Tuesday 23 October 2018

Communication, Internal Seminar, HITS

Yesterday I attended a seminar led by our current science journalist Kerstin Hoppenhaus at HITS. It was remarkable because it made me think how communication works and why trustworthy journalism is important.

Journalists curate news in such a way that is interesting and digestible to the users. A piece of news can have a certain amount of bias, which might creep in consciously or unconsciously. Some of the tricks of the trade to seduce the users are (1) telling a story, (2) engaging the user, and (3) using techniques such as dramatic pause, captivating background score or a protagonist.

The format of delivery can be literary, auditory or visual. Different formats pose different challenges. For instance, consider the 360-degree video format in which the director can no longer direct the user through the intended narrative because of the shift in control from the director to the user. 

We then discussed how the Internet has disrupted the media industry. With the Internet, quick communication is possible. However a major challenge here is fake news. As a reader, how can you trust a piece of news that you see over the Internet? Some of the parameters are reputation of the news source, valid verifiable references, accuracy of the news content, and style of presentation.

Finally we discussed whether simplification of news pays off or not. Simplification improves the extend to which the news penetrates the audience. However over-simplification might have to let go off some necessary details.

Sunday 2 September 2018

Mentalese, The Language Instinct, Steven Pinker

This post is a summary of the chapter "Mentalese" from the book "The Language Instinct" written by the eminent linguist Steven Pinker. This chapter deals with the question - Do we think in language? What is the language of thought?

According to the Sapir-Whorf hypothesis, language shapes our model of the world. For example, forms of addressing the listener are different in many languages depending on age or relation. The demands made by the language might influence the speakers to regard the listener with respect. In languages such as Hindi or Tamil, formalness is frequently employed in day-to-day communication. This is in contrast to other languages such as Malayalam, in which formalness is not commonly employed, in spite of the presence of formal and informal forms of address.

Pinker challenges this hypothesis in various ways. First, it is difficult to test this hypothesis because of the circular nature of the existing experiments. A subject can only be evaluated based on what he/she speaks. Second, the 'fact' that the Eskimos have hundreds of words for snow is nothing but an urban legend. According to one survey, the actual number is less than ten. So the Eskimos regard snow similar to the way others do, contrary to what the hypothesis can be taken to mean. Third, there are many beings that cannot speak but possess the faculty of thought: deaf people, babies, animals (, plants?). Fourth, many a time, even though we have a thought in our mind, we struggle to express it clearly. This can be due to two reasons: (1) lack of command over languages, or (2) lack of devices in language to convey our thoughts. Writers exploit the available linguistic machines such as figures of speech, idioms, proverbs and rhythm to express complex ideas through words in the form of prose and verse. In addition, when a sentence is translated from one language to another, it is highly likely for the subtlety of the original meaning to be lost in translation due to the lack of exact matching words. Fifth, it is possible for us to transform (e.g. rotate or zoom in) an image in our minds without speaking about the process loudly. All of the above suggest that English or any other spoken language is not the language of thought.

Pinker claims the language of thought (a.k.a. Mentalese) to be on a level that is different from spoken languages. All thinking creatures use this language to think. Since only human beings possess the ability to talk, there is a program, similar to a compiler for programming languages, in the human brains that converts the high-level Mentalese to the low-level English. This language is built over fundamental concepts of human thought such as time, space, causality and human intention (ref. Immanual Kant).

Saturday 11 August 2018

Chatterboxes, The Language Instinct, Steven Pinker

This post is a summary of the chapter "Chatterboxes" from the book "The Language Instinct" written by the eminent linguist Steven Pinker. This chapter deals with the statement in the title of the book - Is language an instinct for humans?

Language has never been a cultural phenomenon. Language exists and has existed in every culture on earth. No society can claim the title "the cradle of language." This is one of the arguments for claiming that language is innate in human beings. However, for the skeptics, the universality of language may not single-handedly prove the innate nature of language. For instance, Coca-Cola or Facebook are available almost everywhere on earth. Does this mean Coca-Cola and Facebook are innate too? (According to me, the desire to have a drink and to stay connected are innate in human beings. So the universality of language is a conclusive proof.)

