Computer Science General Knowledge - Part III

GSM

• Short for Global System for Mobile Communications, one of the leading digital cellular systems. GSM uses narrowband TDMA, which allows eight simultaneous calls on the same radio frequency.
• GSM was first introduced in 1991. As of the end of 1997, GSM service was available in more than 100 countries and has become the de facto standard in Europe and Asia.

E-Mail Spoofing

• Forging an e-mail header to make it appear as if it came from somewhere or someone other than the actual source. The main protocol that is used when sending e-mail -- SMTP -- does not include a way to authenticate.
• There is an SMTP service extension (RFC 2554) that allows an SMTP client to negotiate a security level with a mail server.
• But if this precaution is not taken anyone with the know-how can connect to the server and use it to send spoofed messages by altering the header information.

BLOB

• Short for binary large object, a collection of binary data stored as a single entity in a database management systems (DBMS).
•  BLOBs are used primarily to hold multimedia objects such as images, videos, and sound, though they can also be used to store programs or even fragments of code. Not all DBMSs support BLOBs.

AODV

• Short for Ad Hoc On-Demand Distance Vector, a routing protocol for ad hoc mobile networks with large numbers of mobile nodes.
• The protocol's algorithm creates routes between nodes only when the routes are requested by the source nodes, giving the network the flexibility to allow nodes to enter and leave the network at will.
• Routes remain active only as long as data packets are traveling along the paths from the source to the destination. When the source stops sending packets, the path will time out and close.

4G

• Short for fourth generation, 4G is an ITU specification that is currently being developed for broadband mobile capabilities. 4G technologies would enable IP-based voice, data and streaming multimedia at higher speeds and offer at least 100 Mbit/s with high mobility and up to 1GBit/s with low mobility (nomadic).
• 4G is an IP-based and packet-switched evolution of 3G technologies (such as WCDMA, HSDPA, CDMA2000 and EVDO) that uses voice communications. A number of technologies considered to be 4G standards include Long Term Evolution (LTE), Ultra Mobile Broadband (UMB) and the IEEE 802.16 (WiMax) standard.
• While 3G is defined by ITU as IMT-2000, IMT-Advanced is being studied by ITU as 4G. IMT is now used as the generic name for 3G and 4G.

Data Warehouse

• Abbreviated DW, a collection of data designed to support management decision making. Data warehouses contain a wide variety of data that present a coherent picture of business conditions at a single point in time.
• Development of a data warehouse includes development of systems to extract data from operating systems plus installation of a warehouse database system that provides managers flexible access to the data.
• The term data warehousing generally refers to the combination of many different databases across an entire enterprise. Contrast with data mart.

iHTML

• Short for inline HTML, an advanced server-side scripting/programming language that functions as an extension to HTML, allowing the customization of dynamic Web sites that depend on interaction with databases.
•  iHTML eliminates the need for Javascript or CGI programs as it provides the same functionality.

Dual-Core

• Dual-core refers to a CPU that includes two complete execution cores per physical processor. It has combined two processors and their caches and cache controllers onto a single integrated circuit (silicon chip).
• Dual-core processors are well-suited for multitasking environments because there are two complete execution cores instead of one, each with an independent interface to the frontside bus. Since each core has its own cache, the operating system has sufficient resources to handle most compute intensive tasks in parallel.
• Multi-core is similar to dual-core in that it is an expansion to the dual-core technology which allows for more than two separate processors.

Windows CE

• A version of the Windows operating system designed for small devices such as personal digital assistants (PDAs) (or Handheld PCs in the Microsoft vernacular).
• The Windows CE graphical user interface (GUI) is very similar to Windows 95 so devices running Windows CE should be easy to operate for anyone familiar with Windows 95.

Pervasive Computing

• The idea that technology is moving beyond the personal computer to everyday devices with embedded technology and connectivity as computing devices become progressively smaller and more powerful. Also called ubiquitous computing, pervasive computing is the result of computer technology advancing at exponential speeds -- a trend toward all man-made and some natural products having hardware and software.
• Pervasive computing goes beyond the realm of personal computers: it is the idea that almost any device, from clothing to tools to appliances to cars to homes to the human body to your coffee mug, can be imbedded with chips to connect the device to an infinite network of other devices.
• The goal of pervasive computing, which combines current network technologies with wireless computing, voice recognition, Internet capability and artificial intelligence, is to create an environment where the connectivity of devices is embedded in such a way that the connectivity is unobtrusive and always available.

