31 December, 2007

New Year, New World

It's a new world
It's a new start
It's alive with the beating of young hearts
It's a new day
It's a new plan
I've been waiting for you
Here I am

('Here I am' By Bryan Adams)

24 December, 2007

Last Week Recap: Microprocessors

Last week was spent mostly thinking about Microprocessors. Apart from curiosity there are couple of reasons why I am so much interested in Microprocessors.
  • In next few days, I am planning to buy some hardware which is capable of hosting an web-based application. I do NOT know if I could use old (less powerful processor) hardware (many CPUs) and combine it do get something useful, need to find this out. Other option is to buy brand new hardware from Dell/HP/Lenovo.
  • I would like to learn how to write software to take advantage of multiple cores in the processors.
  • I would like to give a try to build simple robots (toy car like) based on simple processor (may not even need processor but still). I wonder how exactly processors are used in real cars.
I read some of the books on Microprocessor's published in 197o's (!) , at the library. Intel 4004, 8008, 8086, Motorola 68000 etc. So far I have understood:
  • Random Access Memory (RAM), types of RAM (DRAM, SRAM), cost trade off.
  • How processor is connected to RAM. (address bus, data bus, control bus)
  • Registers in the processor (program counter, stack pointer, accumulator etc.)
  • Processor clock (uses quartz)
From Ulrich Drepper's paper I could understand some basics about Memory Cache. Processor is fast, DRAM is not, so we need memory cache. Need to re-read stuff about NUMA, relevance of Cache memory for multi-core processors and why a programmer should know these details.
Also need to find more information about OpenMP and actually use it (gcc 4.x has it).

I also wonder if there is Museum of Computer History in either Mumbai or Pune and would it be interesting idea to build such Museum. So that students and school children can appreciate and remember the great people behind today's computers (or mobile phones that they are carrying in their pockets).

Good Read : Great moments in microprocessor history.

17 December, 2007

Conference In Banagalore


I attended FOSS.IN 2007, from 4th to 8th December at IISc Bangalore. I decided to attend the conference because of my interest in Firefox browser and Linux Kernel. The conference had great speakers Rusty, Naba, Ulrich, Mitchell Baker and many others. I hope I learned enough to have motivation to work on source code of one of the projects. Overall It was worth the effort of traveling from Mumbai to Bangalore.

I gave a lighting talk on GLPK in 3 minutes to audience of 15 people. I tried to describe why it is good project for people/students who want to improve their programming skills (specifically C and Linux). The reason are that while working on linear program solver one has to think about floating point arithmetic, numerical stability and how to use multiple processors/cores to make program faster.

The lighting talks were good too. You could give a talk on any talk. This guy gave a talk on egg-omelet, it was so good that my mouth was watery :). Thanks Danese for arranging the talks.

Thanks Mozilla team, Fedora team, Sun team, Kernel hackers and all other speakers for interesting talks.

In the evening temperatures dropped to around 16 degrees Celsius. Most of the days I stayed in my hotel room. One evening I visited M. G. Road to buy few T-shirts. Later I realized I could have shopped in Malleshawaram.

Mumbai Airport

My flight to Bangalore was delayed by 30 mins, so I got to spend few hours at Mumbai International. Airport, domestic terminals. It has quite improved, they have increased the security check area, passenger lounge area. CCD and Crossword are there inside the terminal.

Outside the terminal they have build a huge shelter, should be useful in rainy season. So now passengers should be able to catch a cab without getting wet in case of rains.

Jet Airways In-flight Entertainment System

Flight took of in east direction (strip is east-west I think), sky was clear, got to see other side of Mumbai from the sky. The slums actually look beautiful from the sky. This was first time I used Jet's In-flight entertainment system, it was good.

Basically it is a touch screen (medium size), where you can choose the menus. You plug in the head-phone in the whole on the left hand of your seat. They have lots of music options (classical, pop etc.). Later I watched a Friends episode.

03 December, 2007

Bangalore Conference

I will be attending open source conference FOSS.IN/2007, in Bangalore from 4th till 8th Dec. Drop me a mail if you want to hang out, discuss about airlines industry, algorithms to solve lp/mip, scheduling problems, Linux, computers etc. If there are music festivals going on somewhere in Bangalore, I would be interested.

At the conference I just want to have fun, learn some Javascript, about Linux (process scheduling part) Kernel, parallel processing. Also want to collect info about different option available for fast Internet connection and cheap hardware.

