சுதர்சன் சாந்தியப்பன்

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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Developer Camp 2010
10th July 2010, Chennai

It was my first attempt to take part in a BarCamp / unconference, which excited me very much after reading about them in Wikipedia.  Through some contacts, I was invited to attend the Developer Camp hosted by ThoughtWorks Inc, at Thiru Vi. Ka. Industrial Estate, Ekkattuthangal, Chennai on 10th July 2010.  I had originally offered to give a couple of talks on Text mining and Design patterns.  Though I had some anxiety about whether topics like Text Mining would sell amongst hard core developers, I was comforted by Balaji Damodaran (organizer) that there should be a lot of people interested in exploring AI.

    I reached ThoughtWorks office at 9:15AM and was surprised to find atleast a couple of dozen developers already come in.  Saturday morning for hard core developers start only after 11AM, but I was happy to be wrong then Registered myself as one of the developers and opted to talk about “Text Mining Applications”, “Plagiarism Detection”, “Text Classification using Naive Bayes”, “Design Patterns” for the 9:30AM slot.  The unconference started at around 9:45 with the introduction by Balaji Damodaran.  At that time, atleast 70 developers were there in the hall (cafetaria).  Then I was asked to start the talk by 10AM.  When I went to the hall, it had only 5 people as audience, which kind of killed me as I am always used to having big crowd as my audience (what an EGO I have!?).

   I had asked a couple of the audience boys to go for hunting more audience for the talk.  See I were to advertise and promote my talk, which in fact is critical for everything in the world we live.  One of the volunteers advised to use a microphone and start the talk.  When I started the talk, I was surprised to see that people walked in to fill up the hall.  The talk went on and on with a lot of interesting examples which made everyone introspect about the way we see and assess our neighbourhood.   I am sure my audience have understood now that everything that we see around and solve could be mathematically modeled and be solved using computers.  Hurray, we made it!!

    Followed by that talk, I was asked to talk about Design patterns as a lot of developers had voted for that topic.  Ok, I wanted a coffee break! Went to the cafeteria and made some light south Indian coffee.  I added some pulverized sugar to my coffee and came back to the hall, while I was talking with another developer from LatentView technologies.  To my surprise, the coffee tasted like made with sea water. Then I realized that I had added salt instead of sugar.  I would like to greet the “brahaspathi” who kept the salt bowl near the coffee vending machine.

    The talk on Design pattern started in a small room as the number of votes was ~10 (which is still a large number) in unconferences. When we started that talk, one of the volunteer said, he would want to record the talk which is a good idea. The talk started, and we found that lot of people started to come into the room and we had to move to a bigger hall as the number of audience was over 40, which is like “wow”. The talk went on for a while and we interacted about Singleton vs Multiton, Strategy, Factory vs Bridge patterns with lots of examples. Overall, it was a wonderful discussion forum where we learned a lot of insight about software design using design patterns.

    If I were to use one word to describe the audience, I would say “intriguing”.  It was an awesome experience for me to talk about some of my experiences to a wonderful audience that you had brought it.  It is very rare to find a combination of patient, smart, involved, intelligent, experienced audience who crave for knowledge.  Our talks helped us to introspect on to the technology that we have been practicing. The ambiance was very motivating in the sense, lot of natural light and spaciousness.  Overall, I enjoyed every bit of it.  I am little depressed that I could not enjoy the food as I was rushing back to office.  Also, I wanted to take part in the fish bowl about Industry-Academic Co-op, but couldn’t.  I am sure, there is a lot of people who got benefited by this program, in fact I heard that statement from a lot of the audience after the lecture/talk.

Thanks to Shiv Deepak for introducing DevCamp.
Thanks to Balaji Damodaran for inviting me to the DevCamp.
Thanks to Shaswat Nimesh for the photographs.

EFYTimes news article is here.

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If you are an exclusive BSNL broadband user, you might not have attached the telephone to the phone line.  I have connected my Netgear modem to the DSL/Phone line splitter and left the other connection floating.  Lately, when I noticed that the Netgear modem was not able to make the connection with BSNL servers, originally I thought the telephone line is dead.  To my surprise the telephone line was fine, but I perceived the lines to be little noisy.  I made a complaint to the BSNL portal and as usual nothing much happened.  Accidently, I had to connect my telephone to the splitter for making a local call.  To surprise, the Netgear modem managed to connect to the server this time.  So, the hypothesis is;

When the telephone line is noisy, attach the telephone to the splitter along with the modem connection to get connected to the BSNL Servers.  Most likely it could be because of the Reactive load offered by the telephone on the phone line ends up conditioning the Phase modulated signals for the Netgear modem to connect to the Servers.

