Oracle publishes: Oracle and IBM Collaborate to Accelerate Java Innovation Through OpenJDK [Link].
This means a counter act against the great effort of Microsoft to stabilize its .NET framework. It means two giants of java will cooperate to gain better quality java, Oracle through the formerly SUN JDK, and IBM through OpenJDK. A neat competition and coordination. I am eager to see what is going on to the JSR!
October 11, 2010
Entropy for Dummies
The entropy is the expected amount of information you get in a sample of a distribution. You can think of it as "how surprised are you, on average, on seeing a sample of that distribution".
An unbiased coin toss has one bit of entropy, as any way is equally likely, but a toss from a coin where both sides are heads has entropy 0, as you're never surprised when seeing its results.
The entropy can also be seen as a constant minus the information gain of a distribution over the uniform distribution (and this divergence, as you know, is the number of bits you "save" when you use a code based on the actual distribution instead of on the uniform distribution).
it's best to get used to it by seeing how it works in theorems and algorithms, and for this I recommend Davd Mackay's book, you can get the PDF from here.
Source.
An unbiased coin toss has one bit of entropy, as any way is equally likely, but a toss from a coin where both sides are heads has entropy 0, as you're never surprised when seeing its results.
The entropy can also be seen as a constant minus the information gain of a distribution over the uniform distribution (and this divergence, as you know, is the number of bits you "save" when you use a code based on the actual distribution instead of on the uniform distribution).
it's best to get used to it by seeing how it works in theorems and algorithms, and for this I recommend Davd Mackay's book, you can get the PDF from here.
Source.
October 10, 2010
Wikipedia!
Today (it is 1:23 AM now) I started my very first contribution to wikipedia in Persian (Farsi) by the definition of polyhedron or چند وجهی as a beginning. Feels good! :)
To add your language (e.g. Persian) to the definition of a word I followed the following guide from here:
To add your language (e.g. Persian) to the definition of a word I followed the following guide from here:
To link to a Hindi-language article from a relevant article in another language's Wikipedia, go to the bottom of the other language's article and add a link like this:
[[hi:Article title here]]
(For example, the bottom of the English Wikipedia article "India" contains a link, [[hi:भारत]], to the Hindi Wikipedia article "भारत".)
You will probably see other languages there (French, German, etc) with their links. If you do, then please add the Hindi link in the appropriate spot alphabetically; this helps us keep everything sorted.
[[hi:Article title here]]
(For example, the bottom of the English Wikipedia article "India" contains a link, [[hi:भारत]], to the Hindi Wikipedia article "भारत".)
You will probably see other languages there (French, German, etc) with their links. If you do, then please add the Hindi link in the appropriate spot alphabetically; this helps us keep everything sorted.
October 8, 2010
Age of Data
Recently I have been busy implementing a C compiler as part of the Programming Languages and Compiler course at UTSA. This project is to be built on POET language.
Apart from school, I was interested in the "Journalism in the Age of Data" video post by Geoff McGhee.
Huge amounts of data available around us means something. Extracting and visualizing these data is quite challenging.
Apart from school, I was interested in the "Journalism in the Age of Data" video post by Geoff McGhee.
Huge amounts of data available around us means something. Extracting and visualizing these data is quite challenging.
October 3, 2010
Matt Ridley: When ideas have sex.
I am pleased to announce that I succeeded in contributing to the TED.com community. By translating the fantastic talk When ideas have sex by Matt Ridley, I have the honor of letting a large group of Persian speaking people (across Iran, Tajikistan, Afghanistan, ...) to benefit from this community.
You can access the translation either by choosing the Subtitles in Persian (Farsi) under the video, or through my TED.com translator page.
*****Service, is what matters.*****
You can access the translation either by choosing the Subtitles in Persian (Farsi) under the video, or through my TED.com translator page.
*****Service, is what matters.*****
September 17, 2010
Back to Reality, Back to Math
This was the plan: Linear Algebra --> Linear Programming --> Convex Programming (Semi-definite programming) --> Optimization, Error Bound Analysis Especially in Graphs!