Recently I have been thinking about some of following problems:

- Collecting data from various sources and analyzing it and use it for making better decisions.
  • Patients diagnosis at hospitals.
  • Travel/transportation data.
  • Students performance in school and other places. This data can be combined with his/her preferences/hobbies and used to offer career advise.
- A cheap computer for student with very limited functionality, which will make teenage students ready for using "real" laptops. Basic functionality should allow them to type alphabets and words.

- Hardware re-cycling.
- Portable device to measure quality of air, water and food, quickly.

27 October, 2007

Saturday Morning and Powai Lake

Saturday morning, woke up around 8.45 AM, decided to have tea and donuts at Cafe Coffee Day and then go for jogging inside IIT.
I thought that I could easily walk from CCD to IIT, would be good idea as there is always traffic jam on that part of the road. However after getting to CCD, I realized that it's too much of a distance to walk, wish they had small road which goes over the lake directly into IIT, would be nice to cycle/jog/walk on a road over the lake.

Spent some time at Powai lake, nice water, enjoyed cool breeze, could see IIT building and RENAISSANCE hotel. There were bunch of boys swimming in the lake, don't know what exactly they were doing, finding pots, wooden buckets etc, probably thrown in the water in last week Durga Visarjan. This is of course a bad practice, throwing idols, plastics and other things in the water.

Saw few worker digging ground adjacent to road, for laying cables, mostly manual, even picking big rocks, can they not use machines? I saw similar use of primitive manual saws by workers clearing the trees on the road where I live.

Last weekend I cycled from my house to the CCD, via Mahakali Caves. There is small pass (kaccha road) which joins JV link road, before SEEPZ flyover. It was a challenging ride.

12 August, 2007


My office is around 1 km from my home, getting auto rickshaw is not always easy, because autowallas sometimes refuse to go small distances. I have been thinking about buying a bicycle and use it to commute to office and go on long rides on weekends.

So finally I got Hero Hawk. It's light, fast, single gear ratio, no springs and no problems so far.

Yesterday I managed to cycle from my home to Vile Parle (E), market, Dinanath Mangeshkar Natyagraha.

(Photo Source: http://herocycles.com/boyz.php)

I was wondering how much power do I produce when riding the bicycle and how I can measure it. I need to measure crank rpms and torque. For time being I have following figure showing typical power produced by cyclists.

If I assume peak power of 0.2 horsepower, it's (0.2 * 745) = 149 watts.

(Image Source: http://users.frii.com/katana/biketext.html)

According to article at above URL, you need multiple gear ratios to deal with different slopes.

23 July, 2007

Mumbai: Challenges Ahead

Watched a good program "Mumbai 2005 floods" on National Geographic. They tried to explain what exactly happened on 26th July 2005.

- It rained heavily, around 900 mm in 24 hrs in Suburbs.
- Land reclamation and narrow Mithi river could not carry away water fast enough.
Almost everything (trains, airports, roads, electricity supply, emergency services) came to halt on that day in Mumbai.

I was searching for more information, found this excellent article about challenges in creating drainage, water treatment system for growing Mumbai.

Some of interesting bits are :
year 1947, population 1.7 million approx.
year 1970, population 8.0 million approx.
year 2005, population 15 to 20 million estimated
year 2025, population 26.5 million estimated

"But despite some progress, the World Bank was ultimately disappointed with the outcome. A 1995 audit of its Bombay Sewage Disposal Project found that the plan's implementation was "little short of disaster." Huge cost overruns, insufficient expertise and shoddy workmanship all contributed."

"Many Indian engineers are well-educated and highly skilled, he adds--and in any case, locals tend to have a better grasp of their own problems than foreigners.
What Indian firms often lack, however, are management and supervision skills for big projects, which may also require highly specialized expertise found only in foreign firms."

"Many Mumbai residents don't pay for water and sewerage services; Indians tend to regard them as free. That has discouraged investment in system improvements, which, in turn, has contributed to well-founded complaints about poor service and bolstered resistance to user fees."

"RVA's Indian experience has left Perks with an abiding respect for Indian engineers and administrators who run the existing system. "They do a pretty good job for the infrastructure they have and the pressures they're under," ....

