Friday, December 29, 2006

Robot Bhangra

(Thanks RG)

And now, Ladies and Gentlemen, we have robots dancing Bhangra

That is just frigging awesome ! For some reason, all I'm thinking of now is how the CG moves and the bot stays balanced as it does that somersault.. just analysing it on paper is a daunting task, let alone actually getting it to work! Gyad wonly :-)

Friday, December 22, 2006

Van Eck Phreaking

(Thanks Pota for the novel and the video )

I am just finishing up with Neal Stephenson's Cryptonomicon (don't bother trying to read an e-book version, its some 1000 odd pages). The novel is really nice, but the nicest part of it was Van Eck phreaking. On any CRT monitor, the electron beam is moved around by coils which produce an electromagnetic field. Now, for the coils to 'direct' the beam, the current supplied to them should vary in time in such a way that the effect of the coils' magnetic fields deflects the beam to where it is required. Voila! Currents changing in a conductor automatically mean electromagnetic waves being transmitted into space. You might not think these are strong enough to be picked up, and neither did I till The Pota fished out a youtube video, showing it happening ! The wiki article points at one with a more... practical bent, of compromising electronic voting machines !

Ah, I can imagine Mr. Van Eck ( or the TEMPEST fellows) on a lazy afternoon, gazing into the blue sky, thinking about that inordinate din the TV was making, and FLASH ! Coils, changing currents, phreaking !! Phew, awesome !

Wednesday, December 06, 2006

What the stock!

I was reading the wiki article about the Tokyo Stock Exchange, and came across this paragraph:

During the initial public offering of J-Com on December 8, 2005, an employee at Mizuho Securities Co., Ltd. mistakenly typed an order to sell 610,000 shares at 1 yen, instead of an order to sell 1 share at 610,000 yen. Mizuho failed to catch the error; the Tokyo Stock Exchange initially blocked attempts to cancel the order, resulting in a net loss of 347 million US dollars to be shared between the exchange and Mizuho. Both companies are now trying to deal with their troubles: lack of error checking, lack of safeguards, lack of reliability, lack of transparency, lack of testing, loss of confidence, and loss of profits. On 11 December, the TSE acknowledged that its system was at fault in the Mizuho trade. On 21 December, Takuo Tsurushima, chief executive of the TSE, and two other senior executives resigned over the Mizuho affair.

What the! I can perfectly imagine the scene in front my eyes: there's this dialog box with two text fields, the employee enters the details, and clicks 'OK'. A confirmation box pops up, for probably the 18,000th time that day. No patience to even click, his right pinky hits the Enter key, and whoooooooooosh! 347 million dollars, and three top executives go right off the cliff. And if you really think about it, there is nothing anyone could have/can do about it. Selling 610,000 shares at 1 Yen is a very probable transaction, and so is 1 share at 610,000 yen, so no 'common sense' software check could have caught it. Confirmation dialogs are useless in such high volume work, we all know that. From the side of the employee, it simply is an error that can't be avoided!

Nai had some things to say about this during Shaastra Main Quiz, as these kinds of errors being related to Freudian Slips. I too have been searching high and low for research on 'casual' or 'silly' mistakes that are so common in numericals, but haven't been too successful. At their best, these casual mistakes affect performance assessment (in my experience) by about 5% , and at their worst, render the assessment meaningless (a mistake in CAT, for example).

Is these something 'behind' casual mistakes, something more that 'silly errors' or 'it happens'? I'm trying to design a survey form, and send it by mail to everyone in the insti, and try to get some statistics about it. If you know of any such survey being conducted before, or have some suggestions for the form, please do let me know!

Tuesday, December 05, 2006

Best tribute to Milton Friedman

Found this on 2x3x7 via India Uncut :

If there is a heaven, Friedman is probably up there right now, convincing God that the best thing he can do for the rest of us is to leave us alone.



Dear, Dear me, what a sublimely spirtual message this is to the Youth of the Nation..Hallelujah, orkut be praised !

wll u b my frndshp partnre in orkut? i am nice boy, well setld and hapy studing in colej, u look nise wid cap, we hapy as frnds, have fun togetr. u scrp me, i crp u too, v mesg and share secretes about grlfrnds and boyfrnds and many frnds of all typs. u say u will mary i wll b frnd 2 hlp u 4 mony trubles and bride trubles and moter inlaw trubles. u n i wll hat u r moterinlaw wen i com. gud frnds v r. i wll hlp evn wen u slap me wen i luk at ur wif. evn ur wif's frnd i wll b. v wll b hapy togetr. but b my frnd. PLSS!

