which would destroy the enemy tactical units (the enemy corps and divisions) as well as the operational instrument, in this case the Sixth Army itself, it would be ready to launch the deep operation, striking into the enemy depth on a south-west course to Rostov using <a href="" class="mw-redirect" title="Kharkov">Kharkov</a> as a springboard. The occupation of the former would enable the Red Army to trap the majority of <a href="" title="Army Group South">Army Group South</a> in the Caucasus. The only escape route left, through the Kerch peninsula and into the <a href="" title="Crimea">Crimea</a>, would be the next target. The operation would enable the Red Army to roll up the Germans' southern front, thereby achieving its strategic aim. The operation would be assisted by diversion operations in the central and northern sector to prevent the enemy from dispatching operational reserves to the threatened area in a timely fashion. </p> <h4><span class="mw-headline" id="Outcome_3">Outcome</span></h4> <div class="thumb tleft"><div class="thumbinner" style="width:302px;"><a href="" class="image"><img alt="" src="" decoding="async" width="300" height="180" class="thumbimage" srcset="// 1.5x, // 2x" data-file-width="602" data-file-height="361"/></a> <div class="thumbcaption">Third Kharkov. The shallow penetration was destroyed. The Soviets had not practised deep operations properly.</div></div></div> <p>Operation Uranus, the tactical deep battle plan, worked. However, the General Staff's deep operation plan was compromised by <a href="" title="Joseph Stalin">Joseph Stalin</a> himself. Stalin's impatience forced <i><a href="" title="Stavka">Stavka</a></i> into offensive action before it was ready. Logistically the Soviets were not yet prepared and the diversion operations further north were not yet ready to go into action. </p><p>Nevertheless, Stalin's orders stood. Forced into premature action, the Red Army was able to concentrate enough forces to create a narrow penetration toward <a href="" class="mw-redirect" title="Kharkov">Kharkov</a>. However, it was logistically exhausted and fighting an enemy that was falling back on its rear areas. The lack of diversionary operations allowed the German Army to recognise the danger, concentrate powerful mobile forces, and dispatch sufficient reserves to Kharkov. With the Red Army's flanks exposed, the Germans easily pinched off the salient and destroyed many Soviet formations during the <a href="" title="Third Battle of Kharkov">Third Battle of Kharkov</a>. </p><p>The concept of the deep operation had not yet been fully understood by Stalin. However, Stalin recognised his own error, and from this point onward, stood back from military decision-making for the most part. The defeat meant the deep operation would fail to realise its strategic aim. The Third Battle of Kharkov had demonstrated the importance of diversion, or <i><a href="" title="Russian military deception">Maskirovka</a></i> operations. Such diversions and deception techniques became a hallmark of Soviet offensive operations for the rest of the war. </p> <h3><span class="mw-headline" id="Kursk">Kursk</span></h3> <h4><span class="mw-headline" id="Deep_battle_plan_4">Deep battle plan</span></h4> <p>The <a href="" title="Battle of Kursk">battle of Kursk</a> combined both the defensive and offensive side of deep battle. The nature of Soviet operations in the summer, 1943 was to gain the initiative and to hold it indefinitely. This meant achieving permanent superiority in the balance of forces, in operational procedure and maintaining initiative on the battlefield.<sup id="cite_ref-42" class="reference"><a href="">[42]</a></sup></p><p>The Soviet plan for the defence of the city <a href="" title="Kursk">Kursk</a> involved all three levels of warfare coherently fused together. Soviet strategy, the top end of military art, was concerned with gaining the strategic initiative which would then allow the Red Army to stage further military operations to liberate Soviet territory lost in 1941 and 1942. To do this, the Stavka decided to achieve the goal through defensive means. The bulge in the front line around Kursk made it an obvious and tempting target to the <i>Wehrmacht</i>. Allowing the Germans to strike first at the target area allowed the Red Army the opportunity to wear down German Army formations against pre-prepared positions, thereby shaping the force in field ratio heavily against the enemy. Once the initiative had been achieved and the enemy had been worn down, strategic reserves would be committed to finish off the remaining enemy force. The success of this strategy would allow the Red Army to pursue its enemy into the economically rich area of Ukraine and recover the industrial areas, such as <a href="" title="Kiev">Kiev</a>, which had been lost in 1941. Moreover, Soviet strategists recognised that Ukraine offered the best route through which to reach Germany's allies, such as <a href="" title="Kingdom of Romania">Romania</a>, with its oilfields, vital to Axis military operations. The elimination of these allies or a successful advance to their borders would deny Germany military resources, or at least destabilise the Axis block in the <a href="" title="Balkans">Balkans</a>. </p><p>The operational method revolved around outmanoeuvring their opponents. The nature of the bulge meant the Red Army could build strong fortifications in depth along the German axis of advance. Two rifle divisions defended the first belt, and one defended the second. A first belt division would only defend an area of 8–15 kilometres wide and 5–6 kilometres in depth.