Coffee Break

Apa itu Hosting

2008-04-21T11:44:00.000+07:00

Hosting adalah jasa layanan internet yang menyediakan sumber daya server-server untuk disewakan sehingga memungkinkan organisasi atau individu menempatkan informasi di internet berupa HTTP, FTP, EMAIL atau DNS

Server hosting terdiri dari gabungan server-server atau sebuah server yang terhubung dengan jaringan internet berkecepatan tinggi.

Ada beberapa jenis layanan hosting yaitu shared hosting, VPS atau Virtual Dedicated Server, dedicated server, colocation server.

Shared Hosting adalah menggunakan server hosting bersama sama dengan pengguna lain satu server dipergunakan oleh lebih dari satu nama domain.

VPS, Virtual Private Server, atau juga dikenal sebagai Virtual Dedicated Server merupakan proses virtualisasi dari lingkungan software sistem operasi yang dipergunakan oleh server. Karena lingkungan ini merupakan lingkungan virtual, hal tersebut memungkinkan untuk menginstall sistem operasi yang dapat berjalan diatas sistem operasi lain.

Dedicated Server adalah penggunaan server yang dikhususkan untuk aplikasi yang lebih besar dan tidak bisa dioperasikan dalam shared hosting atau virtual dedicated server. Dalam hal ini, penyediaan server ditanggung oleh perusahaan hosting yang biasanya bekerja sama dengan vendor.

Colocation Server adalah layanan penyewaan tempat untuk meletakkan server yang dipergunakan untuk hosting. Server disediakan oleh pelanggan yang biasanya bekerja sama dengan vendor.

Building a Forex Trading

2008-04-21T11:35:00.001+07:00

Your chosen Forex trading strategy will drive the trading decisions that you make in the Forex trading system. If you are new or a novice to Forex trading systems, you will need to develop an appropriate strategy that will evolve over time. The following steps outline the approach to building a Forex trading strategy that may be adapted and tailored to your needs.

Develop a Forex Trading Plan - A Forex trading strategy should never be considered absolute or complete. Part of having a Forex trading strategy is incorporating a plan for making adjustments to the strategy. You will need to be able to make adjustments without completely revamping your strategy. Though you may consider your trading strategy to be more technical than fundamental or vice versa, you should take advantage of any available market data in making your trading decisions regardless of which discipline it falls under.

Initiate a Forex Trade - You must decide on the currency pairs that you which to trade and the number of units to trade. You must establish either a buy or sell position. You are then ready to initiate a trade as either a market order or a limit order. A market order initiates a trade at the current market price while a limit order permits a trade to be executed when the market price reaches a limit that is predetermined by you. As a safeguard for online trading, particularly with limit orders, you should also establish limits to take profits or stop losses. Take profit and stop loss limits become particularly important with online trading when your Internet connection is loss. In the time it will take to reestablish a connection, the market price may change and fall outside of any established limits. Your trading platform may be able to calculate a suitable set of limits. Limits are set as either the percentage of the trading range or as distance from the market entry price. If you have established an open position, you may adjust these calculated values to suit your needs.

Technologies Desktop Search

2008-04-19T22:26:00.001+07:00

Desktop search engines build and maintain an index database to achieve reasonable performance when searching several gigabytes of data. Indexing usually takes place when the computer is idle and most search applications can be set to suspend it if a portable computer is running on batteries, in order to save power. When indexing the files, desktop search tools collect three types of information about files:

* file and directory names
* metadata, such as titles, authors, comments in file types such as MP3, PDF and JPEG
* content of supported documents.

To search within documents, the tools need to be able to parse many different types of documents. This is achieved by using filters that interpret selected file formats. For example, a Microsoft Office Filter might be used to search inside Microsoft Office documents.

Long-term goals for desktop search include the ability to search the contents of image files, sound files and video by context.

The sector attracted considerable attention from the struggle between Microsoft and Google. According to market analysts, both companies are attempting to leverage their monopolies (of web browsers and search engines, respectively) to strengthen their dominance. Due to Google's complaint that users of Windows Vista can not choose any competitor's desktop search program over the built-in one, an agreement was reached between US Justice Department and Microsoft that Windows Vista Service Pack 1 will enable users to choose between the built-in and other desktop search programs, and select which one is to be the default.

Desktop Search

2008-04-19T22:04:00.001+07:00

Is the name for the field of search tools which search the contents of a user's own computer files, rather than searching the Internet. These tools are designed to find information on the user's PC, including web browser histories, e-mail archives, text documents, sound files, images and video.

One of the main advantages of desktop search programs is that search results come up in a few seconds; Windows search companion can be some help, but it searches through Windows files and folders only, not e-mail or contact databases, and unless you enable the Indexing Service (in Windows 2000 or XP), the Windows search tool is extremely slow.A variety of desktop search programs are available; see this list for examples.

