After all, there are trees on earth’s terrain. Why not on Google earth? Google just don’t delay it any further. Now we can see trees with Google earth 6. Amazing view of SFO, right here. As they say, it is here as it is there.  Now we truly have the world in front of our eyes.  The beautiful 3D world is now ready.

Lipschitz continuity is a stronger property than continuity. First, when I heard this (through Ruediger’s treatment on expectation analysis of codes), it was all haze. For the second time, I made some sense during the Applied Stochastic process course. Anyway, a final appreciation of this concept kicked my brain only when I started working on a problem. Recently, I came across this again and hence thought of penning a few easy lines on this.

Here is a beautiful explanation of this concept.

I was playing a few tricks on a few centrality measures on a few graphs. SO, thought of penning down a quick piece of notes on the notion of centrality (A quick introduction can be found here along with Wikipiedia page on centrality)

Just heard from my EPFL folks that Mathematica 8 is just released. I am yet to get a chance to see it working, but I will look forward to it someday. I am quite happy with Mathematica7 already, but Wolfram always bring radical new stuffs which is special. In fact I am mighty pleased with version 7, but who knows what all new stuffs there in 8? I have been a huge fan of Mathematica since the early 2000, ever since Nandu (Nandakishore Santhi) introduced his new tool. tI use it pretty much for every computational mathematics job. These days, I even use it for plotting, much more than Matlab. Looks like there are a lot of new features added in 8. One of the claim from Wolfram is that, they added a lot of new stuffs on aids to work with (probability) distributions, which I think is going to help me a lot. One stellar new thing I notice (from the announcement) is linguistic argument support. Boy, that is hell a lot killer application. Forget the syntax then. If you want to plot a sin(x) with grid on, type just that sentence! That’s it! Rest Mathematica will do. Wow! Wow! How much is it for an upgrade? Or should I go for a trial? I can’t wait!

Recently (almost a month back), I happened to ask a simple question to an interview candidate. The candidate apparently worked, among other things, on the design of scrambler and descrambler blocks in 3G/LTE terminal development .Naturally, I expected him to know in and out of the block and of course the scrambling idea itself. To my innocence, the answer came: “Scrambling adds protection to the information source”. That was a bit of foot in the mouth reply, which I seldom expected from such a candidate profile. Anyway, come to think of it I shouldn’t overly blame the candidate because many a time, engineers overlook the primary goal of placing a block or unit in the overall design, even when they do a glory traverse with it. I personally think this is ignorance on part of an individual engineer if he or she doesn’t spend time to figure out the reasoning behind every single unit in  design, especially the one he or she works on, if not to an expert level, the intuitive idea gathering is paramount.

Anyway, let us get some facts right with scramblers. Scramblers are there in almost all the standardized data communication systems. It is some kind of randomize acting upon the information bit stream (Well, one can also think of it operating on non-binary symbol sequence or packets, but let us consider binary for the time being, for simplicity.). The input stream upon the act of a scrambler changes the patter of the original bit stream. Naturally, at the receiver should be doing a reverse operation (descrambler) to make sense of the source information. One can argue that, a receiver not having the right descrambler (descrambler is very well based on the scrambler algorithm) cannot retrieve the intended information, adding protection/security on the data stream is NOT the reason for the existence a scrambler/descrambler unit in a communication system. The why? Let us see why.

A typical receiver will have several algorithmic stages such as synchronization, equalization, decoding etc ( These are broad classifications. One can go into finer details. For the discussion on scrambling we can suffice with this much). All these stages are usually designed with the assumption that the source stream is  i.i.d (continuous stream of identically independent ‘0’s and ‘1’s). For example, a long stint of ‘0’s or ‘1’s can degrade the timing/clock synchronizer performance or may even result in loss of synchronization.

The other important argument on the scrambler is the spectral density (spectral mask as defined in standard documents) requirements, usually imposed by the standard specification and (country specific) regulation requirements.  Any periodicity (short or long), can result in spectral spikes, which in turn may result in co-channel and adjacent channel interference due to various nonlinear blocks present in the transceiver chain.

So, scrambler’s job is to make an uniform i.i.d stream so that, the spectrum stays as close to white. Similarly, the  receivers do not misbehave because of arbitrary source distribution.

Phew! Think of this. SAP in 2005 acquired a services company named TomorrowNow for $10 million. In just about 5 years, the new owner is in line to pay $1.3 billion to Oracle. For what? For all the wrong doing of the acquired company in their teens! There had been several corporate white collar crimes in the past. One distinctly vivid case is the Avant!-Cadence battle, but the new one scales much higher. Clearly, SAP wouldn’t have anticipated the literal realization of “tomorrow now” then, but now, it is a blown up penalty that SAP will have to content with.

So, what is the case against TomorrowNow (which is well part of SAP AG now)? Oracle filed a case against SAP for an illegal stealing/usage of Oracle licensed software. Oracle claims that TomorrowNow illegally copied software code needed to support customers without buying licenses (from Oracle) to access it. TomorrowNow made thousands of duplicates of copyrighted software obtained by illegally accessing electronic materials from Oracle’s customer-support websites, the lawyers said. That is quite a mess TomorrowNow brought into SAP. Well, now no go, but to pay the 1.3billion and work harder for future!

Some stomach upset over the last couple of days prompted me to switch off from any serious activity. To make matters worse, I injured my groin too. Anyway, that in a way forced me to read up a bit of news and contemporary stuffs. Two good articles came in my way.

Amazing article by Sainath, “Narcissism of the neurotic” Must read.
http://www.thehindu.com/opinion/lead/article834612.ece?homepage=true
An eye opener on the Indian media:
http://www.thehindu.com/opinion/lead/article907823.ece?homepage=true

I had written a few words already about many of the Indian media houses. One word suffices actually, “pathetic”. Now the latest expose is a formal confirmation. Bharkha Dut, Vir Sanghvi are taken off the cover.

http://www.dnaindia.com/blogs/post.php?postid=318

Does anyone believe that the difference between the Lebesgue and Riemann integrals can have physical significance, and that whether, say, an airplane would or would not fly could depend on this difference? If such were claimed, I should not care to fly in that plane.

I recall hearing this interesting quote. If my memory is correct, I first heard it from Martin Vetterli, who either mentioned this during a talk/class or it was there in the footnote of his forthcoming book. It sounded funny that time, but I didn’t really know to whom this quote is originally attributed to. To my surprise, this has its origin dates to the story man Hamming. Well, why Hamming? Emre Telatar did tell me couple of funny stories about Hamming besides the one famous scream on the computers which eventually led to the discovery of error correcting codes! By the way, Emre is a walking encyclopedia when it comes to stories. He is a treasure in many ways!

Ok, coming back to where we started. Springer has published this nice conversation piece online for free. The title is “Mathematics and Design: Yes, But Will it Fly?”. It is not really a book, but a very interesting conversation discussing the above mentioned quote by Richard Hamming. The preface of the discussion itself couldn’t be more apt, which reads:

“Martin Davis and Matt Insall discuss a quote by Richard W. Hamming about the physical effect of Lebesgue and Riemann integrals and whether it made a difference whether one or the other was used, for example, in the design of an airplane. The gist of Hamming’s quote was that the fine points of mathematical analysis are not relevant to engineering considerations.”

A very fascinating read indeed. An even more fascinating, formal defense on Lebesgue’s right on why aeroplane fly is here. Well, the answer to aeroplane question: here is what Andrew Lewis has to say, “In the event that the reader is consulting this paper in a panic just prior to boarding an airplane, let us answer the question posed in the title of the paper. The answer is, “The question is meaningless as the distinctions between the Riemann and Lebesgue integrals do not, and should not be thought to, contribute to such worldly matters as aircraft design.” However, the salient point is that this is not a valid criticism of the Lebesgue integral.

A nice intuitive to way to explain what a Martingale is found here (Venkat’s Computational Probability course notes). Perhaps it was known already to many. To a layman, this is the best way to introduce Martingale, first up!

A sequence X_{1}^{n} =X_1,X_2,X_3,\ldots,X_n  is called a martingale if  \mathbb{E}\left[X_{k+1}|X_{k} \right]=X_{k}, for all 1< k <n. An intuitive way of thinking about martingales (and indeed the origins of martingales) is to imagine X_k as your total profit after the k th round of a gambling game. Then the martingale condition states that knowing your winnings in the first k games should not bias your winnings in the k+1th round. See the Wikipedia page for examples of martingales. The course notes is fabulous. I am following it on and off!

A superb goal from Messi in the friendly match between the South American football giants, Argentina and Brazil. Many have the same question:Can he do this magic again in Brazil in 2014?

Via Lance’s blog, I came across this hilarious prize known as Ig Nobel prize. The term “Ig” stands for “Ignoble”! The prize is apparently given to something which may appear to be funny, but has some serious reasoning behind. In other words, these are peculiar awards given to something  which”‘first make people laugh, and then make them think”. Quite amazing huh?

I am yet to explore a lot on this. Lance listed one very interesting one. I find it extremely noteworthy! Robert Faid of Greenville, South Carolina, farsighted and faithful seer of statistics, got the Ig Nobel prize for calculating the exact odds (710,609,175,188,282,000 to 1) that Mikhail Gorbachev is the Antichrist.I wonder how he arrived at this magical number! Didn’t Faid know how to play a game in the stock market then?

Wikipedia has an interesting entry on this topic. Would you believe, the young Russian physicist Andre Konstantinovich Geim who just won this years Physics Nobel for his work on graphene had also won the Ig Nobel in 2000! Quite amazing.

Just heard about the 2010 Hay festival was held last week in Thiruvananthapuram. Although I couldn’t have gone there, it felt nice to have had such a great global art and literary event in my own home state in India. The official website hosted some amazing scenes from various parts of Kerala, which to an ardent Kerala fan like me wished to see  all times. The Hay festival of arts and literature has become quite prominent in the public media, recently and what better place to have it, than the beautiful and literary rich Kerala!

Thanks to Youtube, I could gather glimpses from the event. Part of Vikram Seth‘s Storypooja is captured here. The one session, I would have liked to attend is Marcus du Sautoy on “The Number Mysteries: A Mathematical Odyssey Through Everyday Life“. I hope to see a video tape of this program online sometime soon! After all, Marcus claimed to have had a reason for everything, including why bend it like Beckam! Another of my favourite is ONV Kuruppu. His candid and lively talk is an anytime favorite of mine. He was supposed to have had a conversation with poet Sachidanandan. And, how much I missed Bob Geldof‘s conversation, let alone his concert!

D-day in another sport, that has a speed of its on. Sebastian Vettel is on pole, but all eyes are on Fernando Alonso, who will start third in Abu Dhabi. Can Mark Webber pull off a miracle from No. 5?

Thankfully, Michel Schumaker escaped unhurt from that freaking crash. Seeing it live, it appeared to be like a crazy head on. The last race of the season, the crash of this kind would have been a  massive sobermaker, but thankfully no major damages. The Imola crash is still looming large in memory and with Ayrton Senna’s nephew still racing, it just came back instantly, upon seeing the crash scene.

I remember this quote from George Orwell “if you want a vision of the future, imagine a boot stamping on a human face, forever”.

It is beyond comprehension to see that, we can do nothing on this. Think of this. Aung San Suki is detailed for 15 years of the last 20 years.

ABC mini clip

Sion Rain’s fabulous and touching song dedicated to Aung San Suki.

Through Mahdi’s Facebook feed, I bumped across this beautiful composition La Plage by the emerging (already emerged, I must say. Well critics may say, Mozart was already among pantheon of greats by 30!) French musician Yann Tiersen. The linked photo is even more stunning. Apparently this is a photo shot byPaul Patrick (titled “Girl in Gallery, Paris”).  Amazing shot! Just brought back memories. How beautiful it is to see kids in a free world!

Thought provoking start for a day!

I don’t Twitter a lot, in spite of having an account which I visit once in a while and tweet at an even low rate. To me, Tweets are too short and too soon; The 143 characters is something too low a number to post an opinion without multiple breaks. Thats just my take and clearly it is different from the large segment of the rest of the world population.

Anyway, I am still wondering what made the Twitter founders to decided on restricting the length to 143 characters. Yesterday, during a dinner party I hear some of them commenting on this. I didnt get the rationale fully, but it was apparently chosen based on some SMS research, using curtailed English words.

I did a few Google search, but nothing quite came with the explanation. The Wikipedia interestingly has a page for 143. Would you believe? As it turns out, 143 indeed has some very interesting properties.

143 is the sum of three consecutive primes (43 + 47 + 53), as well as the sum of seven consecutive primes (11 + 13 + 17 + 19 + 23 + 29 + 31). But this number is never the sum of an integer and its base 10 digits, making it a self number.

Every positive integer is the sum of at most 143 seventh powers (see Waring’s problem).

143 is the difference in the first exception to the pattern shown below:

32 + 42 = 52
33 + 43 + 53 = 63
34 + 44 + 54 + 64 = 74 − 143

The Jnanapith award for the year 2007 was announced in 2010. What a coly cow is this? What on earth is going to be the explanation for this 4 years of delay? Anyway, the 2007 Jnanapith award (for 2007 – Jnanpith Award Announced on 24th September 2010) quite deserving went to one of the great poets of India. This year’s Jnanapith award went to ONV. I am sure, the first reaction many of us had was “it came late. But better to be later than never”.

Growing up in Kerala, ONV was very much a house hold name. Who can forget his poem “Bhoomikkoru Charamageetham” (A Requiem to Mother Earth), which we were exposed during high school Malayalam language class. The poem was written 30 years or earlier and it is in Malayalam. I am not sure whether there is an English translation out there somewhere, but the poet’s pain is in much similar pain as echoed by the girl who presented a thought provoking talk at UN summit in 2008.

One of my friend pointed me to some of the recent Malayalam documentaries, which included one on Bhoomikkoru Charamageetham. Unfortunately I never got to see them. Hopefully, one of these days, I will get access to them. If any of you have access please don’t forget to share.

Recently, this came up during the lunch discussion with my colleagues at Broadcom.  I remember reading up an article somewhere, quoting the impact of birds migration due to cellular phone towers.

Researchers from Research Institute for Nature and Forest, Brussels, Belgium have investigated into this subject and published an article (more reports here). According to the authors (Joris Everaert and Dirk Bauwens),the house sparrows do not prefer to stay near the GSM base stations because the radiation in the 900 MHz range is adversely affecting them. The paper investigated the male house sparrow population. The statistics quoted in this paper clearly shows that, there is some kind of an impact the cellular tower radiation is causing onto the city birds.Perhaps a more scientific study on this is needed to assess the details, but this itself is a reason to worry.

Another interesting blog comes from India, which also suggests that the Belgian research finding is correlated to what is observed elsewhere.  But then, I am wondering how come there were thousands of sparrows flooded across almost every street at Schaffhausen. We had been on a family holiday there, last year. It was the place where I have seen the highest amount of sparrows, all waiting to get fed and pampered! May be they have adapted to the technology, huh?

Was following the latest test match between India Australia test being held at Bangalore. Today is the 5th day and it is heading for an exciting finish. I was glued to  cricinfo for online updates. Cricinfo ball by ball commentary is always interesting with occasional wits and funny side remarks. With lot of online readers and followers, there is no shortage of hilarious comments. Here is an interesting passage on the final innings when India was chasing 201 on a crumbling, and alarmingly reverse swinging pitch at Bangalore. Tendulkar is batting!

Just to give a prelude, if we turn back the clock to 1999, when India was touring Australia. Remember that infamous LBW decision against Tendulkar? The Umpire Harper and bowler Mcgrath? Here is the video snap for your take on the controversy.

Now, 11 years later, the same two counties are playing each other. The batsman is the very same Tendulkar, but everything else is different, including the playing country (Bangalore and not Adelaide), the  umpire is not Harper either. Anyway, here is cricnfo running commentary:

21.1 Watson to Pujara, no run, 129.3 kph, played off the front foot towards mid-off
“When you play for 21 years, nothing is new to you and everything that can happen has happened before. Even the ‘hit-on-shoulder-LBW’,” says Insachwetrust. Imagine the fun if Harper was here to give this one too.
End of over 20 (5 runs) India 104/2 

SR Tendulkar 8* (15b 2×4) SR Watson 4-0-10-1
CA Pujara 43* (54b 4×4) PR George 4-0-21-0
19.6 Watson to Tendulkar, no run, 131.0 kph, he lets another one pass down leg side
19.5 Watson to Tendulkar, no run, 129.6 kph, left alone down the leg side
19.4 Watson to Tendulkar, no run, 136.2 kph, shades of Adelaide! Tendulkar ducks into a short ball and gets hit on the shoulder by one that does not rise at all. Watson appeals, just like McGrath did in Adelaide, but Bowden says not out, unlike Harper did in 1999. Replays suggest the ball grazing the bails.
19.3 Watson to Tendulkar, no run, 130.2 kph, he wasn’t in control of this one, reaching for the ball outside off and thick-edging towards gully
19.2 Watson to Tendulkar, FOUR, 129.1 kph, perfect. Tendulkar moves forward to a full and straight ball and meets it with a straight bat, driving the ball with care past the stumps at the bowler’s end
19.1 Watson to Pujara, 1 run, 127.0 kph, Pujara stays on the back foot to Hussey at gully, Hussey lobs the ball towards Paine who wasn’t expecting it, the Indians steal an overthrow
No slips in place, just a gully.

I remember reading this Spectrum magazine at a friend’s house in Zurich, last month. I am not going to reveal his identity any further ( I fear a backslash:-)), but he has a nice habbit of keeping pretty good collection of magazines in the bathroom. The collection includes National Geographic, The Economist, Scientific American and Le Monde. I am not one of those guys who relish reading at length in those hot seats, but for once, I did scan through the hanging Spectrum magazine.

