Monday, December 28, 2009

The Khan Academy – One guy making a difference

If someone pinned me into naming a personal hero for 2009, I’d probably pick Salman Khan, though I only heard of him in December. He is the creator of The Khan Academy.

I came to know of Salman’s work, while volunteering at NPTEL. This guy has single-handedly created more 1000 short educational videos, and made them all available for free on the net.

He first started out with a few videos intended for his nephews. They were so well received and satisfying to him that he just kept going and has never looked back.

What is particularly impressive to me is how he has taken the simplest of tools (MS Paint and free web-casting software) to do all of this. And, he’s managed all of this while holding a full time job! (In September of 2009 he quit his job to devote his full time to The Khan Academy.)

He has a great FAQ which is well worth reading. His reply about why he didn't try to make money from this venture really resonated with me:
I've been approached several times, but it just didn't feel right. When I'm 80, I want to feel that I helped give access to a world-class education to billions of students around the world. [...] I already have a beautiful wife, a hilarious son, two hondas and a decent house. What else does a man need?
Because of his background in banking and finance, he even has a few short videos on the government bailout and the Geithner Plan.

Do check out a video or two. Salman is an example of one person making a difference. Do pass on the link ( to any students and learners who you think might benefit.

Saturday, December 19, 2009

Volunteering assignment at NPTEL

When I got this non-paying assignment I was just as excited as I was when I landed my job years ago.

Around 3 months ago I heard about a program called NPTEL, being run in my alma mater. Very briefly, NPTEL is an effort by the Indian Government to develop web- and video-based courses for all engineering disciplines and make them available to the public for free. In Chennai, I am volunteering my time and abilities to the effort.

For the past three months we are working on creating awareness (mainly among engineering faculty in the numerous Engineering colleges that have come up in South India) and in trying to reach out to students. I am helping coordinate workshops with these faculty members – they tell us what’s working and what needs to be tweaked in these web courses.

Volunteering for NPTEL provides me with two things I was hoping for: Scalability and no requirement about me having to spend long durations at any particular office.

For the past 6 months, my wife and I have been talking to a number of people in the public service domain, looking at different volunteering opportunities. Most of the suggestions we received were very generic or they were targeted at very small groups of individuals. As a matter of personal preference, I wanted something that had a larger scope.

For me, NPTEL fits the bill nicely. I fully realize that huge hurdles exist to learning difficult engineering concepts from the Web. This project falls under the HRD Ministry’s very ambitious National Mission for Education (NME) effort. The vision in NME is to expand the NPTEL effort to have courses developed for students of all ages, right from kindergarten to post-graduate courses in all disciplines, not just for engineering.

I will definitely post more about NPTEL later. Meanwhile, if you have acquaintances who are currently enrolled in an engineering degree, direct them to NPTEL’s Official Website.

Over 250 full courses (~40 lectures of 1 hour duration each per course) can be viewed via Youtube’s iit channel. If you have heard of MIT’s OpenCourseWare, this is very similar in the Indian context, and is based strongly on a commonly agreed-upon curriculum.

I don’t have an official designation in the NPTEL office. My initial goal is to just help build awareness. Effectiveness will take time, but will eventually follow after a number of iterations.

Sunday, December 6, 2009

Puzzle: Loop the Loop aka Fences

Several weeks ago, I started to doodle on the newspaper (The Times of India) whenever I saw the “Loop The Loop” puzzle. I liked it enough to research it a bit more.

It is really a logic puzzle, and can vary in difficulty from very easy to very difficult. The rules are simple: You are given a grid of squares, with several cells having a number in them. You have to draw lines such that they form one loop. The number in each cell indicates the number of edges that the loop touches in that cell. There should only be one overall loop.

I found an online version here in (You can choose the degree of difficulty from the left panel). Try it out.

For those of you who want the game to your PC (to play even when you are not connected to the Web) you can download) Loopy.

If you have tried it a few times, like the puzzles and are mathematically or logically inclined, then read on.

Preprocessing: Also, there is lots of preprocessing that is possible. It is pure pattern recognition. Two 3’s together mean something. A 0 next to a 3 is a fairly big hint. Also, by dividing the squares into corner squares, edge squares and interior squares, you can gain some additional insights to help you solve the problem.

Integer Program: This whole problem lends itself very nicely to be modeled as an integer program, with each edge being a 0/1 binary variable. It is a very good IP modeling exercise in itself. Since multiple loops are not allowed, the sub-tour elimination constraints make the model a little unwieldy.)

Composing: To compose one of these problems can be a fun challenge. (Think of it as the dual to solving the puzzle.) The fact that there is only one solution makes it a very challenging puzzle to compose: For a given loop, how to go about revealing only the least number of numbers in cells?

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