Showing posts with label computer. Show all posts
Showing posts with label computer. Show all posts

Thursday, June 2, 2011

DNA computer ‘calculates square roots’


Computing Have Taken A New Shape .A New Era of Computing is made To Set out With the Advent Of Dna Computers As Scientists Design  a New digital circuit designed to use molecules to crunch a Solve variety of complex math problems.
Sounds A Bit Strange But Next Generation of computing Is Possible With DNA.As Scientists Realise The Fact That Millions of natural supercomputers exist inside living organisms, including your body. DNA (deoxyribonucleic acid) molecules, the material our genes are made of, have the potential to perform calculations many times faster than the world's most powerful human-built computers. DNA might one day be integrated into a computer chip to create a so-called biochip that will push computers even faster.

DNA computing uses chemical reactions to solve problems in which a number of DNA strands act as "bits".

The work, reported in Science, required 130 strands of DNA to work in a cascade of programmed chemical changes.

The approach is not designed to rival traditional electronics, but rather to allow computing to occur in biological contexts, perhaps even in the body.

DNA computing was first proposed by Leonard Adelman in 1994, to solve what is known as the "travelling salesman problem" - determining the shortest path that joins a number of geographically separated locations.

Since then, a wide array of approaches has aimed to make use of the properties that make DNA attractive for computing: it can be made to order and its interactions with itself are well-studied and reliable.

In 2006, Erik Winfree of the California Institute of Technology (Caltech) and his colleagues published an article in Science a framework making use of one of these approaches, known as strand displacement.

Stretches of DNA made of just one strand (rather than the two joined strands that form the well-known double helix) were used as anchor points for other single strands.

By carefully "programming" the movement of these strands, the researchers were able to recreate a number of elements familiar from conventional computing, including logic gates, amplification, and feedback.

"Those circuits were smaller [than those of the current work], but more importantly, they were built using more complex DNA molecules that made systems more difficult to debug and had other problems," Professor Winfree told BBC News.

Stranded

Now, Professor Winfree and his collaborator Lulu Qian have employed a scheme using what they call "seesaw gates", which accomplish the shuffling and exchange of DNA strands using simpler machinery.

The work showed that seesaw gates could again be used to create logic gates - the basis of electronic computing's manipulation of information - and represented a five-fold leap in the number of DNA sections ever implemented in such a DNA computer.

The approach can be scaled up in complexity far further, the authors suggest - but the process is slow.

For example, it was used to calculate the square root of a four-bit number, but the process took between six and 10 hours.

However, Professor Winfree said that contrary to conventional electronics, the goal is not just high speeds.

"We are no longer pursuing the goal targeted by Len Adleman's original DNA computing experiment: to compete with silicon by using the massive parallelism of chemistry to solve combinatorial problems in mathematics," he explained.

"Instead, our goal is now - and has been for many years - to enrich chemistry itself so that molecular behaviours can be programmed.

"We'd like to make chemical systems that can probe their molecular environments, process chemical signals, make decisions, and take actions at the chemical level."

Binyamin Gil, a member of the research group that in 2009 published on a DNA computer that could "answer" logical conundrums, told BBC News that the DNA computer of the new work exhibited more "digital behaviour" than other molecular computing approaches and thus that "it may be more robust, reliable and scalable".

"The complexity of the presented work - together with the potential of scalability and of interfacing it with other molecular computers - make this paper important and interesting," he said.


Source :BBC

Sunday, October 3, 2010

How to install a software in ubuntu


Ubuntu is an open source operating system which is Linux based, and thus can be edited by many people. It is free to install and contains many free programs, so it is a great low-cost alternative to Windows.There is an increasing trend in the grwoth of ubuntu users in last couple of years ,As this is a freely available version to users are opting this than the windows which costs around some $200 or even more.Ubuntu is constantly updated by enthusiastic people all around the world.Ubuntu updated its recent version which have various applications,we have Office which supports all ms office formats and we got wine where a virtual envionment is created,it can help to run all our windows applications .
But what makes the users who recently migrated and who want to jump into this world is how to install a software ,Most of the users confuse at this where they download a certain software from third party websites and they wont find a graphical easy interface to install it.
For all those beginners this post will help them to install any kind of software in ubuntu.
Installing through Ubuntu software centre:

Ubuntu comes with a built in application manager which lessens your burden in searching the softwares .
Follow this steps to install a new software:
*Go to Applications
*select Ubuntu Software Center.
*click on  Free software.
*select the department or just go for search
*after searching ,select the one you want and double click it and install by giving authentication,permission.
Installing Manually:
Second way of insatlling is by manually ,when you did'nt find the software requried.
download from the webistes of the software product a .deb extension file
After downloading just double click and install it.
The another of installing software is getting packagae from ubuntu ,in linux distributions software  is often reffered as package
Go to terminal
*change to adminstrator by typing su and then root password
*type the command
sudo apt-get install "software"(software==package you want without quotes)
ex:
sudo apt-get install wine

Wednesday, July 28, 2010

Url Format

Categorias de Descargas gratis, Peliculas de e...
If you've been surfing the Web, you have undoubtedly heard the term URL and have used URLs to access HTML pages from the Web.
so what does the url do??
what is a url?? how it works
The uniform resource locator(URL) is the address of a resource available on Internet.Any resource available on internet need to be accessed must be first identified by this url.Each time when u are clicking on any hyperlink in a site,you are actually instructing browser to find the URL that is embedded in hyperlink.
Url is typed at address ar of browser.url denotes the way to find information avialable in the web.
It consists of three parts -name of protocol,host name,name of document...protocal makes computers to exchange info.host name gives the name of the site in web,document denotes the required info.
Url Format:
protocol://server's address/filename

ex:
http://coolinformation4all.blogspot.com/2010/07/super-8-trailer.html

ex::http://www.onetoone.com/html/ahh.htm



http is protocol...onetoone is domainn name and .com is the top level domain name
 /html/ahh.htm is the file which you are trying to access,the one u want.
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