Referensi Knowledge

How do I Dispose of Batteries

2008-10-20T08:09:00.000-07:00

Once a battery loses power, remove it immediately from its casing or it may leak. Don't place it in your pocket or purse as this may cause it to rupture. Instead, place the battery in a container or resealable bag (ziplock) until you can dispose of it in the correct manner.

Don't store used batteries together to dispose of in a group. Even though a battery might not be able to run a toy or game anymore, it might still have a small bit of power left. If several batteries bang together, they can emit a charge which can cause them to ignite. Don't mix old and new batteries together in order to get an electronic item to work. The batteries can ignite, rupture or leak, causing damage to you as well as the electronic item.

Since many types of batteries are considered household waste, you should follow proper guidelines for disposal. Your town or city will most likely have a hazardous waste pick-up or drop-off day. Check with the city's website or newsletter to find what guidelines, if any, should be followed for properly disposing of batteries. Most hazardous waste days are noted in the local newspaper as well.

Many of the regular alkaline batteries are not considered hazardous waste and can be disposed of in the normal household trash. For other batteries such as lithium, mercuric, oxide, nickel-cadmium, nickel metal hydride and silver oxide however, it's best to err on the side of caution and follow your town's battery recycling guidelines. The batteries contain elements that can leak into the ground presenting a hazard to the environment. In most cases, batteries can be brought to your local recycling center at any time, or they can be picked up on your town's designated household waste disposal days.

Many automotive stores and other places selling batteries will accept batteries for recycling as well. In addition, there are commercial battery disposal organizations which will recycle your batteries for a small fee.

Most of these places can be found using an internet search or by looking in your local business telephone directory. Never take the lazy route and dispose of batteries in a fire. They'll ignite, explode and possibly cause damage to you or the surrounding area.

It's worth it to bring your batteries to your nearest battery recycling location. Not only is it safer for you, but it's safer for the world around you.

How do Networks Know How Many People are Watching a TV Program

2008-09-22T08:02:00.000-07:00

In the US and in Canada, the company that tracks what viewers are watching for television networks is the Nielsen Company. They choose a representative sampling of about 5000 viewers who will allow Nielsen to record what programs they watch. This is a fairly small sampling of the US population, but people are chosen based on their ability to represent varied populations. For example Nielsen must a diverse sampling of viewers and some viewers who fall into differing age groups in order to get a representative sample.

This representative sample from Nielsen is then turned into a percentage representing viewership. Thus if 500 people watch Gray’s Anatomy weekly, Nielsen concludes that 10% of television viewers in all households watch the show. Shows are then ranked by numbers of viewers they garner each week.

People who participate in Nielsen Ratings programs are normally given monthly compensation for having their viewing habits tracked. This amount is relatively small, less than 50 US dollars (USD). Some people turn the money around to pay for their cable bills.

Each Nielsen participant is given a small black box, essentially a cable and modem that sends information about what the person or persons in the family are watching. In general, Nielsen only records what is being watched, and it is possible to have two programs in an hour count as “being watched” by television networks. If one watches one program for ten minutes and then switches to another program for ten straight minutes the data collected can become faulty in determining the popularity of programs on television networks.

Nielsen ratings do not always work because the population of representative viewers is so small. Some programs have been quickly axed by television networks for having a tiny viewing audience. However, write-in campaigns from loyal fans of the show can sometimes get a program back on the air.

With many shows now available on the Internet, the possibilities of tracking viewers have opened up. Television networks can definitely track how many people are willing to pay for, and download a show, and there are many networks that also offer shows for free with limited advertising. The number of downloads can be recorded by television networks and might influence decisions about keeping certain programs airing.

Cable companies might also track a viewer’s habits. For example, a cable company knows how many pay per view movies a household orders. Surveys of what people are watching may also help determine the popularity of a given show.

What are Lasers Used for

2008-07-09T07:43:00.000-07:00

In the medical industry, carbon dioxide lasers are used in many types of surgery because they are more precise and sensitive than scalpels. Lasers remove tattoos without needing skin grafts, as well as painlessly clearing rot out of teeth. These less invasive lasers result in faster recuperation from surgeries such as removing certain tumors and correcting vision by reforming the eyeball lens. Damage to surrounding tissue, as well as bleeding, has been reduced by incorporating lasers.

Many common home or office devices house lasers as an intrinsic part of their performance. CD, DVD and Blu-Ray players use lasers to read the audio and video information on the disc, the way a needle used to read the groove of a record. CD, DVD and Blu-Ray recorders have stronger lasers that can burn the information onto the surface of the disc, either temporarily or permanently. Laser printers also utilize lasers to change a surface, in this case paper, to display text and graphics. Even at the grocery store, lasers scan the barcode on your packages to tell the computerized register what you're buying and how much it costs.

Lasers of the appropriate strength can etch surfaces from plastic to rock. Some companies inscribe a minute identification number on diamonds to keep track of them. Tombstones made of granite or limestone are carved with powerful lasers. Numerous metal pieces can be precisely cut out, drilled, and welded together to make a finished product using lasers capable of melting metal.

Even though the first laser was made in a laboratory back in 1960, it took several decades to apply this tool to various technologies. Now, lasers are indispensable to our daily lives. Visible lasers have even replaced strings, levels, and stakes in surveying equipment. Everyone should be treated to a laser show inside a planetarium, where colored lasers of all widths simulate the night sky.

What Is an Elmo™ Projector

2008-07-08T07:39:00.000-07:00

The main purpose of an Elmo™ projector is to display documents and other objects that are not translucent -- in other words, documents that are not made with transparencies. These documents require a video camera and projection lens in order to work properly. The Elmo™ camera is usually digital. However, they are able to display more than just documents. In many cases, they can be used to display three-dimensional objects as well, though they will be rendered in two dimensions on the screen.

The thought behind the Elmo&trade projector is similar to that of the overhead projector, which came into widespread use during the late 1950s and continued through the 1990s. Such projectors were useful in making materials available to a wide audience in a classroom or group setting, but could only display documents put on transparent material. While duplication to transparencies is easily done, it required an additional step. Further, three-dimensional objects could not be displayed. They would instead be rendered as a black shadow in the area where they were blocking light from passing through.