<sup id="cite_ref-43" class="reference"><a href="">[43]</a></sup> Successive defence belts would slow German forces down and force them to conduct slow and attritional battles to break through into the operational depths. Slowing the operational tempo of the enemy would also allow the Soviet intelligence analysts to keep track of German formations and their direction of advance, enabling Soviet reserve formations to be accurately positioned to prevent German spearheads breaking through each of the three main defence belts. Intelligence would also help when initiating their own offensives (<a href="" title="Operation Kutuzov">Operation Kutuzov</a> and <a href="" class="mw-redirect" title="Operation Polkovodets Rumyantsev">Operation Polkovodets Rumyantsev</a>) once the Germans had been bogged down in Soviet defences. The overwhelming contingent of Soviet armour and mechanised divisions was given to the operational reserves for this purpose.<sup id="cite_ref-44" class="reference"><a href="">[44]</a></sup></p><p>The tactical level relied heavily on fortified and static defences composed of infantry and artillery. Anti-tank guns were mounted throughout the entire depth of the defences. Few tanks were committed to the tactical zones and the nature of the defences would have robbed them of mobility. Instead, only a small number of tanks and self-propelled artillery were used to give the defences some mobility. They were distributed in small groups to enable localised counterattacks.<sup id="cite_ref-45" class="reference"><a href="">[45]</a></sup> Such tactics slowed the Germans, forcing them to expend strength and munitions on combating the Soviet forward zones. The Soviets had counted on the Germans being stopped within the tactical zones. To ensure that this occurred, they distributed large numbers of anti-AFV (armoured fighting vehicle) and anti-personnel mines to the defences. </p> <h4><span class="mw-headline" id="Outcome_4">Outcome</span></h4> <p>The Germans began their offensive, as predicted, on 5 July 1943, under the codename <a href="" title="Operation Citadel">Operation Citadel</a>. The Soviets succeeded in limiting them to a slow advance. In the north, the <a href="" title="9th Army (Wehrmacht)">German 9th Army</a> advanced south from <a href="" title="Oryol">Orel</a>. The Germans failed to breach the main defence lines, stalling at the third belt. The German armies had been forced to commit their mobile reserves to the breakthrough. This allowed the Soviets to conduct the operational and offensive phase of their plan; <a href="" title="Operation Kutuzov">Operation Kutuzov</a>. Striking the <a href="" title="2nd Panzer Army">2nd Panzer Army</a>, the Soviet's fresh operational forces, heavily mechanized, threatened to cut off the <a href="" title="9th Army (Wehrmacht)">German 9th Army</a>. Had they succeeded, nothing would have stood between the Red Army and the <a href="" title="Strategic depth">strategic depth</a> of German <a href="" title="Army Group Centre">Army Group Centre</a>'s front. However the Germans were able to stem the advance by committing their mobile reserves and organize a withdrawal. Still, the two German armies had been worn down, and the Soviet forces in the north had won the strategic initiative. </p><p>In the south, the Soviet plan did not work as effectively and the contingency plan had to be put into effect. The German formations succeeded in penetrating all three Soviet defence belts. This denied the Soviets the opportunity to pin them down in the tactical defence belts and release their operational reserves to engage the enemy on favourable terms. Instead, operational forces for <a href="" class="mw-redirect" title="Operation Polkovodets Rumyantsev">Operation Polkovodets Rumyantsev</a> that were intended for the southern counteroffensive, were ordered to at and near <a href=",_Belgorod_Oblast" title="Prokhorovka, Belgorod Oblast">Prokhorovka</a>. This led to the <a href="" title="Battle of Prokhorovka">Battle of Prokhorovka</a>. While the tactical deployment and operational plan had not worked as flawlessly as it had in the north, the strategic initiative had still been won. </p> <h3><span class="mw-headline" id="Other_campaigns">Other campaigns</span></h3> <p>With improved material means and tactical aptitude enabling complicated large-unit maneuvers, the following later campaigns were able to exhibit an improved application of the Deep operation doctrine: </p> <ul><li><a href="–Carpathian_Offensive" title="Dnieper–Carpathian Offensive">Dnieper–Carpathian Offensive</a></li> <li><a href="" title="Operation Bagration">Operation Bagration</a></li> <li><a href="" class="mw-redirect" title="Jassy-Kishinev Offensive">Jassy-Kishinev Offensive</a></li> <li><a href="–Oder_Offensive" title="Vistula–Oder Offensive">Vistula–Oder Offensive</a></li></ul><h2><span class="mw-headline" id="Cold_War">Cold War</span></h2> <h3><span class="mw-headline" id="Central_Europe">Central Europe</span></h3> <div role="note" class="hatnote navigation-not-searchable">See also: <a href="" title="Seven Days to the River Rhine">Seven Days to the River Rhine</a></div> <p>The Soviet Union and its <a href="" title="Warsaw Pact">Warsaw Pact</a> allies used their massive superiority in numbers and the idea of Deep Battle to intimidate NATO over the <a href="" title="Inner German border">Inner German Border</a>. Some Western observers predicted that the Warsaw Pact could use a mixture of speed and surprise to overrun Western Europe in around 48 hours. While massive air strikes using enormous numbers of aircraft would devastate NATO infrastructure and reinforcements, <a href="" title="Russian Airborne Troops">VDV</a> (airborne units), <a href="" title="Spetsnaz">Spetsnaz</a> ("special purpose troops", i.e. <a href="" title="Special forces">special forces</a>) and <a href="" title="Naval Infantry (Russia)">naval infantry</a> would clear the way for the torrent of tank and motor-rifle divisions that would soon