Desktop search is emerging as a concern for large firms for two main reasons: untapped productivity and security. A commonly cited statistic states that 80% of a company's data is locked up inside unstructured data — the information stored on an end user's PC, the files and directories they've created on a network, documents stored in repositories such as corporate intranets and a multitude of other locations. [2] Moreover, many companies have structured or unstructured information stored in older file formats to which they don't have ready access.
X1 Technologies' X1 Professional Client is an example of a desktop search tool for Windows.
X1 Technologies' X1 Professional Client is an example of a desktop search tool for Windows.

Companies doing business in the United States are frequently required under regulatory mandates like Sarbanes-Oxley, HIPAA and FERPA to make sure that access to sensitive information is 100% controlled. This creates a challenge for IT organizations, which may not have a desktop search standard, or lack strict central control over end users downloading tools from the Internet. Some consumer-oriented desktop search tools make it possible to generate indexes outside the corporate firewall and share those indexes with unauthorized users. In some cases, end users are able to index — but not preview — items they should not even know exist.

History of web search engine

2008-04-19T21:18:00.005+07:00

The very first tool used for searching on the Internet was Archie.The name stands for "archive" without the "v". It was created in 1990 by Alan Emtage, a student at McGill University in Montreal. The program downloaded the directory listings of all the files located on public anonymous FTP (File Transfer Protocol) sites, creating a searchable database of file names; however, Archie did not index the contents of these files.

The rise of Gopher (created in 1991 by Mark McCahill at the University of Minnesota) led to two new search programs, Veronica and Jughead. Like Archie, they searched the file names and titles stored in Gopher index systems. Veronica (Very Easy Rodent-Oriented Net-wide Index to Computerized Archives) provided a keyword search of most Gopher menu titles in the entire Gopher listings. Jughead (Jonzy's Universal Gopher Hierarchy Excavation And Display) was a tool for obtaining menu information from specific Gopher servers. While the name of the search engine "Archie" was not a reference to the Archie comic book series, "Veronica" and "Jughead" are characters in the series, thus referencing their predecessor.

The first Web search engine was Wandex, a now-defunct index collected by the World Wide Web Wanderer, a web crawler developed by Matthew Gray at MIT in 1993. Another very early search engine, Aliweb, also appeared in 1993, and still runs today. JumpStation (released in early 1994) used a crawler to find web pages for searching, but search was limited to the title of web pages only. One of the first "full text" crawler-based search engines was WebCrawler, which came out in 1994. Unlike its predecessors, it let users search for any word in any webpage, which became the standard for all major search engines since. It was also the first one to be widely known by the public. Also in 1994 Lycos (which started at Carnegie Mellon University) was launched, and became a major commercial endeavor.

Soon after, many search engines appeared and vied for popularity. These included Excite, Infoseek, Inktomi, Northern Light, and AltaVista. Yahoo! was among the most popular ways for people to find web pages of interest, but its search function operated on its web directory, rather than full-text copies of web pages. Information seekers could also browse the directory instead of doing a keyword-based search.

Search engines were also known as some of the brightest stars in the Internet investing frenzy that occurred in the late 1990s. Several companies entered the market spectacularly, receiving record gains during their initial public offerings. Some have taken down their public search engine, and are marketing enterprise-only editions, such as Northern Light. Many search engine companies were caught up in the dot-com bubble, a speculation-driven market boom that peaked in 1999 and ended in 2001.

Around 2000, the Google search engine rose to prominence.The company achieved better results for many searches with an innovation called PageRank. This iterative algorithm ranks web pages based on the number and PageRank of other web sites and pages that link there, on the premise that good or desirable pages are linked to more than others. Google also maintained a minimalist interface to its search engine. In contrast, many of its competitors embedded a search engine in a web portal.

By 2000, Yahoo was providing search services based on Inktomi's search engine. Yahoo! acquired Inktomi in 2002, and Overture (which owned AlltheWeb and AltaVista) in 2003. Yahoo! switched to Google's search engine until 2004, when it launched its own search engine based on the combined technologies of its acquisitions.

Microsoft first launched MSN Search (since re-branded Live Search) in the fall of 1998 using search results from Inktomi. In early 1999 the site began to display listings from Looksmart blended with results from Inktomi except for a short time in 1999 when results from AltaVista were used instead. In 2004, Microsoft began a transition to its own search technology, powered by its own web crawler.

As of late 2007, Google was by far the most popular Web search engine worldwide.A number of country-specific search engine companies have become prominent; for example Baidu is the most popular search engine in the People's Republic of China.

How Web search engines work

2008-04-19T21:13:00.000+07:00

Web search engines work by storing information about many web pages, which they retrieve from the WWW itself. These pages are retrieved by a Web crawler (sometimes also known as a spider) — an automated Web browser which follows every link it sees. Exclusions can be made by the use of robots.txt. The contents of each page are then analyzed to determine how it should be indexed (for example, words are extracted from the titles, headings, or special fields called meta tags). Data about web pages are stored in an index database for use in later queries. Some search engines, such as Google, store all or part of the source page (referred to as a cache) as well as information about the web pages, whereas others, such as AltaVista, store every word of every page they find.