The document projector changes all of those limitations. In fact, it is not only possible to display documents and objects on an Elmo™ projector, it is possible to even display moving pictures, such as movies. However, this is, by no means the most effective way of displaying such media. The camera used for a document projector does not operate with as many frames per second as standard video cameras. Thus, any movement would appear jumpy. That is one reason they are often called Elmo™ document cameras. It is understood that motion is not important in displaying documents.

Likewise, when looking at three-dimensional objects with Elmo™ document cameras, they should be kept still, or moved very slowly. Often, this is not a problem. If another side of the object needs displayed, it can simply be moved to face the camera. In such cases, the motion is not important and is only used to facilitate the change in the point of view.

Is it Possible to Send a Text Message to a Landline Telephone

2008-06-23T07:35:00.000-07:00

When a cellular phone customer sends a text message to a landline, he or she must first compose the message using a Short Message Service (SMS) format and then input the ten digit phone number of the recipient's landline phone. The cellular phone service provider will attempt to send the text message to a landline at least three times. If the recipient answers the phone, he or she should hear the automated voice message. If the landline phone is not answered, the message may go to voice mail or an answering machine.

Depending on the cellular provider, customers who have subscribed to the SMS service can send a text message to a landline anywhere in the United States, its territories, and possibly Canada. The text to voice program does not require the recipient to install any special equipment or subscribe to a cellular phone service. The sender usually receives a confirmation message stating that the text message has been successfully delivered to the landline.

While it is possible to send a text message to a landline, it is not generally possible to send a text message from a landline to a cellular phone. The recipient of a text message can sometimes choose from a menu of possible responses and send a voice message, but this voice message will not be converted to text on the cellular phone side.

Standard texting and phone call rates apply when sending a text message to a landline phone, and the phone number must be a recognized landline, not another cellular phone.

What Is Airplane Mode on a Cell Phone

2008-06-16T07:20:00.000-07:00

The idea behind airplane mode is that many people wish to continue using their cell phones on planes to do things like listen to music and check appointments, but the use of cell phones on planes is banned due to the fact that their signals could cause interference. Airplane mode allows cell phone users to circumvent the ban, ensuring that their phones are safe to use on aircraft while the plane is in flight; electronic devices must be turned off for takeoff and landing.

There are two reasons why people are not allowed to use cell phones on aircraft, although the rules against cell phone usage may change at some point. The first reason is that the radio signals emitted by phones could interfere with the communications and guidance systems on the aircraft, which could potentially be very dangerous. In addition, cell phone networks on the ground cannot cope with cell phones being used on planes, because planes travel very fast and at high altitude, so a phone on a plane could confuse a network on the ground.

If a phone offers an airplane mode setting, the user's manual usually clearly shows how to turn airplane mode off and on, and typically it can also be found through the phone's menu. When airplane mode is activated, a small icon often shows up on the screen of the phone to indicate this. In some cases, the user may have to use a password to activate and turn off airplane mode, to ensure that it is not accidentally switched on and off.

Although airplane mode technically makes a phone legal to use on an aircraft, some airlines request that passengers turn their cellphones off anyway, or a flight attendant who is not familiar with the technology may ask you to turn your phone off. Sometimes, explaining that you are using airplane mode is sufficient, and the flight attendant will allow you to leave your phone on, but in other cases, you may be asked to turn it off. Although this may seem unreasonable, it is better to comply; in the wake of the 11 September 2001 terrorist attacks in the United States, airlines are entitled to remove passengers from flights if they fail to comply with requests the airline terms “reasonable.”

What is HSDPA

2008-06-10T07:33:00.000-07:00

HSDPA improves the data transfer rate by a factor of at least five over W-CDMA. HSDPA can achieve theoretical data transmission speeds of 8-10 Mbps (megabits per second). Though any data can be transmitted, applications with high data demands such as video and streaming music are the focus of HSDPA.

HSDPA improves on W-CDMA by using different techniques for modulation and coding. It creates a new channel within W-CDMA called HS-DSCH, or high-speed downlink shared channel. That channel performs differently than other channels and allows for faster downlink speeds. It is important to note that the channel is only used for downlink. That means that data is sent from the source to the phone. It isn't possible to send data from the phone to a source using HSDPA. The channel is shared between all users which lets the radio signals to be used most effectively for the fastest downloads.

The widespread availability of HSDPA may take a while to be realized, or it may never be achieved. Most countries did not have a widespread 3G network in place as of the end of 2005. Many mobile telecommunications providers are working quickly to deploy 3G networks which can be upgraded to 3.5G when the market demand exists. Other providers tested HSDPA through 2005 and are rolling out the service in mid to late 2006. Early deployments of the service will be at speeds much lower than the theoretically possible rates. Early service will be at 1.8 Mbps, with upgrades to 3.6Mbps as devices are made available that can handle that increased speed.

The long-term acceptance and success of HSDPA is unclear, because it is not the only alternative for high speed data transmission. Standards like CDMA2000 1xEV-DO and WiMax are other potential high speed standards. Since HSDPA is an extension of W-CDMA, it is unlikely to succeed in locations where W-CDMA has not been deployed. Therefore, the eventual success of HSDPA as a 3.5G standard will first depend upon the success of W-CDMA as a 3G standard.

What Is a DECT Phone

2008-05-22T21:38:00.000-07:00

Properties and Features

A DECT phone, commonly known as DECT 6.0 in the US, requires a base station to charge the handset and receive the phone's signal. It usually comes with one handset, but additional ones can be added on some models. This makes them useful in homes with multiple floors or large layouts, and for offices that want several cubicles to access the same phone system. Each handset is set up to communicate with the same base station, and usually comes with its own charging dock or "cradle."

The range of use for a handset depends on the phone itself, though it typically can reach over 300 feet (up to 100 meters). Digital technology allows a DECT phone to have much greater range than was previously possible, though this can be affected by various environment factors. Objects between the handset and base, for example, can potentially disrupt the signal and reduce the range of these phones.

