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.

Linkedin


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.

Thanks for the visit. Please feel free to visit my Weblogs.

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Tuesday, May 8, 2012

@Linkedin App for iPad: Review

TL;DR: I liked it, try!

Here is a longer version:
Well, linkedin has emerged as a useful tool in academic circle. It not only helps one to connect and keep in touch, but also get new connections.

They have recently introduced an iPad app, iPhone app was already there. My first feeling about this app is that it is absolutely good app.

Number one: the "home" layout is as if there are  three cards on a table.
"You", "All updates" and "Inbox".
This helps focus whenever we go to the app.

Number two: I find that "linkedin daily" style of updates section impressively drawn out. They could probably use little bit more contrast over the user's comment versus the web contents. Also, when I was sliding through few news pages, back and forth, it felt slightly slower.
Moreover, there is calendar inside the updates section, which I have not used yet.
To linkedin: Do you use Machine Learning to tune up the news section to people? that could be awesomely awesome! ;)

Number three: the inbox, it brings the latest message. Again, just brings the items in focus.

It is a good app, and thanks to linkedin team for a good app. Keep up the good work.

Few snapshots:




Thursday, May 3, 2012

No, you can't "friend" students in NYC

Social Media Rules Limit Student-Teacher Contact - NYTimes.com: "New York City public schoolteachers may not contact students through personal pages on Web sites like Facebook and Twitter, but can communicate via pages set up for classroom use, the city’s Education Department said on Tuesday after it released its first list of guidelines governing the use of social media by employees."

Monday, April 30, 2012

To the fans of Graphene: meet silicene...

Silicene is just one atom thick layer of silicon


  http://www.newscientist.com/article/mg21428625.400-move-over-graphene-silicene-is-the-new-star-material.html

The papers:
Physical Review Letters, DOI: 10.1103/PhysRevLett.108.155501
Appl. Phys. Lett. 97, 223109 (2010); http://dx.doi.org/10.1063/1.3524215
- --
Graphene is one-atom-thick planar sheets of carbon atoms packed in honeycomb-like structures. It has been of great research interest because of its unique physical properties. We already saw that papers with the term "graphine" was increasing drastically since 2006 [Link ].

Silicene is the silicon equivalent of graphene.
Because it can be integrated more easily into silicon chip production lines, newscientist.com speculates that its integration into electronic devices might help produce cheaper electronic devices.

Tuesday, April 17, 2012

Final touchdown for the shuttle Discovery

Discovery has made its final touchdown. This time on the back of another aircraft, Boeing 747, specially made for transporting the shuttle.
Discovery was regarded as a leader of the shuttles, making the most flights: 39 missions throughout its life. The era of shuttle came to an end  in 2011.

It will be in display at the Smithsonian Air and Space Museum.
I have taken few screenshots from the NASA broadcast. Enjoy! ...



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.)