Anyway, the one I wanted to mention is the Spectrum article on “the Internet speed”. The fastest internet speed is enjoyed by South Korea and not the United States. The average speed itself is 11.7 Mbps. When you desperate for the best browsing, now you know where to head to! The list of countries which top the list is a bit of surprise. In Europe for instance, the fastest pal is Romania, the eastern beautiful land which is not really known as the internet bull dog. Switzerland is 10th, which is not really surprising, because I never found the speed less there. The Euro cup live HD streaming was so peaceful that I never had realized the need of TV.

Ah, back to the country statistics! Don’t worry too much if you feel doomed at the prospect of applying for a Korean visa. There are places in US  which are as good; in fact better! If you go by the fastest internet cities/towns, then Berkeley is the place. Average speed of internet at Berkeley is 18.7 Mbps, which is better than the Korea’s national average:-).

All these are published by Akamai technologies. An interesting thing, reported by them is on the trend in the average speed. It turns out that, the average speed has come down, in the recent years. Korea itself slowed down there.  The Korean downloads were 29 percent slower in 2009 than 2008 and they were further 24 percent slower in the fourth quarter than in the third quarter of 2009.

After Neruda (one of the greatest poet of all time, in my book), the first name come to me from Peru is Vargas Llosa. South American writers are always special, for their sheer brilliance in writing. Gabríel Garcia Márquez, Llosa’s contemporary from the Spanish speaking continent,  is more known (who is one of my all time favourite), but the latter is no less in literary genius. So, a well deserved Nobel laureate. New York Times has published a nice report on this year’s literature Nobel.

Via Lance’s blog/Twitter, I came to know that Wolfram alpha can now input TeX. This is very useful. In fact, I believe this is a great addition to the search tool. For someone who is familiar with TeX syntax, it is pretty easy to manipulate with functions, plots and datasets.

This came up again for the nth time, as I hear at various discussions and debates at various places including the internet. But as always there is learning (at least for me) for the taking. Here is a nice and cute summary on the Bayesian philosophy, drafted Radford Neal . Ah, the latest revisit to this Bayesian versus Non Bayesian came up when I was chatting with a Finance friend. I cannot divulge the details of the conversation here, but I thought of writing a bit about the Bayesian inference, which to me is always the formal and correct statistical method (I must admit that, I am somewhat novice to have a strong counter argument, which is tame, but frankly I need to learn more!)

I can never have enough of Aart De Geus, my former CEO who still very much remain as my role model. Every time, I hear something from him, it is inspirational and mind blowing. No wonder  Daniel Nenni is damn impressed by Aart’s presentation at the EDA CEO’s meet last month (A detailed account is here in Nenni’s blog). Well, the point Aart stress is the need of collaboration and more so at these times, where the social networking has spurred by the internet shaping. It happens everywhere these days, more so in research. Many years ago, it was a norm to have single author publications, but things have changed off late. Now we have authors collobarate across boundaries and continents, sometime even without seeing them personally. I think this is a good trend. Everybody benefits. Aart ofcourse was stressing that semiconductor industry need no less. Gone are the days, when discussing problems were considered unethical. In a free world, one needs to be fearless in asking questions. After all,  talking is good!

As always, Aart has that super skill to put things in an eye catching manner. Daniel phrased it more aptly in his blog, as follows: “Aart also introduced the word systemic (yes I had to look it up) and a mathematical equation correction: Semiconductor design enabled results are not a SUM but a PRODUCT. As in, if anywhere in the semiconductor design and manufacturing equation there is a zero, the results will be a bad wafer, die, chip, or electronic device, which supports GFI’s vision for a new type of collaboration between partners and customers.” Beautifully put and phrased.

If you have ever listened to Aart’s talks, it is a no brainier to guess the kind of super presentation slides he makes. Here is the one from this talk (Again, please read Daniel’s blog for elaborate discussion on this). The analogy is the task of finding a vegetarian restaurant without the service of a vegan mother in-law. The point is that, at the moment it is still long and expensive a route. We need smarter ways to speedup (and cheaper of course).  I leave you to Daniel’s blog for further read. It indeed is a fabulous read.

Wireless transmission at rate in the order of 1000Mbps! It was once considered to be  like the holygrail in wireless transmission. Well, now we have the Wireless HD and WiGig, which can scale these mountains.  The new WiGig standard is coping with the possibility of multiple of 1000Mbps. We can transmit up to 7Gbps, albeit short range (in the form of 10 meters or so), all without any wires using WiGig over the 60GHz spectrum available, largely unused across the world. Come to think of it, 7Gbps is hell a lot of data for a tick duration of time. Just about 10 years ago, we would have easily brushed away the need for something like these, because we never really could fathom an application which needs these sack of data. But things changed since then. Now, we have the blue ray players and uncompressed HD video eminent for a wireless transfer to the high-definition displays.

Couple of months ago, the WiGig alliance and WiFi announced a co operative agreement to share the technical specification and compliance testing for the 60GHz and WiFi. So, from a standard point of view things are moving pretty fast. Afterall we seem to have learned from the atrocious delay in the many earlier standard evolution, most notoriously the IEEE 802.11n. A product compliant to WiGig/IEEE 802.11ad is still far away, but there is serious motivation to get the standard spec evolve.

There are two parallel drives on the 60GHz spectrum. In terms of productization, the non standard, some flavour of proprietary solutions are  kind of available in the market.  The Sibeam’s WirelessHD™ and Amimon’s  propritery WHDI solutions on 5GHz spectrum are  available now. On 60GHz only one product (as far as I know) is available and that is compliant to WirelessHD™.

By the way, the WirelessHD™ also published the 1.1 version of their consortium spec. The IEEE spec and WirelessHD™ are now showing no sighs of consensus, which is  abad sign. Hopefully, at some stage these two merge and get one standard spec. My concern is that, in the event dual standard, there is potential interference between the  two standard compliant products. The one chipset WirelessHD™ compliant which is available (not sure whether it is selling) is damn too expensive. So, we need tremendous price scaling down to make these things viable from a business point of view.

The WiGig product is unlikely to hit the market in the next 2 years, but it will come sooner than later. The three main applications of WiGig are  (1) Short range streaming of uncompressed video for HDMI to HDMI devices (2) Desktop storage (which is much like the wireless USB once talked about highly during the UWB days).The much talked about USB3.0 will become an important requirement for this to happen. Intel will have to abide this transition on all processors, which I am sure will happen at some stage  (3) Docking stations: Wireless transfer between monitor and docking station.

Pricing is going to be the single most bottleneck for WiGig to get into the mass market. Under $10 chipset is a bare minimum requirement to have any kind of penetration into the consumer electronic market. Learning from the way, things moved in the past, pricing problem can be scaled in a few years.

In my opinion, the killer need for 60GHz to succeed will be to get serious power savings. The antenna size will be significantly small (because of the higher carrier frequency) and perhaps that may perhaps be a silicon based integrated antenna. To get into portable devices, we may have a solution which stress less on battery. Can we look that ahead now, say 5 years from now?

The new spec has some very interesting features. While it consume 1.6GHz of bandwidth, with multiple antennas it calls for some sophisticated signal processing techniques to scale the 1GHz mountain. The radio design is extremely challenging. Above all, we need backward compatibility with the WiFi. I hope by then we can get away with those annoying IEEE 802.11b out of the box!

So, the days ahead are exciting. It is natural to pose this question: how much more on wireless? As Marconi’ said. “It is dangerous to put limit on wireless”. So true!

It is pity that, I didn’t bother to learn or understand this topic from EPFL. Many a times I had casually walked across and through the rooms where a good flair of this work got done, but never made it to the details. Now, on a completely different context, I came across the paper by Ozger, Leveque and Tse on the capacity scaling. It is fascinating indeed. A gist of this was there for me to grab during one of the IPG seminars, but then it was all misty and cloudy. Over this weekend, I am going to read the paper in a little more detail.

Come to think of it, it may be possible one day, that we can have a realistic relay channel setup. May be future short and medium range wireless LANs. I am going to make a modest attempt and pen down a bit on a possible model in a few days time. I think it has potential.

One of the term which often resonates inside a semiconductor company is “split lots”. Even though I vaguely knew what it referred to, the haziness around was deeper than the meat of the term. Borrowing Mark Twain, ” So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover”. If not fully,  I should know what I am completely dumb about. In the end it is a fairly simple terminology. Here is what I understood. Most of what I gathered are a result of an information gathering attempt, after repeated bugging on many of my VLSI colleagues coupled with my dump fight with Mr. Google.

Firstly, the hero term, “corner lot”. Corner lot is a term referring to the semiconductor fabrication process corners. Basically, the fabrication parameters are deliberately (and carefully) changed to create extreme corners of a circuit etched in semiconductor wafer. These corner chips are expected to run slower or faster than the nominal (average behaviour of) chip produced in large volume. These corner lot chips also function at lower or higher temperature and voltages than a nominal chip. In short they differ from the typical parts, in terms of performance.

Why do this? Well, the simple answer is: To study the robustness of semiconductor chips mass manufactured out of a complicated fabrication process. When millions of chips are produced at the assembly, statistics come into play (think of the law of large numbers and central limit theorems). In order to ensure that, the manufactured chips function within a certain confidence interval  (within certain variance from the typical parts), it is a practice to fabricate corner lots.

When the volume of samples is large, the manufactured VLSI chips are likely to have performance variation, which admit a Gaussian statistical distribution. The mean of the distribution is the nominal performance of the chips. The three sigma or six sigma performance from the nominal one is that entails upon the corner lot chips. The process parameters are carefully adjusted to the three sigma (or six sigma depending on the need) from the nominal doping concentration in transistors on a silicon wafer. This way, one can deliberately mimick the corner chips which comes out in the volume production. In the manufacturing routine, the variation in performance may occur for many reasons, due to minor changes in temperature or humidity present in the clean room. The variation can also happen with variation in the die position relative to the center of the wafer.

In essence, the corner lots are groups of wafers whose process parameters are carefully adjusted according to chosen extremes. How are these corners produced? In other words, what exactly is changed to carefully achieve these extreme wafers? The exact details are not presented here. From this forum, I infer that the main parameters are 1) the doping concentration. 2) The process variation. 3) The resistance of the actives 4) the properties and thickness of oxides 5) The effective width, length of the stray capacitances etc.

What do we do with these corner lot chips? These extreme corners are characterized at various conditions such as temperature, voltages etc. Once the characterization across these corners is proved to be within accepted limits, then the mass manufactured volume of semiconductor chips falls within the required confidence interval. If all the corner lot chips meet he performance, it is safe to assume that, the huge volume of chips mass manufactured also will fall within the performance limits. That way, humongous saving of time and effort from testing of each chips is achieved.

What are the different process corner types? There is no end to the terminologies here. The nomenclature of the corners are based on two letters (we limit attention to CMOS semiconductors alone). The first letter attributed to the NMOS corner and the second letter for the PMOS. Three types exist in each, namely typical (T), fast (F) and slow (S).Here, slow and fast refers to the speed (mobility) of electrons and holes. In all {3 \choose 2 } (i.e., 6) corners and they are FF,FS,FT,SS,ST,TT. Among these, FF,SS and  TT are even corners since both PMOS and NMOS are affected equally. The corners FS and SF are skewed. The even corners are expected to function less adversely compared to the skewed corners, for valid reasons.

By the way, the obvious impact of the “corner” feature is the difference in device switching speed, which is related to the mobility of electrons and holes. The mobility of electron is related to the doping concentration (among others). A rough empirical (as shown) model shows the following relationship. The mobility \mu depends also on the impurity and doping concentration \rho. The parameters vary, depending on the type of impurity. The three common impurity elements are arsenic, phosphorus, boron (See this link for further details)

\mu=\mu_{0}+\frac{\mu_{1}-\mu_{0}}{1+\left(\frac{\rho}{\rho_{0}}\right)^{\alpha}}

where, \mu_{0} and \mu_{1} are the minimum and maximum limits of the mobility. \alpha is a fitting parameter.

In the figure (below), the mobility of electrons due to different impurities and doping concentration are shown. The three commonly used dopants are arsenic, boron and phosphorus.


It is an irony that, the dopant which is deliberately added  to increase conductivity of semiconductor itself slows down the mobility of electrons and holes due to collision (of electrons or holes) with the dopants.

A touch of note on the term mobility too. Broadly speaking, the device switching speed is directly related to the mobility of charged particles (electrons and holes). So, higher mobility somewhat implies that better and faster switching logic etc. When an electric field E is applied to a semiconductor, the electrostatic force will drive the carriers to a constant average velocity v, when the carriers scatter though the impurities and lattice vibrations. The ratio of the velocity to the applied electric field is called the mobility \mu. That is., \mu=v/E. Initially, the velocity increases with increase in electric field and finally reach a saturation velocity at high electric field. When the carriers flow at the surface of semiconductor, additional scattering may occur and that will pull down the mobility.

The kind of interactions which happens at atomic and sub atomic levels within and outside a transistor are way too complex to comprehend (in a blog for sure!). Besides, the millions (and these days billions) of these transistors all must work in tandem to make the system function as desired; And that too, with not a single one failing! To make business, certain economic sense should prevail as well. It goes without saying that, time is extremely critical to get the product into action. The split lot is one heck of a way not to stretch that time window.

(Photo courtesy)

I didn’t see this book before. While trying to dig a little deeper into the sigma delta modulation theory, I bumped across this book by Robert Gray. The book, first published in 1990 hasn’t really become a mainstream reference on source coding, but the book is awesome. I didn’t read the whole book, but the chapter on uniform quantization noise is simply a treat for someone who loves the theory. Among other things, it discusses the Benetts’s conditions for the exactness of the uniform quantization error. I am now going through the noise analysis of the delta modulation and sigma delta modulation schemes.

Initially, I just managed to read a near full chapter content at books.google.com, but later I was convinced myself to get the book at Amazon. After losing the 7.5 USD used book offer, I finally had to content myself from ordering the next cheapest option of 40USD. I am expecting this to arrive in a few days. A brand new book would cost 130 bucks anyway!

I am at Dublin attending the IEEE Information Theory Workshop ITW 2010. The city is small, but beautiful. I will write a bit about my Dublin experience later. Apart from the Whiskey (which I don’t drink anyway, but I am going to go for the whiskey tasting tour organized as part of the ITW program, on thursday evening) there is rich literary legacy. The Bernard Shaw and James Joycee belongs to this famous city. And oh dear, Yeats, my favourite poet in the adolescent years. My wife (then my fiancee) still says that she was truly impressed when I’d recited those Yeats poems, many years ago!  But then, I was so fond of poetry back then. Now, with (lack of) time and tide, things just got locked in nostalgia, alone. I am definitely going to spend sometime in the Dublin literary museum, this weekend, before flying to Geneva.

My talk, (on the joint work with Emmanuel) is on Tuesday afternoon. Need to work a bit on the slides too! Feeling a touch tired, after the sleep being deprived for the last two days! I will also try to pen down a bit on some of the interesting talks I am going to attend.

The Human Resource Department of India, aka HRD ministry made a mockery of itself by doing a foot in mouth call on the nationality of the world chess champion Viswanathan Anand. The Indian citizen who lives in Madrid for logistic reasons is denied a honorory doctorate for insane mess created by the HRD ministry. The reason: He is not Indian! Anand’s wife Aruna, understandably upset by the wrong call from the HRD, duly sent a fax of the Indian passport that Anand holds, but the HRD ministry was still not convinced. What  a piece of joke!  This is not the way to salute a world champion and our own citizen. All this happened in the eve of the ongoing International Congress of Mathematicians held in Hyderabad. Only a blog post earlier I wrote about the thrill of India getting a chance to hold ICM. Now, the hopeless HRD ministry found a way to make a mess of it. What  a shame! They also managed to rebuke the famous Algebraic geometry guru David Mumford. Neither Anand nor professor Mumford needs these extra certificates to proclaim what they are. They are already stellar figures in their respective fields of expertise. The manner in which they are toyed is what annoys people like me and it is simply unacceptable. These are not the signs of a country claiming to become the next super power. Neither this is the way we as children were learned and taught to respect the elders and guests.  Athithi devo bhava, but not to be!

As an Indian, I take a lot of pride to learn that the International congress of Mathematicians 2010 is being held in India. It is currently ongoing at Hyderabad, India between 19th to 27th August. Even though I am many a mile away from there now and in spite of  myself not really directly or indirectly participating, it brings immense joy to see India getting a chance to show a piece of International math progress  in modern times too. The Fields medalists , Nevanlinna prize as well as the Gauss medals and Chern medals are announced during the congress.  It is great to hear that Dan Spielman getting the Nevanlinna honor. As a coding theory enthusiast, it is doubly exciting to hear that for the second time, someone  from the same field (after Madhu Sudan received one in 2001) get to hold the coveted prize.

The award winners are:

Fields medal: Elon Lindenstrauss, Ngo Bao Chau, Stanislav Smirnov and Cedric Villani. One Israeli, a Vietnamese, a Russian who lives in Switzerland and a Frenchman. Here is a nice interview transcript where Robert Siegel talks to Julie Rehmeyer, discussing the award winners. A pretty nice brief bio introduction to the fabulous medalists.

Congratulations to all winners. The Fields Medal announcement is here. Nevalinna, Gauss and Chern medals announcement is here.

