Data Communication - CSEC IT



Contents

Section 4: Applications and Implications of Information and Communication Technology 2

Objective 4.1 Use terms associated with data communication and networks 2

Objective 4.2 Distinguish among Internet, intranet and extranet 2

Objective 4.3 Explain concepts associated with the Internet 6

Objective 4.4 Describe measures to secure data and maintain data integrity. 12

Objective 4.5 Outline ways by which information can be misused. 14

Objective 4.6 Describe appropriate hardware and software to meet the particular needs of a given application; 19

Objective 4.7 Describe current and emerging technological trends; 19

Objective 4.8 Assess the impact of Information Technology on job skills and careers; 31

Objective 4.9 Describe the roles of various personnel in computer-related professionals; 32

Section 4: Applications and Implications of Information and Communication Technology

Objective 4.1 Use terms associated with data communication and networks

Objective 4.2 Distinguish among Internet, intranet and extranet

Data Communication

This is the transmission (movement) of data from one point to another for direct use or for further processing e.g. from one computer to another, from a cell phone to computer or vice-versa, or from a computer to fax machine.

Data communication systems are made up of hardware, software and communication facilities. They may span a small area or they may be set up over a global area. Data is moved through these systems via transmission channels or links. These channels are grouped according to their bandwidth. Bandwidth refers to the volume of data that can be transmitted in a given time. There are three bandwidths:

• Narrow-band channel transmits data at a slow speed of about 10 to 30 characters per second (cps). An example of this is the telegraph system

• Voice-band channel transmits data at a rate of 1000 to 8000 cps. An example of this is the telephone line.

• Broadband channel transmits large volumes of data at speeds of over 100 000 cps. An example of this is a communication satellite, fibre optic cables, coaxial cable, microwaves.

Transmission media

These are the ways and/or materials used to move data. Media can be cabled/wired or wireless. Cabled/wired media include:

• Twisted pair cable: used for home networking where there is no great need for speed. It is a cheap convenient method of connecting computers and peripherals in a network.

• Coaxial cable: used in medium-sized networks to transmit voice, video and data at moderate speeds. This is more expensive than twisted pair because the transmission capabilities are higher.

• Fibre optic cable: used to transmit large volumes of digital data at extremely high speed virtually error-free. These are relatively expensive.

Wireless media include communications satellite, microwave links, infrared. Wireless network technology also called hot spot technologies refers to Bluetooth and Wi-Fi. All of these are used to provide broadband.

Communications satellite is a space station that receives microwave signals from an earth-based station, amplifies (strengthens) the signals, and broadcasts the signals back over a wide area to any number of earth-based stations.

Microwaves are radio waves that provide a high speed signal transmission. It is also called fixed wireless and involves sending signals from one microwave station to another. A microwave station is an earth-based reflective dish that contains the antenna, transceivers and other equipment necessary for microwave communications.

Infrared is a wireless transmission medium that sends signals using infrared light waves. Mobile computers and devices , such as mouse, printer, and smart phones often have IrDa ports that enables the transfer of data from one device to another using infrared light waves.

Hot spot is a wireless network that provides Internet connections to mobile computers and other devices. They are used by mobile users to check e-mail, browse the Web and access any service on the Internet.

Bluetooth is a standard developed by electronic manufacturers that allow any sort of electronic equipment (computers, digital video cameras, cell phones, PDAs, etc to automatically make their connections without wires, cables or any direct action from a user. One disadvantage of Bluetooth is it cannot transmit signals through walls and distances of over 3 meters.

Wi-Fi is short for wireless fidelity. It is a type of broadband Internet connection that uses radio signals to provide Internet connection to wireless computers and devices.

Communication modes

The lines that transmit data are also classified according to the direction in which data flows through them. There are three (3) types of lines:

• A simplex line permits data to flow in only one direction. You can send data or receive data, but not both.

• A half-duplex line can alternately send and receive data. That means that at any particular time you can either send data but not receive it, or receive data but not send it.

• A full-duplex line can simultaneously send and receive data.

Networks

A network is group of two or more computers linked together so that they can share resources (hardware, software and data) and can communicate with one another. Computer networks maybe classified as one of the following:

• Local Area Network (LAN)

• Wide Area Network (WAN)

• Metropolitan Network

• Internet

• Intranet

• Extranet

Local Area Network (LAN)

LANs consists of a collection of microcomputers, such as in an office building, department or school that can share peripherals, files and programs and communicate with each other on the network. Each microcomputer that forms part of the network is connected either by cables or by a wireless link.

Benefits of a LAN are:

• Hardware such as printers can be shared.

• Storage facilities can be shared.

• Software and data files can be shared by many users.

• It is usually cheaper to buy one copy of a software application and pay license fee for several machines, than to buy individual packages for each computer.

• Users can work together on a single document.

• User can communicate using e-mail.

Disadvantages of a LAN are:

• The initial set costs are high

• There is increased risk of data corruption. Since many users will be using the system, there is greater chance of data being corrupted or tampered with.

• There is a greater risk from viruses because they easily spread between the computers that are part of the LAN.

• If the file server fails, all workstations are affected and or work stored on shared hard disk drives will not be accessible; nor will it be possible to use networked printers, etc.

• Networks can be complicated to maintain and may require a network manager. Additional costs may therefore be incurred.

Wide Area Network (WAN)

This network connects mainframes, LANs and PCs across a large geographical area such as a city, a country or the world using a combination of many types of media such a telephone lines, cables microwave links, satellite links. WANs are used mainly by universities, research centres and large organizations with branches in different countries.