Thanks PatrickJMT for the hard work and easy and quick math reminders. L’Hospital’s Rule was just fun!
----
PS:
After starting to read the book "Convex Optimization" by Stephen Boyd and Lieven Vandenberghe; I realized that convex optimization has lots of uses data mining, statistics, control theory, etc apart from the graph analysis topic that I am reading it for. It makes it even more exciting!
Thanks PatrickJMT for the hard work and easy and quick math reminders. L’Hospital’s Rule was just fun!
----
PS:
After starting to read the book "Convex Optimization" by Stephen Boyd and Lieven Vandenberghe; I realized that convex optimization has lots of uses data mining, statistics, control theory, etc apart from the graph analysis topic that I am reading it for. It makes it even more exciting!
September 14, 2010
Keep my eyes in the sky, but my feet on the ground
Reality is we want to be there, but where we are, we have a number of steps before we can overcome all the limitations. Gustavo Stolovitzky (IBM Research)
http://www.youtube.com/watch?v=pKi30ai35mU
http://www.youtube.com/watch?v=pKi30ai35mU
September 10, 2010
Rank Reduction
One of the interesting topics in linear algebra is matrix rank. It outlines ways that columns of a matrix correlate to each other. There are basic and free columns. and you can define free columns in terms of linear combination of basic columns. It highlighted a matter of data redundancy to me. So if you can define a column based on other columns, you won't need the content of those columns any more; just keep the coefficients that should be applied to basic columns and you are good to go! It seemed to be highly useful in matrix compression. An image which is a big matrix could be compressed like this by some matter of rank incrementation.
I succeeded in getting an algorithm to alter the rank. Unfortunately as it is not the current topic of my research, I was prohibited to work on this, deviate less and concentrate more on my research area. Anyway I found interesting relevant researches on matrix rank reduction, this is at the back of my mind for sometime to be used.
I succeeded in getting an algorithm to alter the rank. Unfortunately as it is not the current topic of my research, I was prohibited to work on this, deviate less and concentrate more on my research area. Anyway I found interesting relevant researches on matrix rank reduction, this is at the back of my mind for sometime to be used.
September 4, 2010
Rashomon
Rashomon: One of the best movies I have seen in my life. Whose story is true? Which is to trust? How can you judge?
What would you do if you were involved in the case? If you were the samurai, or the samurai's wife or even the bandit Tajōmaru, or even the farmer witeness? That is a hard situation for each of these characters. Tell me what would you do.
I keep my faith in the man.
What would you do if you were involved in the case? If you were the samurai, or the samurai's wife or even the bandit Tajōmaru, or even the farmer witeness? That is a hard situation for each of these characters. Tell me what would you do.
I keep my faith in the man.
September 1, 2010
Achilles Heel!
When Achilles was a baby, it was foretold that he would die in battle from an arrow. Naturally, his mother Thetis did not want her son to die. So she took Achilles to the River Styx which was supposed to offer powers of invincibility and dipped his body into the water. But as Thetis had held Achilles by the heel, his heel was not washed over by the water of the magical river. Achilles grew up to be a man of war who survived many great battles. But one day, an arrow shot at him was lodged in his heel, killing him instantly.
I had heard Achilles heel several times but never knew what it was about.
I had heard Achilles heel several times but never knew what it was about.
August 23, 2010
Interesting Problems
The Hershey Bar problem:
David Gries's coffee can problem:
Give an optimal algorithm to break an mxn Hershey bar into 1x1 pieces. At each step, you can choose a single rectangle of chocolate and crack it along one of its vertical or horizontal lines. A single crack counts one step. You are to make the fewest number of cracks.
David Gries's coffee can problem:
Given a can of black and white coffee beans, do the following: Pull out two beans: if both are the same color, replace them with a white bean. If the two are different, replace them with a black bean. What color is the last bean?
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