Rugged Laptop

A Panasonic Toughbook.

A rugged (or ruggedized) laptop is designed to reliably operate in harsh usage conditions such as strong vibrations, extreme temperatures and wet or dusty environments. Rugged laptops are usually designed from scratch, rather than adapted from regular consumer laptop models. Rugged notebooks are bulkier, heavier, and much more expensive than regular laptops^[15], and thus are seldom seen in regular consumer use.

The design features found in rugged laptops include rubber sheeting under the keyboard keys, sealed port and connector covers, passive cooling, superbright displays easily readable in daylight, cases and frames made of magnesium alloys or have a magnesium alloy rollcage^[16] that are much stronger than plastic found in commercial laptops and solid-state storage devices or hard disc drives that are shock mounted to withstand constant vibrations. Rugged laptops are commonly used by public safety services (police, fire and medical emergency), military, utilities, field service technicians, construction, mining and oil drilling personnel. Rugged laptops are usually sold to organizations, rather than individuals, and are rarely marketed via retail channels.

Read more...

Computer virus

A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user. The term "virus" is also commonly used, albeit erroneously, to refer to many different types of malware and adware programs. The original virus may modify the copies, or the copies may modify themselves, as occurs in a metamorphic virus. A virus can only spread from one computer to another when its host is taken to the uninfected computer, for instance by a user sending it over a network or the Internet, or by carrying it on a removable medium such as a floppy disk, CD, or USB drive. Meanwhile viruses can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer. Viruses are sometimes confused with computer worms and Trojan horses. A worm can spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a file that appears harmless. Worms and Trojans may cause harm to either a computer system's hosted data, functional performance, or networking throughput, when executed. In general, a worm does not actually harm either the system's hardware or software, while at least in theory, a Trojan's payload may be capable of almost any type of harm if executed. Some can't be seen when the program is not running, but as soon as the infected code is run, the Trojan horse kicks in. That is why it is so hard for people to find viruses and other malware themselves and why they have to use anti-spyware programs and registry processors.

Most personal computers are now connected to the Internet and to local area networks, facilitating the spread of malicious code. Today's viruses may also take advantage of network services such as the World Wide Web, e-mail, Instant Messaging and file sharing systems to spread, blurring the line between viruses and worms. Furthermore, some sources use an alternative terminology in which a virus is any form of self-replicating malware.

Some malware is programmed to damage the computer by damaging programs, deleting files, or reformatting the hard disk. Other malware programs are not designed to do any damage, but simply replicate themselves and perhaps make their presence known by presenting text, video, or audio messages. Even these less sinister malware programs can create problems for the computer user. They typically take up computer memory used by legitimate programs. As a result, they often cause erratic behavior and can result in system crashes. In addition, much malware is bug-ridden, and these bugs may lead to system crashes and data loss.

Read more...

The World Wide Web

Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks

For more details on this topic, see World Wide Web.

Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks

Many people use the terms Internet and World Wide Web (or just the Web) interchangeably, but, as discussed above, the two terms are not synonymous.

The World Wide Web is a huge set of interlinked documents, images and other resources, linked by hyperlinks and URLs. These hyperlinks and URLs allow the web servers and other machines that store originals, and cached copies of, these resources to deliver them as required using HTTP (Hypertext Transfer Protocol). HTTP is only one of the communication protocols used on the Internet.

Web services also use HTTP to allow software systems to communicate in order to share and exchange business logic and data.

Software products that can access the resources of the Web are correctly termed user agents. In normal use, web browsers, such as Internet Explorer, Firefox and Apple Safari, access web pages and allow users to navigate from one to another via hyperlinks. Web documents may contain almost any combination of computer data including graphics, sounds, text, video, multimedia and interactive content including games, office applications and scientific demonstrations.

Through keyword-driven Internet research using search engines like Yahoo! and Google, millions of people worldwide have easy, instant access to a vast and diverse amount of online information. Compared to encyclopedias and traditional libraries, the World Wide Web has enabled a sudden and extreme decentralization of information and data.

Using the Web, it is also easier than ever before for individuals and organisations to publish ideas and information to an extremely large audience. Anyone can find ways to publish a web page, a blog or build a website for very little initial cost. Publishing and maintaining large, professional websites full of attractive, diverse and up-to-date information is still a difficult and expensive proposition, however.

Many individuals and some companies and groups use "web logs" or blogs, which are largely used as easily updatable online diaries. Some commercial organisations encourage staff to fill them with advice on their areas of specialization in the hope that visitors will be impressed by the expert knowledge and free information, and be attracted to the corporation as a result. One example of this practice is Microsoft, whose product developers publish their personal blogs in order to pique the public's interest in their work.