The P versus NP has popped up again in to the mainstream. The HP scientist Vinay Deolaikar has recently prepared a manuscript which claims, it is after all P ≠ NP. Greg’s blog seems to be the one which first broadcasted this to general public. I have not had much time to digest the proof claims or counter arguments in detail. Here is a fascinating series of arguments discussing the proof claims. I am going to do some digesting on this in days to come! We will wait for the experts to have their say. I am going to relish this discussion.

On a lighter note, here is a very interesting blog piece, bringing some sort of similarity to the giant component behaviour on a pile of staple pins. This is sort of a layman view of the Erdos Renyi explanation.

In one version of the Erdős-Rényi process, one start with a set of n isolated vertices and then keep adding random edges one at a time;  More specifically, at each stage one choose two vertices at random from among all pairs that are not already connected, then draw an edge between them. It turns out there’s a dramatic change in the nature of the graph when the number of edges reaches n/2 . Below this threshold, the graph consists of many small, isolated components; above n/2, the fragments coalesce into one giant component that includes almost all the vertices. “The Birth of the Giant Component” was later described in greater detail in an even bigger paper–it filled an entire issue of Random Structures and Algorithms (1993, 4:233–358)–by Svante Janson, Donald E. Knuth, Tomasz Luczak and Boris Pittel.

Ofcourse Joel Spencer has written a beautiful article on AMS commemurating the golden anniversity of the giant component.

I am very thrilled to learn that Ruediger Urbanke has won the 2011 (Koji) Kobayashi award. He and Tom Richardson are named the 2010 receipients of the famous Kobayashi award. Rudi and Tom are awarded Kobayashi prize “for developing the theory and practice of transmitting data reliably at rates approaching channel capacity.” They truly deserve this. Looking at the list of earlier Kobayashi award winners, it really is a place of pantheon of greats. Gottfried Ungerboeck, Don Coppersmith, Rivest, Shamir, Addleman, Jack Wolf, Berlekamp and so on are among the famous awardees of the past.

When pointed this to Rudi, he  was as usual every modest about these. I am sure I will get to have a coffee treat from him, in Lausanne! Place Palud or Ouchy?

The Iceland volcano Eyjafjallajokull (or rather more correctly Eyjafjallajökull) has produced a spectacular view stemmed from the surface of those beautiful white mountains and then went on to stage the show on the air, all alone. The amazing thing is that, the volcano this time made sure that everyone in the world pay attention to it. It didnt allow anybody to spoil the show. Air traffic itself was ceased for over a  week. The question of to fly or not to fly immediately popped up and it was on the not side. Believe it or not, I was never scared of a volcano. Quite frankly I didn’t buy the argument that it was something worth worrying about. But this time, I paid a lot of attention to it. Again, not really had worried about it, but was overwhelmed to learn about the kind of impact a natural event such as this can make even when not really causing any serious casualties directly.

Indeed this Vishy Anand has given me way too Anand (happiness) today. I was looking forward to this news. Was following the game online too. Playing with black, in what was dubbed as  final game is never easy. All results were possible today. Such was the build up which we witnessed in this fabulous championship this year. Several things were pinned against Anand, starting from the 40 hour road trip to reach Sofia just a day before the final. To make matters worse, then Anand suffered a fist game loss. Playing against a fantastic task master in his own courtyard. But then Vishy Anand is known to beat obstacles with courage, stength and determination. Topalov is a tough task master and has a great tactical mind when the chess board is in front. The old USSR blood is in him all around. Vishy could oustclass him too. Well done Anand. You made my day. You are the champion and hero. yet again! As New york times aptly reported, the chess world now has a new king; It is the same old king from Chennai, India .

Here is an interesting recap of the Newcomb and Benford findings on the distribution of the first digit in data records.

A century ago, Simon Newcomb observed an unexpected pattern in the first digits of logarithm tables: The digit 1 is significantly more likely to occur than 2, 2 than 3, and so on. More than a half-century later, Frank Benford rediscovered the first-digit phenomenon and found that it applied to many tables of numerical data, including the stock market, census statistics and accounting figures. New mathematical insights establish the empirical law developed by Newcomb and Benford as part of modern probability theory, and recent applications include testing of mathematical models, design of computers and detection of fraud in accounting.

Here is another interesting finding on temperature data and the final digits.  A proof and formal review of the original work is available, presented by Hall.

Here is an intuitive description of the Benford’s law.

It is beyond comprehension to accept the shocking plane crash which killed the cream of the Polish government, including the president Lech Kacenski. What make it even more startling is the decision to have as many as about 20 of the top administrative layer to pack inside a single aircraft.  Ironically, Kacsynski and the team were enroute to attend the 70th anniversary of the infamous  massacre of the polish army at the hands of the former soviet secret police.  Apprently the pilot was adamant to do a landing at Smolensk in Western Russia, in spite of the warning from the ground traffic control about the increased for prevailed.  If the ground control clearly discouraged a landing in the thick fog, why on earth did the pilot dared to do that insane act. Flying a country’s premier political and defense personnel, it is only a curious case of being silly. What a loss to Poland.

Barcelona, rather Lionel Messi is having a roll there on the green floor.  FC Barcelona floored Real madrid yesterday by a thumping 2-0 win against the Spanish rival in the champions league at El Clasico.  Here is the video highlights clip. It was poised to be a final before the final. After the match, not surprisingly, the Real madrid coach Manuel Pellegrini remarked “ I feel frustrated and impotent” . With foruth straight wins, Barca has the momentum enroute to the title lifting.

Considering the form Lionel Messi has been, we can hope for more from Barca. Can Argentina too pin hope on Messi at the forthcoming world cup title ? Let us hope so!

Alex Bellos listed what he call as the ten best mathematicians (of all time). His list, published in The Guardian, is based on his assessment that the individual contributions of the listed ten mathematicians changed the world, rather revolutionized the mathematics in some sense.

Alex, firstly listed 10 great minds whose contribution to mathematics is simply awesome.  However, the list to me is far from complete and it is grossly incorrect to call the selected 10 are the best.  Perhaps we should have named it “10 amazing mathematicians”.  I am sure Alex didn’t do an exhaustive research on the mathematicians who lived on this planet. If we are to limit the number 10, then there are many other mathematicians whose contribution will any day stand taller than some of these. Newton, Shannon, Kologomorov, Fourier, Galois, Shannon, Abel, Euclid and even Ramanujan are some of the names which comes to my mind at once.  Many French mathematicians are given a miss as well. Some may argue that, these are not pure mathematicians, but they all had produced more than one mathematical theory which for sure changed the world; sometimes beyond mathematical world. Newton for his Calculus can never be omitted from the top ten.  Shannon’s mathematical theory is kind of the underpinning of literary everything in communication including the internet .  Fourier’s once ignored (and painfully debated) work on heat, which eventually  spurred harmonic analysis and the young Galois’s spike all takes merit.

Among the list, Euler, Copernicus, and Gauss will pick themselves any day.  I reckon Cantor will also find a wider consensus to be within top ten. Perelman and Tao are clearly two of the modern greats, but to say that they are among the top ten of the over 3000 year old formal mathematical history comes with a touch of boredom.  Erdos is one of the popular mathematician in the 20th century, who has been an immense contributor to many different areas of mathematics. Moreover, he has been a maverick among the modern mathematicians because of the travel crazy, migrating style life. He is one of my favourite mathematician as well. Whether he ranks himself in the all time top ten is not clear to me.

Nevertheless, Alex has spawn an article which will spur some curiosity to the general reader on the history of mathematics. Mathematicians from 500BC, Copernicus to this date (Perelman and Terrence Tao) are there in the list.

The Italian fame Cardano is apparently one of the original mathematician who paved the probability theory. To my ignorance I have not heard much about him.  I am curious about that part of the history now.  I had heard of the Hypatia legacy in mathematics, and had since forgotten about that Greek tragedy. Reading the new list, it reminded me of the atrocities of a state indulged in certain dogma or religious view do to any new scientific claim. This is clearly not the only instance of such a thing happened.  Galelio also had difficulty convincing the orthodox society of his time. And there are many. Why then, even now, the religious fanaticism in many states mock the Charles Darwin’s theory of evolution. The religious monks and the administration there to, all over the world still latch to the belief that it is some hand of god who created the universe and then every single creatures and plants. Ludicrous to say the least! But then, religious beliefs are often personal and one can be blind sometime.

An interesting and twisted version of the twenty question game came across recently. I saw it in the 2009 ISIT paper on the error correction under Feedback with list decoding, by Ofer Shayevitz.  The problem goes like this (I am going by the nice narration of Ofer with the famous Alice and Bob duo).

The game is being played by Alice and Bob. Alice selects one of M possible objects, and Bob can ask n  binary questions (where the answer can be either  yes or no only), in a quest to identify the object selected. If Alice is always truthful, then n=\lceil \log M \rceil questions are obviously both necessary and sufficient. Now, suppose Alice is allowed to lie up to t times. How many questions n(M, t) does Bob need to get the correct object? Alternatively, given n questions, what is the maximal number of objects M(n, t) that Bob can separate? This version of the “twenty questions game” with lies is known as Ulam’s game.

Whee! The highest number of runs scored in an over is not 36. Not even double that figure. It is only a mere 77 runs. Wow! How silly a bowler that could have been? It is all true apparently. One over in the history of first class cricket has recorded a whopping 77 runs. Check this out for a detailed run through story.

This is the scoring pattern (Much like a UK telephone number including the ISD code!): 0444664614106666600401. Even more striking thing is that, some dot balls figured out in between. Those were the times when batsmen got bored by hitting anything not too cosy for them!

It was only an exhibition match, but for a great cause to alleviate a little bit of the pain of an awestruck nation due  to the earthquake. The damages and the loss of people can never be compensated. It is beyond what we can comprehend and fathom. Hopefully the money collected out of the exhibition help to rebuild the hopes of the unfortunate Haiti people.

The game itself was set with an awesome theatrical presence. Arguably the best two of the men ever played tennis positioned one side. Sampras and Federer need no introduction of any kind, do they. They announced their aura straighaway by a series of volleys and top serves. Afterall, they just have 30 grandslams between them, Just? Who patrolled the other side of the net? Agassi-Nadal combo. Boy, can you ask for more, if you are a tennis fan?

I really enjoyed watching these games. Agassi was at his imperial best, cracking jokes. Equally good were the Sampras-Fedex pair who at best are stoic when it comes to mood display in public. But even these  usually laconic persona gave away to some fun talking throughout the match through the microphone. In all, it was different, but filled with fun. And what is more, it was all done for a good cause.

Stumbled upon this site http://www.bordalierinstitute.com/target1.html

A cool presentation I liked there is about the evolution of the universe tagged against the timeline since the big bang. It goes to show how fast things moved in the beginning; yet how slowly it took to get into this fabulous shape (whatever is known as of today) that we live in. No doubt this is a continual process of marvel.

Yesterday I attended a very nice talk during the Broadcom internal seminar series. It was a nice talk discussing the semiconductor fabrication. For me, it was truly whale swallowing kind of a talk, since a lot of new things learned.  The term “tapeout” is there in the common vocabulary in semiconductor industry and we all use it with such ease that no one really bothered to search the origin of the term itself. I had done it once by doing a wikipedia, but then as usual had forgotten all about it. Anyway, here is the legend behind tapeout. Mike Magee said it all very cleanly, but let me sort of state it again.

Well, tapeout refers to that fancy thing the designers deliver to the (semiconductor fabrication) fab companies in Taiwan (well, I can say so because most of the fab companies are in Taiwan). The fancy algorithm we conceptualized in plain equations, went through the LaTex pages and then C programs finally took shape into RTL and gates and transistors. That then further went through the backend processes to eventually a set of masks. These mask description is what is given to the semiconductor manufacturing companies. These days, it is just a  matter of file transfer using ftp or so. Then you can rightfully ask:why there is a term called tape out? Well there is history to it, fair enough I will say!

Also check as well as this for some more details.

It is official now. The clay memorial millenium prize is to be awarded to Grigory Perelman for proving the great Poincarre conjecture. It is a different matter whether he decides to accept this. The man who dared to ditch the Fields medal may have an opinion of his own on matters pertaining to award and its credentials. Lesser mortals like us get amuzed by his decision, but then he is special and different.

Some interesting tips on binary random matrices again. Kolchin’s book also discusses some aspects of this (see Page 126 for example). It is interesting to see the asymptotic behaviour.

The probability that a random matrix {k \times (k+m)} binary matrix with each element chosen uniformly ({0} and {1} picked equally likely), is of full rank { k} for {m \ge 0} is

\displaystyle\rho =\prod_{i=m+1}^{\infty}{\left(1-\frac{1}{2^{i}}\right)}, \quad m=0,1,2,\ldots\ \ \ \ \ (1)

The probability that a random matrix k \times (k+m) binary matrix with each element chosen uniformly ({0} and 1 picked equally likely), is of full rank k+m  for m < 0 is

\displaystyle\rho =\prod_{i=1}^{k+m}{\left(1-\frac{1}{2^{k-i+1}}\right)}, \quad m=-1,-2,\ldots\ \ \ \ \ (2)

Glanced upon a paper from the 2009 ISIT, titled “LT Codes Decoding: Design and Analysis” by Feng Lu et al. The authors discusses LT decoding strategy which is Peeling decoder (conventional simple LT decoding) followed by an extension based on the well known Widemann algorithm solving a sparse homogeneous linear system. Here is a brief summary as I understood.

On packet erasure channels (internet being one close realization of a model of this kind, where, the TCP/IP suit, one can either gets packets correctly delivered or lost in the wild), Luby Transform (LT) codes forms an easy way to transfer information.  It is well known that, asymptotically (When the number of information symbols  (or packets)  k and the number of packets received $r$ are large) near full recovery is made possible by simple peeling decoder which grows in complextity at \mathcal{O}(k) . The claim is that, for n >10000  or so, with r= k(1+\delta) , on average  we can, with high probability, recover all of  k information packets  by simple unwrapping of xor-ed packets. A more precise statement will read as: If from k information packets, each coded packet constructed independently by xor operation (the number of packets taken for xor operation follows a distribution; Plain vanila version of LT codes uses Soliton distribution), then the content of the original information source can be recovered from any k+\mathcal{O} \left(\sqrt{k} \ln^{2} \left(\frac{k}{\epsilon}\right)\right) packets with probability 1-\epsilon by an average of \mathcal{O} \left(k \ln \frac{k}{\epsilon}\right) symbol operations. However, when the number of input symbols is not large (say less, n < 1000 ) the overhead term \delta is not small. It is not too surprising, since we need sufficiently large n and r to converge the performance in expectation.  One can think of solving the system of linear equations using Gaussian elimination and get the best figures, but the question mark stays on the complexity \mathcal{O}(k^{3}) of this method over the cheaper peeling decoder complexity \mathcal{O}(k) .

Conventional LT decoding based on Peeling decoding rule terminate, once the number of degree -1 packets (ripple as it is called in graph theory parlance) are void. One can hope to continue from there, by using Gaussian elimination and decode a a few more (if the graph matrix rank permits it). If the original graph is full rank, one can technically decode all of them.  Gauissian eliminatio being heavy, one hope to find an easy, preferably recursive method. Indeed there comes Wiedemann and that is what the authors use.  The authors propose what they call as full rank  decoding, which essentially is LT decoding, until there are no more degree one packets. From there, they borrow a packet and then uses Wiedemann algorithm which is somewhat light on computational complexity.

The larger aspect on whether this scheme do any better than conventional LT peeling decoder is the other question they answer. To achieve full recovery we need to have a full rank matrix. Now, the matrix being a sparse matrix defined over \mathbb{F}_{2}^{k \times r} where r is the number of received packets. The probability of the matrix having a full rank will directly help us to infer the decoding merits. This is an interesting piece since I had looked into the computation of the rank of a binary matrix and also the probability of a random matrix rank being equal to an arbitrary value. All this was done during the Modern Coding Theory doctoral course by Ruediger Urbanke at EPFL.  For binary random matrix, we can also setup a recursive formula and thereby a good inference on the probability of decoding can be arrived at.

Even though, the season-3 of the hilarious TV episode is being broadcasted for sometime. I  didn’t have had a chance to view  any of them on TV yet, but the other day, I checked youtube for some snippets. May be because of the two seasons of serials, I didn’t see anything impressive in the new ones. Not bad by any means, but it all started sounding a bit too repetitive now.  I have been an ardent fan of the first two season episodes. Nothing made me laugh broader than watching some of those hilarious picks of Dr. Sheldon and gang.

“One man, two hundred!” was the caption, BBC world news displayed, while broadcasting the (breaking out) news of the world record hit by India’s super star player Sachin Tendulkar.  It was against a formidable South African bowling attack in a one day international cricket match at Gwalior, the little master decided to showcase his fabulous reportoire of pure shot making on a cricket pitch. He has done it so many times in the past, but yesterday was a day when history book needed a fresh page. The first man to score 200 runs in a single innings of a 50 over match is stamped with the name Sachin Ramesh Tendulkar. What a feat from a great crciketer and amazing human being!

Times has published a truly nice article commemorating this new record. Cricket is not wideley popular in all parts of the globe. The United States is not among the cricket frenzy nation either. England and her former colonies are the main countries where the game took the center stage over many years. As for records, cricket is the second most popular game in the planet, after soccer. The article hence put the new feat in perspective for the non-cricketing community. Come to think of this record, we must realize that 200 runs need to be scrored from a maximum of 300 deliveries (excepting illegal deliveries such as no balls). On the average one batsman can hope to get about 150 deliveries. In baseball analogy, this is equivalent to getting 150 pitches. It seldom happens that one get more than this. That means, one will have to consistently hit the balls at a rate exceeding 100% strike rate. Tendulkar achieved the score in 147 balls, at a strike rate of 136.5%. It calls for multiple virtues including patience, stamina, focus and talent. All have to be combined and score runs at a faster rate.  It is not easy, by any means. It was something fabulous if not more. There have been scores close to 200 in the past by great cricketers including that from Tendulkar’s previous outings, but this one will go down as the best, literally because this came against a top quality bowling attack and a formidable fielding unit of the protease.