Let's look at another argument for the innate nature of language. There are evidences to show that children reinvent language, not because they are asked to do so, but because they have to. Before going into the argument, it is important here to burst two myths about child language acquisition: 
    (1) The first myth is that children learn to speak from their parents (e.g. Motherese - dogggie, pappie, ...). This is not true because parents do not explicitly teach children the rules of the grammar. Chomsky reasoned that this argument of poverty of input is the primary justification for the saying that language is innate.
   (2) The second myth is that children learn to speak by imitating their parents. If this is true, then children should not be making any mistakes when their learn to talk. However children do make mistakes when they learn language (e.g. കാവളവണ്ടി, വെക്കള് )

Now it is time to look at two real-world cases where children reinvented language. One of them is the development of creole from pidgin languages such as pidgin English. Second one is the development of sign languages. In both these cases, phrases and crude sentences of a pseudo-language were converted to a bona fide language by the second generation of users i.e. the children of plantation workers and deaf children respectively.

Finally, another argument for the innate nature of language is that language is different from intelligence (or cognition). Those who suffer from Broca's aphasia are language-retarded. However they have sound cognitive skills. Those who suffer from chatterbox syndrome are language-savvy. However they have negligible cognitive skills. These two cases show that the ability to speak and the ability to, say, cook food are managed by different parts of the brain and hence different faculties.

Saturday 4 August 2018

Talking Heads, The Language Instinct, Steven Pinker

This post is a summary of the chapter "Talking Heads" from the book "The Language Instinct" written by the eminent linguist Steven Pinker. The previous chapter in the book was a discussion on syntax. This chapter focuses more on semantics and pragmatics.

Parse trees are different from parsing.  Parse trees define the syntax or structure of sentences in a language. The process of parsing defines the processing of a sentences and thus is related to cognition and semantics of a language. Chomsky demonstrated this feature of language processing using the classic example "colorless green ideas sleep furiously". This sentence is syntactically right. However it is rife with absurdity and does not make sense at all. In other words, the sentence is semantically not right.

The chapter then discusses the differences between a human being and a machine and how they interpret a natural language sentence. There are various types of sentences: (1) onion (or Russian doll) sentences, (2) garden-path sentences, and (3) ambiguous sentences.
The first two types are hard for human beings because humans are not good at memory as compared to machines. By memory, we mean short-term memory, something similar to a stack for a machine. On the other hand, the last type is easy for human beings because humans are good at decision-making.  The decision making employs different kinds of knowledge such as background knowledge, commonsense knowledge and world knowledge. A classic example that demonstrates commonsense reasoning is given below:
             Woman: I'm leaving you.             Man: Who is he?
The converse is true for machines. Machines can process onion sentences and garden-path sentences because of the availability of memory. However they perform very badly when it comes to ambiguous sentences. In addition to this, machines are too meticulous in parsing a sentences and identifies interpretations that a human being will never detect (e.g. pigs in a pen). 

In real-life, the task of text processing is worsened by the fact that dialogues are filled with short utterances, lots of pronouns, and fillers such as 'uh' and 'hmm'.

The chapter concludes with a discussion on pragmatics. Parsing a sentence involves more than simply understanding the sentence syntactically. A conversation between two parties can either be co-operational or adversarial. In co-operational conversation, the assumptions made by the speaker are also made by the listener. This phenomenon is absent in adversarial conversation. Legal documents demonstrate a form on adversarial conversation by clearly specifying each and every nuances of a contract. The following anecdote demonstrates the difference between the co-operational and adversarial conversation. Two psychoanalysts meet in the morning. The first psychoanalyst greets the other "Good Morning." The other wonders what he really meant by that statement.

Friday 3 August 2018

Neural networks, explained - Janelle Shane, Physics World

This post is a summary of  the article published in the 2018 issue of "Physics World." This article is written by Janelle Shane.