Collections of personal web pages published by large service providers remain popular, and have become increasingly sophisticated. Whereas operations such as Angelfire and GeoCities have existed since the early days of the Web, newer offerings from, for example, Facebook and MySpace currently have large followings. These operations often brand themselves as social network services rather than simply as web page hosts.

Advertising on popular web pages can be lucrative, and e-commerce or the sale of products and services directly via the Web continues to grow.

In the early days, web pages were usually created as sets of complete and isolated HTML text files stored on a web server. More recently, websites are more often created using content management or wiki software with, initially, very little content. Contributors to these systems, who may be paid staff, members of a club or other organisation or members of the public, fill underlying databases with content using editing pages designed for that purpose, while casual visitors view and read this content in its final HTML form. There may or may not be editorial, approval and security syste

Read more...

Security engineering

Jump to: navigation, search

Security engineering is a specialized field of engineering that deals with the development of detailed engineering plans and designs for security features, controls and systems. It is similar to other systems engineering activities in that its primary motivation is to support the delivery of engineering solutions that satisfy pre-defined functional and user requirements, but with the added dimension of preventing misuse and malicious behavior. These constraints and restrictions are often asserted as a security policy.

In one form or another, Security Engineering has existed as an informal field of study for several centuries. For example, the fields of locksmithing and security printing have been around for many years.

Due to recent catastrophic events, most notably 9/11, Security Engineering has quickly become a rapidly growing field. In fact, in a recent report completed in 2006, it was estimated that the global security industry was valued at US$150 billion.^[1]

Security engineering involves aspects of social science, psychology (such as designing a system to 'fail well' instead of trying to eliminate all sources of error) and economics, as well as physics, chemistry, mathematics, architecture and landscaping.[1] Some of the techniques used, such as fault tree analysis, are derived from safety engineering.

Other techniques such as cryptography were previously restricted to military applications. One of the pioneers of security engineering as a formal field of study is Ross Anderson.

Read more...

Theory of computation

Classically, the study of the theory of computation is focused on answering fundamental questions about what can be computed, and what amount of resources are required to perform those computations. In an effort to answer the first question, computability theory examines which computational problems are solvable on various theoretical models of computation. The second question is addressed by computational complexity theory, which studies the time and space costs associated with different approaches to solving a computational problem.

The famous "P=NP?" problem, one of the Millennium Prize Problems,^[18] is an open problem in the theory of computation.

	P = NP ?
Computability theory	Computational complexity theory

Read more...

Major achievements

German military used the Enigma machine during World War II for communication they thought to be secret. The large-scale decryption of Enigma traffic at Bletchley Park was an important factor that contributed to Allied victory in WWII.[11Despite its relatively short history as a formal academic discipline, computer science has made a number of fundamental contributions to science and society. These include:

* Started the Digital Revolution, which led to the current Information Age and the Internet.[12]
* A formal definition of computation and computability, and proof that there are computationally unsolvable and intractable problems.[13]
* The concept of a programming language, a tool for the precise expression of methodological information at various levels of abstraction.[14]
* In cryptography, breaking the Enigma machine was an important factor contributing to the Allied victory in World War II.[11]
* Scientific computing enabled advanced study of the mind, and mapping the human genome became possible with Human Genome Project.[12] Distributed computing projects such as Folding@home explore protein folding.
* Algorithmic trading has increased the efficiency and liquidity of financial markets by using artificial intelligence, machine learning, and other statistical and numerical techniques on a large scale.[15]

Read more...

Computer security hackers

Main article: Hacker (computer security)

Bruce Sterling, author of The Hacker Crackdown

In computer security, a hacker is someone who focuses on security mechanisms of computer and network systems. While including those who endeavor to strengthen such mechanisms, it is more often used by the mass media and popular culture to refer to those who seek access despite these security measures. That is, the media portrays the 'hacker' as a villain. Nevertheless, parts of the subculture see their aim in correcting security problems and use the word in a positive sense. They operate under a code, which acknowledges that breaking into other people's computers is bad, but that discovering and exploiting security mechanisms and breaking into computers is still an interesting activity that can be done ethically and legally. Accordingly, the term bears strong connotations that are favorable or pejorative, depending on the context.

The subculture around such hackers is termed network hacker subculture, hacker scene or computer underground. It initially developed in the context of phreaking during the 1960s and the microcomputer BBS scene of the 1980s. It is implicated with 2600: The Hacker Quarterly and the alt.2600 newsgroup.