This cached page always holds the actual search text since it is the one that was actually indexed, so it can be very useful when the content of the current page has been updated and the search terms are no longer in it. This problem might be considered to be a mild form of linkrot, and Google's handling of it increases usability by satisfying user expectations that the search terms will be on the returned webpage. This satisfies the principle of least astonishment since the user normally expects the search terms to be on the returned pages. Increased search relevance makes these cached pages very useful, even beyond the fact that they may contain data that may no longer be available elsewhere.

When a user enters a query into a search engine (typically by using key words), the engine examines its index and provides a listing of best-matching web pages according to its criteria, usually with a short summary containing the document's title and sometimes parts of the text. Most search engines support the use of the boolean operators AND, OR and NOT to further specify the search query. Some search engines provide an advanced feature called proximity search which allows users to define the distance between keywords.

The usefulness of a search engine depends on the relevance of the result set it gives back. While there may be millions of webpages that include a particular word or phrase, some pages may be more relevant, popular, or authoritative than others. Most search engines employ methods to rank the results to provide the "best" results first. How a search engine decides which pages are the best matches, and what order the results should be shown in, varies widely from one engine to another. The methods also change over time as Internet usage changes and new techniques evolve.

Most Web search engines are commercial ventures supported by advertising revenue and, as a result, some employ the controversial practice of allowing advertisers to pay money to have their listings ranked higher in search results. Those search engines which do not accept money for their search engine results make money by running search related ads alongside the regular search engine results. The search engines make money every time someone clicks on one of these ads.

The vast majority of search engines are run by private companies using proprietary algorithms and closed databases, though some are open source.

Hard disk

2008-04-19T11:48:00.000+07:00

A hard disk drive (HDD), commonly referred to as a hard drive, hard disk or fixed disk drive,[1] is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Strictly speaking, "drive" refers to a device distinct from its medium, such as a tape drive and its tape, or a floppy disk drive and its floppy disk. Early HDDs had removable media; however, an HDD today is typically a sealed unit (except for a filtered vent hole to equalize air pressure) with fixed media.

[2]A HDD is a rigid-disk drive, although it is probably never referred to as such. By way of comparison, a so-called "floppy" drive (more formally, a diskette drive) has a disc that is flexible. Originally, the term "hard" was temporary slang, substituting "hard" for "rigid", before these drives had an established and universally-agreed-upon name. Some time ago, IBM's internal company term for an HDD was "file".

HDDs (introduced in 1956 as data storage for an IBM accounting computer[3]) were originally developed for use with general purpose computers, see History of hard disk drives.

In the 21st century, applications for HDDs have expanded to include digital video recorders, digital audio players, personal digital assistants, digital cameras and video game consoles. In 2005 the first mobile phones to include HDDs were introduced by Samsung and Nokia.[4] The need for large-scale, reliable storage, independent of a particular device, led to the introduction of configurations such as RAID arrays, network attached storage (NAS) systems and storage area network (SAN) systems that provide efficient and reliable access to large volumes of data. Note that although not immediately recognisable as a computer, all the aforementioned applications are actually embedded computing devices of some sort.

computer

2008-04-19T11:03:00.008+07:00

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 (around 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.^[1] Modern computers are based on tiny integrated circuits and are millions to billions of times more capable while occupying a fraction of the space.^[2] Today, simple computers may be made small enough to fit into a wristwatch and be powered from a 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 programs makes computers extremely versatile and distinguishes them from . 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 to a supercomputer are all able to perform the same computational tasks given enough time and storage capacity.

what is a Protocol

2008-04-09T23:35:00.003+07:00

Definition: A network protocol defines rules and conventions for communication between network devices. Protocols for computer networking all generally use packet switching techniques to send and receive messages in the form of packets.

Network protocols include mechanisms for devices to identify and make connections with each other, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols also support message acknowledgement and data compression designed for reliable and/or high-performance network communication. Hundreds of different computer network protocols have been developed each designed for specific purposes and environments.

Internet Protocols

The Internet Protocol family contains a set of related (and among the most widely used network protocols.

How Network Protocols Are Implemented

Modern operating systems like Microsoft Windows contain built-in services or daemons that implement support for some network protocols. Applications like Web browsers contain software libraries that support the high level protocols necessary for that application to function. For some lower level TCP/IP and routing protocols, support is implemented in directly hardware (silicon chipsets) for improved performance.

TCP / IP

2008-04-09T23:26:00.004+07:00

The Internet protocol suite is the set of communications protocols that implement the protocol stack on which the Internet and most commercial networks run. It has also been referred to as the TCP/IP protocol suite, which is named after two of the most important protocols in it: the Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were also the first two networking protocols defined

Today’s IP networking represents a synthesis of two developments that began to evolve in the 1960s and 1970s, namely LANs (Local Area Networks) and the Internet, which, together with the invention of the World Wide Web by Sir Tim Berners-Lee in 1989, have revolutionized computing. The Internet Protocol suite—like many protocol suites—can be viewed as a set of layers. Each layer solves a set of problems involving the transmission of data, and provides a well-defined service to the upper layer protocols based on using services from some lower layers. Upper layers are logically closer to the user and deal with more abstract data, relying on lower layer protocols to translate data into forms that can eventually be physically transmitted. The TCP/IP reference model consists of four layers.