lidsblog

Engagement

The opening ceremonies were "frickin' amazing."  Lopez Lomong bore the flag for the USA.  It is quite a story of how he ended up less than a marathon's distance from my birthplace.  (The excellent film God Grew Tired of Us which I saw at Kendall Cinema recounts similar stories.)  His participation was symbolic of the engagement with China that President Bush talked about in this interview. 

Costas: The Opening Ceremonies were glorious. There's much to admire about China's people, China's culture, and its present accomplishments. But this remains an authoritarian state --

Bush: That's true.

Costas: -- with an abysmal human rights record. In the long run, is China's rise irreconcilable with America's interests?

Bush: No. In the long run, America better remain engaged with China, and understand that we can have a cooperative and constructive, yet candid relationship. It's really important for future Presidents to understand the relationship between China and the region, and it's important to make sure that America is engaged with China -- even though we may have some disagreements.

Bush echoes the sentiments expressed by President Lehman in an excellent speech I had the pleasure of hearing at Schoellkopf Field in 2004.  (A quotation from the speech forms the tagline of Krish's blog.)

Lehman: But Ice-9 contamination arguments of this form revolve around other, more limited forms of contact, forms that do not endorse or enable the underlying activity. They take the simple form, “Don’t have anything to do with X because X is bad and if you engage X you will elevate X and debase yourself, X’s name will be legitimated, and yours will be sullied.”

Lehman: My primary message this morning is that you should be very wary of Ice-9 contamination arguments and the sense of despair that is implicitly associated with them. Let me stipulate that there is a special satisfaction one can derive from using them as a reason to withdraw from contact with the world. It is the satisfaction that follows from feeling a certain kind of moral superiority. But I would argue that this satisfaction carries a very heavy price. Yielding to Ice-9 contamination arguments will often, perhaps usually, lead us to miss opportunities to accomplish genuine good in the world through serious engagement.

What does all of this have to do with LIDS?  Working on mathematics and theory, the hazard is to view application and the details of applications as something to be avoided.  From Servo Loops to Fiber Nets written on the fiftieth anniversary of the laboratory by Bob and Sanjoy discusses how LIDS has engaged with various applications through its history.

Gallager and Mitter: Its mathematical foundations lie in complex function theory and harmonic analysis.  Its creativity lies in the discovery of the hidden conceptual structures behind engineering problems and in crystallizing them through the introduction of appropriate mathematical structures.  But the interaction between theoretical and conceptual ideas, engineering synthesis and technological development in the field of systems, communication and control is more complex.  It is in fact a highly complicated feedback process.  Conceptual developments in engineering are incomplete until they lead to a new algorithm, new apparatus or machine.  These in turn require new conceptual ideas for their full utilization. 

The Tunnel

I have passed the technical qualifying exam and research qualifying exam, been in residence for at least four semesters, taken courses and written a master's thesis, satisfied the teaching requirement, and completed the minor program.  I will be turning in my doctoral thesis proposal this week, which is the last of the requirements other than the actual thesis and defense.  My doctoral committee will consist of Alan, John Fisher, Polina Golland, and Josh Tenenbaum.  The road towards graduation in terms of these hurdles is pretty straightforward, but looking at things at that scale misses the tortuosity of the path at the end. 

For no particular reason, I have been following the progress of the tennis player Somdev Dev Varman over the last several weeks.  He turned professional after his college career concluded with back-to-back NCAA championships.  Related in some manner to the royal family of Tripura, Dev Varman went out and won tournaments in Rochester, NY and Pittsburgh, PA on the Futures circuit, won an exhibition tournament in New City, NY, and qualified for and won the tournament in Lexington, KY on the Challenger circuit.  As a professional he has won twenty matches and lost none.  His world ranking has jumped from 797 to 661 to 565 to 345.  This week he is playing another Challenger-level tournament and will very soon be playing full ATP tour level tournaments. 

As discussed by Bill Simmons and James Blake, the ranking system is very definitive and players know exactly what they need to do.  (Doing so is not easy and requires a lot of hard work.)  Many non-research-related careers don't per se have rankings, but the path is about finding the light at the end of the tunnel; it is not about finding the tunnel, as it is with research.  With the thesis proposal now written, I think I have found the tunnel and am now looking for the light at the end of it.

Orange Alert

Last week, Ayres Fan, a fellow student in the Stochastic Systems Group, who is close to finishing, was suggesting that I should write about my beloved Syracuse Orange in this space.  I was completely disillusioned after the first three weeks of the football season, but that changed on Saturday.  Let me not write about the alert sounded by the Orange to the college football world, but a different orange alert. 

