Nabin K. Malakar, Ph.D.

NASA JPL
I am a computational physicist working on societal applications of machine-learning techniques.

Research Links

My research interests span multi-disciplinary fields involving Societal applications of Machine Learning, Decision-theoretic approach to automated Experimental Design, Bayesian statistical data analysis and signal processing.

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Interested about the picture? Autonomous experimental design allows us to answer the question of where to take the measurements. More about it is here...

Hobbies

I addition to the research, I also like to hike, bike, read and play with water color.

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Showing posts with label fun. Show all posts
Showing posts with label fun. Show all posts

Thursday, June 28, 2012

Rock paper scissors, wait there is more...

You can win the game (or battle) with few methods: with intelligence/tactics, and/or with speed (assuming equally powerful players).
The field of Machine learning can use both! :)
So, fasten your seatbelt and think!
Recently I saw a video showing robot system with 100% winning rate "as one example of human-machine cooperation systems". The key was the speed. http://www.k2.t.u-tokyo.ac.jp/fusion/Janken/index-e.html

On the lighter note to the post, because of limited outcomes of the Rock-paper-scissors, there might be draws. So there is more to the game, if you are willing to add the options. As BBT suggests: "Rock-paper-scissors-lizard-spock".

Monday, April 16, 2012

Counting arguments fail, think better!

Here is a puzzle (the answer is below, do not scroll unless you want to see it!):

8809=6            5555=0
7111=0            8193=3
2172=0            8096=5
6666=4            1012=1
1111=0            7777=0   
3213=0            9999=4
7662=2            7756=1
9313=1            6855=3
0000=4            9881=5
2222=0            5531=0
3333=0            2581=?

This one was posted in Lifehacker, the author took it from a flying Facebook post.
The clue provided was that the kids could get the answer faster than the educated thinkers who tend to think in more complex ways.  I can  imagine if your brain is going round the world to solve the problem.
I would urge you to try and guess the answer, which is much fun! Please still do not scroll.
I will even put a youtube video of Simon's cat just to avoid the answer to be seen.





 Please scroll down for the answer.



:)







:)

The answer is
2581=2.

The answer is arrived once you realize that there are two "o" in 8. Go back and check the other answers in the list counting the "o"s in the numbers on the left hand side of the puzzle.

However, this counting argument fails miserably when the numbers are written in another script.
Here, the same example is being provided in coded form of Devanagari numbers. Suppose the left hand side is the code, and right hand is the answer to the code):
८८०९ =6            5555=0
७१११ =0            8193=3
२१७२ =0            ८०९६ =5
६६६६ =4            १०१२ =1
११११ =0            ७७७७ =0   
३२१३ =0            ९९९९ =4
७६६२ =2            ७७५६ =1
९३१३ =1            ६८५५ =3
०००० =4            ९८८१ =5
२२२२ =0            ५५३१ =0
३३३३ =0            २५८१ =?
In this case, You can not count the "o" on the left hand side to arrive at the (same) answer!

 >
--> ---
Symbols: compute the values of the symbols.
Well,  think of the numbers as "variable" So that
०  ०  ०  ०  = 4 means: "०"+"० "+"० "+"० " = ४
 ie 4 of "० " = 4
=> "० " = 1
Similarly,
 ६६६६  = 4
 => "६ " = 1.
9999=4
=> "९ " = 1
and, २२२२ =0 gave: "२ " = 0
 ११११ =0 => "१ " = 0
 ३३३३  = 0 => "३ " = 0
५५५५  = 0 => "५ " = 0
७७७७  = 0 => "७ " = 0
Now do a test case: २१७२  = 0
LHS= "२ "+"१ "+"७ "+"२ " = 0+0+0+0 = 0 = RHS
proved!
Now, to solve, ८८०९  = 6
Suppose, " "=y
Substitute values
 y+y+1+1 = 6
 2y+2 = 6,
 => 2y = 4
 =>y=2
Therefore, y="८ "=2

 We tested it for all the examples.
Therefore, we can say:
2581 = "२ "+"५ "+"८ "+"१ " after substitution:
= 0+0+2+0 =2

The answer is 2. The method is more general


The addition is still the counting argument isn't it?
:P

(Thanks to my wife for bringing this solution to my attention.)

Friday, October 7, 2011

Physics in Alphabet

A = 6.02x10^23 -- Avagadro's constant

B = E/c -- Magnetic field equals the electric field divided by the speed of light

C = 299792458 m/s -- The speed of light

D = sqrt[(X-x)^2+(Y-y)^2)] -- The distance between points (x,y) and (X,Y)

E = mc^2 -- Mass-Energy relation

F = ma -- Force equals mass times acceleration

G = 6.67x10^-11 m^3 kg^-1 s^-2 Gravitational constant

H = 6.626x10^-34 J s -- Planck's constant

I = V/R -- Current equals voltage divided by resistance

J = Newton*meter -- Joule (unit of energy)

