Technically Speaking

Blog on the move

2014-06-28T17:37:00.000+05:30

This blog is now merged with my primary blog "The Perspective Dimension" due to operational ease. Here is the link to the new blog: http://paradoxsolutions.blogspot.com/

Henceforth no new posts will appear in this blog. Thank you, if you have been following the posts. Hope to see your continued interest at the new address!

Visual Search Problem

2014-04-19T17:54:00.001+05:30

Visual perception accomplished in our brains is a fascinating process. There are many interesting features that one comes across. One of them is the visual search problem - the objective is to identify an odd image amidst a group of distractor images in the shortest time. Put differently, certain kind of symbols are more easily recognizable when placed amidst a group of similar looking symbols whilst others are not. For instance - symbol 'V' amidst symbol '^'s (inverted V) are very easy to spot. On the other hand, symbol 'S's are much more difficult to spot amidst symbol '2' (mirrored S).

I could personally relate to this phenomenon while solving a 3x3 Sudoku

Reference Books for Electronics and Communications Engineering

2014-03-08T23:03:00.001+05:30

Few folks had asked me about reference books in electronics and communication (ECE) engineering, I felt that this list may be useful to others as well.. So here it is.. the names of the Books and authors along with the publishers.

Engineering Circuit Analysis - link
Publisher: Tata McGraw Hill Education (2013)
Authors: William H. Hayt, Jack E. Kemmerly

Introduction to Electro Dynamics - link
Publisher: Prentice Hall India
Author: David J Griffiths

Signals and Systems - link
Publisher: Prentice Hall India
Authors: Alan V. Oppenheim, Alan S. Willsky, (2009)

Modern Control Engineering - link
Publisher: Prentice Hall India (2010)
Authors: Katsuhiko Ogata

Digital Design: With an Introduction to the Verilog HDL - link
Publisher: Pearson (2013)
Authors: Morris Mano

Discrete-Time Signal Processing - link
Publisher: Pearson (2009)
Authors: Alan V. Oppenheim, Ronald W. Schafer

Integrated Electronics - link
Publisher : Tata McGraw Hill Education (2009)
Authors: Jacob Millman, Christos Halkias, Chetan Parikh

Op-Amps and Linear Integrated Circuits - link
Publisher: PHI (2009)
Author: Ramakant A. Gayakwad

Communication Systems - link
Publisher: Wiley (2009)
Authors: Simon Haykin

Digital Signal Processing - link
Publisher: Pearson (2012)
Authors: John G. Proakis, Dimitris Manolakis

Microelectronic Circuits - link
Publisher: Oxford University Press (2009)
Authors: Adel S. Sedra, Kenneth C. Smith

Information Theory - link
Publisher: Dover
Author: Robert B. Ash

These are reference books for fundamental modules not text books. So these would come handy long after your course module is over. One may consider buying a personal copy and master them for a life time..

Sanskrit language

2013-04-07T17:26:00.001+05:30

I came across an interesting article published in 1985 in the Artificial Intelligence magazine of Association for the Advancement of Artificial Intelligence (AAAI).

This article titled "Knowledge Representation in Sanskrit and Artificial Intelligence" by Rick Briggs, from Ames Research Center, NASA talks about Sanskrit as a language and its suitability for representation of information that is amenable to processing on computer. The essence of the article that the authors wishes to convey is that Sanskrit has a mean deviation of zero from a language ideal for information processing!

Reference - Rick Briggs, Knowledge Representation in Sanskrit and Artificial Intelligence, AI Magazine, vol. 6 no. 1, 1985. Link to the article:

A new model for scientific publication

2012-09-14T15:01:00.001+05:30

In an article titled "Post-publication peer review: opening up scientific conversation", the inventors of and original advocates for open access now propose a radically new model of “publish first and then referee openly later” system.

Faculty of 1000 (F1000 London) where the author of this article belongs to, its remit is to work with named experts to identify and recommend the most interesting papers published across different subject areas in biology and medicine.

Quoting the article, "Open access removes barriers for readers. Open, post-publication refereeing removes barriers for readers and authors alike, and it refocuses the role of peer review from, at its worst, a behind-the-scenes variety of censorship to, at its best, the process of expert criticism and advice that has always been its core and upon which the progress of science depends".

Researcher in Indian Astronomy

2012-08-26T00:27:00.001+05:30

Dr.S.Balachandra Rao has been researching in Indian Astronomy under successive research projects sponsored by the National Commission for History of Science (INSA), New Delhi since 1993. He is also a member of the Research Advisory Council for History of science and also the editorial board of the Indian Journal of History of Science, INSA.

He has authored numerous books on astronomy and mathematics in English and Kannada. The following lists some of the books.