01 July, 2007

Rain and Books

(Source : http://www.imd.ernet.in/section/satmet/dynamic/sector-vis.htm)

If you sitting at home due to rain outside (this is likely to be the case if you are anywhere in the western Maharashtra), and want to spend time reading, following is list of books you might find interesting.

(Book cover link to Harper-Collins Publishers India)

24 June, 2007

Mumbai Rain

Yesterday (June 23rd 2007) huge amount of rain poured in Mumbai. In the evening, I went to IITB bookshop hoping to get book '(Matrix Computations by Golub et. al.), I should have checked forecast before going out.

At around 7.30 PM large dark clouds gathered in the sky and huge downpour started. I was carrying a umbrella, started walking towards the gate. I decided to go back to home as soon as possible and picked an auto rickshaw.

There is lot of construction going on starting from IIT main gate till hiranandani and Navy training institute. There are no signs "Under construction", so any driver new to the area, its dangerous driving especially in the rain. I saw a car tilted with its left hand side tires beyond the left border of the road. Due to huge level gap car tilted.

There was water everywhere on the road. Near Cafe Coffee Day there was huge amount of water. We were worried about possibility of auto rickshaw breaking down due to water getting into its electrical system. Thats exactly what happened.

I got down, help driver for some time and later got into another auto. To cut the story short, I finally reached home safely, full wet. Two more places to note down where there was water logging are, link road before SEEPZ flyover, and in front of Akruti Center.

Lessons learned :
  • Check local forecast for possible thunderstorms before you venture out in the city.
  • Do not expect much (overestimate) of roads/infrastructure in general, at least for few more years.
There is lot of good work (road,fly-overs, underground drainage) done, but lot remains to be done, and at some places its not up to to the mark. Is it possible that there is lack of enough competent civil engineers?

04 March, 2007

Microfinance: Giving opportunities to small vendors.

Few weeks back, I watched a TV program about Microfinance and Muhammad Yunus who pioneered Grameen Bank in Bangladesh.

An an young economist, one question that bothered Yunus is "Why so many people in his country are poor?".

He met a woman who made bamboo stools in a village. He found that, she borrowed money from "evil lender" for buying raw material. "Evil Lender" gave her money on a strict evil condition that all finished bamboo stools should be sold to only him at price lower than the market price of stools. So woman could earn very small amount of money at end of month, barely enough to buy food, no savings to buy raw material on her own. So next month she has NO other option than to borrow money from "evil lender". Government and private banks won't lend money to her without any collateral (which she did NOT have). She was stuck in hell.

So the microfinance idea is to provide poor woman enough money, trust in her skills, her ability to create small profitable business, her instincts to efficiently manage the money and take care of her children and family, make her independent.

Overall it was a inspiring TV programme. I need to find some more details about microfinance.
There is one idea in my mind, from my observation of street vendors (selling fruits, flowers, vegetables etc.) in big cities in India. Rightnow problem is they do not have a place/shop where they can store their products and sell to customers.
  • A place where they can scale (meaning increase the size).
  • A place which will protect them and their inventory from rain and sun.
  • A place where customers will come to buy.
Maybe a 200 sq. feet. shop in a mall/vegetable marker. How do they get money to buy the shop? Can micro-finance ideas help? Are banks ready to lend them small load? or what if banks lend money to somebody who buys the shop(s) and rents them to poor vendors.
Does anybody knows about such banks?

21 January, 2007

Learning Photography, Cricket

Today afternoon, saw few cricket matches between local teams. I took my camera (Canon PowerShot S2 IS), and experimented a bit with its functions like exposure, shutter speed, and aperture. Took some black & white photos.

I am posting couple of photos, which I think are good. I could not really experiment much with shutter speed and aperture, may be later.

06 January, 2007

Victoria Memorial Architecture

Its made of marble.
From official website of Victoria Memorial, page on architecture.

"The building is 184 ft high upto the base of the figure of Victory, which is another 16 ft high. The groups of figures above the north porch represent Motherhood, Prudence and Learning. Surrounding the main dome are figures of Art, Architecture, Justice, Charity etc. The Memorial is situated on a 64 acres of land with the building covering 338 ft by 228ft."

On the top of dome is 16 ft high statue of angel.
On left hand side is photo of angel being made in Italy (around 1920). (source: http://www.victoriamemorial-cal.org/architecture.html).
Few months back I read in the newspaper that the angels statue actually used rotate (around verticle axis), however now its struct because of some mechanical problems.