Input and output device

 A computer is only useful when it is able to communicate with the external environment. When you work with the computer you feed your data and instructions through some devices to the computer. These devices are called Input devices. Similarly computer after processing, gives output through other devices called output devices.

For a particular application one form of device is more desirable compared to others. We will discuss various types of I/O devices that are used for different types of applications. They are also known as peripheral devices because they surround the CPU and make a communication between computer and the outer world.

Input Devices

Input devices are necessary to convert our information or data in to a form which can be understood by the computer. A good input device should provide timely, accurate and useful data to the main memory of the computer for processing followings are the most useful input devices.

1.   Keyboard: - This is the standard input device attached to all computers. The layout of keyboard is just like the traditional typewriter of the type QWERTY. It also contains some extra command keys and function keys. It contains a total of 101 to 104 keys. A typical keyboard used in a computer is shown in Fig. 2.6. You have to press correct combination of keys to input data. The computer can recognize the electrical signals corresponding to the correct key combination and processing is done accordingly.

2.   Mouse: - Mouse is an input device shown in Fig. 2.7 that is used with your personal computer. It rolls on a small ball and has two or three buttons on the top. When you roll the mouse across a flat surface the screen censors the mouse in the direction of mouse movement. The cursor moves very fast with mouse giving you more freedom to work in any direction. It is easier and faster to move through a mouse.

3.   Scanner: The keyboard can input only text through keys provided in it. If we want to input a picture the keyboard cannot do that. Scanner is an optical device that can input any graphical matter and display it back. The common optical scanner devices are Magnetic Ink Character Recognition (MICR), Optical Mark Reader (OMR) and Optical Character Reader (OCR).

a.    Magnetic Ink Character Recognition (MICR): - This is widely used by banks to process large volumes of cheques and drafts. Cheques are put inside the MICR. As they enter the reading unit the cheques pass through the magnetic field which causes the read head to recognise the character of the cheques.

b.   Optical Mark Reader (OMR): This technique is used when students have appeared in objective type tests and they had to mark their answer by darkening a square or circular space by pencil. These answer sheets are directly fed to a computer for grading where OMR is used.

c.    Optical Character Recognition (OCR): - This technique unites the direct reading of any printed character.

Suppose you have a set of hand written characters on a piece of paper. You put it inside the scanner of the computer. This pattern is compared with a site of patterns stored inside the computer. Whichever pattern is matched is called a character read. Patterns that cannot be identified are rejected. OCRs are expensive though better the MICR.

Output Devices

1.   Visual Display Unit: The most popular input/output device is the Visual Display Unit (VDU). It is also called the monitor. A Keyboard is used to input data and Monitor is used to display the input data and to receive messages from the computer. A monitor has its own box which is separated from the main computer system and is connected to the computer by cable. In some systems it is compact with the system unit. It can be color or monochrome.

2.   Terminals: It is a very popular interactive input-output unit. It can be divided into two types: hard copy terminals and soft copy terminals. A hard copy terminal provides a printout on paper whereas soft copy terminals provide visual copy on monitor. A terminal when connected to a CPU sends instructions directly to the computer. Terminals are also classified as dumb terminals or intelligent terminals depending upon the work situation.

3.   Printer: It is an important output device which can be used to get a printed copy of the processed text or result on paper. There are different types of printers that are designed for different types of applications. Depending on their speed and approach of printing, printers are classified as impact and non-impact printers. Impact printers use the familiar typewriter approach of hammering a typeface against the paper and inked ribbon. Dot- matrix printers are of this type. Non-impact printers do not hit or impact a ribbon to print. They use electro- static chemicals and ink-jet technologies. Laser printers and Ink-jet printers are of this type. This type of printers can produce color printing and elaborate graphics.

Input device

In computing, an input device is a peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as a computer or other information appliance. Examples of input devices include keyboards, mice, scanners, digital cameras and joysticks.

Many input devices can be classified according to:

• modality of input (e.g. mechanical motion, audio, visual, etc.)
• whether the input is discrete (e.g. key presses) or continuous (e.g. a mouse's position, though digitized into a discrete quantity, is fast enough to be considered continuous)
• the number of degrees of freedom involved (e.g. two-dimensional traditional mice, or three-dimensional navigators designed for CAD applications)

 

Output device

An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) which converts the electronically generated information into human-readable form.^[1][2]

ICT Audit

 ICT Audit is the process of collecting and assessing evidence on whether IT operates in accordance with company asset protection, data integrity maintenance, efficient support of company's goals and efficient use of information resources with the main objective of achieving high level of business and IT alignment.

An   ICT   audit   is   an   essential   component   of   a   successful   ICT operation. It is necessary to confirm one's starting point before a single step can be taken.  So it is with ICT, as well as meeting statutory and regulatory requirements regarding record keeping and information systems, it is essential to maintain up-to-date records of computer systems to plan for the future.

IT auditing supports many types of internal auditing in companies because today it is not possible to conduct auditing processes without IT support.