This past week was career week at MIT and a lot of representatives from companies were in town.  One Course 6 undergrad, in order to stand out at the career fair, fashioned some LED-laden bling.  My officemate Emily, in fact, complimented this student on her piece of flair at the fair.  On Friday, we heard that she had been arrested at gunpoint at the airport as a suspected terrorist. 

Note to self: 'flying while brown' is already an issue for me, so I shouldn't compound things by carrying conspicuous electronics -- I should really hide any electronic items I have on my person. 

So how do intelligence analysts investigate whether someone is a terrorist or not? 

Also on Friday, I was invited by my friend Zennard Sun to a dinner and demo hosted by Palantir at the upscale Nine Zero Hotel in Boston.  Palantir is a fairly new company that is developing very powerful software platforms for analysts, both in the intelligence community and the financial industry.  The intelligence platform is a way to deal with data about links among people and to analyze whether a group of people forms a clique, whether two people are really the same person, how money flowed from leaders out to operatives and then whether this resulted in coordinated travel, etc.  Some screen shots are available here, but my verbal description and the screen shots do not do the product justice.  It was really, really impressive, and apparently completely unlike anything currently deployed. 

Palantir incorporates some aspects of machine learning into their product, but their goal is not to have one button that will do everything -- they want to use human capabilities as well.  One thing I have been discussing with Alan recently is the idea of machine learning for a purpose, possibly an unspecified or underspecified purpose at that.  The usual modus operandi in machine learning is maximum likelihood -- finding the most likely explanation given a model.  In discussions Alan has had with people like military commanders, what he has observed is that commanders do want the most likely explanation, but also the most dangerous explanation and the most unusual or weirdest explanation. 

Some recent work by Sujay Sanghavi and Vincent Tan looks at doing machine learning for a purpose, where the purpose is hypothesis testing.  They learn graphical models from data to minimize hypothesis testing decision error.  What do you do when the cost or utility function to optimize is not given a priori?  That is an interesting line of inquiry that I may look at in the years to come. 

I wonder whether Ayres will encounter Palantir's financial platform Hedgehog in the years to come after he starts his job at Goldman Sachs. 

Mind Games

Yesterday's LIDS lunch brought the academic year to a close and was the occasion for the release of the third volume of LIDS-All magazine; despite the absence of a trip inside the mind of Erik Sudderth, it contains many nice features.  A secret about the end of the semester is that professors and TAs are more thrilled about it than students. 

In the last lecture of the linguistics class I have been taking this semester, Semantics & Pragmatics, Kai introduced us to the Wason selection task, a psychology experiment that shows that humans behave illogically when making snap decisions about abstract correlations.  However, we are much, much better when the same exact task is presented in terms of social interactions, conventions, or contracts. 

Semantics is the study of meaning in natural human language.  Formal semantics makes use of partial functions, logic, and set theory to describe the truth conditions of a sentence, i.e. when it is true and when it is false.  Bob receives most messages is true if and only if the cardinality of the set of messages that Bob receives is greater than half the cardinality of the set of messages.

Pragmatics concerns itself with implicatures that can be drawn from sentences assuming cooperative communication among agents.  Through the logic of pragmatics, we infer that Bob does not receive all messages.  Bob receiving all messages entails Bob receiving most messages.  The hearer of the sentence would be interested in knowing whether Bob receives all messages and to be cooperative, the speaker should give the proper amount of information; since the speaker does not say that Bob receives all messages, the hearer believes that it must not be true. 

Detection, estimation, communication, and decision theory built upon probability theory, which is itself built upon set theory, is much more like semantics than pragmatics.  On the other hand, humans have difficulty separating semantics and pragmatics because we are always busy trying to make inferences.  In communication, we would like it if not sending a signal were to give us a free bit of information, but in some schemes it doesn't seem to work out that way in terms of communication theory, but in terms of human social interaction, not sending a signal provides a wealth of information. 

Two recent happenings in the world of sports and common reactions to them reveal something about how different the mind is from the axioms upon which study in LIDS is based.  The selection committee for the NCAA lacrosse tournament seeded Cornell fourth despite their primacy by many criteria.  Reactions did not bring up the mathematical fact that there is no optimal way to rank (Arrow's theorem), but focused on social/psychological aspects like fairness, bullying, and manipulation.  An econometric study was released showing that NBA referees are biased.  Reactions here disputed the math and statistics as much as, if not more than, the bias/illogicalness of humans when making snap decisions. 

The focus on social interaction differentiates us from systems that we design at present.  The quest for semantic communication is really a misnomer; it is pragmatic communication that we ought to seek, and taking a trip inside the mind is one way to go.