Here is the list of the top ODI scores.

SR Tendulkar 200* 147 25 3 136.05 India v South Africa Gwalior 24 Feb 2010 ODI # 2962
CK Coventry 194* 156 16 7 124.35 Zimbabwe v Bangladesh Bulawayo 16 Aug 2009 ODI # 2873
Saeed Anwar 194 146 22 5 132.87 Pakistan v India Chennai 21 May 1997 ODI # 1209
IVA Richards 189* 170 21 5 111.17 West Indies v England Manchester 31 May 1984 ODI # 264
ST Jayasuriya 189 161 21 4 117.39 Sri Lanka v India Sharjah 29 Oct 2000 ODI # 1652
G Kirsten 188* 159 13 4 118.23 South Africa v U.A.E. Rawalpindi 16 Feb 1996 ODI # 1049
SR Tendulkar 186* 150 20 3 124.00 India v New Zealand Hyderabad (Deccan) 8 Nov 1999 ODI # 1523
MS Dhoni 183* 145 15 10 126.20 India v Sri Lanka Jaipur 31 Oct 2005 ODI # 2290
SC Ganguly 183 158 17 7 115.82 India v Sri Lanka Taunton 26 May 1999 ODI # 1463
ML Hayden 181* 166 11 10 109.03 Australia v New Zealand Hamilton 20 Feb 2007 ODI # 2527
IVA Richards 181 125 16 7 144.80 West Indies v Sri Lanka Karachi 13 Oct 1987 ODI # 457

Among them, Richards 189 against the then England may be the one comes closest in terms of quality of opposition bowling. Syed Anwar’s 194 against India is also a glorious innings played by the elegant left hander against India at Chennai. But neither Engalnd nor India will claim to have a strong fielding mastery when compared to the South African unit. So Tendulkar’s new innings clearly own special merit.

It is difficult to comprehend the stardom associated with a five foot tall man. To know this all, one need to be in India. Tendulkar earns the respect of close to a billion souls in India alone. Expectations are at levels beyond one can associate to any moving object. No parallels, really. Every time he goes to bat,  millions glue to the television sets (and now internet).  Social hierarchy still exist at large in Indian lsociety. Religion and politics still separates people. People fight for reasons less than logical, but in the name of religion and castes. It sometimes goes beyond what civilized society can comprehend. The difference between rich and poor is startling. But nothing of that

Numerically there is only a digital swap between 2001 and 2010. Similarities are more instead. Plenty of things were in common between the test match between India-Australia in 2001 and the one between India-South Africa which concluded yesterday. First, they both were great matches. Sheer classics in cricketing parlance, especially test cricket! Nothing can quite scale up to that  2001 epic event, which ended the great Australian juggernaut of consecutive test victories  (and that too at a phenomenal level of domination) but 2010 indeed lived up to the Eden garden’s charm and reputation. With high level of tension and hanging fortunes, Eden gardens was much  like a  grand theater set up for the climax . The balance was between a win for India and survival for South Africa. In the end, quite fittingly India managed to win and gave the home fans something remarkable to cheer about for years.

The final stage had two actors at their imperial best. Harbhajan singh and Hashim Amla. Amla was the epitome of concentration, all personified in human form. Things surrounding him was chaotic and noisy. None of the furies around him however bothered one cool mind of his. Googly, leg breaks, off spin all were dealt with the impeccable calmness. Yet, Harbhajan was the hero emerged in the grand finale. His reaction when Morkel was adjusted LBW has literally pumped the Eden gardens.  That heralded the match, curtains were down on the cricket field, but the celebrations had only began.  Test  match cricket came alive yet again. What treat!

If Harbhajan was the pivotal figure in the finishing stages, one cannot forget Zaheer Khan‘s contribution in the first innings. That one session post tea in day one triggered a possible result in India’s favour.   The stage was well set for the Indian batsmen to drive home the advantage. Boy, did the famous Indian batsmen cash in? The master and student combo were at their best show on day two. The way Tendulkar handled the day and his attacking student Sewhag was amazing. Their innings paved the way for the man who own part of the Eden pitch to come and do a stroll. VVS Lakshman in the company of Dhoni did the routine. When India declared their innings on day three, it was ample clear that India is well within a big win.

The nature had her own ideas to add to the drama. Bad light and rain shared the stage time on day four. But action on the curtailed day favoured India with three top order wickets, including that of the important number of Jacques Kallis. Day five was yet again bright and sunny. Amla stood the ground like a rock, even when things around him followed a different formula. Indian bowlers tried their best, but nothing seriously worked against Amla. The leg before shout by Harbhajan when Amla was in the 70s had serious merit, but that was the lone chance the cool mind offered to the 11 folks. Otherwise he was knocking everything came in his way to still.

In the final stages Tendulkar came to bowl a couple of overs or so. Considering that, it was he who took three pivotal wickets in the 2001 stage, it was a great ploy by the captain. The dangerous opener Hayden, the ever so dangerous Gilchrist and the flashy Shane Warne all were tapped by the magic of Tendulkar in the 2001 classic. But things changed a lot since. Lot of water has flown away under the bridge over nine years. Tendulkar hardly bowl these days,even at nets. Yet, the very second ball almost curtailed the match. One pitched a few inches outside the offstump took a near 90 degree turn and missed the Morkel stumps by a whisker. It was a fabulous delivery.  Not as great as the famous one to Moin Khan, but it still had some magic.  He had done this many a times in the past. So, I hastened to believe that, he was going to have a different script for the final moment. But how can Harbhajan leave his favourite ground without a five wicket haul? It was only fair to have him take that final wicket and seal the match.  As they say, so be it.

For South Africa, there will be disappointment,but no one needs to remind them where they lost the plot. The first day evening proved too costly for them. They were outstanding at Nagpur, but Calcutta favoured India. In all, it was a fabulous test series. It was hastily arranged.If only the cricketing authorities gave it a thought to have a longer test series (by ignoring the flashy one day series)! Not to be! Anyway why complain, when we had two great matches. Long live test cricket!

It is somewhat ironic that, the day to celebrate love is not named after Cupid, the Roman god of love. His mother goddess Venus and father Mercury are not considered either.  The Greek mythical folks cannot be happy either. Eros, the Greek god of love or his mother Aphrodite, the goddess of love are not the ones remembered by the lovers of this century. In the Hindu mythology, encomium is poured over to Kama (or Kamadeva), but who listens when it comes to naming the modern love day? All the accolades instead went to a saint who to his innocence did not really had any fun himself when it came to love, but he was generous enough to facilitate the young lovers.

One of the legend of St. Valentine’s day go like this. Valentine was a priest who served Rome during the third century. Emperor Claudius II decided to bring in a law to outlaw marriages. His claim was that, single men, without wives and families make better soldiers. The priest Valentine, apparently was not quite ready to bulge to this idea of Claudius. In those days, of course you don’t challenge a ruler in public. How powerful democracy is. We are lucky, don’t we?

Anyway, defying Claudius, Valentine continued to secretly perform marriages for young lovers. When Valentine’s actions were discovered, the king ordered that he be executed. The martyr Valentine became one of the most popular saints in centuries to come in Europe, especially in France and England.

Valentine day of the modern world has surely made St. Valentine proud for his worthy sacrifice. After all, it was all for a good cause. Love is beautiful. It is up-to the people to decide, what way they want to celebrate. There is nothing as beautiful than seeing people in love.  The very sign of love is pleasing to the eyes. Let love relish.

Happy Valentine’s day.

Hearing the news about the massive earthquake, I thought how unfortunate, the people of that island nation is.  The latest natural calamity accounted to the death of easily over a quarter million helpless people, not to forget the many maillions injured and displaced.  Already the people were dragged into a state of helplessness, by the shabby governance, lack of administrative will to prevent crime and corruption besides the general economic and social crisis, which has been prevailing for years in the island nation. The frequent calamities visiting the nation, is literally draining all hopes for a decent humane life there. Natural calamities of this scale can shatter any country, even the most developed ones. But, looking at the images and reading reports of the Haiti catastrophe, I feel for the people. Even when there is  increasing support from the world community to extend aid to the ailing nation, there are significant hurdles before the affected people get to bite a bread.  It seems that, even a relief camp positioned 2 km away from the airport is not accessible, because of the poor infrastructure.

The infrastructure and development in general was poor even before the calamity. The nation is one of the poorest nation in the world, let alone in the American continent. The governance is often criticised for sheer negligence. What is agonizing is that, the country has rich resources, both natural and people. Yet, the reality paints a sorry picture. It is agonizing. Is this all human?

While trying to analyze the effect of PA bias on the linearity aspects of power amplifier, I came across an analytical model of a BJT amplifier. It is known as the Gummel Poon model.  A quick Wikipedia check on the history suggests that, the model is about 40 years old. I need to figure out the model in detail. I am not sure how good they are as a model equivalent for a cmos. In any case I reckon this may be useful to analyze things such as RF power amplifier nonlinearity?

Great to find and read an article/report in EEtimes about a company founded by many of my ex colleagues and friends. Saankhya labs seem to be in good shape to make that big impact in the fabless startup  arena. So far, the success of Indian startups have been mainly in the service sector and a few in the IP/networking boxes.  Saankhya is targetting a niche market, thrived by the software defined programmable radios, targetting for the digital TV market.  It is beyond doubt that, a universal demodulator is of tremendous potential in the consumer TV market, yet largely untapped.  With so many different standards running around the world for digital tv transmission itself, it is of heavy interest to have one decoder which does work for all locations. Saankhya also have analog decoder (for the US ATSC schemes) which will be handy during the period of  transition  when  the service providers swtich from analog to digital. Best wishes to Saankhya.

I’ve stumbled upon to this nice article (titled Principles of Effective Research) (I saw it through Mahdi’s  blog) by Michael Nielson (yes, the same Nielson who is known for his work on Quantum computation: the author of the popular (technical) book Quantum computation and quantum information). Even though, the title states “effective research”, I thought the underlying methods are applicable to any work, not merely research work. If you trust my word, then many of the points jotted down by Nielson applies well to life and work in general. It appears that he is writing a book on “The future of science“. I am looking forward to that too!

Wireless gigabit alliance (WiGig) has a new(updated) website. For a first up, there is a link How WiGig Works which nicely explain what  WiGig is all about, in a clear layman’s terms. If you ever wondered whether we saw the finale of the wireless rate surge, just re-think. We are still a lot far from drafting even a proposal, but there is surely plenty of light seen in the wireless horizon. As an example, HDTV would require about 3Gbps rate. WiGig is addressing applications such as this which demand rates beyond 3 giga bits per second. The brief tutorial is a compelling read.

Martin Gardner‘s 95-th Birth day today. I dont think any other soul can claim to own the legacy of aspiring enthusiasm, among children and adults alike, on the subject of mathematics, in the most interesting and playful mode; Recreational mathematics transcended to newer heights thanks to Gardner’s amazing production of puzzles and games. A philosopher by education and a Navy man by profession, Gardner’s transition post World War II is something worth a story telling! I was (still remain so) a huge fan of Gardner ever since romping on to his old articles in the Scientific American volumes, which I greedily grabbed from NIT Calicut library. There was a time (in the pre internet and digital era) when I used to maintain a notebook of Martin Gardner puzzles, where I had handwritten the riddles and games. It is incredible to know that he is still active and steaming. Thank you Martin Gardner for spurring enthusiasm to many a generations. His “Colossal book of mathematics” is one of the worthy possessions in my library!

Many many happy returns of the day Martin. NY times has a nice page published on his birthday!

As someone who has seen a good part of the great Australian dominance in world cricket, I found it a little anti-climatic when England drubbed Aussies in the fifth test at Oval to regain the Ashes trophy. England bowling has been good and occasionally brilliant, but I would rather put my weights on the lack of batsmanship from Australia for this defeat. Australia has been a touch unlucky in the first test as well, but will be a mean thing to hold as an excuse for not not giving credits to the English victory. For Australia, the absence of Langer, Hayden and Gilchrist made a mountainous difference. Ponting is not the old score machine anymore. Hussey is not the reincarnation of Bradman as he used to be in the initial few tests in terms of scoring, Clark has been brilliant, but his failure in few crucial innings didn’t help. And, England got the luxury of facing an Aussie attack without Warne and Mcgrath. If only Shane Warne had played this series (even at this age, post retirement) the Ashes owner would have been different. Looking at the way, the Oval pitch turned, I hasten to think that Warne would have ran over the 11 chaps in the England team. It is not realistic, I agree, but such is the nostalgia associated with the domianant Australia in the 1990s with Warne,Mcgrath,Waughs, Hayden, Ponting,Gilchirst, Langer etc.

To be fair, England under the low profile Andy Flower simply capitalized the Aussie weakness in bowling and to some extend on their batting. The over hyped Peterson didn’t make any significant contribution and considering that, it is an incredible achievement to the team coached by Flower. The English press must be over the moon with encomium showered on the cricketers and system around it.

The other big event came down with the Ashes 2009 curtain was the retirement of Andrew Flintoff from test cricket. A fascinating cricketer, an enthralling breed at times will be missed in tests. His gesture as a gentleman when his team is in the loosing side has been something worth recalling. I would like to think that he under achieved, but his commitment as a cricketer (in the playing arena) is largely unquestionable. He is not the best all rounder, as many calls, especially in the English press, but in my book he was a fine cricketing all rounder that England had over the last 10 years or so.

A pretty cool handwritten tex symbol identifier software is unleased and it is known as Detexify. I thought this is such a handy piece of online suit for the TeX community. One can try to write  symbol and it simply display a list of nearest matching symbols.  There is no absolute guarantee that it display the intended latex symbol immediately, but it does the job pretty well on most occasions.

Usain Bolt got it bettered. The man who had a difficult preparation after a minor car accident in Jamaica a few months ago, now came up with another thriller. He is unstoppable now. A mere 9.58 seconds to cross 100 meters! Phew! Tyson Gay did his best to better his own best, but Bolt had pinned other ideas for Berlin. Amazing Bolt. Taking a bow Mr fastest! The cricket lover and a fan of Tendulkar, this lighning champion is a darling. I love his typical West Indian style celebration! I am sure Tendulkar will be cherishing his fast paced fan having a dream run!

After a long gap (over six months or so),  I finally played some tennis again. Much to my surprise, I wasn’t all that rusty in spite of the long layoff from any major sporting (barring some recent treks and once in a while cricket) activities during this period. After a few hits, my serves started holding and I slowly felt the rhythm. I started enjoying this beautiful game once again! In the Swiss heat, it was almost unbearable at times to absorb the hot air from the synthetic surface. On Friday and Saturday’s I played for two hours each until late evening. Yesterday, after the game we took dip in the Lake Geneva near the UNIL sports center arena at St.Sulpice. I never felt a better swim than this before. Such was the feeling of taking a clean water swimming after a good game of sports. It was getting darker and a swim between 2100 to 2200 on the fading summer light in the foothills of the Alps was simply amazing. I just cant compare a place to this amazing Lake Geneva region. Quite a place this is. After the swimming I seemed to have regained all vigour to play a few more games. Had there been floodlights, we were on for a few more perhaps! They say winning is an elixir for eternal youthfulness, but did I feel that swimming in lake Geneva comes close to that?

While, standing in the lake  with chest level water and overlooking the Alps mountains,  it reminded me of the photos of saints in olden days taking a morning yama’s in the Ganges overlooking the Himalayas. I’ve never been to Ganges, but for once I could perhaps feel a sense of their state of mind. I felt like singing one of those Yesudas classical songs, standing with half immersed body. I don’t quite remember whether I did one. I was in a state of fulfilment sort to say!

Lake geneva

Have you ever imagined, a helicopter lifting a big catamaran? I for sure didn’t harness such hopes.  Hence, it came as a jerk when I received some Emails from EPFL colleagues showing photos of the Alinghi-5 being lifted from Lake Geneva to the Mediterranean cost Genoa (Italy). The photographs are stunning and it undermines the power of these modern warfare choppers. The helicopter used is apparently a Russian Super Puma breed.

I just finished listening/watching a very nice conversation between Harry Kreisler and Kenzaburo Oe.  I remember how much I had enjoyed his very touching style of story telling and how soon I had become a fan of Oe after reading his remarkable book  “A personal matter”. Oe’s “A personal matter”  depicted an amazing journey of a father through the cultutal walls, creativity, honesty and responsibility. Since then, I have almost forgotten about him (and my reading has come down drastically, after I started working in industry). I  think he is one of the finest writers of this century, perhaps not known outside Japan as much as he should be. I really enjoyed this conversation. It is quite touching, the way, he and his wife learned to react to his brain damaged child converse with them, for the firstime when their son was five years old or something. Incredibly human!

It has been raining since evening here in Lausanne.  It was about 19.50 when I came back home for dinner. The light was getting dimmer and the sign of rain was there very much looming. Almost when I romped home, the rain started. My windows shutter seems to love this rain drops falling tirelessly onto them. They make a pretty nice chitter chatter sound which I just cant stop cherishing. Tired to do anything else today, but the rain is still there and the aluminium shutter still make that rhythmic reaction to the rain drops. It is only a moderate rain, but the sound of the water droplets when it embrace the tree leaves and this window is a lovely one. I have been an avid rain fan since childhood. The tiled house of my parents in Kerala in monsoon come close to this. I am ecstatic and now just want to wait longer to enjoy this beauty. Sleep can wait for a while, cant it? Let me stop everything now and just embrace this rain music. How beautiful this Suisse rain?