Indian Astronomy - A Primer, Gandhi Center, 2008 This is the first book that one should read in order to familiarize onself with Indian astronomy
Eclipses in Indian Astronomy, Gandhi Center, 2008 This book has an interesting chapter on determining the date of Mahabharatha apart from covering the methods for computing eclipses, including improved siddhantic procedures.
Transits And Occultations in Indian Astronomy, Gandhi Center, 2009 This book is a sequel to the eclipses book dealing with transits. It also has interesting accounts of modern Indian astronomers
Indian Mathematics And Astronomy, Gandhi Center, 2004 This is the must read and have a copy book. It introduces contributions in mathematics and astronomy from India.
Astrology : Believe It Or Not?, Navakarnataka Publications, 2000 For all the believers of astronomy, this book is a must. It is an eye opener which analyzes astrology from a scientific point of view.
Tradition Science And Society, Gandhi Center, 2009
Indian Astronomy : An Introduction, Universities Press, Hyderabad, 2002 (Alternate link). This book has computer programs for calculating all the algorithms discussed
Indian Mathematics And Astronomy: Some Landmarks, Gandhi Center, 2004
Ancient Indian Astronomy: Planetary Positions and Eclipses, B.R.Publishing Corp, Delhi, 2000 (Alternate link)
Differential Calculus (with programs), New Age International, New Delhi, 2005
Numerical Methods with programs (Alternate link), Universities Press, Hyderabad, 2004
Differential Equations with applications (with programs), Universities Press, Hyderabad, 2002

Adhika masa and Kshaya masa

2012-01-18T16:20:00.003+05:30

This article is regarding the concept of Adhikamasa and Kshayamasa (intercalary months) used in some luni-solar calendars in India. Luni-solar calendars are in vogue since lunar months determine the high and low tides while the solar year determines the seasons. But the use of luni-solar calendars create a unique problem.

Since the lunar year (12 lunar months) lags behind the solar year (~365.25 days), this creates a need to keep the lunar year and the solar year in synchrony. Hence the need to use Adhika masa (extra month) and Kshaya masa (removed month)! The reason for their asynchrony is explained next.

Pitch correction in Music

2011-09-12T23:43:00.002+05:30

It is long known that popular singer's vocals are pitch corrected through software. I mean off-key notes are adjusted. Yes technology can do wonders!

Computer Software is changing the way musicians create, record, and manipulate music. Software called Music Objects Recognition (MOR) can dynamically adjust music elements like harmony, tempo, melody, etc. and can even emulate human performance on the piano..!

Dr. Andy Hildebrand, Inventor of Autotune

Loudness war: over-compression in music

2011-09-01T16:22:00.002+05:30

Ten minutes after you start listening to your favourite music album, you feel that something isn't right. Even though you love this album, you can't listen to it anymore. You shut it off, tired, puzzled, and confused.

This always seems to happen when you switch from a classic album to a modern one. What you've just experienced is something called over-compression of the dynamic range. Welcome to the loudness war.

Deciphering Indus Valley Civilization

2011-07-02T22:48:00.000+05:30

Indus Valley is the largest among all the ancient civilizations that existed around 4500 years ago, spread in region of what is now the modern day Pakistan, Afghanistan, and northern parts of India. Interestingly, Indus Valley Script is the world's oldest script that still remains undeciphered. Recently, I came across this awesome TED talk on "Computing a Rosetta stone for Indus Valley Script". Here is the link:

Determining the distance to a star cluster

2011-05-25T19:37:00.001+05:30

How to determine the distance to a star cluster using its H-R diagram?

Background and Need

Having covered the background on Star Clusters, H-R diagram, Main sequence and the need to study star clusters in our previous article on estimating the age of a cluster, we will discuss about ZAMS. Zero-Age Main Sequence (ZAMS) is the locus of all newly formed stars main sequence (MS) stars on the H-R diagram of a cluster – forming a boundary to the lower left of the main sequence.

Idea

Ideas and Mathematical tools

2011-05-10T17:21:00.001+05:30

IEEE Medal of Honor for the year 2007 goes to Prof. Thomas Kailath for "exceptional development of powerful algorithms in the fields of communications, computing, control and signal processing".

How can one work and contribute at highest level in so many varied fields? What is his recipe for success?

Estimating age of a star cluster

2011-05-02T18:34:00.000+05:30

How can we determine the age of a star cluster using its H-R diagram.

Solving Sudoku - Tactics part 2

2011-04-03T17:38:00.003+05:30

Continuing with the tactics for solving Sudoku from my earlier post, here is the second part of the post. Here we will discuss tactics referring to level 2 and 3. For legend and terminologies please refer the earlier post.

Superb Moon

2011-03-23T01:35:00.005+05:30

All of us heard about the recent super moon phenomenon that took place on March 19 2011. Yes, I too witnessed the event late in the might and here is one of my pic.

Solving Sudoku - tactics

2011-03-17T13:10:00.004+05:30

Sudoku, the puzzle of this decade, is quite a fun to solve.!
But if you find it boring and think it is fun only as long as one can solve it.. then do take my word..

"Sudoku is lot more fun to solve when it gets harder, but only if you have the right tactics and solving strategies."