cross the border. The forward units of these tank and <a href="" title="Mechanized infantry">motor rifle</a> divisions would be given the task, rather unusually, of avoiding engagements with the enemy and simply to advancing as far and as fast as possible, therefore enabling a victory before any replacement aircraft and <a href="" class="mw-redirect" title="REFORGER">REFORGER</a> units came to Europe from America. </p> <h3><span class="mw-headline" id="Asia">Asia</span></h3> <p>Ever since the 1960s when the Sino-Soviet alliance <a href="" title="Sino-Soviet split">came to an abrupt end</a>, the <a href="" title="Stavka">Soviet High Command</a> considered invading China by deep battle offensive operations, envisaging a rapid drive deep towards the latter's main industrial centers before they could have a chance to mount a credible defense or even stage a counterattack. However, the extremely vast numbers of the <a href="" title="People's Liberation Army">Chinese Army</a> and their knowledge of the terrain, coupled with their then-recent possession of <a href="" class="mw-redirect" title="Nuclear weapons and China">nuclear weapons</a>, made such a drive the Soviets were to execute extremely unlikely. Although both sides nearly went to war in three separate occasions in 1968, <a href="" title="Sino-Soviet border conflict">1969</a> and 1979 respectively, the Soviets were rather hesitant to go to war and invade China, thanks to the fact that both possessed huge armed forces and nuclear weapons at their disposal. </p> <h2><span class="mw-headline" id="Major_proponents">Major proponents</span></h2> <ul><li><a href="" title="Vladimir Triandafillov">Vladimir Triandafillov</a></li> <li><a href="" class="mw-redirect" title="Georgii Isserson">Georgii Isserson</a></li> <li><a href="" title="Nikolai Efimovich Varfolomeev">Nikolai Efimovich Varfolomeev</a></li> <li><a href="" class="mw-redirect" title="Georgi Zhukov">Georgi Zhukov</a></li></ul><h2><span class="mw-headline" id="See_also">See also</span></h2> <ul><li><a href="" title="Rogers Plan">Deep Strike</a></li> <li><a href="" class="mw-redirect" title="Operational art">Operational art</a></li> <li><a href="" class="mw-redirect" title="Tank Corps (Soviet)">Tank Corps (Soviet)</a></li> <li><a href="" class="mw-redirect" title="Mechanized Corps (Soviet)">Mechanized Corps (Soviet)</a></li> <li><a href="" title="Blitzkrieg">Blitzkrieg</a></li></ul><h2><span class="mw-headline" id="References">References</span></h2> <h3><span class="mw-headline" id="Citations">Citations</span></h3> <div class="reflist columns references-column-width" style="-moz-column-width: 20em; -webkit-column-width: 20em; column-width: 20em; list-style-type: decimal;"> <ol class="references"><li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text"><cite class="citation book">Simpkin, Richard E. (1987). <i>Deep battle: The brainchild of Marshal Tuchachevskii</i>. Bassey's Defence Publishers, London. p. 24. <a href="" title="International Standard Book Number">ISBN</a> <a href="" title="Special:BookSources/0-08-031193-8"><bdi>0-08-031193-8</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Deep+battle%3A+The+brainchild+of+Marshal+Tuchachevskii&amp;rft.pages=24&amp;;;rft.isbn=0-08-031193-8&amp;rft.aulast=Simpkin&amp;rft.aufirst=Richard+E.&amp;" class="Z3988"/><style data-mw-deduplicate="TemplateStyles:r886058088"><![CDATA[.mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation .cs1-lock-free a{background:url("//")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration a{background:url("//")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-subscription a{background:url("//")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-ws-icon a{background:url("//")no-repeat;background-position:right .1em center}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-maint{display:none;color:#33aa33;margin-left:0.3em}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}]]></style></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Harrison 2001, p. 4.</span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Harrison 2001, pp. 4–5.</span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Cody and Krauz 2006, p. 229.</span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Harrison 2001, p. 123.</span> </li> <li id="cite_note-Harrison_2001,_p._126.-6"><span class="mw-cite-backlink">^ <a href=",_p._126._6-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._126._6-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 126.</span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Harrison 2001, pp. 129–131.</span> </li> <li id="cite_note-Harrison_2001,_p._140.-8"><span class="mw-cite-backlink">^ <a href=",_p._140._8-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._140._8-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 140.</span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Harrison 2001, pp. 187–194.</span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Harrison 2001, p. 187.</span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Watt 2008, p. 673–674.</span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz 1991a, p. 40.</span> </li> <li id="cite_note-Harrison_2001,_p._193.-13"><span class="mw-cite-backlink">^ <a href=",_p._193._13-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._193._13-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 193.</span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="">Army Field Manual (FM) 3-0, <i>Operations</i>, June 2001, p. 2–3. This manual changed to FM 3-0 from FM 100-5 due to the attempt to link Joint Publications and Army Publications in terms of their numerical naming convention</a>.</span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text"> <a rel="nofollow" class="external free" href=""></a></span> </li> <li id="cite_note-Harrison_2001,_p._204.