Phew, "many frnds of all typs", I'm laughing so hard my stomach hurts !

Monday, December 04, 2006

SIGGRAPH is God, too. I'm going Pantheistic!

(Thanks a ton, Adarsh!)

Guess where this pic is from :

A saturday morning cartoon ? Some Russian CG expert with loads of time on his hands? Caps from a movie, perhaps?

Ok, how about this:

(I can't think of any way of demonstrating how excited I am; Caps, bold, italic, underline, blink are all for lesser occasions. This one is way beyond their league, so I'm just going to say it plain.)

These pics are from a SIGGRAPH paper that describes a method to dynamically calculate deformations in sets of tens of objects! Yes, thats right, there is only one 'non-rigid' shoe and one 'rigid' die that is modelled, a simple config file tells the inital position of each shoe, and the algorithm calculates the deformation dynamically, and gives the coordinate by oordinate output!

Anyone who's done a course on Strength of Materials will easily realise this is a TREMENDOUS achievement! To calculate strains in a simple block with a hole in it is a dauntingly challenging task, and here are these guys, with a method to crush duckies (elastic duckies, so they bounce back up) and pile shoes on dice!! Simply put, AMAZING!!!!

(Maybe I should spend more time writing up a more detailed post on why exactly this is earth-shakingly brillaint, but I just had to put this up the moment I saw it :-) )

Purposeless Note 1: Blogger's HTML is pathetic. I fart in your general direction, you overpaid overrelaxed Google codemonkeys !

Purposeless Note 1.5: That phrase is what started a GTalk conversation between Adarsh and me, which finally led to this.

Purposeless Note 2: I should stop watching Monty Python for a while.

Saturday, December 02, 2006

TED Talks

(Thanks Pota)

TEDTalks are these set of brilliant lectures, sponsored by BMW,  covering a very wide range of topics. I happened to watch two of them, and I'm totally stunned.

The first one, "The Paradox of Choice" by Barry Schwartz, is about how too much choice is choking us. It makes for extremely interesting viewing, and the fishbowl metaphor at the end really set me thinking.

Another one, "Myths about the Developing World", is a perfect case study of how a normally very boring topic can be made remarkably interesting, by presenting it in a thoughtful way. It does provide info about its subject matter, the demographies of developing countries, but the insights it gives into how data should be presented are far more valuable, imho. contains a lot more of these; You'll probably find most of them on Google Video, in case that site proves too slow.

More Genius!!

Remember that link to a paper I gave in the 'nice comments' part of the previous post?

I followed that link and read that paper, and my God, it is AWESOME! All that the guy had in front of him was 5 obscure lines of code and a befuddling 'magic' constant, and he sat on it, worked it out, and using simple calculus and error analysis that anyone can understand, got back the constant that was used, and whats more, he suggested a better value for the constant with proof. Do read the paper !!!!

Whoa, what a morning it has been !

Friday, December 01, 2006

Pseud-est piece of code I've seen

 This . piece . of . code . is . GOD.

What does it do ? It calculates 1/sqrt(x). Um, why? Because in any graphics application, one of the most common operations is to normalize a vector. If this peice of code can improve performance by 10%, it will cause a colossal net performance increase, since there are thousands of normalization ops taking place for each frame! Ok, so this is from? The Quake 3 source code !!

Rejoice, my brethren, Real Programmers still walk the Earth !

Update: People, here is absolute proof that Slashdot, too, is God. These comments just made my day !

(x^(1/2))^2 != 1

Interesting smiley... is that a dead man with a fraction in his mouth and a prominent Adam's Apple, wearing a bow tie and a dress and standing on a toy race car?

What's your point, man?

An extremely detailed description on how it works.

"The real genius here is Isaac Newton. 'course, that's not news to anyone."

You mean that Newton thought about taking advantage of the IEEE float format to initialize the algorithm using "i = 0x5f3759df - (i>>1);"? Wow, now that's a clever guy!

What a reply !

I have a truly marvelous proof of who wrote this code which this comment box is too narrow to contain.

ROFLMAO :D !!!!!! lolz even !!!

The linked site seems to be down (gee, you think it might be slashdotted?), but this paper [] seems to be covering the same topic

Do read the paper, might be interesting it is AMAZING! VERY CLEAR! .

6. "It was fast" #17070808 .php?section=ffi&page=sqrt []

And before you know it, someone found a comparative study :P

Aha! A link to HAKMEM !

And finally,

8. #17071866

Look son, crazy people...