An information technology audit, or information systems audit, is an examination of the management controls within an Information technology (IT) infrastructure. The evaluation of obtained evidence determines if the information systems are safeguarding assets, maintaining data integrity, and operating effectively to achieve the organization's goals or objectives. These reviews may be performed in conjunction with a financial statement audit, internal audit, or other form of attestation engagement.

IT audits are also known as "automated data processing (ADP) audits" and "computer audits". They were formerly called "electronic data processing (EDP) audits".

E-Governance

 E-Governance is the application of Information and Communication Technology (ICT) for delivering government services, exchange of information, communication transactions, integration of various stand-alone systems and services between Government-to-Citizens (G2C), Government-to-Business (G2B), Government-to-Government (G2G) as well as back office processes and interactions within the entire government frame work.

 Benefits of e-Governance

•It  greatly  simplifies  the  process  of  information accumulation for citizens and businesses.

•It    empowers    people    to    gather    information regarding any department of government and get involved in the process of decision making.

•E-Governance   strengthens   the   very   fabric   of democracy by ensuring greater citizen participation at all levels of governance

•E-Governance  leads  to  automation  of  services, ensuring that information regarding every work of public welfare is easily available to all citizens, eliminating corruption.

•This revolutionizes the way governments function, ensuring much more transparency in the functioning, thereby eliminating corruption.

•Since  the  information  regarding  every  activity  of  government  is  easily  available,  it  would  make  every government department responsible as they know that every action of theirs is closely monitored.

•Proper implementation of e-Governance practices make it possible for people to get their work done online thereby sparing themselves of unnecessary hassles of traveling to the respective offices.

•Successful implementation of e-Governance practices offer better delivery of services to citizens, improved interactions with business and industry, citizen empowerment through access to information, better management, greater convenience, revenue growth, cost reductions etc.

•  Furthermore, introduction of e-Governance brings governments closer to citizens.

•  E-Governance practices help business access information that might be important for them at a click.

Extranet

 An extranet is a network that is limited in scope to a single organization or entity and also has limited connections to the

networks of one or more other usually, but not necessarily, trusted organizations or entities—a company's customers may be given access to some part of its intranet—while at the same time the customers may not be considered trusted from a security standpoint. Technically, an extranet may also be categorized as a CAN, MAN, WAN, or other type of network, although an extranet cannot consist of a single LAN; it must have at least one connection with an external network

Digital Signature

 A digital signature or digital signature scheme is a mathematical scheme for demonstrating the authenticity of a digital message or document. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, and that it was not altered in transit. Digital signatures are commonly used for software distribution, financial transactions, and in other cases where it is important to detect forgery or tampering. In some countries, including the United States, India, and members of the European Union, electronic signatures have legal significance. Uses of digital signatures

•        Authentication: Although messages may often include information about the entity sending a message, that information may not be accurate. Digital signatures can be used to authenticate the source of messages. When ownership of a digital signature secret key is bound to a specific user, a valid signature shows that the message was sent by that user. The importance of high confidence in sender authenticity is especially obvious in a financial context. For example, suppose a bank's branch office sends instructions to the central office requesting a change in the balance of an account. If the central office is not convinced that such a message is truly sent from an authorized source, acting on such a request could be a grave mistake.

•        Integrity: In many scenarios, the sender and receiver of a message may have a need for confidence that the message has not been altered during transmission. Although encryption hides the contents of a message, it may be possible to change an encrypted message without understanding it. (Some encryption algorithms, known as nonmalleable ones, prevent this, but others do not.) However, if a message is digitally signed, any change in the message after signature will invalidate the signature. Furthermore, there is no efficient way to modify a message and its signature to  produce a new message with a valid signature, because this is still considered to be computationally infeasible by most cryptographic hash functions (see collision resistance).

•        Non-repudiation: Non-repudiation, or more specifically non-repudiation of origin, is an important aspect of digital signatures. By this property, an entity that has signed some information cannot at a later time deny having signed it. Similarly, access to the public key only does not enable a fraudulent party to fake a valid signature.

Digital Bangladesh

 Digital Bangladesh implies the broad use of computers, and embodies the modern philosophy of effective and useful use of technology in terms of implementing the promises in education, health, job placement and poverty reduction. The party underscored a changing attitude, positive thinking and innovative ideas for the success of “Digital Bangladesh”.

The philosophy of “Digital Bangladesh” comprises ensuring people’s democracy and human rights, transparency, accountability, establishing justice and ensuring delivery of government services to the citizens of Bangladesh through maximum use of technology, with the ultimate goal being the overall improvement of the daily lifestyle of general people. This includes all classes of people and does not discriminate people in terms of technology.

The government further emphasized on the four elements of “Digital Bangladesh Vision” –

i.     human resource development,

ii.    People involvement,

iii.   Civil services and

iv.   Use of information technology in business.