Advantages:
  1. They are excellent at recognizing patterns in multivariate data.
  2. They are suitable for problems that are not very well-understood. Traditional systems were either rule-based or feature-based. However manually coming up with rules or features is intellectual challenging and infeasible in many cases such as face recognition. Neural networks are good at feature engineering. 
 Limitations:
  1. Interpretability is an issue with neural networks. A neural network acts like a black box because humans cannot easily interpret the the features learnt by the model.
  2. It is necessary to review the results by human experts because neural networks might learn features that are not at all relevant to the task at hand.
  3. Neural networks might suffer from class imbalance in training examples. This is a major issue in the case of rare events, for which it is hard to generate sufficient number of training examples. 
  4. Neural network might suffer from overfitting to training examples. Overfitting can be resolved by testing the network on unseen examples.
"Neural networks can be a very useful tool, but users must be careful not to trust them blindly. Their impressive abilities are a complement to, rather than a substitute for, critical thinking an human expertise."

Tuesday 22 May 2018

Dark World

I have listed below some issues that are threats to (my?) peace. This is the result of the quest for answers for a few questions I asked myself over the past couple of days: "Is the world a safe place to live in?", "Is the world as dangerous as the media portrays it to be?", "What are the areas in which a complete overhaul is necessary to make things right?", and "Is it time to move to Mars?"

My list is given below:
  1. Greed
  2. Poverty - e.g. India
  3. Corruption - e.g. India, South Korea, Brazil
  4. Consumerism - e.g. McDonald's, Subway, Amazon, Walmart
  5. Nepotism - e.g. INC, SP, DMK, JDS, TRS, TMC, BJD
  6. Intolerance - e.g.  Kalburgi, Pansare, Dabholkar, Gauri Lankesh
  7. Unemployment - e.g. Greece, Spain 
  8. IT - Fake News, AI, Monopoly by Tech Giants, Targeted Marketing
  9. Social Divide - e.g. Casteism, Classism, Racism
  10. Economic Divide - e.g. Mumbai, Healthcare, Education
  11. Cultural Divide - e.g. North India vs. South India, East vs. West
  12. Religious Divide - e.g. Shia vs. Sunni, Hinduism vs. Islam, Christianity vs. Judaism
  13. Nationalism - e.g. US, Brexit, India, Hungary
  14. Terrorism - e.g. ISIS, Al-Qaeda, Hamas, Hezbollah, Boko Haram
  15. War - e.g. Syria
  16. Refugee Crisis - e.g. France, Germany
  17. Cold War - e.g. {US, Saudi, Israel} vs. {Russia, Iran, Syria}, India vs. Pakistan, Greece vs. Turkey
I am yet to reach a conclusion.

However recently I came across a TED talk by Steven Pinker, according to which the world has come a long way in terms of progress: democracy as opposed to theocracy that was the practice in major parts of the world (e.g. Russia, England, Spain, India), freedom for colonies (e.g. India), freedom from slavery (e.g. US), improvement in literacy levels and human rights, modern sanitation facilities (e.g. toilets) and dissemination of information (e.g. WWW). So there are indeed reasons to be happy about. However the extend to which these ideas have been fulfilled in practice is debatable.

Friday 18 August 2017

The Purity Principle, Randy Alcorn

“Confessing your sins is great, confessing your temptations is even greater" - Randy Alcorn

This article is a summary of the book The Purity Principle by Randy Alcorn. The book discusses sexual purity, why is important to maintain sexual purity and how we can achieve the same. Randy quotes the scripture as and when required in order to authenticate the message he wants to convey to the reader through this book. Nobody is free from temptations. Even pastors are prone to temptations. Throughout the book, Randy shares his own experiences and thus the reader is able to connect with the author.

The book begins with a brief account of the lives of various people such as Eric and Tiffany (fictitious names, probably) who have pursued immoral, impure paths of life and ended up with disastrous results. Although God forgave their mistakes, they had reached a point of no return in their lives. This was because, as Randy asserts, punishment is built into sins we commit. Randy views purity as wise and impurity as stupidity.