After a long thought and a near decision call against it,  I eventually succumbed to the temptation of going to the best firework show in Europe. The finale of Fêtes de Genève 2009 was today! We took the 20.45 train from Lausanne and reached just in time for the festive event. It was a bit of struggle initially to find a place, when folks were moving and parading across the streets in all possible directions. We walked and walked and finally stopped when the fireworks started.  A good way to decide when to stop moving, huh!

The musical fireworks show was awesome.  That is an understatement.  It was a not to miss event.  A touch overcrowded Geneva was, but that was to be expected off an event of this magnitude.  I didn’t take any photos.  It wouldn’t have come nicer anyway with my outdated camera. Not to be disappointed nevertheless.  Here is a link (Note: This is not my photo. The copyrights stays with the owner of the link and its sources).  I hope to post some more, depending on the photo availability from friends who may have taken a few snaps.

fetedegeneve

The fire show was coupled with traditional music (and hence it was more of a musical fireworks) and rhythmic tunes. It simply drew admiration from everyone present there, which in number was anything more than a 10000. Even though it was not that Sth clear, it appeared to me that, music from all over the world were played.  A Hindi (India rather) one from the movie Lagaan too was played (I guess it was  this).  In a way, this presented the crowd a journey around the world of music, a little lip service, but nevertheless highly enjoyable experience. The stupendous thing is the setting of the Lake in a moonlit night, with remarkable display of colourful magic in the air.

As they say, the fireworks outshine the stars, the sky bursts with colour and the lake reflects it all. It was well and truly that. Every year a different theme is chosen for the show. The theme gives meaning and rhythm and grandour to the event. This year, a pyrotechnic vision of one thousand and one nights (Arabian nights as we know in English) was chosen and it simply rocked the Geneva crowd for about 1 hour from 2200 hrs on a rather pleasant day (The afternoon rain infact cleared things a bit). From East to West, through the Tropics, three acts presented amazing visual displays cast by music from the local area and elsewhere selected by the pyrotechnics’s themselves.

The show opened with traditional Arabian music, apparently chosen because the guest of honour presented was the Sultanate of Oman. It was marvellous to say the least. It sounded a little like Punabi to me, but then as you would guess, there are many similarities of music from the east (and partly because of my lack of knowledge in vividly distinguishing musical style). The first scene reflected the thousand and one eastern nights, from Arabia to Asia. The initial act evoked the shimmering splendour of the East with a superb golden rain. Yes, it was a fabulous scene where it appeared as though there was a drizzle of gold in the air. So charming it was.  A superb oriental music tuned to its rhythm made it even more stunning.

The second scene reflected tropics, apparently conceived by some famous Argentine from in Buenos Aires (They mentioned the name during commentary, but I failed to pick the name). With south American (Latin American to be exact) music in the background, it was indeed a magical display of colours depicting the thousand and one tropical nights.

The third and final reflected Western nights. It was a mix of slow and fast notes of western music. I was wondering why such a mix, but I was told later that, it was deliberately chosen to depict the surprise effect. Some people liked it, but it sounded a bit too noisy for me at times. Some french (European!) and north American music were played. The firework was big and loud this time, needless to say it was great, barring the excessive sound. The sound however shook the crowd and made them heavenly alert and cheerful. It was a fabulous scene, to the eyes, but not so soothing to my ears (I would have preferred more to see and lesser burden on ears; But largely people wouldnt have complained!).

The famous fountain of Geneva (Jet d’Eau) was  switched off during the fire show. In the end it appeared to be on, but the smoke around didnt make it so visible from the bridge where I was standing. I had to catch up a train to Lausanne and hence didn’t spend too much time in Geneva after that.
In the end, my last minute decision to take a train to Geneva paid off. It was worth it. I was initially pondering on whether this is better than the firworks in New York during the July 4 independence day. Or for that matter, a Trichur Pooram fireworks in India. Those have their charm, but Fêtes de Genève has a charm of her own. It is definitely a beautiful event.

The one hour pyrotechnic in the air resulted in quite a bit of smithereens of paper and powder floating in the air. A fair share of it came to my body as well. A hot shampoo shower at midnight cleaned up a bit of it. The Geneva river looked more like a polluted river in the end, but the civic authorities will hopefully clean it tomorrow. The river is so beautiful to be dirtied! What is to be a good city if not there a clean river flowing through her heart?

Update [2009, Aug 10]:

Here is a video sample I found in youtube. It spans just over a minute only, but the (video) quality is pretty good.

and another one here (You can check the Youtube follow up links for more).

As the race enters the seventh stage, Armstrong is only fraction of a second behind the leader Swiss Fabian Cancellara. It is already incredible for Armstrong who is on a comeback trial after retiring from the event a few years ago. Mind you this is the game which he ruled unconquered in his hay days. Considering the physical strain this sport imposes, it is commendable that he is keeping up with that sweet sweat. And today is the key day for the racers since they are entering the mountainous terrain stretch. This is where Armstrong once used to thrive at the challenge offered. Can he do it again? It will be amazing if he does it again. Let us wait and watch. My office mate Reda is full time watching this game and I can see the excitement in many such enthusiastic tour de france fans. Apparently,  they will touch Switzerland on 19th and 20th. It is not too far from here. Maya will be coming by then. It will be fun to take atrip to Verbier.  I will be tuned to check the Armstrong progress in anycase!

Oh boy, what did we see this evening at Wimbledon? A grandslam final, filled with nothing short of a breathtaking drama. A near neck to neck battle between king Federer and a fabulously charged up Roddick. Guess who was watching that epic cliffhanger? The emperor of that piece of grass strip in central London! No point in guessing the name: Pistol Pete Sampras. Sampras was visiting Wimbledon after 2002, perhaps just to witness another great champion Federer get past him in the number of grandslam titles. What an occasion! Unbelievable tennis on display when blue sky topped the roof in clean light. I feel for Rodick here. This was ‘the chance’, he had at hand: and truly well he deserved, one must say. I for one had written him off yesterday, even though he had played great tennis in the semi final to beat British hope Andy Murray. From one Andy to another Andy, the other finalist name changed, breaking the great British hope, since Henman (Well, Henman was not really a realistic hope, when Sampras was taking a stroll down the Wimbledon park).  I was expecting Fedex to just roll over him in the title clash. But alas! Didn’t he give Fedex  a run for his crown?

In the end, Federer had that extra epsilon, call it luck or experience.  He was there on that center court final stage on every single year for the last seven summers. Last year he lost it only by a whisker to the Spaniard Nadal. Federer truly deserved to be the grand-slam record holdert. He is the best player on the circuit and he is so very effortless, athletic and passionate.  The great man is a beauty and indeed is a treasure to this great game.   I cant have enough praise on the way he played tennis over the years.  He is so very smooth and graceful. A touch of Lara, Tendulkar or Dravid in cricket. I really was feeling a lot low when Sampras retired in 2002, but the Swiss has indeed made up that void since then.  A humble soul Federer typify the Swiss people I guess. So gentle and an amazing role model to the new generation. I really hope that he gets a few more grand slams titles.

Turning back to the losing finalist, I can imagine how hard it would be to be an Andy Roddick who narrowly missed the crown by perhaps one or two moments of marginal shots.  Sometimes sport can be so cruel! In the end winner takes it all and it is agonizing. It must be hard to be a second at that level. But then, that is what it takes it to be the best in the world. Only thin air make the separation. It is courage and wisdom at times to grab that silver line.  Grabbing is secondary, seeing it in the first place is what separates the best from the next best. After all, it is not easy to get there. Isn’t life beautiful?

Ramani visited me during the weekend. He arrived from London this afternoon. It truly brought memories of undergrad days. We had quite a lot of fun cracking PJs and chilled out with memories of funfilled undergrad days. How time flies? We had a game of cricket as well to spice things up. I leave you with a picture shot at St.Sulpice near the EPFL UNIL sports center.

ram_rat_Lausanne_epfl_around

The memorial service for Ralf Koetter held at UCSD is video archived. Quite many of the stalwarts in Information theory field found it difficult to control their emotions when they spoke about him. Such was the level of closeness many people had with him.  I have never got to directly interact with Ralf , but was aware about his stellar contributions to many areas in and related to coding. The most notable thing other than his well known research contribution is his amazing teaching skills. The two guest lectures given by him during David Forney’s MIT class in 2005 were simply stunning. He then had talked about Reed Solomon codes and that is by far the best lucid presentation of such a difficult topic, that I have ever seen. His sudden and untimely  demise leaves an irreplaceable void on this planet. He was that good. So woefully cut short by cancer.

Alex Vardy knitted down a fitting tribute to his friend and colleague.

Vous l’avez fait Federer! Federer is the French open 2009 champion. Something in me was telling, even before the start of this grandslam tournament, that this is the year for Fedex to win at Roland Garos. Ever since Nadal lost to Soderling earlier, his case was strengthened even further. He has done it finally.  What an year to win this. He is expecting his son to be born in few months and now, he can be at peace with the agony of not winning the French open, in spite of reaching the finals so many times. What a player he has been over the years. Todays match was much like the Federer-Murray US open final last year. Federer was superb. Soderling didn’t do too wrong, but that is the elegance and class of the great man Federer.

He has already moved to the pantheon of greats. Now it is a matter of adding more flavour to his already colourful charisma. All grand-slam championship as well now comes with this win. Incredible. Thank you Fedex for keeping us enthralled by your genius. Seeing it from Switzerland is even more exciting.

Footnote:  Whenever I cross the Ecublens area near Crochy, the tennis courts, I remember  Federer. I was told that he used to train there in early days of his wonderful tennis life. I am yet to figure out where exactly he did that school tennis training. Just out of curiosity! It may be just a few maters of walk from where I stay!

Shocked to hear about Rajiv Motwani’s sudden demise. I couldn’t believe it. So tragic and sudden end to one of the smartest computer science guy we ever had. So sad.  Apparently, he met with an accident in  swimming pool at home.  The world lost such a terrific talent and entrepreneur. May his soul rest in piece.

Three days on and no positive signs of any survival after that sudden disappearance of French commercial plane. These are tragic moments and my heart goes to the relatives and friends of the missing. The Air-France flight AF 447 was heading from Rio de Genero to Paris when it was lost early on Monday. There are reports emerging that some debris found on the Atlantic ocean may have been that of the missing airline. The present inference leads to a possible crash of the airbus into the middle of Atlantic.

I began to wonder the difficulty of carrying out search in the middle of a rather ominous ocean stretch, with difficult weather conditions, compounded with higher depths in the range of several thousand kilometers. If we were to do that in the night, you can imagine that extra difficulty with artificial light too. This clearly is an arduous task.

I was checking the specifications and features of the Airbus 330-200. They are ultra modern and almost disaster free.  They are supposedly very robust engines equipped with superior communication, control and electrical safety devices. Since went into operation in 1993, there was no fatal accidents, until this unfortunate thing happened on Monday. The only deaths reported on this bus was during a test flight in 1994, killing the pilots and two engineers on board. That accident was widely attributed to pilot errors and faulty autopilot systems. The latest disaster by far is the most fatal in terms of casualties and the extend of failure. As often is the case with air accidents, the survival chances are grim.

The A330-200 is a wide bodied two engine carrier. It is one of the dominant carriers for many of the medium/economical airliners operating. They include Air France, KLM and Etihad.

The loss of 228 passengers on board is beyond one could have imagined, especially with the advent of superior technology in modern airbuses. At the same time, this also give us a perspective on how well they function, every time a successful flight is seen through. The engines, the communication control devices, the pilots, the crews, all have to work rather seamlessly to make a trip safe as is the case, most of the time. I have seen people making huge furies over few minutes of delay at airports, reportedly caused by engine maintenance etc. Sometimes, I wonder whether such sudden outbursts by some passengers are reasonable at all. I get annoyed when some weird nuts behave like this. It is understandable that they value time as precious as ever, but we must surely give credit and due respect to the airline staff for making every journey as safe as possible. Sometimes, even the best effort may not lead to guaranteed goals, but then such is life.

Disasters like this latest one, might have occurred due to catastrophic failure of several parts of the system. Unfortunately everything seemed to have gone wrong with this airbus, including weather, location and extend of engine failures. Experts are worried about the chances of recovering the black box too. Just imagine the difficulty of the Brazilian and French air force, navy and military to get into the troubled waters of the vast Atlantic to search for the missing links. Quite a task that is going to be.

The Air France accident feel a touch more dearly to me. I have travelled quite a lot of times with Air France, almost always thanks to the economical advantage over other European carriers (They charge the least airport tax within continental Europe! and they have direct flights to Bangalore, connecting a Geneva-Paris as well).  This unfortunately is the biggest disaster for this Airline. It must be terrible time ahead for them too, to try and find the causes of such a catastrophic failure. The major surprise I noted is the absence of ay radio communication from the cockpit crew to ground. Some says it indicates the almost instant collapse of the system thereby leaving no time for the crew to react. I was wondering whether any of the following could have been done, at least as a futuristic goal!

1) The Satellites take frequent pictures of these airline routes. The rate of sensing, storage and power requirements, perhaps are the obvious limitations here. May be a potential compressed sensing application here? I am curious to know whether Satellites do scan the whole earth and if so, how frequent? I was told that, they do in parts, skipping the ocean for instance.

2) Let Satellites sense communication from all the airlines and report a failure of trajectory instantly. Considering the present day amount of traffic in the air, this may be quite a task. Besides, some form of this may already be in place.

3) Air France flights interestingly have these flight camera operating live. I have seen them beaming the live video of the ground while it is landing and taking off. I am wondering whether they could relay it down to its ground terminal so that they get to know when things go wrong.

None of these perhaps avoid a disaster. They can at the most help to trace the airline wreckage after a disaster. Considering the state we are in at the moment, aftermath of such a tragedy, this might be of some use. Never sure!

Nadal losing at French open: This wasn’t forthcoming! Until yesterday this piece of statement would have created sighs and huh-s. Raefal Nadal losing at Roland Garos was un heard off, even in the tennis folklore. Such was the authority Nadal had on this strip of clay in Paris during summer.  Roger Federer, the invincible champion of this decade, even in his hay days found Nadal a bitter nut to crack. The four time champion Nadal of this very famous clay grand slam was all expected to beat the record held by the famous Swedish player Bjorn Borg who had won the same from 1978-81. Today, incidentally another Swedish player put a stop, a break so to speak, to that charge. Now the question and equations are relatively easier for a Fedex charge, but never know. Given that, a few upsets in the last couple of days, we can still hope for some more uncertainty, but I would expect Federer to sail through from here on. Andy Murray and with a less probability Roddick are the bigger stumbling blocks for Federer now.

Robin Soderling seeded 25 will now be known as the man who entered the record book for being the first and only player to beat Nadal at French open. He was a clay court no big boy so far, but given the form he is in, we can expect some sort of excitement in the coming days.

I get the feeling that Nadal was coming to this match, with almost no rest season. He was playing non stop and it was a bit of overkill, considering that he was in for a big season ahead. I remember Vijay Amritraj mentioned a few years ago on Nadal playing a bit too many matches and thereby risking serious games along with injury scares. I am sure he will get time to ponder over it and arrive at the right decision for him. He is a lively player to watch and I hope to find him rejuvenated before the next grand slam.

Sport is exciting for this reason. Just when we thought the tables are in order, we get to see a surprise from an unexpected corner. Now the room look different. Are we in for more shuffle? Let us wait for the action to continue…

On  a sunny Lausanne morning, I woke up much later than usual. A game of cricket last evening had its due share in settling my body parts and indirectly in this wake up delay as well. I was all excited to re start working on the one sided set constraint problem which I pondered about a little the other day. After a routine coffee, decided to check Indian newspapers on line and the first news said Kamala Suraiyya’s passed away. To most of us, especially the ones associated with Kerala, she is the one and only Madhavikutty known to outside world as Kamala das. A name change and a religion hop didn’t really bother a secular Malayali. However the truth remains that, she was easily one of the most misread, misinterpreted writers of this generation.

I have not read a lot of Madhavikutty’s major works. That is a shame, I must accept. But I remember reading many short stories of hers, published in magazines, newspaper supplements and weeklies. One of the stories I still remember is  Punnayoorkulam where she touchingly depicts the life of a poor servant. Other short stories instantly coming to my mind are chandana marangal (Sandal wood trees, ചന്ദന മരങ്ങള്‍) and Pakshiyude maNam (Smell of a bird, പക്ഷിയുടെ മണം).  Her story telling style was unique; most notably with her precise and careful selection of words. It is incredible that she could write so well in both Malayalam and English. Not many people know that she was nominated for Nobel prize in 1984.  Unfortunately I didn’t get to know much of her English works other than a collection of short stories titled Padmavati the Harlot and Other Stories , which I happened to read sitting inside a book store in Trivandrum during the summer of 1996. That was an experience of some sort. I didn’t have money to buy books then. I used to spend a lot of time inside the book store (thankfully they allowed that) and spend nearly the whole day there. In two days of a week I could read quite a lot. I had restricted visits to two days a week to pretend that I was not exploiting that facility. Nevertheless, over a period, I had befriended with some of the shop guys and they politely let me enjoy this habit, realizing that I was a mere student who couldn’t afford to buy anyway.