Some DECT phones can be used with general wireless technology, allowing different handsets connected to the same base station to be used as walkie talkies. Other standards, such as Wi-Fi®, have been more popular in some markets, however, so DECT technology has not expanded to many other devices in places like the US. A DECT phone can often be used with Voiceover Internet Protocol (VoIP) technology, allowing it to remain functional with the new communication platform.

Risks and Concerns

One of the biggest issues with DECT 6.0 technology in the US is that it does not include a single technology profile for use by all manufacturers. This means that a handset produced by one company does not typically function with a base or accessory made by another. Someone using a DECT 6.0 phone should look for accessories and parts made by the same manufacturer to ensure all of the components are compatible.

There is some question of how secure the signal is from this type of phone. DECT technology uses encryption to protect the signal, but the encryption has been broken and someone could potentially listen in on a phone call. It is also possible for someone to intercept the signal from a handset to the base. This allows a different device to act as the base, sending a call through it to another location, rather than through the actual base and phone line.

There is concern among some people about the radiation released by DECT phones. In general, they emit only a low level of radiation during use and while charging; even using the phone frequently should not cause any health issues. Many devices used on a daily basis do emit some radiation, however, and while individually these items are harmless, there is some concern about the possibility that long-term use of multiple devices could result in sufficient cumulative exposure for health concerns. Research into this exposure is ongoing.

History and Terminology

The DECT phone was initially introduced in Europe, and was first referred to as a "Digital European Cordless Telephone." It has since become an industry standard in many parts of the world. The term "DECT" by itself is typically used in Europe and other regions, such as Australia and different Asian countries.

In the US, the term "DECT 6.0" is used, but this does not indicate any particular technological designation. The "6.0" was chosen simply to indicate that it was a new technology for American consumers. A DECT phone in the US operates at 1.9 GHz, and often replaced phones that used the 5.8 GHz frequency. It was decided that "1.9" might seem inferior to "5.8," despite this not being technically accurate, and so "6.0" was chosen for US marketing.

What are Some Common Abbreviations Used in Text Messaging

2008-05-20T21:34:00.000-07:00

Many of the common abbreviations used in text messaging are shortened versions of expressions, such as AAMOF (as a matter of fact), IMHO (in my humble opinion), or PLMK (please let me know). Other common abbreviations that replace expressions include:

BBT: Be back tomorrow
BIB: Boss is back
CM: Call me
CYE: Check your email
DIKU: Do I know you?
F2F: Face to face
HB: Hurry back
JFF: Just for fun
KOTC: Kiss on the cheek
OMG: Oh my God!
OOTO: Out of the office
PSOS: Parents standing over shoulder
PU: That stinks!
SLAP: Sounds like a plan
TMB: Text me back
UGTBK: You’ve got to be kidding

Other abbreviations used in text messaging represent people or relationships, like BIL (brother in law), SO (significant other), or DWF (divorced white female). Some additional text message abbreviations that indicate people:

B/F: Boyfriend
BFAW: Best friend at work
DD: Dear daughter
DH: Dear husband
DS: Dear son
DW: Dear wife
G/F: Girlfriend
GRL: Girl

Even other abbreviations used in text messaging represent shortened versions of commonly used words, such as B4 (before), NE (any), or W? (why). Other abbreviations used in text messaging for frequently used words include:

AIGHT: Alright
GB: Goodbye
GL: Good luck
HV: Have
K: Okay
M8: Mate
ONL: Online
OVA: Over
PEEPS or PPL: People
PLS: Please
PZ: Peace
TTLY: Totally
W? Why
X: Kiss
Z: Zero

Some abbreviations used in text messaging incorporate symbols to represent words or phrases, like 411 (need information), 121 (private chat), and ?4U (question for you). Not as many common abbreviations start with symbols, but some others are <3 (represents a sideways heart), 4COL (for crying out loud), and 2G2BT (too good to be true).

What are the Disadvantages of Solar Power

2008-05-13T21:32:00.000-07:00

One disadvantage of solar power is consistency and reliability. Solar-powered devices rely on the steady delivery of special particles called photons to keep the electricity generating process going. As soon as the sun falls below the horizon at night, photons stop striking the solar panels and the power drops instantly. This means that storage technology, such as batteries, or an alternative source of energy is always required to ensure uninterrupted power flow. Otherwise, if there is no sun, there is simply no power.

Some of the major disadvantages of solar power are economic in nature. Solar panels designed to generate electricity are still fairly expensive to produce. Since single solar panels can only generate a relatively small amount of electricity, an large arrays of solar panels are needed to provide a sufficient level of electricity to power a number of homes. These solar panels also have to be adjusted throughout the day in order to maintain a direct angle with the sun, so a mechanical orientation system also needs to be implemented to turn all of the solar panels.

Other disadvantages of solar power are technical. The materials used to create a solar panel are constantly exposed to other things besides photons. The constant bombardment of ultraviolet (UV) rays and other solar radiation often causes the panels themselves to deteriorate, much like any other material left exposed to the sun for extended periods of time. Other environmental factors like rain and dirt also take their toll.

Technology changes rapidly, and the number of disadvantages of solar power that seemed virtually insurmountable only a few years ago are now relatively minor inconveniences. With continuing advances in photovoltaics and other solar power technology, the cost of adding solar panels to houses, for example, has dropped significantly. The growing "green movement" has also spurred further development of alternative fuels, and created a greater interest in overcoming those disadvantages of solar power that remain.

What Is a Firewire® to USB Adapter

2008-04-21T21:28:00.000-07:00

Even if you don't have a Firewire® to USB adapter cable, it doesn't mean that your Firewire® devices are useless if you have a USB port, or vice versa. Several companies do provide dual hubs. This type of device has two ports in a single hub, which may be either external or internal; one port is used Firewire® and one for USB, allowing either type of device to function. The combination hub is actually two separate ports combined into a single form factor for convenience; there is no conversion between Firewire® and USB taking place when you use one of these hubs.

Another alternative is simply to add two separate cards, assuming your computer has enough available slots. Firewire® and USB cards are both coming down in price, and adding whichever one is missing should not represent a major expense.

Both Firewire® and USB are efficient, high-speed bus standards. A Firewire® hub can support a data transfer rate of up to either 400Mbps or 800Mbps, depending on the standard, and a single Firewire® port can connect up to 63 devices and deliver a guaranteed rate of speed to each one. Firewire® is often used for devices that require real-time operation such as audio and video systems because of this guarantee, and it is also used frequently in storage area networks.