Sin can be of various types. However sexual sin is different from other kinds of sin. Sodom and Gomorrah, the cities destroyed by God, had fallen deeply into sexual sin. Paul reiterates this in his letters to the Corinthians (1 Cor 6:18) and the Thessalonians (1 Thess 4: 3-8). An interesting point to note is that sex is more of what you are, rather than what you do. Sex defines us. Thus it is important to purify ourselves by keeping away from sexual sin. Also, by accepting Jesus as the Christ, we were bought at a price and hence, our body belongs to God (1 Cor 6:19-20). As a result, we cannot do anything that we please with our body.

When it comes to temptations, Christians are the most vulnerable because of the constant threat from the devil. It is important to be careful about the mind to maintain purity. Sometimes, it is better to avoid temptation rather than resist temptation. Notice how avoid is different from resist. If we keep resisting, we are subjecting ourselves to the temptation. On the other hand, when we avoid temptations, we are staying away from them altogether.

Randy lists down various aspects of life where it is necessary to maintain a pure mind and body and thereby follow the purity principle. In spite of the wickedness of larger sins such as infidelity, it is important to focus on the lesser ones that feed our minds on a daily basis in the form of media, peers, novels, movies and arts. For example, if we regularly watch a TV programme that shows immoral content then avoid it. We live in an era where media and technology (e.g. Whatsapp, Facebook, YouTube, Instagram) can control our lives immensely. We have to have a prudent approach towards the manner in which we use these resources. Randy contrasts his words with what Jesus instructed in Mathew 5:29. Randy claims that whatever he instructed is nothing radical compared to Jesus’ command.

Randy makes it a point to handle the cases of singles, and married couples differently. Single, unmarried men and women should prepare themselves for their marriage. Randy explores various issues related to dating, masturbation, and peer pressure. Now for married couples and parents, Randy observes that umpteen marriages have suffered due to dishonesty by either of the partners. Even after entering into marriage, we are not free from sexual temptations. It is necessary for couples to be open with each other about everything, especially sexual temptations, and request prayers from one another.

The book concludes with a discussion on maintaining accountability with others. Randy recalls how on one occasion he underwent temptation and how the temptation vanished after a phone call with his friend. Thus, we are in a constant battle with the devil. However, this is a battle that we can win. It is indeed possible to avoid temptations and thereby maintain sexual purity and holiness.

And that's what The Purity Principle is all about!

Sunday 9 July 2017

Blogs/Websites that I follow

I share here some of the blogs that I follow. Most of the articles in these blogs are about research, education, PhD, and computer science.
I hope these blogs will be of help to you.

Sunday 12 February 2017

Maps

The map lists various areas of study that come under the aegis of mathematics. It is a Herculean task to enumerate all the disciplines in mathematics. Dominic has done an amazing job here.
  • Foundations - Fundamental Rules, Mathematical Logic, Set Theory, Category Theory, Theory of Computation, Complexity Theory 
  • Pure Mathematics
    • Number Systems - Natural Numbers, Integers, Rational Numbers, Real Numbers, Complex Numbers,
    • Structures - Number Theory, Combinatorics, Algebra, Linear Algebra, Group Theory, Order Theory
    • Spaces - Geometry, Trigonometry, Fractal Geometry, Differential Geometry
    • Changes - Calculus, Vector Calculus, Chaos Theory, Dynamical Systems, Complex Analysis
  • Applied Mathematics - Numerical Analysis, Game Theory, Economics, Engineering, Computer Science, Machine Learning, Probability, Statistics, Cryptography, Optimization, Biomathematics, Mathematical Physics, Mathematical Chemistry

Tuesday 3 January 2017

Vijay Amritraj @ IITM

I had the opportunity to listen to Vijay Amritraj as part of Shaastra '17.

He is a great orator. He has worked as the messenger of peace in United Nations, directly reporting to the then UN general secretary Kofi Annan. The Vijay Amritraj Foundation takes up various social causes.

He is confident of the improvements taking place in the sports scenario of the country. When he was playing tennis in the 70s, cricket was the only sport in India. Now, people in India pursue and follow various other sports such badminton, chess, shooting, kabaddi, and wrestling.

He commented that people in our country like to play everything safe. That is the reason why still not many people pursue sports as a career. He is confident that there is talent in the country.

