Archive for the ‘General’ Category

Clicking noise from HDD??

April 22nd, 2013 No comments

Have you wondered replaced your hard drives (HDD), when there is “clicking” noise from the HDD?  When you hear that noise, it means the drive is performing a “hard-reset” internally.   I have always thought that the disk is a goner, when there is too much clicking noise from the HDD.

Lately, it was found that when the gave the HDD the 5 pin power cord, the clicking noise is gone.  In general, 4 pin power has <+12v, 0v, 0v, +5> and the 5 pin power cord has an additional 3.3v orange line.  Another discovery recently is that, the clicking noise is gone when I changed the SMPS.  When the SMPS is over loaded or so, I think it is not able to supply the current that the HDDs want, which in turn makes the HDDs to perform a hard reset internally.

So, before applying for a replacement HDD, please do try changing the power cord to a 5pin cord and when you cannot try replacing the SMPS.  Typically, when you have lot of devices in your machine, ensure you use a reasonably powerful SMPS to avoid outages.

Naan Ee

July 7th, 2012 No comments

I watched this movie tonight at Rakki.  After a long time i had a satisfaction of watching a good and interesting movie in tamil. This movie is definitely one of its kind that one could not avoid appreciating.  The casting for the Fly character is really wonderous. Thanks the animators from India and Russia. Looks like indo-russia collaboration is working out well. The villian character is very well done.  Although there are some logical glitches, this movie is a great entertainer. I loved every bit of it.

Symmetric Sigmoid

May 14th, 2011 No comments
When unknown signed intervals are expected to be normalized to -1 to +1, a symmetric sigmoid function could prove very useful.  A Symmetric Sigmoid function is a modified version of the Sigmoid function by stretching it across the Y axis.  As per wikipedia, it is defined as a symmetric function is a special case of logistic function whose plot appears like a ‘S’ with the Y-axis intercept as 0.5 and min/max as 0/1 respectively.

The function definition for a sigmoid is:

In programming languages the implementation should be in order to overcome the numerical overflow and underflow issues:

if ( t < 0 )
    exp( t ) / ( 1.0 + ::exp( t ) )
    1.0 / ( 1.0 + ::exp( -t ) )













In the plot, if the curve is stretched in Y-axis to make the Y-intercept at 0.0, the lower bound would get stretched to -1.0.
The function definition for a symmetric sigmoid is:
P symmetric (t) = 2.0 * P(t) – 1.0

The function can also be defined in terms of hyperbolic tangent as:
P symmetric (t) = tanh(t)

With sigmoid functions, it becomes possible to normalize any range in [-∞, +∞] onto [-1.0, +1.0].

யுவன் சங்கர் ராஜாவின் யுக்தி

May 4th, 2011 No comments
வித்தியாசமான ஒலிகளை எழுப்பும் கருவிகளை தத்தம் இசையமைத்த பாடல்களில் உபயோகிப்பதில் யுவன் மிகவும் கைதேர்ந்திருக்கிறார். எப்போது கேட்ட ஒலிகளை தாண்டி, தனித்த ஒலிகளை கேட்கும்போது வரும் கிறக்கமே தனிதான்.  ஹாரீஸ் ஜெயராஜ் கூட இதே யுக்தியை பயன்படுத்துகிறார்.

ஆண்டு படம் பாடல் இசை
2011 மங்காத்தா விளையாடு மங்காத்தா.. யுவன்
2011 பேசு வெண்ணிற இரவுகள், I have a dream.. யுவன்
2011 கோ அக நக ஹாரீஸ்
2010 நான் மகான் அல்ல கண்ணோரம் காதல் வந்தால்.. யுவன்

Modern wet grinder

May 1st, 2011 No comments


When I went to Kanchipuram to visit Ekambareswarar, I came across this shop where I’d stopped by to have some tea.  Though the tea tasted like neemcake soaked in hot water, I was intrigued to find that the gentleman in picture was preparing rice batter in a machine, that is typically used for dry grinding.  During my schooling days, I had been to flour mills several times to grind rice, wheat, chilly powder, etc.  There I used to observe how those grinding machines indeed work to grind the items quickly.

Not withstanding my curiousity, I went and asked the gentleman about the machine that he was using to make rice batter.  He said, such machines are available in use for quite some time, about 8 years.  But I have never seen this type of wet grinder before.  He said, these machines are quick and can produce batter that is very fine, unlike the traditional stone type wet grinders.  With him permission, I clicked this photo.

For the uneducated people, here is how the dry grinder work.  The machine’s main component is a pair of gear like perforated steel plates, where one is rotated by a heavy 3 phase motor and the other is stationary.  The plates operate very much like a clutch plate in an automobile.  The distance between the plates is controlled by a wheel.  Upon rotating it clockwise, the stationary plate gets closer to the rotating plate and vice versa.  The material to be ground, is feed through these plates where they are broken into smaller pieces.  Upon 2-3 iteration of grinding, the material can be ground to whatever finer requirement is by keeping the plates closer to each other.