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முயற்சி திருவினையாக்கும்;
முயற்சியுடையார் இகழ்ச்சியடையார்;
எறும்பூற கல்லும் கறையும்;

நான் கூறுவேன்; என்னோடு சேர்ந்து உரக்கக் கூறுங்கள்…

1) என்னால் முடியாதது ஏதுமில்லை
2) எல்லைகள் ஏதும் எனக்கில்லை
3) என் முயற்சிகளுக்கு யாரும் தடைபோட முடியாது
4) என்னால் எதையும் வெல்ல முடியும்
5) நான் மிகவும் திறமைசாலி
6) எனக்கு உதவ பெற்றோரும், நண்பர்களும் இருக்கிறார்கள்
7) எனக்கு தன்னம்பிக்கை நிறைய இருக்கிறது
8 ) என்னால் எதையும் சாதிக்க முடியும்
9) நான் எப்போதுமே சோர்ந்து போகமாட்டேன்
10) என் இலக்கை அடையும்வரை ஓயமாட்டேன்

என்ன சிந்திக்கிறீர்கள் ?

உறுதியாக, இப்போது உங்களை வெல்ல யாருமில்லை.. வாழ்த்துக்கள்

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I have downloaded a lot of videos uploaded by aXXo from mininova.org.  Lately, I found that all the videos that I download from aXXo, were getting a blue patch or bunch of green lines while playing in VLC player (0.8.6b).  I am not able to take a snapshot of the video to show how bad the patches are.  Interestingly, VLC’s snapshot option is giving out the snapshots that are pretty clean.  I searched in many places for a solution.. People adviced of a) remove YV12 in ffdshow b) install XVid instead of the MP4 plugins c) disable WMV acceleration d) setting de-interlacing to Discard/Mean in VLC e) reinstall nVidia driver f) reinstall VLC player and many more. I tried all of them and nothing worked out for me.

Finally, I figured out the answer from the following URL:
http://forum.videolan.org/viewtopic.php?f=14&t=41484

The answer is pretty simple.

a. Click on Setting->Preferences
b. Open Video on the Left pane
c. Click on Output Modules
d. On the right hand side, check enable on the “Advanced Options”
e. You will see a pull down menu named “Video Output Module”
f. Select DirectX 3d video output
g. Click on Save
h. Restart VLC.

There you go.. The video plays super smooth.

Still, I am not able to figure out why should I do this to make the video work. The problem is definitely not a codec problem, not a de-interlacing problem.. I am yet to discover what got changed for aXXo’s videos.

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The procedure to enable inline viewing of Word documents in Mozilla Firefox is the following:

1. Enable Mozilla plugin by checking Tools->Options->Internet->Mozilla Plugin in OpenOffice Writer.
2. Check whether you’ve got the OpenOffice-Mozilla Plugin at /usr/lib/openoffice.org2.0/program/libnpsoplugin.so
3. Create a symbollic link at /usr/lib/mozilla/plugins/ to the above
libnpsoplugin.so to enable mozilla-openoffice plugin in firefox. You
need to restart firefox after this step.
4. Edit ~/.mozilla/firefox/pluginreg.dat for the following changes:
4.1 Search for the following text

OpenOffice.org Plug-in handles all its documents:$<br/>
OpenOffice.org Plug-in:$
31

4.2 Note the italicized count.
4.3 To the end of the list add the following text

31:application/msword:Opendocument Text:doc:$
32:application/vnd.ms-excel:Opendocument Spreadsheet:xls:$
33:application/vnd.ms-powerpoint:Opendocument Presentation:ppt:$

4.4 The index of the left of the above text should be relative.
4.5 The count should be updated as count = count + 3 ( as you are adding 3 more entries )
5. Restart firefox
6. Try opening a document in firefox; It will take few extra seconds to
start but eventually it will open the document inside firefox brower
itself.

A typical openoffice section would look like the following:

/usr/lib/openoffice.org2.0/program/libnpsoplugin.so:$
:$
1160152037000:1:5:$
OpenOffice.org Plug-in handles all its documents:$
OpenOffice.org Plug-in:$
34
0:application/vnd.stardivision.calc:StarCalc 3.0 – 5.0:sdc:$
1:application/vnd.stardivision.chart:StarChart 3.0 – 5.0:sds:$
2:application/vnd.stardivision.draw:StarDraw 3.0 – 5.0:sda:$
3:application/vnd.stardivision.impress:StarImpress 3.0 – 5.0:sdd:$
4:application/vnd.stardivision.impress-packed:StarImpress-packed 3.0 – 5.0:sdp:$
5:application/vnd.stardivision.math:StarMath 3.0 – 5.0:smf:$
6:application/vnd.stardivision.writer:StarWriter Template 3.0 – 5.0:vor:$
7:application/vnd.stardivision.writer-global:StarWriter Global 3.0 – 5.0:sgl:$
8:application/vnd.staroffice.writer:StarWriter 3.0 – 5.0:sdw:$
9:application/vnd.sun.xml.calc:StarOffice 6.0/7 Spreadsheet:sxc:$
10:application/vnd.sun.xml.calc.template:StarOffice 6.0/7 Spreadsheet Template:stc:$
11:application/vnd.sun.xml.draw:StarOffice 6.0/7 Drawing:sxd:$
12:application/vnd.sun.xml.draw.template:StarOffice 6.0/7 Drawing Template:std:$
13:application/vnd.sun.xml.impress:StarOffice 6.0/7 Presentation:sxi:$
14:application/vnd.sun.xml.impress.template:StarOffice 6.0/7 Presentation Template:sti:$
15:application/vnd.sun.xml.math:StarOffice 6.0/7 Formula:sxm:$
16:application/vnd.sun.xml.writer:StarOffice 6.0/7 Text Document:sxw:$
17:application/vnd.sun.xml.writer.global:StarOffice 6.0/7 Master Document:sxg:$
18:application/vnd.sun.xml.writer.template:StarOffice 6.0/7 Text Document Template:stw:$
19:application/vnd.oasis.opendocument.text:OpenDocument Text:odt:$
20:application/vnd.oasis.opendocument.text-template:OpenDocument Text Template:ott:$
21:application/vnd.oasis.opendocument.text-master:OpenDocument Master Document:odm:$
22:application/vnd.oasis.opendocument.text-web:HTML Document Template:oth:$
23:application/vnd.oasis.opendocument.spreadsheet:OpenDocument Spreadsheet:ods:$
24:application/vnd.oasis.opendocument.spreadsheet-template:OpenDocument Spreadsheet Template:ots:$
25:application/vnd.oasis.opendocument.graphics:OpenDocument Drawing:odg:$
26:application/vnd.oasis.opendocument.graphics-template:OpenDocument Drawing Template:otg:$
27:application/vnd.oasis.opendocument.presentation:OpenDocument Presentation:odp:$
28:application/vnd.oasis.opendocument.presentation-template:OpenDocument Presentation Template:otp:$
29:application/vnd.oasis.opendocument.formula:OpenDocument Formula:odf:$
30:application/vnd.sun.xml.base:OpenDocument Database:odb:$
31:application/msword:Opendocument Text:doc:$
32:application/vnd.ms-excel:Opendocument Spreadsheet:xls:$
33:application/vnd.ms-powerpoint:Opendocument Presentation:ppt:$

When I was writing this, the following are the version numbers:

1. OpenOffice.org 2.0.4-5.3
2. Mozilla Firefox 1.5.0.10

Before the login screen appears in Fedora, you may get a popup saying
“Greeter Application appears to be crashing. Attempting to use a
different one”. You may think, this could be due to video driver fault.
In most of the cases, it is because your root directory “/” is 100%
full. When you free you space in the “/” drive, the problem goes away.

I solemnly agree that there are few passionate people in public service departments. I reside at Thirumullaivoyil which comes under the control of Avadi Township. I had recently applied for BSNL broadband connection, which took little more than a month to really materialize. The broadband department of Avadi Exchange was quick, but the Linemen and the Broadband servicemen were poor. The guy who had come for installation knew nothing about broadband connection. But he was boasting that he is the incharge of all broadband activities. Poor we!

Though, it had taken little extra time, it was really worth waiting for. The speed of BSNL broadband is awesome. While checking the download speed, the ticker showed more than 1.6Mbps. Hmm, all these excitements shattered on day 3. The telephone line went dead. I had made complaints through all possible channels viz. BSNL portal, via 198 AVR, and also
through the customer care centre of Avadi Exchange. It is more than a week now, and there is no improvement to this.

But like a ray of hope, I got hold of the BSNL JE’s office number. The JE is Mr. Jayachandran. This man is very different from another government employees. I was told that the JE would respond to customer problems ASAP. I had to try several times to get the number connected. At around 11 AM, I got lucky to get the JE on phone. To my surprise, this man is really different. He heard my problem patiently and instantly gave orders to the field people (I was able to hear him calling the Linemen by name to fix the problem immediately). It was like breeze to see a public service person in action. I thanked him several times to have responded very fast.

But, when I came back home, to my surprise the phone line is still dead. Most likely it should be the mistake of the Lineman again. Even though the service call is not completed, I am not getting frustrated. It is just because the way Mr. Jayachandran acted so responsibly.

Mr. Jayachandran, JE BSNL Avadi Exchange, may be contacted at 044-20029423. He comes to office only at 10.00AM Monday-Saturday.

Update 27.01.2009
1. JE’s number has changed to 044-26383456
2. Thirumullaivoyil::CholambeduMainRoad Line man’s number is 044-20006064