-16"><span class="mw-cite-backlink">^ <a href=",_p._204._16-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._204._16-1"><sup><i><b>b</b></i></sup></a> <a href=",_p._204._16-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 204.</span> </li> <li id="cite_note-Harrison_2001,_p._205.-17"><span class="mw-cite-backlink">^ <a href=",_p._205._17-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._205._17-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 205.</span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Harrison 2001, p. 189.</span> </li> <li id="cite_note-Harrison_2001,_p._190.-19"><span class="mw-cite-backlink">^ <a href=",_p._190._19-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._190._19-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 190.</span> </li> <li id="cite_note-Glantz_1991a,_p._124.-20"><span class="mw-cite-backlink">^ <a href=",_p._124._20-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._124._20-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Glantz 1991a, p. 124.</span> </li> <li id="cite_note-Harrison_2001,_p._194.-21"><span class="mw-cite-backlink">^ <a href=",_p._194._21-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._194._21-1"><sup><i><b>b</b></i></sup></a> <a href=",_p._194._21-2"><sup><i><b>c</b></i></sup></a> <a href=",_p._194._21-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 194.</span> </li> <li id="cite_note-Harrison_2001,_p._195.-22"><span class="mw-cite-backlink">^ <a href=",_p._195._22-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._195._22-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 195.</span> </li> <li id="cite_note-Harrison_2001,_p._196.-23"><span class="mw-cite-backlink"><b><a href=",_p._196._23-0">^</a></b></span> <span class="reference-text">Harrison 2001, p. 196.</span> </li> <li id="cite_note-Harrison_2001,_p._197.-24"><span class="mw-cite-backlink">^ <a href=",_p._197._24-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._197._24-1"><sup><i><b>b</b></i></sup></a> <a href=",_p._197._24-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 197.</span> </li> <li id="cite_note-Harrison_2001,_pp._197–198.-25"><span class="mw-cite-backlink"><b><a href=",_pp._197–198._25-0">^</a></b></span> <span class="reference-text">Harrison 2001, pp. 197–198.</span> </li> <li id="cite_note-Harrison_2001,_p._198.-26"><span class="mw-cite-backlink"><b><a href=",_p._198._26-0">^</a></b></span> <span class="reference-text">Harrison 2001, p. 198.</span> </li> <li id="cite_note-Harrison_2001,_p._199.-27"><span class="mw-cite-backlink"><b><a href=",_p._199._27-0">^</a></b></span> <span class="reference-text">Harrison 2001, p. 199.</span> </li> <li id="cite_note-Harrison_2001,_p._200.-28"><span class="mw-cite-backlink">^ <a href=",_p._200._28-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._200._28-1"><sup><i><b>b</b></i></sup></a> <a href=",_p._200._28-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text">Harrison 2001, p. 200.</span> </li> <li id="cite_note-Watt_2008,_p._677-29"><span class="mw-cite-backlink">^ <a href=",_p._677_29-0"><sup><i><b>a</b></i></sup></a> <a href=",_p._677_29-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Watt 2008, p. 677.</span> </li> <li id="cite_note-30"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Watt 2008, p. 675.</span> </li> <li id="cite_note-31"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Watt 2008, pp. 677–678.</span> </li> <li id="cite_note-32"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz 1991a, p. 25.</span> </li> <li id="cite_note-33"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz 1991a, p. 89.</span> </li> <li id="cite_note-34"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz 1991a, p. 88.</span> </li> <li id="cite_note-35"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Harrison 2001, p. 220.</span> </li> <li id="cite_note-36"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz 1991a, p. 89: "Pomnit' uroki istorii. Vsemerno ukrepliat' boevuiu gotovnost'" – Remember the Lessons of History. Strengthen Combat Readiness in every possible way, VIZh, No. 6, 1988, 6.</span> </li> <li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz in Krause and Phillips 2006, p. 248.</span> </li> <li id="cite_note-38"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Krause and Phillips 2006, p. 250</span> </li> <li id="cite_note-39"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz &amp; House 1995, p. 106.</span> </li> <li id="cite_note-40"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz &amp; House, p. 106.</span> </li> <li id="cite_note-41"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Krause and Phillips 2006, p. 251.</span> </li> <li id="cite_note-42"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">V.M Kulish 1974, p. 168.</span> </li> <li id="cite_note-43"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz 1991a, p. 135.</span> </li> <li id="cite_note-44"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Watt 2008, pp. 675, 677.</span> </li> <li id="cite_note-45"><span class="mw-cite-backlink"><b><a href="">^</a></b></span> <span class="reference-text">Glantz 1991a, p. 136.</span> </li> </ol></div> <h3><span class="mw-headline" id="Bibliography">Bibliography</span></h3> <ul><li><a href="" title="David Glantz">Glantz, David M.</a>, Col (rtd.) <i>Soviet Military Operational Art: In Pursuit of Deep Battle</i>, Frank Cass, London, 1991a. <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886058088"/><a href="" title="International Standard Book Number">ISBN</a> <a href="" title="Special:BookSources/0-7146-4077-8">0-7146-4077-8</a>.