Although, the above wet grinder is quick and capable of finer batter, I am wondering how it should be cleaner.  The process to be messy unlike the easy cleaning process of the stoned wet grinder.  May be, that’s the reason for the unpopularity of this wonderful machinery!

அழகன்: சங்கீத ஸ்வரங்கள்..

January 10th, 2011 No comments

“அழகன்” படத்தில் வரும் “சங்கீத ஸ்வரங்கள்” அதனுடைய திரைக்கதை, படம் எடுத்த விதம், பாடல்வரிகள், இசை, திரை அமைப்பு மற்றும் தொலைக்காட்சி, சாலைகள், வெளிச்சம் போன்ற மெல்லிய நுணுக்கங்களுக்காக மிகவும் பிரபலமானது.

ஆனால் ஒரு அடிப்படை தவறு இருப்பதை இன்றுதான் உணர்ந்தேன். பாலசந்தர் படங்களில் தர்க்கம் தெளிவாக இருக்கும். இருந்தாலும் இரவு 9 மணியில் இருந்து பகல் 7 மணிவரை battery charge போடாமல் பேசக்கூடிய wireless handset அந்த படத்தின் காலத்தில் இருந்ததாக தெரிவில்லை!

Know the Social Network that’s spun around you

December 20th, 2010 No comments
Social Networks have become a buzz in the contemporary world.  Most of us use them without understanding what they are and what they could do.  Basically, social networks are a platform the enable friends and family to be touch.  A good deal eh? Yes, it started just like that.  It started as a proxy for a pubs, playgrounds, parties where friends hang around.  Instead of going  for meeting a person, these social networks enabled friends to be in touch over instant messaging, blogging, scribbling, sharing pictures and videos by making use of the Internet technology.  This is definitely good, so far.  Do you know what else these social networks could do to you?  Let’s see some possibilities for an arbitrary ‘X’ whom you never know who that is:-
  1. Find your friends.  If you are little dumb, one can easily find your crush, hated ones, and what not.
  2. Find your likes and dislikes based on your messages, scribblings
  3. Know your places of interest based on what you have written about places, pointers on meeting spots that you chose to meet your friends, etc.
  4. Potentially know your neighborhood, by going through your blogs of scribblings about your neighbors or happenings in your vicinity.
  5. Find out what food you eat, and what you are allergic to.
  6. Find out what type of network connection you have, based on your connectivity logs.
  7. Find out paths from friends-of-friends for connecting an arbitrary person to you through your contacts.
  8. Find out which communities you belong to, and hence your social and professional networks
  9. Find out where you work, what your hobbies are.
  10. Find out where you studied, what you studied, what you aspire and where you are heading to; based on your professional community memberships, activity in forums, answers queries, etc.
  11. Find who you would meet, when and where based on your conversations
  12. Find out your mood swings, based on the vocabulary of your conversations
  13. Find out your pictures, and the pictures of the related ones in family and profession.
Remember something, whatever is meant to be private is never private in Social networks or any other electronic 3rd party services for that matter.  I have listed a very brief potential possibilities.  Please use these platform with fullest caution.

One side of the Internet researchers are working on “Internet Anonymization”, an idea to protect one’s identity; on the other hand, Internet giants are pushing “Social Networks” where they build intelligence on the so-called privacy of people.  What a weird world !?!

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Tobacco Helps!

October 25th, 2010 No comments
There is very nice use for tobacco even for the non-smokers!  Most of the LMV, MMV, HMV drivers would know about this  trick, so I am just documenting a world’s secret. 

If you had driven your car on high ways on a rainy day, despite having a nice wiper, you might have had severe problems with water staying on the wind shield glasses.  When the windshield gets wet, water stays there for long to deplete the clarity of driver’s vision on the roads.  If it is night and raining, highways and high beam lamps, you would know how bad it feels to drive.

This is where Tobacco comes for help.  When tobacco is wiped on glass, it gives glass repulsion to water.  Assume that you have wiped a bit of oil on glass and sprinkle water over glass.  You would see that the water droplets are never attached to the glass, rather they roll out faster without disturbing the surface of the glass.  Likewise, tobacco adds a thin layer of protection against water without disturbing the transparency of glass.   So, if it rained, take some tobacco and apply it over the glass, following by wiping the glass with tobacco.  You would witness water droplets running on your windshield rather than sticking on it. 

Disclaimer: Test the acceptance of tobacco on your glass in small scale before applying it in full.  Because tobacco can stain your windshield glass permanently, if inappropriately used.  Also, the application of tobacco is one-time use only.  If it rained very heavily, this trick may not work as the force water would remove the layer created by the application.