He remarked that technological advents, such as computer ranking and hawk eye prediction, has impacted tennis in many ways. The average height of players has gone higher. The strength of rackets has increased. The surface has become slower. The ball has become heavier. The quality of the game has improved a lot.

Thursday 22 December 2016

To Kill A Mockingbird, Harper Lee

Awesome Read! 

In To Kill A MockingbirdLee discusses a lot of issues - gender disparity, class distinction, race division, capital punishment, rape, The Great Depression, and ethics and morality - as viewed from the perspective of the young girl, Scout. TKAM is one of the best fictional novels I have ever read.

To spice things up, I gave my own titles to each chapter in the book.

Part I Part II
Chapter 1 - Radley Opening Chapter 12 - Cal Church
Chapter 2 - Morning Sickness Chapter 13 - Finch Pride
Chapter 3 - Afternoon Show Chapter 14 - Dill Flee
Chapter 4 - Vacation Drama Chapter 15 - Cunningham Encounter
Chapter 5 - Tweet Radley Chapter 16 - The Courthouse
Chapter 6 - Peep Talk Chapter 17 - Tate-Bob Witness
Chapter 7 - Thank Cement Chapter 18 - Mayella Witness
Chapter 8 - Tundra Blaze Chapter 19 - Tom Witness
Chapter 9 - Landing Tussle Chapter 20 - Closing Remarks
Chapter 10 - Dead Shot Chapter 21 - The Verdict
Chapter 11 - Dubose Deadly Chapter 22 - Tears of Injustice
Chapter 23 - Gender-Class-Race Divide
Chapter 24 - Missionary Tea Hypocrisy
Chapter 25 - Maycomb Tribune
Chapter 26 - Grace Double Standards
Chapter 27 - Back to Normal
Chapter 28 - Bob Attack
Chapter 29 - Boo Save
Chapter 30 - Alternate Story
Chapter 31 - All is Well

Tuesday 6 December 2016

English Grammar Punctuation

Notes from Eats, Shoots& Leaves (Lynne Truss)
 
Traditionally punctuation made it easier to read text aloud or to signal a pause. This was especially useful for actors on stage. In modern usage, punctuation serves additional functions such as indicate emphasis, for syntactic reasons or to avoid ambiguity.

Every publication house follows different style guides for punctuation. Additionally, the British usage differ from the American one (e.g. usage of punctuation within quotation marks).

Apostrophe: possessive marker (e.g. Jack's, boy's, boys'), to indicate omission (e.g. summer of '69), indicate time or quantity (e.g. two month's notice), plurals of letters and words (e.g. f's, do's and don't's); no need to use for plurals or abbreviations (e.g. MPs and MLAs) or dates (e.g. 1980s)

Comma: for lists (e.g. Tom, Dick and Harry), for joining complete sentences, bracketing commas (instead of em-dash or parenthesis);

Semicolon and Colon: to indicate pause and emphasis

Exclamation mark, italics, quotation marks (single and double), brackets (round, square, curly, angle)

How to choose between single and double quotation mark?
How to choose among round bracket, em-dash and comma?

Hyphen: to combine words (e.g. pre-train), when a noun phrase acts as an adjective (e.g. state-of-the-art model), to split unfinished words at the end of a line, to avoid ambiguity (e.g. re-formed vs. reformed)
 
Punctuation Marks
  • Full stop 
    Alice met Bob.
  • Comma
    Alice gave Bob a pen, paper, and a pencil. 
    Alice, a student, met Bob.
  • Semicolon
    Alice gave Bob a paper; Bob took it reluctantly.
  • Colon
    Alice gave Bob a few items: a pen, a paper, and a pencil.
  • Question mark
    Did Alice meet Bob?
  • Exclamation mark
    Hurray, we won! Yipee!
  • Quotes
    ``Come,’' Alice told Bob.
  • Apostrophe denotes contraction and possession.
    it’s, Alice's, p’s, 7’s, 1990s, MPs
  • Hyphen
    Does your organization have a by-law?
  • Dash denotes comment
    Alice will not come - I hope so.
  • Parentheses denotes supplementary information.
    Alice (a student) met Bob.
 