</li> <li><cite class="citation book">Glantz, David M. (1991b). <a rel="nofollow" class="external text" href=";lpg=PA95&amp;pg=PA94#v=onepage&amp;q&amp;f=false"><i>The Soviet Conduct of Tactical Maneuver: Spearhead of the Offensive</i></a> (1. publ. ed.). London u.a.: Cass. <a href="" title="International Standard Book Number">ISBN</a> <a href="" title="Special:BookSources/0-7146-3373-9"><bdi>0-7146-3373-9</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=The+Soviet+Conduct+of+Tactical+Maneuver%3A+Spearhead+of+the+Offensive&amp;;rft.edition=1.+publ.&amp;;;rft.isbn=0-7146-3373-9&amp;rft.aulast=Glantz&amp;rft.aufirst=David+M.&amp;;" class="Z3988"/><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886058088"/></li> <li>Habeck, Mary. <i>Storm of Steel: The Development of Armor Doctrine in Germany and the Soviet Union, 1919–1939</i>. Cornell University Press, 2003. <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886058088"/><a href="" title="International Standard Book Number">ISBN</a> <a href="" title="Special:BookSources/0-8014-4074-2">0-8014-4074-2</a></li> <li>Harrison, Richard W. <i>The Russian Way of War: Operational Art 1904–1940</i>. Lawrence, Kan.: University Press of Kansas, 2001. <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886058088"/><a href="" title="International Standard Book Number">ISBN</a> <a href="" title="Special:BookSources/0-7006-1074-X">0-7006-1074-X</a></li> <li>Krause, Michael and Phillips, Cody.<i>Historical Perspectives of Operational Art</i>. Center of Military History, United States Army. 2006. <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886058088"/><a href="" title="International Standard Book Number">ISBN</a> <a href="" title="Special:BookSources/978-0-16-072564-7">978-0-16-072564-7</a></li> <li>Naveh, Shimon (1997). <i>In Pursuit of Military Excellence; The Evolution of Operational Theory</i>. London: Francass. <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886058088"/><a href="" title="International Standard Book Number">ISBN</a> <a href="" title="Special:BookSources/0-7146-4727-6">0-7146-4727-6</a>.</li> <li><a href="" title="Richard Simpkin">Simpkin, Richard</a>. <i>Deep Battle: The Brainchild of <a href="" title="Mikhail Tukhachevsky">Marshal Tukhachevsky</a></i>. London; Washington: Brassey's Defence, 1987. <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886058088"/><a href="" title="International Standard Book Number">ISBN</a> <a href="" title="Special:BookSources/0-08-031193-8">0-08-031193-8</a>.</li> <li>Watt, Robert. <i>Feeling the Full Force of a Four Point Offensive: Re-Interpreting The Red Army's 1944 Belorussian and L'vov-Przemyśl Operations</i>. The Journal of Slavic Military Studies. Routledge Taylor &amp; Francis Group. ISSN 1351-8046</li></ul><h2><span class="mw-headline" id="External_links">External links</span></h2> <ul><li><a rel="nofollow" class="external text" href=""><i>The Evolution of Operational Art</i> by Georgii Isseson, 1936</a> – PDF, available on <a href="" title="United States Army Combined Arms Center">United States Army Combined Arms Center</a>'s website</li> <li>"Georgii Isserson: Architect of Soviet Victory in World War II": <a rel="nofollow" class="external text" href="">Video</a> on <a href="" title="YouTube">YouTube</a>, a lecture by Dr. Richard Harrison, via the official channel of the <a href="" title="U.S. Army Heritage and Education Center">U.S. Army Heritage and Education Center</a></li></ul><!-- NewPP limit report Parsed by mw1337 Cached time: 20190811004219 Cache expiry: 2592000 Dynamic content: false Complications: [vary&#8208;revision&#8208;sha1] CPU time usage: 0.556 seconds Real time usage: 0.708 seconds Preprocessor visited node count: 2864/1000000 Preprocessor generated node count: 0/1500000 Post&#8208;expand include size: 43822/2097152 bytes Template argument size: 4224/2097152 bytes Highest expansion depth: 13/40 Expensive parser function count: 3/500 Unstrip recursion depth: 1/20 Unstrip post&#8208;expand size: 33460/5000000 bytes Number of Wikibase entities loaded: 1/400 Lua time usage: 0.233/10.000 seconds Lua memory usage: 12.61 MB/50 MB --><!-- Transclusion expansion time report (%,ms,calls,template) 100.00% 555.634 1 -total 26.63% 147.993 1 Template:Lang-ru 17.73% 98.534 1 Template:Reflist 12.42% 69.004 2 Template:Cite_book 11.01% 61.159 6 Template:ISBN 9.75% 54.154 3 Template:Fix 8.81% 48.952 2 Template:Qn 8.45% 46.944 1 Template:Use_dmy_dates 5.70% 31.689 4 Template:Category_handler 5.16% 28.698 1 Template:Authority_control --><!-- Saved in parser cache with key enwiki:pcache:idhash:2856495-0!canonical and timestamp 20190811004219 and revision id 903105573 --></div><noscript><img src="" alt="" title="" width="1" height="1" style="border: none; position: absolute;"/></noscript></div> <div class="printfooter">Retrieved from "<a dir="ltr" href=";oldid=903105573">;oldid=903105573</a>"</div> <div class="visualClear"/> Sat, 17 Aug 2019 20:06:36 +0000 The Serious Money Is Warming to Bitcoin <p><span class="lede">There’s an arms </span>race afoot over who can store cryptocurrency safest. Perhaps you’d like your bitcoin <a href="" target="_blank">buried in a vault</a> under a mountain in the Swiss Alps? Xapo has offered that as a service to wealthy investors, for free. Coinbase, best known for its popular cryptocurrency exchange, prefers elaborate key-printing rituals along with <a href="">a Faraday cage</a>. Anchorage, an Andreessen Horowitz-backed startup, promises easy-access digital storage with some cryptographic voodoo. And now old-school firms like Fidelity and Bakkt, which shares an owner with the New York Stock Exchange, are jumping into the fray with storage solutions of their own.</p><p>The aim behind all these sophisticated security arrangements: wooing Wall Street.</p><div class="inset-left-component paywall"><h5 name="inset-left" class="inset-left-component__el"><a href="">Gregory Barber</a> covers cryptocurrency, blockchain, and artificial intelligence for WIRED.