USB can connect more devices (up to 127), but supports data transfer rates of only up to 12Mbps. It is more often used for standard peripherals, such as mice, modems, and keyboards. The USB 2.0 standard supports speeds of up to 480Mbps, which makes it more competitive with Firewire®. On 17 November 2008, USB 3.0 specifications were released, with a transfer rate 10 times that of USB 2.0; consumer devices that use this standard were expected to be available by 2010.

If you cannot purchase a Firewire® to USB adapter, using a hub allows you to use devices that are compatible with either technology. Both technologies support Plug-and-Play and hot-plugging (hot-swappable).

What is the Difference Between GSM and CDMA

2008-04-15T21:24:00.000-07:00

The GSM Association is an international organization founded in 1987, dedicated to providing, developing, and overseeing the worldwide wireless standard of GSM. CDMA, a proprietary standard designed by Qualcomm in the United States, has been the dominant network standard for North America and parts of Asia. However, GSM networks continue to make inroads in the United States, as CDMA networks make progress in other parts of the world. There are camps on both sides that firmly believe either GSM or CDMA architecture is superior to the other. That said, to the non-invested consumer who simply wants bottom line information to make a choice, the following considerations may be helpful.

Coverage: The most important factor is getting service in the areas you will be using your phone. Upon viewing competitors' coverage maps you may discover that only GSM or CDMA carriers offer cellular service in your area. If so, there is no decision to be made, but most people will find that they do have a choice.

Data Transfer Speed: With the advent of cellular phones doing double and triple duty as streaming video devices, podcast receivers and email devices, speed is important to those who use the phone for more than making calls. CDMA has been traditionally faster than GSM, though both technologies continue to rapidly leapfrog along this path. Both boast "3G" standards, or 3rd generation technologies.

EVDO, also known as CDMA2000, is CDMA's answer to the need for speed with a downstream rate of about 2 megabits per second, though some reports suggest real world speeds are closer to 300-700 kilobits per second (kbps). This is comparable to basic DSL. As of fall 2005, EVDO is in the process of being deployed. It is not available everywhere and requires a phone that is CDMA2000 ready.

GSM's answer is EDGE (Enhanced Data Rates for GSM Evolution), which boasts data rates of up to 384 kbps with real world speeds reported closer to 70-140 kbps. With added technologies still in the works that include UMTS (Universal Mobile Telephone Standard) and HSDPA (High Speed Downlink Packet Access), speeds reportedly increase to about 275—380 kbps. This technology is also known as W-CDMA, but is incompatible with CDMA networks. An EDGE-ready phone is required.

In the case of EVDO, theoretical high traffic can degrade speed and performance, while the EDGE network is more susceptible to interference. Both require being within close range of a cell to get the best speeds, while performance decreases with distance.

Subscriber Identity Module (SIM) cards: In the United States only GSM phones use SIM cards. The removable SIM card allows phones to be instantly activated, interchanged, swapped out and upgraded, all without carrier intervention. The SIM itself is tied to the network, rather than the actual phone. Phones that are card-enabled can be used with any GSM carrier.

The CDMA equivalent, a R-UIM card, is only available in parts of Asia but remains on the horizon for the U.S. market. CDMA carriers in the U.S. require proprietary handsets that are linked to one carrier only and are not card-enabled. To upgrade a CDMA phone, the carrier must deactivate the old phone then activate the new one. The old phone becomes useless.

Roaming: For the most part, both networks have fairly concentrated coverage in major cities and along major highways. GSM carriers, however, have roaming contracts with other GSM carriers, allowing wider coverage of more rural areas, generally speaking, often without roaming charges to the customer. CDMA networks may not cover rural areas as well as GSM carriers, and though they may contract with GSM cells for roaming in more rural areas, the charge to the customer will generally be significantly higher.

International Roaming: If you need to make calls to other countries, a GSM carrier can offer international roaming, as GSM networks dominate the world market. If you travel to other countries you can even use your GSM cell phone abroad, providing it is a quad-band phone (850/900/1800/1900 MHz). By purchasing a SIM card with minutes and a local number in the country you are visiting, you can make calls against the card to save yourself international roaming charges from your carrier back home. CDMA phones that are not card-enabled do not have this capability, however there are several countries that use CDMA networks. Check with your CDMA provider for your specific requirements.

According CDG.org, CDMA networks support over 270 million subscribers worldwide, while GSM.org tallies up their score at over 1 billion. As CDMA phones become R-UIM enabled and roaming contracts between networks improve, integration of the standards might eventually make differences all but transparent to the consumer.

The chief GSM carriers in the United States are Cingular Wireless, recently merged with AT&T Wireless, and T-Mobile USA. Major CDMA carriers are Sprint PCS, Verizon and Virgin Mobile. There are also several smaller cellular companies on both networks.

What Are Unlocked Cell Phones

2008-04-07T21:19:00.000-07:00

Potential Advantages

One advantage to buying an unlocked cell phone is the ability to buy almost any GSM (Global System for Mobile Communications) phone, rather than being restricted to a limited selection offered by a specific carrier. This can include phones only distributed in certain countries, or with features that are not available on all carriers. People also don't need to wait for a contract to expire to buy a new phone; they can remove the SIM (Subscriber Identification Module) card from an existing phone and insert it into a new one when they are ready for a replacement. This allows them to keep their number while upgrading the phone, without having to go through the carrier.

Additionally, the ability to use an unlocked cell phone with a variety of SIM cards can be convenient for travelers. Most carriers only supply service to a particular country or area; when traveling outside the coverage zone, the mobile phone user will have to "roam" on another carrier's network, which often comes with a high fee. To avoid roaming fees, a person can buy a SIM card from a local carrier at his destination and insert it, preserving all his existing phone settings but getting a new number and a local calling plan. In addition to less expensive calling rates, this provides the added benefit of having a local number while in the area.

Potential Disadvantages

Not all unlocked phones have all the same features as their locked counterparts even when the provider is the same. Carriers may include such features only on locked phones, which use their proprietary software and settings. Some carriers offer free calling to a number of contacts or one-button access to certain features that can only be used on locked phones. Consumers concerned about specific features may want to check with a carrier to see if they are available on unlocked cell phones.