Bangladesh is going to observe digital year in 2011 to mark the journey to digital Bangladesh. The government has taken up an initiative for setting up Union Information Centers (UIC) in 1000 unions in line with the dream to build Digital Bangladesh by 2021. This programme is a welcome development towards reaching information technology facilities to the doorsteps of  rural  people.  The village people will easily get information about agriculture, health, education, marketing and employment from the UICs. The government has also moved to formulate new laws empowering an authority to set up six hi-tech parks with the aim of establishing foreign investment in the information technology sector. The Supreme Court (SC) is going to be digitalized soon. All cases related to information of the SC will be available in its website. Dhaka Metropolitan Police is also going to install a hi-tech monitoring system in the central control room to make contact with the on-duty police anywhere within the metropolitan area. Digitalization will largely change banking and financial activities. Worldwide money transfer and transaction of business have now become a matter of clicking the mouse of a computer. Some products like software and TV programmes are also amenable to digital transmission. We will be able to buy and sell goods through the electronic screen if we can make a Digital Bangladesh. Undoubtedly, encouraging development towards digitalization of Bangladesh by 2021 can be possible. The ambitious dream for a Digital Bangladesh will remain a dream if the government cannot equip the people with the technology needed for establishing the digital era.

Data Warehouse

A Data Warehouse or Enterprise Data Warehouse (DW, DWH, or EDW) is a database used for reporting and data analysis. It is a central repository of data which is created by integrating data from one or more disparate sources. Data warehouses store current as well as historical data and are used for creating trending reports for senior management reporting such as annual and quarterly comparisons.

The  data  stored  in  the  warehouse  are  uploaded  from  the  operational  systems.  The data may pass through an operational data store for additional operations before they are used in the DW for reporting.

The typical ETL-based data warehouse uses staging, data integration, and access layers to house its key functions. The staging layer or staging database stores raw data extracted from each of the disparate source data systems. The integration layer integrates the disparate data sets by transforming the data from the staging layer often storing this transformed data in an operational data store (ODS) database. The integrated data are then moved to yet another database, often called the data warehouse database, where the data is arranged into hierarchical groups often called dimensions and into facts and aggregate facts. The combination of facts and dimensions is sometimes called a star schema. The access layer helps users retrieve data.

 

Benefits of a data warehouse:

 

•  A data warehouse maintains a copy of information from the source transaction systems.
• Gather data from multiple sources into a single database so a single query engine can be used to present data.
• Mitigate the problem of database isolation level lock contention in transaction processing systems caused by attempts to run large, long running, analysis queries in transaction processing databases.
• Maintain data history, even if the source transaction systems do not.
• Integrate data from multiple source systems, enabling a central view across the enterprise. This benefit is always valuable, but particularly so when the organization has grown by merger.
• Improve data quality, by providing consistent codes and descriptions, flagging or even fixing bad data.
• Present the organization's information consistently.
• Provide a single common data model for all data of interest regardless of the data's source.
• Restructure the data so that it makes sense to the business users.
• Restructure the data so that it delivers excellent query performance, even for complex analytic queries, without impacting the operational systems.
• Add value to operational business applications, notably customer relationship management (CRM) systems.

Computer Virus

 A computer virus is one of thousands of programs that can invade computer systems and perform a variety of functions ranging from annoying (e.g., popping up messages as a joke) to dangerous (e.g., deleting files or destroying your hard disk). Many are harmless but others can be very destructive. Trojan horses or worms are specific types of clandestine programs (loosely categorized as viruses) and can be just as dangerous. For simplicity’s sake, future mention of viruses in this document will refer to viruses, Trojan horses, and worms taken as a whole.

A computer virus is a malware program that, when executed, replicates by inserting copies of itself (possibly modified) into other computer programs, data files, or the boot sector of the hard drive; when this replication succeeds, the affected areas are then said to be "infected".^[1][2][3][4] Viruses often perform some type of harmful activity on infected hosts, such as stealing hard disk space or CPU time, accessing private information, corrupting data, displaying political or humorous messages on the user's screen, spamming their contacts, logging their keystrokes, or even rendering the computer useless. However, not all viruses carry a destructive payload or attempt to hide themselves—the defining characteristic of viruses is that they are self-replicating computer programs which install themselves without user consent.

Some of the best-known viruses include: Love Bug, Melissa, Bubbleboy, Code Red, Nimda. The following steps can be taken to prevent a virus infection:

o Protect your computer with strong security software and keep it updated.

o   Use a security-conscious Internet service provider (ISP) that implements strong anti-spam and anti- phishing procedures.

o   Enable automatic Windows updates or download Microsoft updates regularly to keep your operating system patched against known vulnerabilities.

o Use caution when opening attachments.

o Be careful when engaging in peer-to-peer (P2P) file-sharing.

o Use security precautions for your PDA, cell phone, and Wi-Fi devices.

o Configure your instant messaging application correctly.

o Beware of spam-based phishing schemes. Don't click on links in emails or IM.

o Back up your files regularly and store the backups somewhere besides your PC.

o Stay aware of current virus news by checking sites like McAfee.