</h5></div><p class="paywall">A key property of crypto is that it’s proven a <a href="">pretty</a> <a href="">dang</a> <a href="">easy</a> target for thieves. Whether it’s North Korea <a href="" target="_blank">hammering crypto businesses</a> around the world or an exchange founder <a href="">absconding with cash</a>, vulnerabilities are abundant. For the crypto industry, that’s not a good look, especially when it comes to institutional investors—pensions and hedge funds and university endowments—for whom there are major consequences when breaches occur. For them, it’s not just a good idea to nail down the furniture, it’s the law.</p><p class="paywall">This week, the <a href="">still-fringe</a> world of crypto custody saw a spike in activity. Late Thursday, Coinbase’s custody arm purchased the institutional business of rival Xapo for a <a href="" target="_blank">reported $55 million</a>. The deal wasn’t a surprise, following reports this spring that Coinbase had outbid Fidelity Digital Assets, which started offering custody to clients in March. Then on Friday, <a href="" target="_blank">Bakkt announced</a> that it had received approval to offer bitcoin futures in September, following months of regulatory delays.</p><p class="paywall">So is crypto the next big thing in institutional investment, or is this fighting over scraps? For now, crypto custody still involves a relatively small pool of money. Coinbase got a boost earlier this month when Grayscale Investments moved its $2.7 billion worth of crypto funds from Xapo to Coinbase, more than doubling the company’s assets under custody. That’s tiny compared with the trillions under management for a company like Fidelity. Custody competitors like Palo Alto, California-based BitGo have <a href="" target="_blank">reportedly been circling</a> for Xapo’s other clients.</p><p class="paywall">Still, companies like Coinbase and Fidelity think there’s room for growth. In May, Fidelity <a href="" target="_blank">released a survey</a> of more than 400 institutional investors that found 22 percent already held cryptocurrency, and another quarter saw potential to do so.</p><div class="inset-left-component paywall"><h4 name="inset-left" class="inset-left-component__el">LEARN MORE</h4><figure class="image-embed-component"/><h5 name="inset-left" class="inset-left-component__el">The WIRED Guide to <a href="">Bitcoin</a></h5></div><p class="paywall">The companies point to the recent surge in bitcoin’s price as a sign that investors are warming up to crypto. Fundamentally, nothing has changed since late 2017, when the price of bitcoin spiked to nearly $20,000, driven mainly by hysteria. It’s still backed by nothing and managed by no government; it’s still dominated by a select set of mining pools, based mainly in China. Now, though, there’s a more sophisticated economy being built around crypto, says John Sedunov, a professor of finance at Villanova University. In February, <a href="" target="_blank">JP Morgan announced</a> it would start a coin of its own. Then in June, Facebook <a href="">announced its Libra cryptocurrency</a> with the backing of large consumer tech companies like Uber and Spotify. New vehicles like futures contracts offer investors, who might’ve balked at an asset with price shocks that come out of nowhere, more of a buffer.</p><p class="paywall">Another interpretation is that bitcoin is increasingly seen as a way to hedge against uncertainty, notes Sedunov. While volatility means that it’s not a safe harbor, like gold or the Swiss franc, it is a potential hedge when nations take up arms in a global trade war. “There’s uncertainty in where we’re heading, and that makes cryptocurrency more attractive,” he says. The better custody arrangements are another draw, he suggests, making it more appealing for institutional investors who could potentially store hundreds of millions of dollars worth of digital assets.</p><p class="paywall">Perhaps crypto presents a more acceptable store for your money—at least for the time being, and if only to mix things up a bit. For Coinbase, the move is a bid to diversify from its fee-dependent exchange business, which spikes and dives along with the price of digital assets. CEO Brian Armstrong <a href="" target="_blank">told <em>Fortune</em></a> Thursday that he hopes to expand the custody business, and potentially extend it into other more bank-like realms, like lending.</p><p class="paywall">But as with anything in crypto, things can change quickly. As recently as April, when the price of bitcoin was less than half what it is now, the prevailing wisdom was that <a href="" target="_blank">cryptocurrency didn’t have legs</a> among institutional investors. “There’s going to be growth spurts, setbacks, all these things that come with figuring things out,” says Sedunov. “It’s a somewhat fragile ecosystem right now.”</p><hr class="paywall"/><h3 class="paywall">More Great WIRED Stories</h3> Sat, 17 Aug 2019 22:02:47 +0000 Athens on the Colorado <div readability="13"><img src="" alt="Hogg Auditorium"/><p><span class="caption">Hogg Auditorium, University of Texas Campus, Ellison Photo Company, February 2, 1934</span><span class="citation">Austin History Center, Austin Public Library CO6812</span></p></div><div readability="42.150395778364"><p class="intro">Although not typically given much attention, Austin's music scene during the 1930s and early 1940s was unexpectedly vibrant for the modest size of the city at the time. It was a pop music world whose character largely reflected an emphasis on modern sophistication, dance orchestras, universities, and segregation. As a place with a consistent, large student audience, Austin had numerous local orchestras during these decades and also attracted major national “star” talent. Beyond sweet and swing bands, Depression-era Central Texas supported a wide and varied environment of informal and vernacular performers and music as well, including jubilee quartets, cowboy songs, and street corner blues singers.