In addition, such phones tend to be more expensive. Locked phones are often costly because they usually come with phone service contracts that commit the consumer to that service provider for a certain period of time (like two years). Unlocked phones typically sell at or close to retail price because the buyer can use the phone with a number of different carriers.

Another issue with unlocked cell phones is that they may not work on all GSM bands; as of 2012, a quadband phone could operate anywhere in the world with a GSM network, but other phones could not. This may be a concern for international travelers especially, since not all bands are used in all countries. For example, in South America, the 850 MHz band is in common use, but others may not be available. It is advisable to check on which bands the phone uses, and which bands are available in given travel destinations.

Getting an Unlocked Phone

One way to get a phone without proprietary settings is to buy it new from a third party vendor in its original, unlocked state. Third party services are also available to unlock a person's cell phone for a fee, usually by attaching it to a special piece of hardware specially designed for this purpose. This doesn't guarantee the phone will always work correctly, as carrier settings might remain in the software.

There are also instructions online to unlock most models. In many cases, unlocking a phone is just a matter of activating the phone and entering a specific code; some phones, however, require a series of steps before the code can be entered. Not all codes work, and trying to enter codes that are incorrect can cause the phone to "hardlock" and prevent it from being unlocked. Certain models of cell phones can only be unlocked using the hardware method, which may also worked for hardlocked phones.

Some cell carriers sell unlocked phones at full price, usually allowing consumers to pick a flexible plan such as month-to-month or pay-as-you-go billing. This can provide access to carrier-specific features with the flexibility of an unlocked phone. If a customer has been with a carrier for some time — sometimes for as little as 90 days — the carrier may even be willing to supply an unlock code for a locked phone, although they may charge a fee.

Cell Phone Carriers

The majority of the world — 99% — uses the GSM network, and numerous carriers use it for their services. The competing network is CDMA, or code division multiple access. Most carriers on the CDMA network do not, as of 2012, use card-enabled phones; instead, subscriber information is stored in the cell phone's memory, which means it cannot be transferred to another phone. The CDMA equivalent of the SIM card — the R-UIM — is likely to be used by these carriers in the future, and is already in use in some parts of Asia. This card contains software that allows it to be used in GSM phones as well.

Jailbroken Phones

A jailbroken phone is not exactly the same as an unlocked phone. Most often used in reference to Apple's iPhone®, when a phone is jailbroken, it has been modified to allow it to download applications (apps) not approved or sold by the carrier, such as the Apple App Store. A phone that has been jailbroken is not unlocked, although it may be necessary to jailbreak a phone before unlocking it is possible. Jailbreaking a phone is considered legal in the US, although it may violate the warranty.

Why Can't You Use Your Cell Phone on an Airplane

2008-03-17T21:17:00.000-07:00

The FCC regulates the use of all electronic devices, including cell phones, on airplanes under the assumption that they may affect the communication systems on board. The Federal Aviation Administration (FAA) agrees with the FCC that cell phones may cause substantial interference with aircraft systems and supports the ban for all commercially operated airplanes. The use of cell phones on private or charter planes is not regulated, however, and many private flights permit passengers to use cell phones while in flight.

Lots of debate has surrounded the use of cell phones on airplanes. The primary concern is that cell phones may interfere with the navigation and communication systems of the plane, potentially resulting in devastating failure. Numerous airlines have reported disruptions in cabin pressure, compass function, and wireless navigation systems associated with the use of cell phones on board. The FCC, it seems, erred on the side of caution when it enforced an outright ban on the use of radio frequency emitting devices which could potentially cause an aircraft to crash.

There have also been some reports that the use of cell phones on planes may cause disruptions in ground communications because of interference. Others claim that the airlines and the FCC would simply prefer that consumers use the telecommunications systems mounted on most seat backs in commercial airplanes, because these phones are said to be highly profitable. Newer cell phones are capable of operating on very low power settings, which may not interfere with the aircraft as much. The FCC is attempting to establish an acceptable threshold of radio frequency emissions, so that cell phones could be used on airplanes without any fear of the navigation system failing or service on the ground being disrupted.

How can I Make a Room Soundproof

2008-03-17T21:12:00.000-07:00

The best way to prevent a noise problem is to construct the room with building materials and techniques that will reduce the noise that enters or leaves a room. Pre-planning in this way is not always possible, however, especially for renters. In those cases, soundproofing a room centers on how to absorb unwanted noise after the walls already are in place.

Soundproofing Walls

If you are building the walls or are willing to re-do existing walls, consider using two layers of sheetrock with a small amount of space in between. They can be glued together using a layer of silicone or a special type of sound-dampening glue. For existing walls, a layer of sheetrock can be added over the wall. Sounds waves are reduced as they travel through mass and as they go from substances of different densities, which is why two layers of sheetrock that are slightly separated are better than one layer that is twice as thick. Various sound-reducing materials also can be added to the interior of walls, such as fiberglass insulation, rockwool insulation, mass-loaded vinyl or certain types of soundproofing foam panels.

Doors and Windows

Doorways and windows can also contribute to unwanted noise problems. Thick, solid doors and double- or triple-paned vinyl-framed windows will block more sound than thin doors and single-paned windows. Also, just like the way that a draft of air can travel through leaks around a door or window, sound can enter or leave a room through them. Weatherstrips or caulk can be applied to the gaps around door frames and windows to reduce the amount of sound that sneaks through the gaps.

Floors and Ceilings

Floors and ceilings can be soundproofed as well. Carpet can be installed over carpet padding on floors. Special sound-reducing mats also can be laid under the carpeting. A ceiling can be soundproofed by adding a drop ceiling, which is sometimes called a false ceiling or suspended ceiling. This type of ceiling consists of special panels hung from the ceiling.

Less-Expensive Options

If money is a concern or time is limited, a less drastic, inexpensive approach to making a room soundproof might be needed. This might include using a large bookcase or other furniture against a wall, effectively making a thicker wall through which the sound must travel, or using thick curtains over windows to help keep sounds from traveling through the window as easily. Other simple techniques that can reduce the noise in a room involve absorbing the sound that is already in the room, rather than blocking it from entering or leaving the room.