Over the next few weeks we will discuss solving tactics of varying levels and difficulties starting from the easiest to the difficult ones. We will only discuss the tactics for 3x3 sudoku ppuzzle..But before we start on that, I have a few points to make:

Calculate the day of any date

2011-03-11T01:03:00.003+05:30

Do you want to know How to calculate the day of any given date off hand?

Then read on..

For any given date, there is a simple workable formula to calculate the corresponding day. Since for most of the times we would work with dates in 20th and 21st century, So let me just limit myself to explain a simple formula that would work for these 200 years!

Naming the days of the week

2011-03-07T13:00:00.002+05:30

How are Days of the week named?

Continuing with the last post of why there are 7 days in a week, here I will try to elucidate the idea behind the naming and the order of the days in a week. This was the method used in the olden times (Babylonian civilization) to arrive at the names for the days and their order.

7 days in a week

2011-03-04T02:10:00.003+05:30

Many civilizations and religions have the concept of 7 days making a week. Is there any astronomical significance for this (7 days in a week)? How come all civilizations chose exactly to have 7 days in a week?

I had asked the very same question to Dr.S.Balachandra Rao of the Gandhi Center at the M.P.Birla Research Foundation. (Some of you might know him as the mathematics professor & HOD and former principal of National College).

He is an exponent in the subject of calendars and has authored many books. Link to all his books (both math and astronomy) is provided here.

Age of the universe

2011-03-01T02:07:00.002+05:30

How do they calculate the age of the universe

Hubble constant (Ho) is used to estimate the age of the universe..

How Do They Do It..

This is how...

Bridging The Digital Divide

2005-12-15T16:18:00.000+05:30

Information Rich, Information Poor - Digital divide

At the beginning of the last century, the brilliant Indian mathematician Ramanujan showed by example that great riches can come from coupling an individual's innate talent - his was a truly remarkable one - with a small tool set. In his case, it took a single volume: G.S. Carr's Synopsis of Elementary Results in Pure Mathematics. Using the book, the young Ramanujan taught himself math and by the time he was 19, he had already begun to do groundbreaking work in number theory.

Today, we can do much the same thing for children by giving them their own simple tool: a laptop. Laptop will not only be something to own and feel empowered by, it will also be portable and a tool for collaboration. Students will be able to access thousands of textbooks electronically and learn how to program, one of the best ways to "learn how to learn". And when students attach cameras, microphones, and printers, the basic laptop will become a foundation for innovation, a tool in tune with their different interests and talents.

But the present situation, more than 80% of people in the world have never even heard a dial tone, let alone surfed the Web. And the gap between the information haves and have-nots is widening. This is the digital divide. And it has become quite essential to bridge this much widening gap.

The accessibility of rural areas to the Internet is a test of the digital divide. But nowadays there are different ways to eliminate the digital divide in rural areas like Power line communication, Broadband Wireless (WiFi), proprietary and upcoming WiMAX systems, Communications satellite with two-way access to the Internet, The Simputer, a handheld computer intended for the masses of India and other developing countries developed at IISc Bangalore, and MIT Media Lab's $100 laptop, intended to be purchased by education ministries and distributed to poor children world wide.

But there exists few barriers like the cost, and the connectivity. Some technological improvements are also required. And any technology which aims to bridge this divide should be universally and cheaply accessible. The price can be brought down by large consumption (Moore’s Law) but the consumption volume increases only when we have a low price.

Does it seem like a Paradox to you? May not be, but it needs constant focus and concerned efforts towards developing technical and technological Solutions for “Bridging The Digital Divide”.

Evolving languages

2005-04-20T03:15:00.000+05:30

You would have seen that the way of communication has changed very much in comparision with what was earlier. This is because as time passes by we evolve, so does our style. It might be to better itself in more than one way. Language is one of them which constantly reflects the changes in its usage.

For instance I could give an example in our way of communication. Instead of acknowledging by saying a complete sensible phrase we tend to say "Ya .. Ya.." we can also ascertain by telling "YES". But as I said we would prefer to use slang with a repetition. Now to put it technically, We first decrease the amount of information to be conveyed from YES.. to Ya..

This is similar to source encoding employed in "Communication Systems". Source encoding decreases the redundant information. If one can understand that you acknowledge by saying Ya instead of Yes than simply why to spend extra energy on telling the longer one. Remember, evolution is all about conserving energy by finding newer ways of doing the same thing.

Now the point to be noted is that we tend to repeat the slang "Ya.. Ya..". This is done to ensure that the message does reach the destination and also with the right amount of emphasis. The corresponding analogy in communication systems is that we perform "channel encoding" .

Channel coding puts in redundant data into the message so that it can be decoded properly even under the effect of noise. Now don't you wonder that we had just removed redundant data during source encoding but now we are putting in redundant data during channel encoding.

But the important point to note is that we can't do away with channel encoding due to the omnipresent noise.
So instead of putting in redundant data for the actual message, we first decrease the amount information through source encoding then perform channel encoding. So now we do know how and why at all the slangs originated. Don't We? "Ya.. Ya.."