</p><p class="intro"><a class="read-more" href="">Read more…</a></p></div> Thu, 15 Aug 2019 03:58:55 +0000 Wells Fargo Closed Their Accounts, but the Fees Continued to Mount <div readability="43"><div class="css-53u6y8" readability="31"><p class="css-exrw3m evys1bk0">Xavier Einaudi did not want to wait for Wells Fargo to send him a check.</p><p class="css-exrw3m evys1bk0">The bank informed Mr. Einaudi that it was closing all 13 of the checking accounts it provided his roofing company, CRV Construction, for a reason it called “confidential.” The letter said the accounts would be closed on June 27, and he would be mailed a check for the balance in his accounts.</p><p class="css-exrw3m evys1bk0">Mr. Einaudi went to his branch and collected the money, so he did not have to wait for a check to arrive in the mail. But the accounts did not close on the preset date.</p><p class="css-exrw3m evys1bk0">For weeks after the date the bank said the accounts would be closed, it kept some of them active. Payments to his insurer, to Google for online advertising and to a provider of project management software were paid out of the empty accounts in July. Each time, the bank charged Mr. Einaudi a $35 overdraft fee.</p><p class="css-exrw3m evys1bk0">Mr. Einaudi called the bank’s customer service line. He went to his local branch. Nobody could help him. “They told me, ‘The accounts are closed out — we cannot do anything,’” he said.</p></div><aside class="css-o6xoe7"/></div><div readability="51"><div class="css-53u6y8" readability="47"><p class="css-exrw3m evys1bk0">By the middle of July, he owed the bank nearly $1,500.</p><p class="css-exrw3m evys1bk0">“I don’t even know what happened,” he said.</p><p class="css-exrw3m evys1bk0">Current and former bank employees said Mr. Einaudi got charged because of the way Wells Fargo’s computer system handles closed accounts: An account the customer believes to be closed can stay open if it has a balance, even one below zero. And each time a transaction is processed for an overdrawn account, Wells Fargo tacks on a fee.</p><p class="css-exrw3m evys1bk0">The problem has gone unaddressed by the bank despite complaints from customers and employees, including one in the bank’s debt-collection department who grew concerned after taking in an estimated $100,000 in overdraft fees over eight months. It is not clear how many people have been affected, but aggrieved customers have brought complaints to the Consumer Financial Protection Bureau, griped on the discussion sites Reddit and Quora and voiced their displeasure through the “Community” section of Wells Fargo’s website — a public comment feature that is now disabled.</p><p class="css-exrw3m evys1bk0">A spokesman for the bank said he could not comment on specific accounts for privacy reasons, but said the bank reviews accounts to protect customers and was “committed to doing so in ways that minimize the risk and impact to our customers.”</p><p class="css-exrw3m evys1bk0">“As a company, we are focused on continually improving this process,” said the spokesman, Jim Seitz.</p><p class="css-exrw3m evys1bk0">Wells Fargo takes employee complaints seriously, Mr. Seitz said, and encourages clients to engage directly with it to fix problems. “Wells Fargo works hard to foster a culture that is centered on doing what is right for our customers and exhibiting high ethical standards and integrity,” he said.</p></div><aside class="css-o6xoe7"/></div><div readability="30.050724637681"><div class="css-53u6y8" readability="9.2463768115942"><p class="css-exrw3m evys1bk0">Wells Fargo has been trying to rebuild its credibility after a series of scandals. The bank has paid more than <a class="css-1g7m0tk" href=";mime=PDF" title="" rel="noopener noreferrer" target="_blank">$15 billion in settlements</a> since the financial crisis to resolve investigations into misdeeds including the creation of fraudulent accounts in customers’ names and requirements that auto-loan borrowers pay for unnecessary insurance.</p></div><aside class="css-o6xoe7"/></div><div readability="41.363973313566"><div class="css-53u6y8" readability="32.171979243884"><p class="css-exrw3m evys1bk0">The bank is searching for a <a class="css-1g7m0tk" href="" title="">new chief executive</a> after its previous chief became <a class="css-1g7m0tk" href="" title="">a lightning rod for critics</a> in Congress, and it is still operating under <a class="css-1g7m0tk" href="" title="">restrictions imposed by the Federal Reserve</a> that bar it from increasing its assets until it improves its oversight practices.</p><p class="css-exrw3m evys1bk0">Wells Fargo’s customers have complained about reopened accounts, but banks can have a good reason to reactivate an account. Bank of America and JPMorgan Chase warn their customers — <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">albeit in fine print</a> — of the possibility that their accounts could be reopened if, for example, the bank receives a deposit bound for a closed account.</p><p class="css-exrw3m evys1bk0">When Wells Fargo decides it will close an account, it usually informs customers in a letter that lists two important dates. The first is the date deposits can no longer be accepted. The second, which is two weeks after the first, is the date after which no more withdrawals will be honored and the account will be closed.</p><p class="css-exrw3m evys1bk0">“Any payments you make to others that are automatically withdrawn from your accounts will be discontinued after your accounts are closed,” the letter says. The New York Times reviewed four such letters.