Sunday, January 9, 2011

Bsnl Broadband Connection setup in Ubuntu


We need to create a point to point protocol connection to make the modem interface active.
**Method I:
Connecting broadband through command-line-Bridge Mode
/* all ubuntu versions*/
Note: your modem must be set in bridge mode
Steps:
1. Open a terminal
2. Type sudo pppoeconf
3. Enter sudo password if prompted
4. A window with blue screen pops up notifying the devices that are found
5. Follow the on screen instructions and press yes till you reach the screen which asks you to enter username
6. Backspace to delete the text username and then enter the username your ISP has provided you with
7. Press yes again and then enter the password
8. Follow the instructions till it asks you "Do you want to start the connection at start up."
Give yes if you want.
9. After setup is complete you will be prompted with a message in the terminal
10. To start the connection type pon dsl-provider in the terminal
Now, your internet connection gets activated.

11. To terminate this connection type poff in terminal


**Method II:
Ubuntu 8.10(hardy) and 9.04(jaunty) users often face a problem
Problem:The network menu does not appear in System>Administration
The solutions are:
*Method I:
1. Goto Applications>Add/Remove
2. In Show, from the drop-down menu select All available applications
3. In Search tab: type network
4. In Application: check the box next to Network(configure network devices and connections)
5. Apply changes
/*To download this file you need active internet connection*/

*Method II:
1. Open a terminal
2. Type network-admin
3. If your Network Settings is not installed then it will ask you to type
sudo apt-get install network-admin
4. If there is an active internet connection the Network Settings will be installed and it can be located under System>Administration>Network


Now,coming to configuration of Bsnl broadband connection through Network Settings
Steps:
1. Switch off your modem
2. Open Network Settings dialog box form System>Administration>Network
3. Select Wired Connection and click on Properties
4. In the Connection Settings Menu select Static IP and type in the following values and save:

IP Address : 192.168.1.2
/*Assigning the Ethernet Card an IP different from that of the modem*/

Subnet Mask: 255.255.255.0
Gateway address: 192.168.1.1

/* The Modem is being made the default gateway*/

5. Switch on the Modem .
6. Open the Terminal and type sudo pppoeconf
7 .A window with blue screen appears notifying the devices found
8. Press yes till the screen appears that asks you to enter username
9. Backspace to delete the text username and then enter the username your ISP has provided you with
10. Press yes again and then enter the password

Now, your internet connection gets activated.

Note: To check the IP configuration open a terminal and type ifconfig ppp0
The IPV4 address, default gateway and subnet mask addresses are shown

Tuesday, January 4, 2011

The Social Network (2010) - FaceMash Algorithm (


I saw Social Network three times in 1 week. Not for entertainment. Not because I had nothing better to do. But because I wanted to understand the math and computer science fundae used in the movie. I would like to discuss one particularly interesting scene from the movie.

You may remember Mark inviting his friend Eduardo to give him his chess algorithm at the beginning of the movie (Mark was drinking, blogging and hacking simultaneously and creating Facemash.com). You may also remember the scribbles on the window:

and

What is this? This is actually the math behind Elo Rating System. Elo rating system is a method for calculating the relative skill levels of players in two-player games such as chess. It is named after its creator Arpad Elo, a Hungarian-born American physics professor.

As explained in the movie, Facemash was quite simple. Not unlike hotornot.com, students went to a page and 2 random images of girls were picked and presented to them. The students then had to click on the hottest girl presented to them and then another set of two girls would be presented asking the students to repeat the same actions they had done. The difference with hotornot was that the girls presented were all Harvard students. In other words, the students were rating girls of Harvard based on their looks (You can imagine why Mark got into trouble).

The algorithm used - The Elo Rating system - insured a fair rating and ranking of the girls. A hot girl A winning over hot girl B girl would gain more points than winning (or being picked) against ugly girl C. Same goes for the following: ugly girl C wins over ugly girl D. ugly girl C gains some points in her general ranking. If ugly girl C wins over hot girl A then ugly girl C gains more points because the ranking of hot girl A is much higher than ugly girl D. The previous scenario is roughly what the algorithm implemented by Mark was doing. It was somewhat insuring a level of fairness despite the misogynistic nature of the product.

In today’s society, the Elo Rating system is used by many rating and ranking system to predict the outcome of matches but also insure a level of fairness between teams of different levels playing against each others. FIFA uses it to rank football teams.

You can read more about the system on wikipedia page(http://en.wikipedia.org/wiki/Elo_rating_system).

The Social Network (2010) - FaceMash Algorithm

The Social Network (2010) - FaceMash Algorithm




I saw Social Network three times in 1 week. Not for entertainment. Not because I had nothing better to do. But because I wanted to understand the math and computer science fundae used in the movie. I would like to discuss one particularly interesting scene from the movie.

You may remember Mark inviting his friend Eduardo to give him his chess algorithm at the beginning of the movie (Mark was drinking, blogging and hacking simultaneously and creating Facemash.com). You may also remember the scribbles on the window:

and

What is this? This is actually the math behind Elo Rating System. Elo rating system is a method for calculating the relative skill levels of players in two-player games such as chess. It is named after its creator Arpad Elo, a Hungarian-born American physics professor.

As explained in the movie, Facemash was quite simple. Not unlike hotornot.com, students went to a page and 2 random images of girls were picked and presented to them. The students then had to click on the hottest girl presented to them and then another set of two girls would be presented asking the students to repeat the same actions they had done. The difference with hotornot was that the girls presented were all Harvard students. In other words, the students were rating girls of Harvard based on their looks (You can imagine why Mark got into trouble).

The algorithm used - The Elo Rating system - insured a fair rating and ranking of the girls. A hot girl A winning over hot girl B girl would gain more points than winning (or being picked) against ugly girl C. Same goes for the following: ugly girl C wins over ugly girl D. ugly girl C gains some points in her general ranking. If ugly girl C wins over hot girl A then ugly girl C gains more points because the ranking of hot girl A is much higher than ugly girl D. The previous scenario is roughly what the algorithm implemented by Mark was doing. It was somewhat insuring a level of fairness despite the misogynistic nature of the product.

In today’s society, the Elo Rating system is used by many rating and ranking system to predict the outcome of matches but also insure a level of fairness between teams of different levels playing against each others. FIFA uses it to rank football teams.

You can read more about the system on wikipedia page(http://en.wikipedia.org/wiki/Elo_rating_system).