Her life and works were dragged into so much controversy. I am not sure whether that helped her to increase the readership. I personally think she was an incredible writer who didn’t need these controversies to claim fame and readership. Her autobiography and the frank style of telling stories created public attention. Perhaps it came at a time when it was unusual for an Indian woman to be that open to express her emotions and life. I do not know much into that controversy, other than learning that it had some. I did not read her autobiography either to judge whether it had some explosive presentation of vivid emotions of a woman. Anyhow, such was her life. Some people would remember purely because of such controversies. Sadly many would have failed to realize the pure writing talent of such a bilingual writer, one of the best Kerala produced. Her death will surely create a void, considering that the language writing has become so thin these days.

Many people in Kerala were surprised when she converted her religion in the last stretch of her life. It was not because of the religion she chose to or the one she was born into. It was more because of the fact that she chose to give importance to latching onto a religion for keeping piece with her life. Anyway, that was her personal choice and everyone accepted it, period.

Madhavikutty’s departure is a big loss. May her soul rest in peace. I leave you with this documentary on Kamala das by Ignou:

In the end, Barcelona, quite fittingly became the champions league champions by drubbing Manchester United 2-0.  It is only fair to say that, they outsmarted Man United in the final.The semifinal between Barcelona and Chelsea had its fair share of drama, but the final was pretty much a Barca show, throughout. Andres Iniesta was awesome today.  It was he who stole the show, amidst all the talk of this match as a Ronaldo versus Messi showdown. For ManUnited part, they had their best share of the game in the first few minutes. Barring that, it was nearly one sided to my eyes.

I was watching the game on line sopcast through some Chinese TV. It was awful for two reasons. One, I couldn’t understand the language (my fault that in entirety), but the more funny and annoying thing was their pure dumpness when Barcelona advances or scored. I guess the commentators were hard core ManU fans. Earlier, I was watching the EPFL multicast, which had the french commentary. It was quite exciting and neutral. Once I reached home, the only thing worked for me was this Chinese TV. Anyway, glad that I could watch the final. That is satisfying!

Man United fans will surely find themselves let down by their team. Ronaldo did his best, but that apart, the team had nothing in display. When the Chelsea-Barcelona semifinal was lined up, I had two things to balance. One to support one of my favourite team, Chelsea and the other to seek a possibility to beat Man U in the final. Clearly Barcelona had a better chance to beat the united and they showed us with minimal contest. Well done Barca. You are the champions, truly and squarely.

Shrini Kudekar yet again showcased his creativity and acting skills on the eve of Dinkars public defense. Here is the video.

Yesudas and Mohammed Rafi singing the same melody: How about that for a treat to the ears? I didn’t realize that they have done it already for us. Rafi singing Jis Raat Ke Khwab Aaye (Film Habba Khatoon) and later Yesudas making that beautiful song Anuraga lola gathri (Movie Dwani) to a classic. I’ve learned that this melody is the creation of Naushad Ali. I am not going to make a comparison between these two legends (Well I am too in eligible to do that anyway). Both are so soothing. I find Yesudas has an amazing skill to vary the pitch with ease and that is perhaps quite critical in Malayalam language. Anyway, I have enjoyed both masters at work.

Sadly, these days, truthful, sensible and objective reporting are missing from many mainstream media houses. This is true globally including Europe, USA and without exception in India too. Take for instance Kerala, a tiny piece of land in the south west tip of India. The media over the past many weeks or months are just doing a masala gaga over silly factional arguments within a section of the ruling party. They go wild to picturize every tiny statements given by leaders and then glorify with their on puerile interpretations. It is a mess, the Kerala media at the moment;to say the least. Where are truthful media and journalists? Is any of them sensible enough to do truthful and objective reporting, sans yellowing the news? In an attempt to sell their masala craps, everyone go mad and go after such third rated reporting. The masala and gosspis can be at most a desert, but that cannot be the main course. Unfortunately, in reality the media changed their roles and glorified the wrong one. 

The Hindu, is the only paper I find as an exception. It is indeed commendable that we have one source to reply upon. While the entire Kerala media was behind gossipping, The Hindu published this report (by C. Gouridasan Nair )on the progress of Kerala government over the last three years. This simply opened my eyes. While the sensational media events otherwise created an impression that the current government is not functioning at all, the truth clearly is the opposite. Surely, the common man do not get to read The Hindu and hence is caught in the wrong net of fallacy world spooned with incorrect information. I am sure that reflected in the vote share too.”

Whither goest thou media? Will you please grow up to be much more sensible and judicial? Thank you The Hindu for standing tall as a true piece of hope in the journalistic world. If only, the other media house learned a piece of your ideology!
http://www.thehindu.com/2009/05/18/stories/2009051854680700.htm

I had written a couple of blogs on this long running, rather unfortunate SriLankan civil war. I was terribly annoyed and saddened by the plight of millions of poor people docked in the name of a separate land. While their objectives and goals were reasonable, the method of violence to achieve the same was clearly beyond any common sense. LTTE and the war against the Sri Lankan civil government over the last several decades, not only killed their ethnic rivals, but also a vast majority of their very own people and displaced millions away from their land. Besides, he killed many promising leaders, most notably Rajiv Gandhi, India’s promising youth prime minister in 1991. If you go by the rationale of that assassination, you feel pity about LTTE as an organization, devoid of a genuine social and civil agenda. They just act like terrorists, which clearly  is not the way to solve problems in a modern civil society. If only they did have some sense prevailed, they should have gone to fight for their cause politically within the social rule. That would have in turn saved many innocent lives! Sadly, not to be! 

Now, the news is breaking out that, the ruthless terror guerrilla leader of LTTE Velupillai Prabhakaran is killed along with many of associates. I condemn killing anyone, but this surely is a news, which in the long run will lead to stoppage of mass deaths and disaster to millions of people. This hopefully will end the civil war which ran over 25 years in the name of an ethnic (shame that we have to call it ethnic, since there is hardly any difference you cane make out from the two people involved in this fight) difference.  This end in many ways will pave ways for a better society for all the SriLankans, irrespective of their ethnic and language difference. 

The end of this surely have to be a beginning of some sort for the small island nation to learn and live in harmony. They can learn from their big neighbour India, which has thousands of different societies, with multitude of languages, colour, culture, politics all coexist in harmony. Let all your citizens of SriLanka get to live together; let all kids get to go to the same schools;play together; grow up together; That is when your country look more beautiful. Not when you fights trying to show who owns this and that. Now, is the time to make that great move to future. Best wishes for a better tomorrow to all Sri Lankans. 

Now is the time for international governments to help SriLanka to re build the nation. It is also time for them to force issues to evenly rehabiliate and integrate the minorities into mainstream. I seriously hope they do that. 

Footnote: I was going through some of the photos circulating in the Internet on Prabhakaran. These are pictures released today, probably after raiding some of his hideouts. It appears that, he was living a comfortable life when thousands of people on their name, he played this big war were docked to doldrums. What a pity leader?

The 2009 Indian Parlament election results are out. The Congress lead government is all set to return for the second successive term. I personally think this is the best governmet at the moment available to the people. Manmohan singh is an able man and largely they seem to have a vision. His last five year term has been one with many accolades and a very few dulls. The Congress under the leadership of Sonia Gandhi seem to be freed of large scale problems within the party. Congress even though have a lot of sycophants, the top leadership acts more or less sensibly to larger issues concerning the nation.

Now this being a clear mandate to Congress, it is an opportunity for them to take India forward with a stronger vision and clearer direction. A vision not merely targeted to improve the India shining media tag or sensex alone, but the one which genuinely helps to scale the rural and poorer section of the population. It is important now than ever to improve their lives by providing education, food and employment. While cities have gathered some colour and prospetrity in the recent years, the villages in many part of India still have a different story to say. I really hope this government begin addressing such issues with utmost importance. We need development stemming from rural areas, because immense potential are to be tapped from that often underprivilaged segment of society.

The defeat suffered by many regional parties which lacked any ethical base in some sense is going to be a blessing in disguise. We have seen over the years, the ugly negotiations between major parties and these swinging parties, in order to hang on to power. Some of them still are in there. I hope we don’t get to see such pity party MPs make mockery of people. I really hope that party leaders like Amar Singh, Mayawati and their respective parties don’t get to play that ugly negotiations.

The left parties, who have always stood as one of the rare political parties in India, for certain ideological standing also do not have much strength in this parliament. While many would consider their less than expected performance as an aid for a trouble free governance, I still consider their standing in many social issues has helped the current government to implement many people friendly schemes. This faiure is also a time for them to introspect into the ugly political factions within their party. As they say, you can learn more from failures than victory. I hope they learn to become a better outfit, by raising above pity individual factionism.

In Kerala, I personally, find the result as a mixed bag. I am indeed thrilled to see Shashi Tharoor winning with a handsome margin. He is surely our next foreign minister, largely because of his UN employment credentials. My wishful thinking is to have him taking up a ministerial portfolio involving rural society. Say for instance agriculture or rural development. I know this may not happen, because these are seen more of second class port folios, with no glamour or media hype around it. My argument however is to have someone who can make that policy vision for the future, which can transform a nation forward. One thing for sure. Kerala, which is often overlooked as a non-important state in national scene will get some preference, because some heavy weights including Shashi are going to be housed in parliament as representatives from Kerala. Apart from Shashi Tharoor, the better representatives are the young CPI(M) Mps such as Rajesh and Biju. Kasargod MP Karunakaran of CPI(M) and Vadakara MP Mullapally Ramachandran of Congress are also known to be good vocal representatives of people in the parliament. I hope they all live up to people’s expectations. Some of the winning MPs are less than useful to people and indeed it is sad to learn about this verdict, especially the ones from Kannur, Alappuzha, Kollam,Ernakulam,Trichur,Kottayam etc. End of the day, it is people’s verdict and we should respect it. We can only hope for these elected candidates to be model representatives for their people.

Meanwhile, the much underrated Laloo Prasad Yadav made it from one of the two constituencies he tried. He has been an amazing railway minister, in spite of his ridiculed public view among elite social circle. To me, he is the champion minister who made the Railway from an organization of deep debt to one of the very successful outfit. Considering that Indian Railways is the largest employment providing organization in the world (claimed to have over 1.4 Million employees!), his contribution is nothing less than extra ordinary. Many people, including your truly had once thought of him as a mere laughing stock, but now he has my respect in lump-some. I hope he continue his promising work and stay as Railway minister.

Elsewhere, the most dynamic minister in the current cabinet Chidambaram just survived a scare at Shivaganga. I am glad that he made it, simply because he is too good a minister to miss out. With Rahul Gandhi in, the new Cabinet is going to have some promising members. Together with many others, including many young and vibrant representatives, we have the making of a very dynamic cabinet under Manmohan singh. I am really looking forward to a more stable, cleaner and efficient government which can take our nation forward, eradicating the mark of poverty in many villages to one India of prosperity.

The much expected Wolfram alpha has gone for a soft launch since last night. It had some start up glitches, as Wolfram briefed during the live demo, but nothing major fortunately, prevented  me from getting a first feel of it. Erick Schonfeld  has a nice blog with a detailed first hand feel description of this new computing web search engine.  He also did a one to one comparison with Google for a few specific search queries.

My first impression is in much the same line as what I expected after reading Wolfram’s pre-launch blog. This is not a Google competitor for sure, but instead an incredibly complementing brother.  Wolfram alpha is more of a scientific and quantitative information search engine. For instance, if you want to know the Taylor series expansion of  exponential function e^{x}, you can do it easily by entering “Taylor series of Exp[x/2]”. As you would imagine, Google does not give this precise answer, but instead give you a list of documents matching this query, for instance a set of PDF links where this is already calculated. Clearly, Wolfram gives a more accurate and clever presentation of this query result. Wolfram alpha seem to use quite a lot of Mathematica capabilities too, like plot etc. Any mathematical query, will lead to pretty good result, sometimes including plots, histograms, Taylor expansions, approximations, derivatives, continuity etc. It is a nice feature to have for students and engineers.

wolfram1

This is the sort of query it likes the most and not something like “proof of Sanov’s theorem”. Google will incredibly list a set of documents which has the proof one is looking for, since it simply search down the web and display a listof  matching queries, ordered based on pagerank, which is loosely speaking in the order of relevance.

Not all queries are bound to get a result with wolfram alpha, atleast for now. That is expected since it is not yet in launch mode, but on soft launch. In the coming days they are likely to have it running full fledged with all kind od queries supported.

So, the wolfram alpha is definitely going to be useful for very many cases and it surely is going to rock in scientific searches. I initially thought the Google squared which is going to come from Google shortly is addressing the very same segment of search area, but it is clearly different.

I tried “tallest mountain Switzerland” . It gave a very nice cute quantified table. I love this kind of result. It is also state things with less ambiguity. For instance the height is mentioned in meter, but there is a list of unit conversions listed along, which help people to map them into the units of their convenience.

I tried a query “Who is Claude Shannon”. This is what it displayed. Of course, the result you get is a very brief information about him. Same query in Google will lead you to the more detailed Wikipedia entry of Shannon or may be the Mathworld entry of Shannon among the list of hits .  Wolfram alpha gives information more like in capsule form. If you need to know more, you should ask more. Clearly, what search engine to use is thus subject to the query type.  I strongly see Google and Wolfram alpha are complementary. Wolfram alpha gives more or less one reply to a single question. Of course you can renew the query and then get answer to that. In some sense, this is like people asking questions to one another in real physical scenario. Imagine you ask a friend, knowledgeable pal that is: Who is Shannon? He would perhaps start answering in those lines as Wolfram Alpha do. On repeated question he will give more details. On the other hand, Googling is like broadcasting your query to a large pool of friends, each one of them sends what they know or heard about Claude Shannon. It is you,who decides whichamong the many answer(s)/explanation(s) suit your need!

We can afford some amount of spelling errors while entering the query in wolfram alpha. Since it is natural language based, that is a decent feature to have. I deliberately typed the query “distnace from Bangalore to geneva ” instead of “distance from Bangalore to geneva “. It understood the intended query and displayed the result in a nice quantified table. Eve the geographical trace between the two places is shown. Incredible!

When I tried “weather in Lausanne”, this is as good as it gets.  Spot on with all possible things you want to know in one screen! It had a list of mountains and their heights mentioned!

In a nutshell, Wolfram alpha give you the best cooked food, given a user recipient as input. Google will give you a list of foods available and then you pick the one tasting suit . It  really then is a question of preference, time, and satisfaction of the end user on what to choose from. As far as I am concerned, it is subjective. I see both of these are invaluable and both will co-exist. Scientists,economists, finance folks, mathematicians, historians are all bound to benefit from this new computing engine.  I am waiting for a full release!

Today, I attended a very good talk given by Emo Welzl of ETHZ. I could not quite appreciate the drinks and snacks prior to the event, since the organizers kept too little of them and by the time I arrived,  smart guys had grabbed hold of almost all of them. I had to content with a glass of orange juice! Anyway nothing comes free in this country. So getting an orange juice is itself luxury, one would say! Nevertheless, glad that I attended this talk. Monika Henzinger did the speaker introduction part, which she did very well. She mentioned that Emo comes from the same village as that of her husband (Thomas Henzinger). That is not really relevant, but I like such personal, less formal introductions. It takes the audience to a touch curious and close. He indeed proved her (Monika promised us that we are in game for a great talk) right with a truly nice lecture, calm, composed and thoughtful;words precisely chosen, well articulated throughout. He gave some insights into a problem which was never known to me. My field is not quite into SAT or algorithms, but at the end of this talk, I got to learn some thing. Moreover, he instigated me to learn a little more about these nice problems.

Here is a gist of what I understood. If you are interested in the talk subject, perhaps you should visit his homepage. What I state down is something my little brain, which never for once trained on this topic, digested out. Suppose we are given a Boolean function (that is a logic function which has either true or false, equivalently 0 or 1 results). Deciding satisfiability (known as SAT problem) of such formula in conjunctive normal form is known to be an NP complete problem. He discussed some nice (surprisingly simplified bounds) combinatorial bounds on the number of clauses (or equivalently constraints) for unsatisfiability. As usual in talks, I hardly could grasp the proof in total, but he began quoting the Lovász lemma as an essential ingredient. I got to learn a little bit about this rather nice and cute lemma. Loosely the lemma has the following setting.
If we consider a sequence of events s_1,s_2,\ldots s_k where each of these events occur with a probability at most p. Suppose each event is independent from all other events, except at most d of them, then ep(d+1) \le 1, where e is the Napier constant (named after the famous Scottish mathematician John Napier). This did not strike me instantly, but pondering a little bit about it, I have realized that this is really cute a bound. I can think of a nice, little example scenario, where this can be applied. Let me figure out another cute one. You can expect me to post it. Now let me get back to that optimization problem on compound sets of channels that I have been stuck for the last four days.

Soccer matches, champions leagues in particular are never short of emotions. It reached the very pinnacle during this years champions league semifinal between Chelsea and Barcelona. Players went a little too far in the climax stage. Norwegian referee Tom Henning Ovrebo was the perceived villain in the whole drama, while Chelsea players went a little wild to protest against the faulted referee.  Considering the significance of a decision separating a finalist from a tournament exit; that too one of this magnitude, it is partly understandable, the outburst in the heat.

