Thursday, June 16, 2011

Do you want $1,000,000? Then Solve one of these problems

There are set of 7 puzzles, which are called as Millennium Prize Problems. These problems belongs to mathematics. But they have considerable impact on the computer science also. These problems were quoted by Clay Mathematics Institute of USA. If you solve any one of these problems, you will be awarded with 1 Million dollars.

Those Seven Problems are

1. P vs NP Problem
2. Hodge Conjecture
3. Poincare Conjecture
4. Riemann Hypothesis
5. Yang- Mills Existence and Mass gap
6. Navier Stokes Existence and Smoothness
7. Birch and Swinnerton- Dyer Conjecture

Out of these 7 problems, one problem was solved by Dr. Grigoriy Perelman of St. Petersburg, Russia last year. He solved the 3 problem i.e Poincare Conjecture. Obviously he will get 1 Million dollars, but he declined to take it.

Do you want $1,000,000, then try your luck here. The details of each problem was available from the portal of Clay Institute.

Tuesday, June 14, 2011

Signing an Assembly(DLL) without recompilation

While i was working on migration of one of our old application, i came across one situation where, i need to deploy a DLL into GAC. So what, what is the problem? Yes there is a problem, my old assembly is not strong named or signed. Thats it. As we know, we can't deploy non signed assemblies in to GAC.

That assembly was developed using .net framework 1.1 and i have no access to the development machine now. What to do now? Then, I have started exploring different options. I found one blog, where he has given few commands for strong naming assembly without recompilation. That's awesome. I gave a try with a sample DLL. Simply superb!!!!! Only 3 Steps, It worked perfectly.

Here is the Commands,

Go to your Visual Studio command Prompt, then navigate to the folder where you have the DLL to be signed. then type the following commands.

> ildasm MyAssembly.dll /
> sn -k MyKeyFile.snk
> ilasm /dll /key=MyKeyFile.snk

That's it, the DLL is strong named or signed. Now give a test by dropping the dll in to GAC.

Tuesday, May 31, 2011

The Object-Oriented Thought Process, 3/e by Matt Weisfeld

Currently I am reading this book on OOPs concepts to refresh my knowledge. It is very nice book and the author has explained each and every concept in a very good manner, so that you will understand easily and you will remember it very easily. Moreover you get bored and feel sleepy while reading this book. It's nice to read.

If you want one, You can buy it from here.

Wednesday, May 18, 2011

WORK speaks louder than WORDS - Don't believe?? Watch this.

A boy from a poorest village in Africa has built a Windmill when he was just 14 years old. His name William Kamkwamba. He built his family an electricity-generating windmill from spare parts, working from rough plans he found in a library book.

Watch this video, you will believe the saying "WORK speaks louder than WORDS".

Do you believe now?

another video from the same guy. " How i harnessed the wind".

Do you believe, he didn't finish his school yet. After he finished his first speech at ted stage, he went back home, and started going to school to finish his schooling.

Now, his life was documented and coming as a book "
The Boy Who Harnessed the Wind: Creating Currents of Electricity and Hope ". I think it's already published.

I saw few comments on his video's. But i like this most. It's from
Agam Shah.
Oct 5 2009: Bravo man. Extraordinary courage and determination. Thought! I am 25 and well educated, got masters degree in environmental design, read a lot, seen a lot, heard a lot of energy and green stuff...but if I compare myself to William, i feel i am too small. I don't think i would have thought of making a wind mill or have the confidence that I would make one and it would work.

Amazing man. Lot to learn from you. WORK speaks louder than WORDS. You are an inspiration to me and to all who will see the video.
Because it well suits me.

Do you want to see that kid? Here he is, with his windmill which will generate 12watts of power.

Thats why, our forefathers said "Necessity is the mother of all inventions".

Monday, May 24, 2010

Subnet Mask Calcualtions

For example, if the number of hosts(510) given and a sample IP( has given. How to find out the subnet mask?

=> Here in this case answers is is an IP Address of type Class B. So the possible subnet mask will be

As per the problem only 510 hosts are allowed and 0,255 reserved for special purposes. So the total of 512 hosts possible.

i.e. 512(Decimal) = 2^9.

only 9 bits will be used for IP and the remaining will be used for Sub net Masking.

As we know, each IP will have 4 Octets and each Octet will be represented by 8 bits. So out of 9 bits, 8 bits will be used by Fourth Octet and 1 bit will be used by Third Octet.

If you see the, Class B sub net mask, First and Second Octets will be represented by 255. Means all the bits are used for Sub net masking only.

First Octet - 1111 1111 - 255
Second Octet - 1111 1111 - 255
Third Octet - 1111 1110 - 254(only 7 bits)
Fourth Octet - 0000 0000 - 0

So, the final subnet mask will be 255.255.254. 0

For more details on Sub net mask calculations,

Any comments ? suggestions?