Tablet Pc

• A type of notebook computer that has an LCD screen on which the user can write using a special-purpose pen, or stylus. The handwriting is digitized and can be converted to standard text through handwriting recognition, or it can remain as handwritten text.
• The tablet PC relies on digital ink technology, where a digitizer is laid under or over an LCD screen to create an electromagnetic field that can capture the movement of the special-purpose pen and record the movement on the LCD screen. The effect is like writing on paper with liquid ink.
• The Microsoft Windows operating system designed for tablet PC technology.

MPEG-4

• A graphics and video lossy compression algorithm standard that is based on MPEG-1 and MPEG-2 and Apple QuickTime technology.
• Wavelet-based MPEG-4 files are smaller than JPEG or QuickTime files, so they are designed to transmit video and images over a narrower bandwidth and can mix video with text, graphics and 2-D and 3-D animation layers.
• Wavelet technology can compress color images at rates of 20:1 up to 300:1 and grayscale images at 20:1 to 50:1. MPEG-4 was standardized in October 1998 in the ISO/IEC document 14496.

Smart Card

• A small electronic device about the size of a credit card that contains electronic memory, and possibly an embedded integrated circuit (IC). Smart cards containing an IC are sometimes called Integrated Circuit Cards (ICCs).
• Smart cards are used for a variety of purposes, including:

o          Storing a patient's medical records

o          Storing digital cash

o          Generating network IDs (similar to a token)

• To use a smart card, either to pull information from it or add data to it, you need a smart card reader, a small device into which you insert the smart card.

GPS

• Short for Global Positioning System, a worldwide MEO satellite navigational system formed by 24 satellites orbiting the earth and their corresponding receivers on the earth. The satellites orbit the earth at approximately 12,000 miles above the surface and make two complete orbits every 24 hours.
• GPS was developed and is operated by the U.S. Department of Defense. It was originally called NAVSTAR (Navigation System with Timing and Ranging).
• GPS has applications beyond navigation and location determination. GPS can be used for cartography, forestry, mineral exploration, wildlife habitation management, monitoring the movement of people and things and bringing precise timing to the world.

JAR

• Short for Java Archive, a file format used to bundle all components required by a Java applet. JAR files simplify the downloading of applets since all the components (.class files, images, sounds, etc.) can be packaged into a single file.
•  In addition, JAR supports data compression, which further decreases download times.
• By convention, JAR files end with a .jar extension.

Data Migration

• The process of translating data from one format to another. Data migration is necessary when an organization decides to use a new computing systems or database management system that is incompatible with the current system.
• Typically, data migration is performed by a set of customized programs or scripts that automatically transfer the data.
• The process of moving data from one storage device to another. In this context, data migration is the same as Hierarchical Storage Management (HSM).

T-SQL

• Short for Transaction-SQL, an extended form of SQL that adds declared variables, transaction control, error and exception handling and row processing to SQL??s existing functions.
• Microsoft SQL and Sybase both support T-SQL statements. Up until version 4.2, the Microsoft SQL Server and Sybase relational database were developed together to work together.
• It should be noted that Sybase refers to its statements as T-SQL while Microsoft refers to its statements as Transaction-SQL.

DSN

• Short for Data Source Name. Data Source Name provides connectivity to a database through an ODBC driver. The DSN contains database name, directory, database driver, UserID, password, and other information. Once you create a DSN for a particular database, you can use the DSN in an application to call information from the database.
• DSN is often used by Active Server Pages (ASP) and Visual Basic programs when a query to a database is necessary to retrieve information.
• There is also what is known as a "DSN-less connection." Instead of using a DSN to connect to a database, the developer specifies the necessary information right in the application. With a DSN-less connection the developer is free to use connection standards other than ODBC, such as OLE DB.