Sound-Absorbing Surfaces

Hard, smooth surfaces in a room typically do nothing to help eliminate sounds, and they might make the noise problem worse. Soft rugs, carpet and curtains can absorb sound. Rough surfaces on walls and ceilings, such as sprayed-on texture, can help reduce the sound waves in a noisy room.

Wall Treatments

Wall treatments or decorations also can help make a room soundproof. This usually involves tacking on or hanging some sort of heavy material that will block sound waves. The material can range from carpeting to blankets to manufactured paneling — even cardboard egg cartons are an option in some situations. As with most soundproofing materials, the thicker, the better.

What is Technology

2008-03-10T21:09:00.000-07:00

When the word “technology” is used today, it is most often used to refer to high technology – computers, cell phones, rockets – rather than technology in general. But when anthropologists use the word “technology,” they go all the way back to the controlled use of fire (from about 500,000 – 1 million years ago), the invention of the wheel (c. 4000 BCE), and beyond. The first technological tools were simple hand-axes made by our hominid ancestors millions of years ago.

The earliest technological divisions are from mankind’s early history, divided into the Stone Age, the Bronze Age, and the Iron Age depending on the primary tool and weapon-making material at the time. Each building material is superior to the one before it, but more difficult to develop requisite metallurgical techniques. The Iron Age began in about 1400 BCE.

Since the formulation of the scientific method in the 15th century, technological progress has apparently been accelerating. Some technologies developed since then include the telescope, the microscope, the clock, the engine, the electric generator and electric motor, radio, nuclear power and weapons, television, computer, and many others.

Technological development continues strongly today, fueled by the multibillion-dollar economies of the world’s most prosperous nations. The hottest developments in technology today are happening in computers, nanotechnology, materials science, renewable energy, entertainment, space travel, and medicine.

Philosophers as well as laypeople often debate whether or not technological progress is, on the whole, a good thing for humanity. On the pro-technology side of the spectrum are techno-progressivists such as transhumanists, on the anti-technology side are anarcho-primitivists, and Neo-Luddites.

What Is 4G Mobile Technology

2008-02-18T21:05:00.000-08:00

The use of G, standing for generation, in mobile technology covers the major advances of the past 20-30 years. 1G technology involved the first widely available mobile phones. 2G technology, which began in the early 1990s, switched to a digital format and introduced text messaging. 3G technology improved the efficiency of how data is carried, making it possible to carry enhanced information services such as websites in their original format. The latest iPhone is the best known example of 3G technology.

4G mobile is not yet established as an agreed set of standards, so its features are currently simply goals rather than requirements. As well as drastically increasing data transfer speeds, 4G mobile should use enhanced security measures. Another goal is to reduce blips in transmission when a device moves between areas covered by different networks. 4G mobile networks should also use a network based on the IP address system used for the internet.

Within the United States, there are two major systems using 4G mobile technology. One is known as WiMax and is backed by Clearwire, a firm whose majority owner is Sprint Nextel. It began testing services in Baltimore in 2008 and was set to expand this into major new markets in 2009. Sprint intended to have 80 cities covered by the end of 2010.

The rival system, Long Term Evolution or LTE, is backed mainly by Verizon. It was expected to be ready for testing in 2010 but not available for widespread use until 2012. LTE's backers hoped to overcome this disadvantage by offering faster speeds and producing cheaper equipment.

Unlike previous generations of mobile technology, 4G mobile will be widely used for internet access on computers as well as carrying cell phone communications. Customers in areas which have strong 4G coverage will be able to use it for a home broadband connection which doesn't require any cabling to their household. It can also be used for accessing the internet on the move without having to be in a wireless hotspot such as those offered by some coffee shops, airports and libraries.

What Is Microfiche

2008-02-13T20:59:00.000-08:00

How it Works

Microfiche is a subtype of microform, a term used to describe several mediums that provide storage for exact, miniaturized copies of documents. Unlike microfilm, which producers spin into a reel, microfiche is a flat sheet of film. These thin, flat cards take up less space than microfilm and do not require a separate canister for storage.

It is impossible for the human eye to read microform as is, one must use a specially designed machine. These machines include a magnifier and a simple projector that allows the user to read the greatly magnified image or document on a screen. These machines are usually expensive and can be found in institutions that use microform documents, such as libraries or government offices.

Advantages

The advantages of microfiche include its storability: Even a small storage cabinet could hold thousands of cards which, in turn, contain tens of thousands of pages of material. In addition, computers or specialized software is not required to read a microform document. Unlike some digital storage methods, such as CD-ROMs, microform is also remarkably stable and, if kept in a temperature controlled environment, can last as long as 500 years.

Libraries, museums and businesses that own valuable or important documents also value this data storage method as a way of providing researchers with access to important records and archives without significant risk of loss or damage. Since it is impossible to read without a special machine and has no aesthetic value of its own, microform data is of little interest to thieves. If a card becomes damaged, the organization that owns the original document can have a new one created.

Disadvantages

Microfiche lacks the portability of digital files: Special equipment is needed to both read and duplicate the cards. Microform readers, for example, are bulky and aren’t as accessible as personal computers. Making a paper copy of a microfiche also requires using a special printer integrated into the machine. It is usually impractical to use color ink in microform, meaning that documents are usually stored only in black and white.

Researchers may also have difficulty using microform documents. For example, if a needed document is only in microfilm or microfiche, a researcher may have to travel to the physical location where the record is actually stored. If the data was in digital form, the researcher could receive the data via email or a document sharing system and then read it on his or her personal computer. Machines used to read microforms are also cumbersome to use, sometimes requiring the user to scroll through the documents in order to find needed information. Digital data, on the other hand, is easily and quickly searched through the use of specialized software.

What Are LED Christmas Lights

2008-02-05T21:01:00.000-08:00

LED Christmas lights use light emitting diodes rather than the traditional miniature incandescent bulbs. LEDs are much like incandescent bulbs except that they do not have a filament inside that can burn out and take the entire string of bulbs with it. Instead, they are illuminated by the movement of electrons in a semi-conductor material. Another benefit of this light source is the absence of excessive heat and wasted electricity.