Have your ever wondered the value of three minutes of time? Try to seek an answer from Chelsea players and fans! That three minutes of extra time brought the team from heaven to earth. The simmering semifinal at this year Champions league saw high drama throughout the match and especially towards the end, where an equalizer from Barcelona shutting all hopes for the home team’s chances to get through to the final. I have been quite unhappy with the away goal rule as an equivalent to win mandate, but that is a rule which is well into the league and nothing can be done about it. But the sad thing in this event is that Chelsea was badly overlooked by the referee in many penalty claims. At least one for sure for the handling the ball by Gerard Pique in the Barcelona penalty box. Hard core Chelsea fans would consider that they were clearly denied of as many as five penalty claims.   The emotion displayed by the players in the heat of those high sensitive moments is partly justified in that sense.

I can understand the heart breaking letdown for Chelsea fans. It is not that big a club in terms of history or fan following, but Chelsea managed to gather a reasonable fan base since Abramovich poured money in the last few years. Considering that they were in the final of the championships last year, this loss would bite the fans so dearly, shutting that elusive wish list of a repeat final and a possible return of fortune against Manchester United. Alas! That was not to be! In any case, the match was an incredible one. Both goals were stupendous. But Sanford bridge fans would have never ever imagined that three minutes of extra time would break their heart so very dearly. But that is the way sport and sporting emotions go at times. That is the beauty of sport too. It can bring in surprises from the most unsurprising corners. This match will be remembered for a very long time.

Barcelona on the other hand is playing well and can seriously challenge ManU in the final. So, we are in for a thrilling contest in the finals.

On an impact side, the danger coming with this loss for Chelsea is the money investment by its boss Abramovich. The billionaire owner is hit recently  by the world wide economic downtime where in a single year he found himself poor by 40%. That being said he still has over 10 Billion USD or so, but the question is whether he will still have the enthusiasm to pour (his precious) money to feed the Ballacks and the Lampards. After all you need a lot of money to keep these boys.

Now, looking forward to the final, I hope Barcelona beat ManU! Barca is in great form and the chances are high for them to clinch that trophy. I wouldnt care less if ManU wins another one, but Barca and ManU, please give us another thriller.

I am eagerly waiting for this new search and compute engine promised by Stephen Wolfram.  They call it wolfram|alpha (If google always went with the beta release, Wolfram is going even early).This, if it work in the promised lines is going to rock the Internet evolution. From the outset, this is not just a search engine. It is kind of an intelligent searcher who can loosely understand the human requirements. 

wolframalpha1

For long, it was perceived that a search engine driven by natural language processing is the way forward. But it is pretty hard to build such a system since natural language processing is no mean business.  Wolfram’s idea is to create an abstraction and then algorithm of these realizable models. Once we can do a mapping of the requirements  to algorithm that is computable, at least in principle we can build such a system. But that is a whole lot of heavy statements already. How easy it is to build all these methods and models into an algorithmic framework? He is using the New Kind of Science (NKS) armoury to realize that. We have to wait to get the full rainbow, but when he promises we can confidently expect something big. 

Now once the algorithmic mapping (and implementation) is done, then the question of natural interacting between humans and the system comes. Natural language is the way, but according to him we don’t have to worry about doing that as such. Once the knowledge of the individual is made into a computational framework, then that is enough.  I am not an expert in this natural language processing and NKS framework, but for sure this is pretty exciting,both from an algorithmic point of view as well as a practical MontBlanc. As Wolfram himself pointed out Pulling all of this together to create a true computational knowledge engine is a very difficult task. Indeed it is still being considered a difficult problem, both in academia and industry. So there is excitement aplenty in the offing. I am eagerly waiting for this to hit soon.

Considering that, the big wig search engine houses including Google are still struggling to make that dream natural language engines (the many pseudo ones in the market are not quite approved). I remember http://www.ask.com started their business in those lines, but never seemed to have crossed that elusive mark of acceptance, atleast not to an extend to capture a world wide wow!  If Wolfram has a new way to get this through, that will be a big breakthrough. I cant wait to see that. Wolfram promises that it is going to be very soon. He says it is in May 2009. My guess is that they will release it on May 14,2009.

I had earlier promised to update on the Xitip, when a windows setup is ready.  Though delayed, I have something to say now. I have finally made a windows installer for the (Information theoretic inequality proverXitip software, which was working pretty smoothly on linux, cygwin and mac for a while. I was not too keen on making this windows installer since a few DLL files are involved with it. Besides it was  a bit painful to include these nasty DLL files which would unnecessarily increase the bundle size.  Some of these may not be required if Gtk is already installed on the machine, but anyway I made one double click style version to suit the layman windows users in information theory community. 

Vaneet Aggarwal is the one who motivated me to make this up since he uses Windows. He showed some interest to use it, should a windows version be available. If atleast one user benefit from it, why not make it. In the process, I got to learn about an easy way to produce a windows install (setup maker) program. I used the freeware Install creator to produce it. 

I will put this installer available at the xitip website, but for the time  being you can access it from here. A lot of people suggested to revamp the xitip webpage which is pretty unclean at the moment. May be a short tutorial is impending. That will take a while; the next two and a half months are out of equation since I am pretty busy till then.

It was today. I’ve just come back to office, after the dinner party hosted as part of the I&C anniversary celebrations at EPFL. Andrew Viterbi was the guest of honour and largely because of his fame, there was considerable crowd attending the function. Martin Vetterli made a nice colourful, flashy presentation illustrating the history of I&C in EPFL as well as scientific progress in Switzerland. He mentioned the names including Jim Massey, Ungerboek who are undoubtedly pioneers of modern communication theory and practice. He began saying that “…Ungerboek is our friend, and now not quite..I will come to that in a minute…”. And of course he didnt come back and fill the circumstance in which the friendship derailed. But I reckon it was a casual remark, perhaps to indicate that Ungerboek, now with Broadcom is a bitter rival to Qualcomm. Since Qualcomm recently established a scientific partnership with EPFL and Viterbi being a Qualcom founder and associate, he perhaps just jotted that remark. It was a nice, usual interesting presentation by Martin.

He also mentioned a nice story about the current EPFL president Patrick Aebischer. Interestingly Patrick Aebischer after an MD (Medical science) degree was fond of computer science and decided to venture into taking a MS degree in CS . He then decided to test his luck at EPFL and approached the admission committee with a formal application. CS was affiliated to the Math department in those days. EPFL politely rejected his application and in due course that ended Patrick’s quest for an EPFL CS degree. He then moved to the US, as a successful surgeon and took a career path of entirely different trace. Years later, as one would say, due to the uncertain turn of things in the great cycle of life, he became the EPFL president and now ruling not only the CS department, but the whole school.

Viterbi talked about the Digital Communication history. He started giving a perspective of this field starting from the days of Maxwell, Rao, Cramer, Wiener and Nyquist. Then he discussed the impact of Shannon’s work. He said the three driving force which made this digital mobile revolution are

1) Shannon’s framework (1948)

2) Satellite (Sparked by the Sputnik success in 1957)

3) Moores’s law, which is more of a socio economic law, which dramatically kept driving the industry so successfully.

The talk as such wasn’t too attention gathering, but he made a rather comprehensive presentation discussing the impact of  digital communication evolution spurred since Shannon’s days (and even early) knitting a dramatic success story of digital wireless world with millions of cell phones and similar devices, which showcased literally the realization of theoretical promise Shannon made in 1948. He himself has his name etched in part of that success story, at least in the form of Viterbi algorithm, which is (one of the instance of it) an algorithm used to detect sequences when perturbed by a medium.

Quite a lot of fun activities were organized by the committee. It was quite fun. Since many programs (especially the fun part) were in french, the appeal was considerably deaf to non-french speakers. But then the rationale given was that, the alumni in good percentage are french! I found it funfilled , mainly to see these successful people like Viterbi sharing their views in real. After all we can learn from history. Not many people can claim to have done so well in everything he touched. In the case of Viterbi, he is an academician, researcher, successful entrepreneur and now a venture capitalist, all scaled to the possible limits. Incredible role model, whichever way we look.

Oh God! ? Shattering scenes coming from SriLanka

The incoming pictures and videos from the civil war in Srilanka is making a mockery of what human lives and values should be. We are in 21st century and belong to what is perceived as a modern society. Yet, millions of people are caught between two ethnic ideologies in a small country in the foot hills of India, the largest multicultural, democratic country in the planet. What an irony! Well, I am not suggesting that India is freed of problems, but looking at the magnitude of the ethnic problem to its total size bemuses me. The LTTE who have used various despicable methods of terrorism over more than a quarter century in the name of a seemingly improbable Tamil Ealem goal has made the life of poor people, nothing less than hell furnace.  The Sri Lankan government on the other hand seems to be in no mood to stop the bloody battle before they see the end of the Veluppillai Prabhakaran

War has never solved any problem,irrespective of the goal it ever aspired to achieve. What it leaves instead is the loss of millions of innocent lives and an unrepairable, long lasting trauma. Children who are caught between ethnic rivalry and stupid power struggle are denied of a life. It is easy to blame one another for this mass misfortune of innocents. The LTTE, now in the brink of being annihilated are wounded and are further exploiting poor peopleas human shields to counter attack the more powerful army force. It is a battle of loss. Sadly, the loss is imposed on to their own people for no genuine fault of theirs. What kind of doctrine is it? People are forced to flee from their dear land in desperation, hoping against hope. Clearly, their supposed leaders and power points have made life hell than the promised dream land. 

What  (and still is) needed was a political solution, not war. It is a shame that such a tiny country couldn’t arrive at a political situation.  If that had happened, we could have avoided one of the most shameful refugee crisis in modern era. LTTE is a terrorist organization which caused havoc not only in SriLanka, but they also made a mess in India by killing a promising youth leader Rajiv Gandhi. In the name of achieving a mirage, they let the downtrodden Tamils in the northern Srilanka to suffer.  It is easy to promulgate an ideology of creating a dreamland, but the price you pay is in the form of innocent lives. It would have been far better to become part of the existing political system to put forward their demands. It might sound so silly, but in a country as big as India, it worked. Millions of religions and sub castes with varied social classes lives without a civil crsis as big as the one faced in a tiny SriLanka. I hope Kashmir too learn from this hard lessons from SriLanka and get to a more peaceful dialogue path than weapon confrontation.

I may be a little naive to comment on this SriLankan struggle, since I am not really aware of the intricate issues between these ethnic groups. No matter what the extend of enmity exist, as an outsider I find it hard to chew these gross deaths and massive refugee crisis. Seeing the pictures of millions of refugees walking away from their little homes, children and old people included, make me sad. We cant do this in a modern society. What is worse is that, the actual ground realities may be much more heinous and gruesome than the few aired videos and pictures. Oh! God, if only we learned to live in harmony! 

Now, when the war end, what next? Will those refugees get a life back? A generation is in danger. What is the UN doing? War! no more of that beasts please. We have had enough of trauma. 

Here are two video documentary on this unfortunate ethnic trouble in the naturally beautiful island nation.

Todays IPG seminar had Fritz Eisenbrand (the Disctete Opt chair, Math department EPFL) talking about Diameter of Polyhedra:Limits of Abstraction. I don’t think I followed the topic too well, but this is a share of what I understood.

The topic is about a convex geometric problem on the diameter of a polyhedra. The question of whether the diameter of a polyhedron is polynomial or not seemed to be a longstanding open problem. The largest diameter {\Delta_{u}(d,n)} of a {d} dimensional polyhedron with {n} facets has known upper and lower bounds.

{n-d+\lfloor d/5 \rfloor \le \Delta_{u}(d,n) \le n^{\log d +1}}.

The lower bound is due to Klee and Walkup and upper bound to Kalai and Kleitman. These bounds also hold good for combinatorial abstractions of the 1-skeleton of non-degenerate polyhedra (Polyhedron here is called non-degenrate). What Fritz and his colleagues have done is to look into the gap between these known lower and upper bounds. Apparently, the gap is wide and they have made some progress to get a super linear lower bound {\Delta_{u}(d,n) \le \Omega\left(n^{3/2}\right)} if {d} is allowed to grow with {n}.

The way they showed this bound is by establishing the bound for the largest diemeter of a graph in a base abstraction family. Let us say, the abstraction family of connected graphs be denoted by {\mathcal{B}_{d,n}}.The largest diameter of a graph in {\mathcal{B}_{d,n}} is denoted by {D(d,n)}. They find that,{D(d,n) =\Omega\left(n^{3/2}\right)} and then using the fact that {\Delta_{u}(d,n) \le D(d,n)}, they conclude the bound {\Delta_{u}(d,n) \le \Omega\left(n^{3/2}\right)}

I have not had a chance to see their paper yet. I must say, the proof was not all that within my grab during the talk. However it appeared that it is based on some layering and combinatorics. He said some applications to covering problem, in particular disjoint covering design which I didn’t follow that well. Sometimes I get the feeling that I am a little dumb to grasp these ideas during a talk. I wonder whether others understand it very well on a first shot presentation. I have put it in my agenda (among the millions of other papers to read) to see through this problem and proof, one day! His presentation was very clear and legible though.

…and it is Oracle! Quite a surprise! Thats the least I felt, when the news broke out stating that Oracle is buying Sun Microsystems. The once great and proud maker of some of the best servers and computing power houses is now leading to the hands of a software giant, largely focused on database solutions. There is no natural connection to the obvious eye But who knows? Oracle may be eying something big! I cant see a justification of spending 7.4Billion $ to get hold of Java and MySQL alone. These are the big software solutions from Sun, apart from Solaris.  Anyway both these are open source software too. Afterall Sun is known for its champion make of servers right? Is it that Oracle feared an imminent acquisition by some other competitor, which might have distracted their lead? For a good amount of time the speculation was on whether IBM would still buy Sun. Then it was the Cisco, and the HP taking rounds as potential buyers. None of these materialized, but Oracle, the one choice with maximum entropy!

Would it be that, Oracle saw something big with Solaris? Are they eying on a solid operating system market? In any case, a decision to buy a company for 7.4Billion cant be for fun. Surely there got to be a plan, at least in theory!As someone opined in some article recently about possible consolidation of SAP and a possible buy over by one of he bigger fishes like IBM or HP. Now, that would take some shape too. Nothing can be ruled out at the moment. This is the sort of indication floating around.

Today, during the evening chat, Emmanuel Abbe threw an interesting question: Whether the sum of square roots of consecutive binomial coefficients converge to some closed form! That is, {S(n)=\displaystyle \sum_{k=0}^{n}{\sqrt{\binom{n}{k}}}}. We tried a few known combinatorics tweak, but no meaningful solution arrived. We were also wondering whether this has some asymptotic limit, but that too did not yield anything. A quick check on Mathematica wasn’t helpful either. Now the question is: Does this sum yield some closed form expression.

While playing with this sum in Mathematica, I found that for the sum of squares of binomial coefficients, there is a nice simple closed form.

{S_{2}(n)=\displaystyle \sum_{k=0}^{n}{{\binom{n}{k}}^{2}}=\binom{2n}{n}}

I was toying with a proof. It turns out that, the proof is extremely simple and is a one line tweak of the Vandermonde identity {\binom{p+q}{m}=\displaystyle \sum_{i=0}^{m}{\binom{p}{i}\binom{q}{m-i}}}. Simply substitute {p=q=m=n} and we have the results on table. The natural question then would be: Is there a generalization for { S_{r}(n)=\displaystyle \sum_{k=0}^{n}{{\binom{n}{k}}^{r}}} for any {r\in \mathbb{N}_{\ge 1}}. Ofcourse now for {r=1,2} it is trivial.

Apparently, it turns out that, there is no closed form expression for a general (all) {r}. There are some interesting divisibility properties of these sums. An interesting account of that is addressed by Neil Calkin (Factors of sums of powers of binomial coefficients).

At the moment, I get a feeling that sum of fractional powers of binomial coefficients is not trivial. May be there is no closed form. May be not!

It was almost unthinkable that a single company would rule the EDA world. At least this is what I strongly perceived, a few years ago. Now, put the present dishes on the table and I see that, Synopsys is giving nightmares to all other EDA shops. While working with Synopsys, we always saw Cadence as the rival company to get floored on. All of that, was in the wish list and not many of us thought we could do that, ever so easily. Cadence was the obvious leader of EDA for many years and Synopsys strongly stood at the second position. Then there were the Mentors and the Magmas, at a fair distance down. Magma was the emerging company with a strong future predicted by many pundits within and outside the EDA world. It was imminent that Magma one day would give a stronger competition to both the big brothers Synopsys and Cadence. They may still be a force to reckon, but sadly they tried to act over smart and it all triggered a downfall. I am not sure whether their, rather peculiar sue attempt on Synopsys was wholly responsible for their slide. Definitely that may have had a role. 

Now it appears that, the discounts offered by the EDA big fellows are giving more aches to smaller players. It is well known that the EDA tools are phenomenally expensive and the marketing always revolved around giving deals for bulk purchase of tools. What is more colourful is that the buyers offer to make the deal public in exchange of more discounts. The concept of primary EDA vendor was not that prevalent a few years ago. However, the trend these days is to grab that extra mileage by roping with leading semiconductor houses. It is a big win for both the buyer and seller. Synopsys for sure  is going to enjoy this. First they are among the very few making profit even in these difficult economy. They are perhaps the only one from EDA. Considering that the EDA market itself is only about 4 or 5Billion dollar market, the impact of a near 1.5billion dollar Synopsys doing too well is going to give more headache to other little fellows, in the coming days.

Cadence is literally having a plate of their own problems and now with the whole semiconductor market trying to minimize their R&D spending, it is double advantage for Synopsys; That too with newer friends adding to their primary EDA friends list. Magma is becoming more or less a prospective buying target than a rival. A few years ago, Synopsys had worries about a growing Magma. Now I wouldnt rule out a potential buy over by Synopsys itself, may be Cadence or Mentor Graphics! 

