♥Communication And Network♥

Modulation

In electronics, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted . On the other hand, the purpose of modulation is usually to enable the carrier signal to transport the information in the modulation signal to some destination . Besides that , in telecommunications , modulation is the process of conveying a message signal , for instance a digital bit stream or an analog audio signal  inside another signal that can be physically transmitted . Modulation of a sine waveform is used to transform a baseband message signal into a passband signal , for instance low-frequency audio signal into a radio-frequency signal (RF signal).

 

Demodulation

The use of demodulation data or "enveloping" is an excellent complement to narrow band spectral analysis in detecting faults in rolling element bearing and gearboxes . This article describles what demodulation is from a qualitative viewpoint , and how it is used in practice . It also purposely avoids using highly technical terms so that it can be understood by those without a technical background . 

 

Bandwidth

Bandwidth is the John A Hartford Foundation's one-stop , online source for communications tools and information . The site is designed to help grantees and other professionals enhance , strengthen and ass visual impact to a variety of publications , presentations and communications about aging and health .

TCP/IP

The Internet Protocol  Suite is the set of communications protocols used for the Internet and other similar networks . It is commonly also known as TCP/IP named from two of the most important protocols in it : the Transmission Control Protocol (TCP) and the Internet Protocol (IP) , which were the first two networking protocols defined in this standard . The Internet Protocol Suite consists of four abstraction layers . From the lowest to the highest layer , these are the Link Layer , the Internet Layer , the Transport Layer , and the Application Layer . The layers define the operational scope or reach of the protocols in each layer , reflected loosely in the layer names . Each layer has functionality that solves a set of problems relevant in its scope . 

 

Node 

In communication networks , a node is a connection point , either a redistribution point or a communication endpoint as some terminal equipment . The definition of a node depends on the network and protocol layer referred to . A physical network node is an  active electronic device that is attached to a network and is capable of sending , receiving or forwarding information over a communications channel . A passive distribution point as a distribution frame or patch panel is  is consequently not a node .  

 

Client

A client is an application or system that accesses a remote service on another computer system , known as a server , by way of a network . The term was first applied to devices that were not capable of running their own stand-alone programs , but could interact with remote computers via a network . These dumb terminals were clients of the time-sharing mainframe computer .  

Server

In computer networking , a server is a program that operates as a socket listener . The term server is also often generalized to describe a host that is deployed to execute one or more such programs . A server computer is a computer or series of computer , that link computers or electronic devices together . They often provide essential services across a network , either to private users inside a large organization or to public users via the internet .

 

Networking Operating Systems 

Networking operating system typically are used to run computers that act as servers . They provide the capabilities required for network operation . Network operating systems are also designed for client computers and provide functions so the distinction between network operating systems and stand alone operating systems is not always obvious . 

Networking Administrator

A networking Administrator is a person responsible for the maintenance of computer hardware and software that comprises a computer network . This normally includes deploying , configuring , maintaining and monitoring active network equipment .

♥Secondary Storage♥

Disk Caching

A disk cache is a portion of a system memory used to cache reads and writes to the hard disk . It may be referred to as the most important type of cache on the PC , because of the greatest differential speed between the layers , that is the system RAM and the hard disk . Disk caching works under the same principle as Memory caching , but instead of using high-speed SRAM , a disk cache uses conventional main memory . The most recently accessed data from the disk , it first checks the disk cache to see if the data is there . Disk caching can dramatically improve the performance of applications because accessing a byte on a hard disk .

 

File Compression

File compression is commonly used when sending a file from one computer to another over a connection that has limited bandwidth . The compression basically makes the file smaller and , therefore the sending of the file is faster . The next step to compressing a single file is the combining of multiple files into a single compressed archive . Finally , combining multiple files into a single archive is to maintain the organization of those files once inside the archive .

File Decompression

Data decompression is the reverse , the decoding of compressed data to restore the original data .
Compression or decompression algorithnms look for redundancies in data , then minimize them using predetermined algorithms (methods) . There are different algorithms used to achieve different compression rates . Solid files are called 'archives' . They can hold more than one file . There is a tradeoff between higher density rates and compression or decompression time . Archive files can be manipulated utilities such as WinZip or IZArc .

Internet Hard Drive

The sole purpose of an Internet hard drive is to offer a means of accessing your computer files , for instance , pictures , document , music , video and many more from any computer , as long as that computer has access to the Internet . Similar to depositing money into your bank account and later withdrawing that same money from any ATM machines , an Internet hard drive will allow you to 'deposit' your computer files into a remote hard drive and then later access those very same files from any other computer .

Solid State Storage

Solid-state storage is a nonvolatile, removable storage medium that employs integrated circuits (ICs) rather than magnetic or optical media. It is the equivalent of large-capacity, nonvolatile memory .The main advantage of solid -state storage is the fact that it contains no mechanical parts . Everything is done electronically .The absence of moving parts may translate into longer operating life, provided the devices are reasonably cared for and are not exposed to electrostatic discharge.

♥Input And Output♥

Ergonomic Keyboard

An ergonomic keyboard is a computer keyboard designed with ergonomic considerations to minimize muscle strain and a host of related problems . Typically such keyboard are constructed in a V shape , to allow right to left hands to type at a slight angle more natural to the human form .

Inkjet Printer

An inkjet printer is a type of computer printer that creates a digital image by propelling droplets of ink onto paper . Inkjet printers are the most commonly used type of printer and range from small inexpensive consumer models to very large professional machines , that can cost up to thousands of dollars .

Laser Printer

Laser Printer is a common type of computer printer that rapidly produces high quality text and graphics on plain paper . As with digital photocopiers and multifunction printers (MFPs) , laser printers employ a xerographic printing   process , but differ from analog photocopiers in that the image is produced by the direct scanning of a laser beam across the printer's photoreceptor . 

Magnetic-Ink Character Recognition

Magnetic Ink Character Recognition (MICR) is a character recognition technology used primarily by the banking industry to facilitate the processing of cheques . The technology allows computers to read information such as account numbers off printed documents . MICR characters are printed in special typefaces with a magnetic ink or toner , usually containing iron oxide . The use of magnetic printing allows the characters to be read reliably even if they have been overprinted or obscured by other marks such as cancellation stamps and signature .

Optical character recognition

Optical Character Recognition usually abbreviated to OCR is the mechanical or electronic translation of scanned images of handwritten , typewritten or printed text into machine-encoded text . It is widely used to convert books and documents into electronic files , to computerize a record-keeping system in an office , or to publish the text on a website . On the other hand , OCR makes it possible to edit the text , search for a word or phrase , store it more compactly , display or print a copy free of scanning artifacts and apply techniques such as machine translation , text-to-speech and text mining to it .

Optical-Mark Recognition

Optical Mark Recognition (OMR) is the technology of electronically extracting intended data from marked fields , such as checkboxes and fill-in fields , on printed forms . It is generally distinguished from OCR by the fact that a recognition engine is not required . This requires the image to have high contrast and an easily-recognizable or irrelevant shape . OMR technology scans a printed form and reads predefined positions and records where marks are made on the form . This technology is useful for applications in which large numbers of hand-filled forms need to be processed quickly and with great accuracy , such as surveys , reply cards  questionnaires and ballots .