LEDs have been around for a long time, but only caught on for use as Christmas lights in recent years. One reason is that older LEDs originally came in only red. Incandescent bulbs, on the other hand, emit only white light but are encased in colored glass. Another problem was a lack of brightness of LEDs. The potential was there however, and advanced LEDs solved these problems. Today you can find LED christmas lights in all kinds of shapes and sizes. They can blink just like the regular incandescent varieties and come in a wide range of colors.

The end result is a string of lights that use about one-tenth of the electrical current of the more commonly used incandescent lights. They are also encased in thick plastic rather than flimsy glass, so broken bulbs and mistakenly stepping on one won't result in a holiday tragedy. As mentioned, the life of LEDs are extremely long-they are used often in the dashboards of jet planes-so burn out after one season is highly unlikely. One last benefit is the relative thickness of the wires used for these lights, making wires less likely to get tangled in the closet or garage.

Caring for LED lights is simple with such a long life and tough casing. Users can simply roll them up and store them at the end of the holiday and fully expect to come back next year and find them still functioning.

What Is a 4G Network

2008-01-29T20:54:00.000-08:00

The first wireless network, known as 1G, was founded during the 1980s. 2G was introduced in the early 1990s as a way of allowing more transmissions to occur per communication channel. The foundations of 3G were established in the late 1990s and have been implemented throughout the majority of the world as of the early 21st century. While the 3G network was the first to allow for multimedia applications, 4G promises to take this basic technology and amplify its usage.

The specifics of the 4G network are geared towards a higher quality of service. Better reception and less dropped data and information exchanges are a priority. The International Telecommunications Union (ITU), the organization that oversees the standards of the present wireless networks, has stated that it requires substantial improvements to multimedia messaging services, including video services, in order to approve a new generation. It wants a data speed transfer rate of at least 100 megabits per second while a user is physically moving at high speeds and a one gigabit per second data rate in a fixed position. The ITU also requires interactive roaming between networks.

A variety of working groups have been established to help develop the 4G network. Proposals from these organizations include implementation of WiMax, a faster version of wireless data transfer than WiFi networks. The groups also plan to utilize packet-based information exchange based on standard IP technology. This promises to be the fastest mobile communication method without cables ever devised.

In order to make the 4G system work, the concept of smart antennas must be developed and implemented. With the establishment of the 2G and 3G networks, a number of different methods of data transmission were created. Many of these technologies can be rolled into the 4G network, however, the working groups and ITU prefer a standardized antenna system that can communicate across company lines.

One of the proposed technologies to make this happen is known as spacial multiplexing. Spacial multiplexing uses a series of antennas linked into a single transmitter and receiver. These antennas are capable of functioning simultaneously, speeding up the space-time data exchange rates.

Overall implementation of the 3G network around the world took nearly a decade. The ITU plans to have the 4G network rolled out to the global market in a much more effective and timely manner. With the speeds and video technology, the possibilities for wireless communication will revolutionize the global communications network. However, concerns over stability and security are also prime factors in the development.

What Is BD Wise

2008-01-23T20:52:00.000-08:00

In order for BD Wise to work, both the BD Wise DVD player and the television set must be Samsung™ products. If one or the other is not, the inter-connectivity will not work, and the feature will be useless. Therefore, if you are in the market for a new player and considering Samsung™ for the BD Wise feature, then you need to make sure that your television set is compatible. In addition, the television set must be a high definition set that is capable of adjusting its own resolution.

The main benefit of the technology is that it seeks to find the best resolution setting possible for viewing DVD products. Most DVDs were created before high-definition televisions became extremely popular. Therefore, the resolution of the DVD, while better than the old-style VHS tapes, is not set to a level where it can take advantage of the resolution available on a high definition television. The BD Wise system helps by not only providing an enhancement, but also setting the television in way that can take advantage of that enhancement most effectively.

In some cases, user may wish to rely on their own settings rather than the automatic settings that the automatic process may use. The automatic settings may be better most of the time, but there could be times when the system does not adequately set an optimum resolution for a particular disc. In those cases, users can turn off the BD Wise feature and proceed to come up with their own settings. While this may take a little more time to set up and get right, it may be the better option for some discs.

The BD Wise feature does not come standard on all Samsung™ Blu-ray™ players. Most of the newer, higher-end models do include the technology, but you should check the features on the box or product to make sure. The higher-end models also include other features such as BD Live, which allows users to connect to the Internet and download content.

What is a Ten Key

2008-01-08T20:48:00.000-08:00

Learning ten key is a little bit different than learning to type. For example, the home row contains the numbers 4,5,and 6, and is typed by the index finger, middle finger and ring finger respectively. The right hand is used, though there are left handed people who modify ten key for the left hand. There are also some keyboards with the ten key pad on the left side of the keyboard.

Instead of measuring speed of ten key proficiency with words per minute (wpm) measurements as in typing, ten key is measured in either keys per minute (kpm) or strokes per minute. Most use the kpm designation when seeking employees and set a minimum kpm for applicants. Minimal proficiency in ten key is considered at least 140 kpm, though some companies which require only a little data entry might accept less.

Employment agencies frequently ask for applicants to take typing and ten key tests so they can pass this information along to interested employers. Usually most people gain proficiency in a short period of time, since there are fewer keys to learn. If you claim a certain kpm rate, however, you must be certain you can prove consistent error free ten key typing at this rate.

Few traditional ten key classes exist for those who wish to become proficient. However, there are some excellent software based courses that can easily help one acquire the skills to perform proficient ten key work. Many consider one the best of these to be Mavis Beacon Teaches Typing, which teaches not only traditional keyboard typing but also ten key fingering. The software is available on both PC and MAC platforms and tends to be fairly inexpensive, usually about 20 US dollars (USD).

With a few weeks of practice, you can usually learn all the keys of ten key and demonstrate proficiency. If you are already an accomplished typist, the skills may take less time to acquire.