By 1983, hacking in the sense of breaking computer security had already been in use as computer jargon,^[16] but there was no public awareness about such activities.^[17] However, the release of the movie WarGames that year raised the public belief that computer security hackers (especially teenagers) could be a threat to national security. This concern became real when a gang of teenage hackers in Milwaukee, Wisconsin known as The 414s broke into computer systems throughout the United States and Canada, including those of Los Alamos National Laboratory, Sloan-Kettering Cancer Center and Security Pacific Bank. The case quickly grew media attention,^[18][11] and 17-year-old Neal Patrick emerged as the spokesman for the gang, including a cover story in Newsweek entitled "Beware: Hackers at play", with Patrick's photograph on the cover.^[12] The Newsweek article appears to be the first use of the word hacker by the mainstream media in the pejorative sense.

As a result of news coverage, congressman Dan Glickman called for an investigation and new laws about computer hacking.^[19] Neal Patrick testified before the U.S. House of Representatives on September 26, 1983 about the dangers of computer hacking, and six bills concerning computer crime were introduced in the House that year.^[20] As a result of these laws against computer criminality, white hat, grey hat and black hat hackers try to distinguish themselves from each other, depending on the legality of their activities.

Read more...

Computer Science Degrees & Resources Online

Introduction

Computer science is the overarching title attributed to the discipline of utilizing computation and information in computer systems. Whereas computer programmers create source code and use programming language to make software, the computer scientist uses these software applications for practical purposes and to understand and utilize computational systems.

Computer Science Books

To master computer science, you will have to do a lot of reading on the subject. While your specific program may recommend certain computer science books to you, you will do well to read as many of the best computer science books as you can get your hands on. Some good texts to start with include 'The C Programming Language' by Brian W. Kernighan, 'C++ Primer' by Stanley B. Lippman, 'Introduction to Algorithms' by Thomas H. Cormen, 'Introduction to the Theory of Computation' by Michael Sipser and 'Concrete Mathematics, a Foundation for Computer Science' by Ronald L. Graham. Places to find computer science books online include Amazon.com, FreeTechBooks.com and your school library website.

Computer Science Articles And Databases

A terrific source of computer science articles is the Citeseer.Continuity database. This database lists all the most cited articles in computer science from 2006 back to 1990, so you have a great chance of finding the article you need, whether it be for research, information or to verify a theory. The database, is updated on a regular basis.

Online Computer Science Journals

Of course, most of the key computer science articles will be found in leading computer science journals. There is no shortage of computer science journals out there, many of which may be accessible through your school libraryís web page, the web pages of other libraries or through other computer science resources online. Some of these include Artificial Intelligence, Computer Graphics, IEEE Transactions on Evolutionary Computation, the Journal of Web Semantics and Logical Methods in Computer Science.

Read more...

History of Computer

A computer is a machine that manipulates data according to a list of instructions.

The first devices that resemble modern computers date to the mid-20th century (1940–1945), although the computer concept and various machines similar to computers existed earlier. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers(PC). Modern computers are based on tiny integrated circuits and are millions to billions of times more capable while occupying a fraction of the space. Today, simple computers may be made small enough to fit into a wristwatch and be powered from a watch battery. Personal computers, in various forms, are icons of the Information Age and are what most people think of as "a computer"; however, the most common form of computer in use today is the embedded computer. Embedded computers are small, simple devices that are used to control other devices — for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and children's toys.

The ability to store and execute lists of instructions called programs makes computers extremely versatile and distinguishes them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital assistant to a supercomputer are all able to perform the same computational tasks given enough time and storage capacity.

Read more...

Tracking the IP address

1. Tracking the IP address of a site
To know the IP address of a site, we can ping the site these. How: Go to the command prompt and typing PING WWW.SITUS-THE-DILACAK.COM and press enter. It will appear Ip address site these.

2. Track the location server (a real address) of a site
We can track the location of a server with only the site address the site only. You try to stay open www.domainwhitepages.com enter the IP address was the site or enter the address of the site and you will get info full on the server of these sites are the locations of countries and city.

3. Tracking the IP address opponent's chat
When we use Yahoo messenger, we can actually know the IP address from the opponent we chat. How:
:: Send a file on the opponent we chat.
:: Then go to the Command Prompt (MSDOS) and N-type NETSTAT and press
enter, then the IP address of your opponent chats (which you have the file was sent)
will appear along with the port used for sending files.
:: To know the location of your opponent chat (real address) as it is
on campus or in the cafe where you live in check www.domainwhitepages.com
using the IP address that you get.

Read more...