</p><p class="css-exrw3m evys1bk0">But two current and two former employees said Wells Fargo had set up its computer system to keep such accounts open if they have a balance — whether positive or negative — even after the closing date.</p></div><aside class="css-o6xoe7"/></div><div readability="52.816461916462"><div class="css-53u6y8" readability="51.335626535627"><p class="css-exrw3m evys1bk0">Most banks program their systems to stop honoring transactions on the specified date, but Wells Fargo allows accounts to remain open for two more months, according to current and former employees. Customers usually learn what happened only after their overdrawn accounts are sent to Wells Fargo’s collections department.</p><p class="css-exrw3m evys1bk0">If the customers do not pay the overdraft fees, they are reported to a national database like Early Warning Services, which compiles names of delinquent bank customers. That often means a customer cannot open a new bank account anywhere, and getting removed from the lists can take hours’ worth of phone calls.</p><p class="css-exrw3m evys1bk0">One current Wells Fargo employee who spoke on the condition of anonymity said two workers in a debt-collection office complained about the problem through the bank’s anonymous ethics hotline late last year. One, a member of a 40-person office, had collected an estimated $100,000 as a result of the practice, making up 5 percent of the employee’s total collections over an eight-month period.</p><p class="css-exrw3m evys1bk0">There are several ways the balance of an ostensibly closed account can fall below zero. They often involve an unexpected payment from the account, such as a gratuity later tacked on to a restaurant bill paid with a debit card. But fraud is another common culprit, according to current and former employees.</p><p class="css-exrw3m evys1bk0">Matthew Valles, a former employee who is <a class="css-1g7m0tk" href="" title="">suing the bank</a> claiming he was wrongfully fired, said he tried to raise an alarm about the overdraft problem in 2017, because it seemed to most frequently affect fraud victims, who often had little or no money to begin with. And a current employee recalled receiving a complaint from a fraud victim who said he was told he owed $4,000 in fees after his checking account was closed.</p><p class="css-exrw3m evys1bk0">Fraud victims are particularly vulnerable to the overdraft problem: Those that are tricked into depositing <a class="css-1g7m0tk" href="" title="" rel="noopener noreferrer" target="_blank">bogus checks</a>, for example, can easily end up having their accounts closed with a negative balance because they unwittingly spend the money before the fraud is discovered.</p></div><aside class="css-o6xoe7"/></div><div readability="29.144981412639"><div class="css-53u6y8" readability="8.1970260223048"><p class="css-exrw3m evys1bk0">Wells Fargo has faced scrutiny before over its handling of accounts of fraud victims. The bank <a class="css-1g7m0tk" href="" title="">disclosed in August 2017</a> that the federal consumer bureau was investigating it for closing fraud victims’ accounts without determining whether they had done anything wrong.</p></div><aside class="css-o6xoe7"/></div><div readability="48"><div class="css-53u6y8" readability="41"><p class="css-exrw3m evys1bk0">The overdraft problem hits those who are financially challenged the hardest, yet they are the least likely to realize they have been wronged, said Chris Peterson, a law professor at the University of Utah who is also a senior fellow at the Consumer Federation of America.</p><p class="css-exrw3m evys1bk0">“They don’t know who to complain to,” he said. “They don’t know how to explain what the problem was, and they don’t have the time and resources to deal with getting involved.”</p><p class="css-exrw3m evys1bk0">Mr. Einaudi still does not know why his accounts were closed, despite repeated requests since early May. He knew he was incurring overdraft penalties only because the inaccessible business accounts were still visible when he logged into his personal accounts.</p><p class="css-exrw3m evys1bk0">Another Wells Fargo customer, Anna Tchorbadjiev, is receiving calls from the bank about debits and overdraft penalties it says she owes since her checking account was closed in February.</p><p class="css-exrw3m evys1bk0">Ms. Tchorbadjiev, 23, said she learned her account had been closed when she visited a Wells Fargo branch in Manhattan to withdraw some cash before brunch with friends. (Mr. Seitz said: “We take appropriate steps to notify our customer of account closures in advance.”)</p><p class="css-exrw3m evys1bk0">Ms. Tchorbadjiev, a freelance assistant to real estate brokers who also works as a model, had $40,000 in her account. She refused to leave without the full amount. Eventually, bank employees handed her a paper bag containing stacks of bills.</p></div><aside class="css-o6xoe7"/></div><div readability="39"><div class="css-53u6y8" readability="23"><p class="css-exrw3m evys1bk0">“Just a straight-up paper bag like people use for lunch,” Ms. Tchorbadjiev said. “It was almost like something out of a movie.”</p><p class="css-exrw3m evys1bk0">Weeks later, representatives of Wells Fargo began calling. They said Ms. Tchorbadjiev owed $3,000 in debits and overdraft fees incurred since her visit, and the bank had reported her to a national database.</p><p class="css-exrw3m evys1bk0">Ms. Tchorbadjiev said it took her a month of phone calls to get the report removed so she could set up an account elsewhere. In the meantime, the bank keeps calling about what it says she owes.</p><p class="css-exrw3m evys1bk0">“I’m not going to deal with them,” Ms. Tchorbadjiev said.</p></div><aside class="css-o6xoe7"/></div> Sat, 17 Aug 2019 16:42:08 +0000