What Are Polarized Lenses

2007-12-30T15:01:00.000-08:00

How They Work

When light bounces off of a surface, its waves tend to be strongest in a particular direction — usually horizontally, vertically, or diagonally. This is called polarization. Sunlight bouncing off a surface like water, a road, or metal will usually reflect horizontally, striking the viewer's eyes intensely and creating glare. Most polarized lenses in glasses are laminated with tiny vertical stripes that only allow vertically angled light to enter the wearer's eyes. Glare is eliminated because the horizontal light waves cannot bypass the vertical filter.

Lenses can be polarized to different degrees and in different ways. Most inexpensive polarized sunglasses have a thin film applied on one side of the lens. Many higher quality lenses have film laminated between two layers of lens material, preventing it from being scratched or rubbed off. In addition, the more dense the film is, the more polarization it provides.

In most cases, polarized sunglasses don't look any different from regular sunglasses. While denser films tend to be darker, the color of a lens does not determine how much polarization it provides. A very dark pair of sunglasses with a light film will not block more glare than a lighter shade of glasses with a denser film. The color of the lens is also variable; although they cannot be made clear, polarized lenses can be made in gray, brown, green, or other colors.

Uses

Drivers, fisherman, and photographers were some of the first to use polarized lenses. Reducing glare can ease the eye strain drivers feel from long hours on the road. Fishermen can often see under the surface of water using the lenses, which helps them to see fish or other objects. Photographers use polarizing filters on camera lenses to enrich the images they capture by giving them more contrast, and to increase the range of effects they can produce.

Using horizontally and vertically polarized lenses together makes one type of three-dimensional (3-D) movies possible. Two images are projected onto a 3-D movie screen: one is polarized vertically and one horizontally. The lenses of the glasses that moviegoers wear are also polarized, one vertically and the other horizontally, so the user sees one image in one eye, and the second, slightly different image in the other. The brain is able to combine both of these images in a way that produces a realistic sense of depth.

Limitations

Polarized glasses do not provide universal protection from glare. If the wearer tilts his or her head past 45° or so, more of the horizontal light can enter and cause bright spots. In addition, these lenses do not usually work with snow glare because snow tends to reflect light equally in all directions, rather than the mostly horizontal reflection off of liquid water. It is strongly recommended that downhill skiers in particular not wear polarized sunglasses; ice does reflect horizontally, and these glasses can make dangerous icy spots less visible.

Because the polarizing stripes reduce the amount of light entering the eye, these lenses should not be used at night or in other situations where clear lenses are required. It is not possible to make such lenses truly clear; even those with low levels of polarization have a slightly gray hue. Some people find that looking through the lenses for too long a period of time can cause headaches and eye strain.

Polarized lenses can cause distortions in the way wearers see liquid crystal displays (LCDs), rendering some cell phone screens, clocks, and other displays unreadable. The texture of laminated or heat-treated glass, like a windshield, can be made more prominent by looking at it through a polarized lens, making the glass difficult to see through. Pilots should not use polarized glasses because they can make flight instruments difficult to read and other objects in the sky — including other airplanes — less visible.

Is It a Good Idea to Buy a Refurbished Mobile Phone

2007-12-23T14:58:00.000-08:00

A refurbished mobile phone should, in all respects, work exactly as a new phone. This is probably more likely to be the case when the refurbished mobile phone does not have many complex features, such as a camera, personal digital assistant and Bluetooth® capabilities. Cell phone customers routinely upgrade their mobile phones every couple of years or so, and the old ones have to go somewhere. Some are discarded, if they are no longer compatible with the cellular system, but many are sent back to the factory to be refurbished. This is also the case for phones that malfunction.

Whether buying a refurbished mobile phone is a good idea depends greatly on the manufacturer. Reputable makers usually produce a good product, but this may not be the case with "off" brands. A consumer should also always ask his or her cellular service provider if they have many refurbished phones returned for malfunction. Sometimes, the manufacturer will provide a warranty of some description, but the consumer should insist on one from the service provider.

The question of getting a refurbished mobile phone may be crucial for someone who needs a phone at a moment's notice and cannot afford to risk having a refurbished mobile phone malfunction. On the flip side of that coin are elderly customers who have a good phone that they like. Many elderly customers don't want to have to learn how to use their phones all over again, and if a refurbished mobile phone in their preferred model is available, they may want one.

Price is another consideration. No customer should be asked to pay top dollar for a refurbished mobile phone. This is not fair. Even if a phone has many features, if it is refurbished, the customer should not have to pay what she would for a new phone. However, cellular service providers are aware of this, and they often offer a refurbished mobile phone as one of the free models for upgrade or for signing a service contract.

The main things a customer needs to consider when thinking about a refurbished mobile phone, then, are quality, warranty and price. If these are resolved to his satisfaction, then buying a refurbished mobile phone may be a sensible purchase.

What is an Unlocked Phone

2007-12-10T14:56:00.000-08:00

One of the ways that cell phone companies attract new customers is to offer free or inexpensive phones when the customer signs a contract. In addition to charging a high termination fee if the customer cancels their phone line before the contract is up, cell phone companies protect themselves by locking all of the phones they sell to their network. This keeps them from losing money on customers who would buy a phone for a good deal from their company, then activate it with another network for a better rate.

Cell phone companies are able to do this because every modern cell phone has a tiny card in it called a SIM card. The SIM card is what identifies a cell phone as a certain phone number. In other words, a cell phone user can move their SIM card from one phone to another and still keep the same number. In addition, the SIM card is coded with the network’s identification information.

A locked phone essentially has software that prevents it from working with a SIM card that has any other carrier’s information coded into it. Unlocking a cell phone therefore enables the phone’s owner to leave one cell phone company for another. With an unlocked phone, a person can use whichever cell phone company is offering the best rate or the highest quality services.

Another advantage is that an unlocked phone is worth more money. Many sellers on eBay and elsewhere sell cellular phones. Since an unlocked phone appeals to a wider audience, instead of only those with a certain carrier, it is often worth the minimal expense to unlock the phone.

Unlocking a phone can be done online for very little money, usually under twenty U.S. dollars. Some phones require a special code to unlock them, which can be purchased online. Other phones can be unlocked by downloading software online and hooking the phone up to the computer. Unlocking a phone is generally not difficult, and since an unlocked phone gives users more options, the time and money it takes is usually considered worthwhile.