Character
Code Point
Name
Purpose
u2010
Hyphen
To represent compound terms
u2014
Em dash
In place of commas, parentheses
(use em dash sparingly and instead use the alternatives)
u2013
En dash
To denote ranges
u2212
Minus
To represent subtraction
-
u002D
Hyphen-minus
ASCII hyphen

Friday 16 September 2016

Information Theory, Khan Academy

Recently, I have been going through some interesting videos on information theory. I am posting the link here: Information Theory, Khan Academy, for the benefit of those who want to learn something new, fundamental and interesting. I will try to summarize what I understood from the lectures below.

1. Ancient Information Theory
It is interesting to note how humans started communicating with each other. Ancient humans used pictographs and ideograms engraved on rocks and in caves to share information. Later on, symbols and alphabets were devised for ease of communication.

With the passage of time, advanced communication technologies were developed. For instance, Greeks and Romans used torches, especially in battles, for quick long-distance communication. In the 17th century, shutter telegraphs were the norm. It could cover all the letters in English alphabet. With the help of a telescope, it was possible to send information across an incredible amount of distance. But still, these techniques were not sufficient for effective communication due to their low expressive powers and low speeds.

With the discovery of electricity, the information age had begun. The visual telegraphs were soon replaced by electrostatic telegraphs. It was possible to send large bits of information to long distances in short amounts of time.

2. Modern Information Theory
How fast can two parties communicate with each other? The limiting rate at which it is possible to send messages depends on symbol rate (baud) and difference. Symbol rate stands for the number of symbols which can be transferred per second. There is a fundamental limit on the distance between two pulses. Due to noise, a pulse may not be perfect. If two pulses are very close to each other, there is a very high chance for inter-pulse interference to occur between them. This makes it difficult for the receiver to decode the signal. The difference stands for the number of signaling events per symbol. Message space denotes the number of messages possible.

How is it possible to quantify information? A possible way solve this problem is by considering a scenario where the receiver asks a number of yes/no questions to the sender to receive information. Based on the minimum number of questions required to receive the complete message, it is possible to quantify information. This unit is called a binary digit or bit, in short. Mathematically, this is nothing but logarithm (to the base 2) of the size of the message space. For example, to pass the name of a book from the Bible, 6-7 bits are required. To pass the names of 2 books from the Bible, 12-14 bits are required.

Human communication is a mix of randomness and statistical dependencies. Claude Shannon uses a Markov model as the basis of how we can think about communication.  Given a message, a machine can be designed which generates a similar-looking text. As we progress from the zeroth-order approximation to first-order and second-order approximations, the similarity of the text generated by the machine with the message increases.

Entropy - Shannon gives a mathematical method to quantify information. He calls this quantity entropy H= -Σp. log2(p), where p is the probability of an outcome of the event. If all the outcomes are equally likely, then entropy is maximum. If there is some predictability in the outcomes, then entropy comes down. For example, a text with random words and letters will have higher Shannon's information than a text with "normal" letters. This seems counter-intuitive at first because information theory doesn't deal with the semantic information in the message but with the number of symbols required to communicate a message. The only way to regenerate the random text is to copy the text as is. However, it is possible to compress the "normal" test using rules due to its predictable nature.

Coding theory - If the entropy is not maximum, then it is possible to compress a message. But, what are the ways in which we can compress a message? David Huffman came up with the Huffman coding strategy to compress a message with the help of a binary tree by encoding symbols into bits. However, the limit of (lossless) compression is the entropy of the message source. The information in the message would be lost when the message needs to be compressed beyond the specified limit.

Error detection & correction - During communication, noise in the channel corrupts the message resulting in difficulty for the receiver to understand the message. How is it possible to deal with noise? Richard Hamming came up with the idea of parity bits built upon the concept of repetition. Thus, error correction is done by using more symbols to encode the same message resulting in an increase in the size of the message.

Reference
Shannon, Claude Elwood. "A mathematical theory of communication." ACM SIGMOBILE Mobile Computing and Communications Review 5.1 (2001): 3-55.