K = 8.9875*10^9 N*m^2/c^2 -- Boltzmann's constant

L = m(v x r) -- Angular momentum equals mass times the cross product of the velocity and radius

M = (Y-y)/(X-x) -- Slope equals the rise over the run

N = kg*m/s^2 -- A Newton (N) is a kilogram meter per second squared

O = (0,0,0) -- The origin is usually designated as an "O"

P = mv -- Momentum equals mass times velocity

Q = c*m*(delta)T -- Heat loss/gained equals the specific heat times the mass times the change in Temperature

R = v/w -- Radius equals velocity divided by angular velocity

S = E x B -- The Poynting vector

T = 2(pi)*sqrt(L/g) -- The period of a simple harmonic oscillator

U = mgh -- Potential energy equals mass times gravitational acceleration times height

V = dx/dt -- Velocity equals the change in position over time

W = F*d -- Work equals force times distance

X = [-b / sqrt(b^2 - 4ac)]/2a -- The quadratic equation

Y = F(x) -- Y is a function of X

Z = (delta)(lambda)/(lambda) -- Redshift (the change in wavelength divided by the rest wavelength)

Source: internet

---

Wednesday, September 14, 2011

I'll leave you something to imagine

Symphonyofscience has brought quite an interesting music video (made with the auto tunes).
The latest video is named "The Quantum World".
It examines the nature of the atoms and subatomic particles that make up everything we know. Watch the video, have fun!




They feature the followings:
Richard Feynman - Fun to Imagine
BBC Visions of the Future - the Quantum Revolution
Through the Wormhole with Morgan Freeman
Into the Universe with Stephen Hawking
Brian Cox TED Talk
BBC What Time is it
BBC Wonders of the Universe
BBC Horizon - What Is Reality

I loved the last punch line...

The Lyrics:

[Morgan Freeman]
So, what are we really made of?
Dig deep inside the atom
and you'll find tiny particles
Held together by invisible forces

Everything is made up
Of tiny packets of energy
Born in cosmic furnaces

[Frank Close]
The atoms that we're made of have
Negatively charged electrons
Whirling around a big bulky nucleus

[Michio Kaku]
The Quantum Theory
Offers a very different explanation
Of our world

[Brian Cox]
The universe is made of
Twelve particles of matter
Four forces of nature

That's a wonderful and significant story

[Richard Feynman]
Suppose that little things
Behaved very differently
Than anything big

Nothing's really as it seems
It's so wonderfully different
Than anything big

The world is a dynamic mess
Of jiggling things
It's hard to believe

[Kaku]
The quantum theory
Is so strange and bizarre
Even Einstein couldn't get his head around it

[Cox]
In the quantum world
The world of particles
Nothing is certain
It's a world of probabilities

(refrain)

[Feynman]
It's very hard to imagine
All the crazy things
That things really are like

Electrons act like waves
No they don't exactly
They act like particles
No they don't exactly

[Stephen Hawking]
We need a theory of everything
Which is still just beyond our grasp
We need a theory of everything, perhaps
The ultimate triumph of science

(refrain)

[Feynman]
I gotta stop somewhere
I'll leave you something to imagine

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Thursday, September 8, 2011

Happy g (9.8) day!

Sept 8th is written as (9.8.YYYY).
When I was trying to update my lab-book, I realized that today is 9.8.2011. The first two numbers represent the acceleration due to gravity (g). Since we started celebrating pi day, tau day and what not day... why not celebrate a g day!

In the context of "g", I remember one incident as told by my close friend (happened in Nepal).
He was teaching a lab and one of his strict instruction was to write down the title of the lab report in ALL CAPS!!!!
Then the next day the report came back which read...
A STUDY OF SIMPLE PENDULUM TO ESTIMATE THE VALUE OF G.

Hilarity ensues


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Thursday, May 19, 2011

Miss-pronounced Names and Excuses

http://bit.ly/j5WYh7
While doing the Teaching Assistantship (TA) duties, I always advertised my name.
"My Name is this and you can Google me!" and I wrote them with big letters on the corner of the board. Corner because it will stay till the end of the class, just in case. And I always encouraged them to call me by name... instead of "excuse me!".

I also gave them semester specific Email address such as "Email+Fall2020@gmail.com". That way I could filter the Emails according to the semesters/courses.

I always try to relate the name of the students with their faces. Sometimes I mis-pronounce the names of the students. It is a weird situation, you can read it from their face, but I would tell them immediately that "If I mis-pronounced your name once, I allow you to mis-pronounce my name three times". They seemed happy with that deal.
Moreover, Knowing each other by name is good for future networking too. They  grow up fast and become your friend.

Selling  your name, even the first few letters of your name, is better than the situations when  students looking for you asks others with  your description such as the TA with the weird cap, sandle, or may be BIG nose etc. 

Have you ever mis-pronounced names? Any interesting stories that you faced with names?

Thursday, September 4, 2008

Large Hardon Collider Rap

This is fun .
Besides being funny, it is peculiarly educative.


Try to follow the details. It is amazing.
I liked it!