Text Mining Question Bank

July 19th, 2010 No comments

1. Natural Language Processing

  1. Give 5 examples for Holonyms, Hyponyms, Hypernyms, Metonyms, Meronyms, Homonyms, Synonyms, Polysems.
  2. Draw the Venn diagram of Spellings-Meanings-Pronunciations.
  3. Why are Context Free Grammars Context free ?
  4. What is the difference between RTN and ATN ?
  5. Give examples of Prepositional Phrases.
  6. Compare CFG and ATN.
  7. Give 5 examples for Anaphora, Cataphora, Endophora, Exophora.
  8. Give 5 examples of NP ellipsis, VP ellipsis.
  9. Write a CFG, ATN for the following:
    1. “Tech Companies queue up for Open Source Professionals”.
    2. I love my language.
    3. Patriotism is not about watching cricket matches together.
    4. AMD’s microcode is more richer than Intel.
    5. Ron Weasley should marry Hermoine Granger.
    6. Krishna is a metonym for uncertainty.
    7. PMPO is 8 times that of RMS power measured for a 1KHz signal with an amplitude of 1V.
  10. What are the Named Entities in
    1. “Open Source helps Life Spring Hospitals” ?
    2. I want to work for Burning Glass Technologies Inc.
    3. The university life at SRM is very informal.
    4. AMD Phenom 5500 Black Edition can be unleashed to 4 cores.
    5. Hail Hitler!
    6. Anushka is taller than Surya.
  11. Do NP chunking on
    1. Tips and Tools for measuring the world and beating the odds
    2. The crazy frog is an awesome song
    3. Time flies like arrow.
    4. Thevaram was written by Appar.
    5. Text mining is awfully interesting.
    6. I need to get placed is a good company.
  12. Write a Regular Expression for replacing the beginning and end of all the lines in a text file with the strings “” and “” respectively.
  13. Write a regular expression for capturing Indian mobile numbers, land line numbers and Indian pin codes with maximum possible inherent validation.
  14. Write a regular expression for capturing the vehicle numbers, PAN numbers, Passport numbers in a new paper article.
  15. Identify rules to capturing dates and discriminating the job dates, education dates and date of birth.
  16. Give examples for Noun stemming in English & {Tamil or Telugu or Hindi} languages.  Transliterate the Indian language.
  17. Give examples for Verb stemming in English & {Tamil or Telugu or Hindi} languages.  Transliterate the Indian language.
  18. How does a spell checker work ?
  19. Take some arbitrary texts and summarize them in to a line or two.  Justify the reason for the choice of words and sentences in your summary.
  20. Show some examples for word-by-word, sentence-by-sentence, context-by-context machine translation.

2. Information Extraction & Statistical NLP

  1. If Prob(A) is 0.4 and Prob(B) is 0.6, what is Prob(A,B), Prob(A|B), Prob(A u B), Prob(A – B), Prob(A n B) ?  If some data is missing, assume a reasonable value for it.
  2. Let A be a random variable with instances a1, a2, a3, a4, a5.  If P(a1) = 1.8e-4, P(a2) = 5.2e-8, P(a3) = 0.042, P(a4) = 0.00052, P(a5)=0.2, compute Sigma P(A), PI P(A) without mathematical underflow.
  3. Give real life examples for 1st order markov processes.
  4. Give real life examples of Expectation-Maximization.
  5. If p[[0.1 0.3 0.2 0.4],[0.3 0.4 0.2 0.1],[0.3 0.3 0.1 0.3], [0.2 0.4 0.1 0.3]] is the state transition probability of any 4 states {A,B,C,D} in a HMM, calculate P(A->B->C->D).
  6. Based on (5), check whether the probability of state sequence is commutative (ex: P(A->B->C) = P(C->B->A) ?)
  7. If the observation probability is [[.2 .4 .1 .3], [.6 .1 .0 .3], [.0 .0 .0 1.0], [.1 .1 .1 .7], [.4 .4 .1 .1]] for observations {i, j, k, l, m} in states as per(5). Compute the P(O={k,l}).
  8. Annotate the items in (9) of Section 1 and build the state transition, observation, initial probability matrices.
  9. Show that usage of forward probabilities reduce the time-complexity of evaluation problem.
  10. Show that usage of forward-backward probabilities reduce the time-complexity of decoding problem.

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Only Coffee

April 11th, 2010 No comments

NH45 தேசிய நெடுஞ்சாலையில் பயணிக்கும்போது மறவாமல் மதுராந்தகத்தின் சாலையோரம் இருக்கும் “Only Coffee” என்ற தேனீர்விடுதியில் காப்பி அருந்திப்பாருங்கள். இந்த விடுதி சரியாக “Highway Inn”க்கு எதிர்புறமாக இருக்கிறது. நேற்று இங்கே காப்பி குடிக்கும்போது ஏன் இந்த இடத்தை தேர்தெடுத்தார்கள் என்று சிந்தித்தேன். இப்போது புரிகிறது, சரியாக அடையாளம் காட்டதான் போல.

கும்பகோணம் டிகிரி காப்பி, அவ்வளவு அருமையாக இருக்கும் என்று இப்போதுதான் தெரிந்துக்கொண்டேன். ஒரு காப்பி ரூ10, ஆனால் சரியான விலைதான் போல, சுவையை கருத்தில் கொண்டால்.