Some people say that Synopsys is going to be the next Microsoft in EDA. Aart perhaps rightly said they want to be the Apple of EDA. I would prefer Aarts view here. Not just because Synopsys was my breadwinner for a while and not because I attended the same grad school as De geus, nor because of the well known fact that yours truly is an ardent fan of Aart de Geus. But because Synopsys is  well managed by a great management team with great work ethics. When the ratable (subscription) revenue/ licensing model was announced there were lot of eyebrows, but it was a long term vision and Synopsys is really reaping the fruits now. 

Having said all these, like many of you, I am too worried by this single monopoly trend in EDA. We need smaller players in every market and we need more innovation. From Synopsys standpoint having less competition would yield relaxed days ahead, but for the market we need better products and superior innovation. We need Cadence to revive and at the same time companies to emerge to take position for the next Magma. At this stage, I am worried about Magma. Is Magma to follow the Avant! route to get merged with Synopsys?

Aart has aptly mentioned that “I understand that the entire world is under economic pressure,” he said. “When that happens, some will do better than others”. One thing for sure. Among all the EDA executives, Synopsys folks must be getting better sleep these days.

…High above the city, on a tall column, stood the statue of the Happy Prince.

Oscar Wilde‘s ‘The Happy prince‘ is one of the many stories that I have read during early school days. Remarkably, this is one of the few I still remember! I was barely able to read difficult English literature per se then, but still the story of Happy prince was within my grab. I don’t recollect whether I had understood all the words of Wilde, back then. This was at a time, when I was happily enjoying my schooling and life in my mother tongue Malayalam. Malayalam literature had its penchant style and aura, which is difficult to explain to non-Malayalam readers.  I was ‘at-home‘ when it came to reading the Malayalam literary works. Yet, I had thrived to learn English stories, albeit at a reduced speed. That whenever, I got a chance to read. Oscar Wilde was one of the rare English writers whose work, somewhat accidentally came to my reading list.  I was surrounded and enthralled by the works of great south American and Russian writers, otherwise. Partly, thanks to the communist influence in Kerala society, the translations of great Russian and south American books were far more available at ease  and at cheap rate (In fact I don’t remember buying anything, but all borrowed from various small local libraries around). 

Coming back to the Happy prince, the story had indeed put a stamp in my memory as a child.  I may have been 10 years or so when I was ‘introduced to’ the ‘Happy prince’.  The subdued request of the prince to the little swallow was by heart to me. When the prince says ” Swallow, swallow little swallow…”, my heart seemed to have resonated at a lower pace.  As a child, I had never seen an European city, for that matter any great city including the ones in India, let alone city across the Atlantic. It was all in my mind, that I’d imagined a mythical model of such a city, a city of the happy prince!  I used to visualise the position of the Happy prince statue standing tall in the middle of a city. Did I ever imagine the enormity of a city as big as this? As a child it is difficult to fathom and relate the seriousness of people’s struggle, a statue could see.  For sure, I was touched and moved by his sorrows and pain.

The swallow represented a role model so to speak  when it comes to helping others. Subconsciously, the little swallow literally drenched my cheeks by living through that difficult winter.  Back then, I had never seen what it is to be a snowy winter, still, could feel the chill of that season, when the shivering swallow wholeheartedly fulfilled the Prince’s wishes. Years later, the words “…Swallow, Swallow, little Swallow. Stay with me one night longer” still linger my ears. Tears still beckons! Perhaps that story have had a deep influence to me since childhood, to an extend that I’ve never imagined. As a child, I wished if only the swallow could go to Egypt, but alas!

Now, I have accidentally come across that very same story in video form in youtube. That brought in a rewinding of years! I feel the same chill now, as a 10 year old that I had felt years ago. I had told this story to Nivedita a few times. I could see her expression when I uttered the prince’s humble request “…Swallow, Swallow, little Swallow. Stay with me one night longer” .. The impact of Oscar Wilde’s powerful writing tells a story in itself. Don’t they?

…High above the city, on a tall column, stood the statue of the Happy Prince.

The prince and the swallow still stays on.. in my memory…I really want to tell this story to many kids! The youtube video is commendable too.

I’ve finished reading the memoirs of Walter Rudin. It was a quick read for a few hours. His autobiography is titled The way I remember it, published by AMS in the history of mathematics series.  It wasn’t particularly interesting, to say the least. From a mathematician who wrote excellent books on functional analysis and several others,  I was expecting a much better story. Of course one cant write an imaginary story in an autobiography, but then the incidents in his life is pretty much the story of any European intellectual during the war days. The best I liked is the one from Karl Popper. However, I could connect many incidents from Rudin’s life, primarily because of the geography. There is a chapter on his days in Switzerland, which also touched upon Lausanne. That part for once enthused me! Was wondering how Lausanne would have been 70 years ago! If you are completely unaware of the life in Europe around the WW period, then this will give you a perspective.  Like many scientific minds of that era, he had a long route to the United States. He discusses the path and family traits of that journey, in a somehat uncomplicated language.

In his autobiography, Rudin has discussed some of his contributions to mathematics as well. That part appeared a little informative, but technical read. If you know his work already, you would connect it nicely.  I particularly liked the chapter on Function Theory in the Unit Ball of Cn. 

In all, not a book I would recommend, unless you are a Walter Rudin fan and knows his contributions in much more detail. However, this may be a motivating read for a young school kid aspiring to be a mathematician. Why did I say that? I don’t know! Don’t ask me why either!

A very interesting report on the neuro socio development and progress of children from poorer background, is reported in the recent edition of The Economist. In the report they discuss the research study by Martha Farah of UPenn.  Their investigation came out with a worrisome conclusion that, children born with poorer socio economic background have a greater chance of becoming underachievers (read as under performers compared to their middle-class counterparts). The study is of course based on statistical inference and hence there ought to be scope for exceptions (Large deviation theory!). However, being a statistical method, we can well assume that the behaviour is true on the average (expectation). This is truly not a conclusion we would like to hear, but to me, it appears to be a careful study and its conclusion opens up the ramifications of the larger crisis faced by millions of people all over the world, especially from developing countries and Africa.

What these researchers did is to study the stress level suffered by a person over the span of his/her life. They combined various type of pressure (such as systolic and diastolic blood pressure) and formed an index, what they called allostatic load. They found that this index is on the higher range among people from poorer background than those from middle class. They also have found that, the duration of the poverty life of  a person is correlated with allostatic load.

The report appears to conclude that, stress is more or less the sole reason for spoiling the working memories of an individual. We could say that it is a little too strong a statement. Children under too much socio-economic stress tend to do badly in studies and that unfortunately carries on for ever. I am tempted to argue that, a socio-economic push, say by providing opportunities to such children will change the performance of an individual. After all, we know many instances of children born into poorer backgrounds scaled highs.  But if you read the report carefully, they are not refuting this either. What they simply say is that, on a relative scale, the impact of stress during early childhood is much more serious than what we perceived to be. Children of poor perform poorly in school and stay on that way and sadly, remain as poor (under achievers) adults. Clearly, the authors refer ‘poor’ adults as state of ‘under achieving’ compared to their counter parts from a middle class background. In that case, one can always argue on the definition. True, one doesn’t have to be a genius to do well in life. But, the larger picture however is clear. A poorer childhood may limit his/her potential. 

It can be very easily mistaken for that, this report is derived from a non scientific study. I too was inclined to think in those lines when I read the title.  A careful reading however convinced me that, there could be genuine truth in  their argument. After all, the conclusion is not on a single individual, but on a collection.  

I am sure the wider picture of this report may have a scientific explanation too.  Too much stress, at an earlier stage of life may prevent development of nerve cells. Bottom line is that, we simply do not want to take a risk. It isindeed very important that our children and future generations not to undergo that ill fate. We have a social responsibility to be aware of these and try to do a part to ease up the trouble, as much as we can.

A few years ago, during undergrad days, myself and  friend Ramani during our lazy 75 paise mini canteen tea outing, were discussing a small riddle. It was motivated from a real world experience from our computer center in NIT Calicut (REC Calicut). In REC those days, we students almost exclusively used rubber slippers (Yes, those Paraqon brand which used to cost 20 rupees or so), usually called by the name ‘chappels’. With that, we were not only comfortable while walking and running around, but we’re equally at ease playing cricket and badminton with the very same foot support; and many other things too, including jogging. Those thin hard rubber slippers used to last an year or more without giving much trouble, other than perhaps an occasional tearing of the rubber tie. In all, we were at peace with that.

But there was an issue, not exclusively for this brand, but for chappals in general (shoes were a luxury of sort in the campus;atleast it wasnt very common). Not for everyone though! If and only if you were fancied of visiting the computer center! Well, computer center wasn’t all that fanciful then, since we were provided with only graphics less Unix terminals (no colour monitors!). You might wonder, huh! what age am I talking about? Besides, Internet and Emails were only taking shape then. Chats and browsing were not quite there yet;Unless you felt a touch inferior to the computer wizkid around, that was not a compelling centre de visite. As, ‘would be‘ electronics and communication engineers we had that occasional inferiority complex!. Computer center was air conditioned and was strictly slippers free. We were expected to keep our valuable slippers outside (no clock room luxury! well that was not a necessity either) before entering to that cooler room, filled with monochromatic terminals. Since most of the chappals dropped outside were alike (in size and also sometimes color) there was a good chance that at the time return, we ended up with a different pair of slippers (Some folks found happy for themselves by a visit to the computer center, just for a pair change, often to an improved lot!).  Sometimes, we ended up having differently colored ones, say left foot white and right foot blue. That wasn’t a problem socially either, as long as you stayed within the campus. It was socially accepted within the walls!

Anyway, coming back to the riddle we were busy conjecturing on. We wanted to automate a clock room. The idea then would be to just deposit the chappals there at random. The clock room work automatically. Upon asking (at the time of return, say) it will select a pair at random and give it to you. Sorry, you cant have a choice. Just accept and hope for the best. We asked the questions:

1) What is the probability that everyone gets their own chappals

2) What is the probability that none of them get their submitted pairs

Assume n number of  people (and hence n pairs). We can assume that, a pair is a single entity (say both left and right slippers are tied and submitted as one) . This simplified the problem to n people n slipper scenario. A simplistic model assumeed that all n people submit their slippers at the same time. We wanted to build that great randomized clocker machine! And we wanted that to work for any n, which means, the algorithm had to be implementable and to work well in expectation!

We had thought and pondered about it for a while, then. In the end, we had found that the first one is easy, but the second one a little harder to generalize for beyond n=10 or something.  As busy undergrads, we left the problem after an hour of discussion, probably until we had finished sipping the tea. Aside, we were busy with many other extra curricular activities including a 3 hour daily cricket match at the lush green international hostel ground. The megadeth team, as we proudly grouped ourselves, the electronics and communication batch hardly missed those cricket matches. We were electronics engineers and had taken pride in ourselves by not really bothered to ask any fellow discrete math or combinatorics folks! That perhaps helped in some sense.  Ramani found management more interesting than those technical details of counting. I am sure he took the right career. Anyway…too much digressing already!

Now, it turns out that, the very same problem is akin to a well known problem in combinatorics. It is called the Hatcheck lady problem. It is fairly easy to solve it using the inclusion exclusion principle. The proof outline is shown below. As I type, memory fetches that discussion,  sitting leg-folded on the cement bench at the REC mini-canteen, perhaps an occasional cool breeze around too. 

The inclusion exclusion principle is the following:

\lvert \bigcup_{i=1}^{n} A_{i} \rvert=\displaystyle\sum_{i=1}^{n}{\lvert A_{i}\rvert}-\displaystyle\sum_{1\le i_{1}<i_{2}\le n}^{n}{\lvert A_{i1}\cap A_{i2} \rvert}+\displaystyle\sum_{1\le i_{1}<i_{2}\le n}^{n}{\lvert A_{i1}\cap A_{i2}\cap A_{i3} \rvert}

                 +\displaystyle\sum_{1\le i_{1}<i_{2}\le n}^{n}{\lvert A_{i1}\cap A_{i2}\cap A_{i3} \rvert}+\ldots+

                 +(-1)^{n-1}{\lvert A_{1}\cap A_{2}\cap A_{3}\cap\ldots\cap A_{n} \rvert}

The Hatchek lady problem can be stated with a similar story as the random clocker machine. (From Harris, Mossinghoff, Hirst’s book on Combinatorics and Graph Theory)

A lazy professor gives a quiz to a class of n students, then collects the papers, shuffles them, and redistribute them randomly to the class for grading. The professor would prefer that no student receives his or her own paper to grade. What is the probability that this occurs? This indeed is an equivalent statement of the well known Hatcheck lady problem (I guess the exact name come from a hatcheck lady who collects hats and absentmindedly return them)

For Hatcheck lady problem, the probability P(n)=\frac{D(n)}{n!}.

D(n)=n!-\lvert A_{1}\cup A_{2}\ldots\cup A_{n}\rvert=n!-\frac{n!}{1!}+\frac{n!}{2!}-\ldots+(-1)^{n}\frac{n!}{n!}

= n!-\displaystyle\sum_{k=1}^{n}{(-1)^{k-1}\binom{n}{k}(n-k)!}=n!-\displaystyle\sum_{k=1}^{n}{(-1)^{k-1}\frac{n!}{k!}}

P(n)= 1-\displaystyle\sum_{k=1}^{n}{(-1)^{k-1}\frac{1}{k!}}

When n gets larger and larger it converges asymptotically to a constant!

\displaystyle\lim_{n\to\infty} P(n)=\displaystyle\lim_{n\to\infty}{\displaystyle \sum_{k=1}^{n}{\frac{1}{k!}}}=\frac{1}{e}

While the talk and boom about multimode multiband phone in CMOS is turning greener, there should be a natural question around it.  How about doing all these in software? Rather add a level of programmability such that a great deal of issues from a  hardwired implementation are shifted to more flexible firmware.  Without contention, pros and cons with the idea of programmability still prevail. Clearly, one definite advantage I see with programmable design is the significant cost reduction and reuse.  Additionally a migration or upgrade, which is imminent from a future gadget design point of view, can get done with relative ease with a programmable multimode chip. Building a suitable processor architecture to suit the modulations schemes (say an OFDM based scheme can have an inbuilt FFT engine or a WCDMA can have a correlator engine). Aren’t anyone working seriously in these directions? I am sure there are many, atleast startup ventures.  Vaanu and Icera indeed are two things coming to my mind.  How about the big boys? There were lot of furies about software programmable baseband chips being developed. Not quite sure what is the latest in that front.  Isn’t it the next big thing in the offing? I am sure the EDA big houses have thought ahead for building tools for a heavily software oriented design, at least for years ahead. Or is it that, I am jumping the gun a little too far? However,  I see some top level bottlenecks in making this programmable multimode chips realizable at an easier pace than a textbook concept. One of them is difficulty in getting away the analog front end. As a matter of fact, now I feel that, analog is going to stay.

So where are we heading to? Clearly, an all CMOS multiband multimode single chip (baseband and analog) with a near perfect RF and a software architecture would be the ultimate holy grail of cellular chip design. How many bands and how many modes to be incorporated becomes less important, if the programmability aspect is assured. Challenges within a single chip concept are themselves many.  Clearly the RF portion is expected to take up lesser share of the overall chip size. An all digital front end is aimed in that direction. While a direct digitization of radio signal of high frequency eliminates analog life process significantly, there are several practical bottlenecks with this Utopian design model.  We are not quite there to say good bye to analog entirely. Analog signal processing is still critical and inevitable, even for a programmable multimode dream.  I will give you some numerical facts to substantiate my claim:

Suppose we decide to build  programmable all digital zero if receiver for a 2GHz system (around the UMTS band). Then,  Shannon Nyqusit sampling would demand at-least 4 G samples/second.  Even with  a processor which clocks 4Ghz and say 8 operations per cycle, our full steam purchase is going to be a maximum 32000000 operations per second. This theoretical figure is based on the assumption that processor memory is fully utilized. At the sampling rate of 4G samples/second, we only are going to get \frac{32 \times 10^{9}}{4\times 10^{9}}=8 operations per sample. How are we going to have all the fancy radio algorithms shape life with this? Even to implement realistic functionality of a typical modern radio, this is inadequate. Another important thing is the imminent power dissipation to run a processor at 4 GHz. For a portable gadget, where  these chip are targeted for, we still need more and more hand in hand optimization and integration with analog processing, software as well as digital processing, in addition to an optimized system architecture. My feeling is that, the analog front end is going to stay for some more time, if not for ever. At least on the immediate future, we need more inroads from analog processing, to realize the small size, cost effective multiband multi mode chip dream.

From this blog piece, I came to know that the smart MIT theoretical computer scientist Madhu Sudan is making a move from MIT to industry. He is set to take up a research position with Microsoft. At this economy troubled days, lesser mortals would take the conservative route that ensure stability and so on. They would say a move from a tenured professorship to a more volatile industry is risky. But then one of the smartest mind in the world can have a world revolve around him, if need be. So no surprises here. On the positive side it is a gain for industry, while it is a big loss for MIT, if Madhu decides to stay away from academia for too long.

Interestingly, on the very same blog, someone commented about other famous moves. Apparently, Venkatesan Guruswami, Madhu’s celebrated student is also making a permanent move from UWash to CMU.  In industry, we are often associated with frequent hops. Academia is not too immune to attrition either. However, I see no harm in making smart moves. It is going to help the world, atleast  in expectation.

As in EPFL too, there is imminent big fish attrition(s). Tom Henzinger and his wife Monika Henzinger are about to leave EPFL to take up a permanent position in Austria. The awesome twosome will be missed in EPFL.

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