Metropolitan Network (MAN)

This network connects LANs in a metropolitan area such as a city, state or town. It includes one or more LANs but covers a smaller geographical area than a WAN. It is usually managed by a single network provider that sells the service to users. Telephone companies and cable television operators provide connections to the MAN.

Intranet

This network is a micro-version of the Internet within a company or organization. It offers the same features of the global Internet but limited to a small area such as a factory site or an office. Authorized users within the company can use the company’s intranet to find information easily and quickly. The documents in the intranet have links to other documents in the network or outside the wider Internet. This network uses browsers and software just like those used on the Internet.

Extranet

This is an Intranet that allows limited access to it by people outside the company. A company may set up an extranet, for example, to provide technical support information to its customers based on products it sells or services it provides.

Objective 4.3 Explain concepts associated with the Internet

The Internet

This is the world’s largest WAN. It is a network of networks that connects computers worldwide via a huge set of telecommunication links. The Internet does not have a central authority. No one is in charge of the Internet. There are organizations which develop technical aspects of the network and set standards for creating applications on it, but no one governing body or government is in control.

Advantages of the Internet

• Vast volumes of information are available on virtually any topic.

• Information can be updated regularly.

• Much of the information is free.

• It allows people to telecommute i.e. work from home using Internet facilities like e-mail, and keep in touch cheaply and quickly with friends and relatives.

• It is convenient for many common chores e.g. booking flights and Internet banking.

• It is easily accessible: all you need is a PC with modem and a phone line.

Disadvantages of the Internet

• Lots of incorrect information is available; there is no authority to check the accuracy of Internet documents, etc.

• It can be difficult to find exactly what you need because of the large volume of information available.

• Computer viruses can easily be downloaded without the user realizing.

• There are lots of undesirable websites on the Internet (pornography, racist, propaganda (half truths), etc.).

• The security of computers and WAN/LAN systems connected to the Internet may be at risk from hackers.

For a basic connection to the Internet you need the following:

• Computer hardware – a personal computer and modem

• Communication link – a phone line or cable or satellite dish

• An Internet Service Provider (ISP)

• Computer software – facility to implement TCP/IP and an Internet browser.

Modem

A standard telephone line can transmit only analogue data, whereas data emitted from a computer is in a digital form. A modem (modulator/demodulator) is a device used to convert the digital data emitted from the computer into analogue data that can be transmitted over a telephone line. When the data gets to the other end of the line, a modem converts the analogue data back into digital data for the computer at that end of the line to process. The data transmitted can be sound, pictures, video or text. Modems can be external or internal (attached to the mother board). There are also different types of modems:

• Integrated Services digital network (ISDN)

• Asymmetric digital subscriber line (ADSL)

• Cable modems

Internet Service Provider (ISP)

This is a company that has a direct connection to the Internet and gives users access to it, usually for a fee. The company usually has a small network that is linked via a high-speed communication link to a high-speed link that forms part of the Internet’s backbone (supercomputers and other large networks that make up the Internet worldwide).

TCP/IP

Computers on the Internet use a protocol called TCP/IP. This is a set of protocols used to transfer data from one computer to another over the Internet. A protocol is asset of rules that defines how computers interact or communicate with each other. TCP/IP is not designed for any specific type of computer so it enables hardware and operating systems software from different computers to communicate. E.g. an IBM computer can communicate with an Apple computer.

Browser

In order to navigate (go through) the World Wide Web (WWW), you need a web browser. A web browser is a program that resides in your computer and enables you to find, retrieve, view and send hypertext and hypermedia documents over the web. Popular browsers are MS Internet Explorer and Mozilla Firefox. Some of the things you can do with a browser are:

• View hundreds of millions of web pages from all over the world.

• Send and receive email

• Participate in conferences

• Chat

• Shop online

• See and hear recorded broadcasts

Internet Protocol (IP) addresses

Each computer on the Internet has a unique address that identifies it as a node so that information can be sent to it. This unique address is really a number consisting of four sets of up to three digits each, separated by full stops, e.g. 196.361.232.4. Because this address is difficult for humans to remember, names are used to correspond to each IP address. The names are determined through the Domain Name System (DNS). The DNS divides the Internet into a series of domains which are further divided into sub-domains, and the sub-domains into lower level domains. The top-level domains are grouped into categories. Some of them are:

• Educational institutions .edu

• Commercial entities .com

• Public organizations .org

• Government bodies .gov

• Military .mil

Using the different domains from top down, a computer’s (host’s) name is determined. The complete name of a computer on the Internet includes the computer’s name, all sub-organizations, the organization and the top – level domain.

E.g. shop.

Top-level domain

Sub-domain

Computer’s name

Internet Application (uses)

There are four main types of services available on the Internet:

• Terminal emulation services

• File access and transfer services

• Communication services

• The World Wide Web (WWW)

Terminal emulation services (TES)

These enable you to connect your computer to a remote host and use the services available as if your computer were a terminal of the remote computer (host).Some of the services accessible are online databases, library catalogues and chat services. A popular TES is Telnet. This is a program that allows you to access data and programs from a Telnet server. When connected to a Telnet site, your computer becomes a dumb terminal that can only send text-based messages to the Telnet site and allow you to view the results.

File access and transfer services

These allow you to locate and use electronic files stored on computers across the Internet.

File transfer protocol (FTP)

This is a set of rules for communicating over the Internet. An FTP program enables you to find an electronic file stored on a computer somewhere and download it (take a file from one computer on the Internet and copy it to a storage device on your computer). It also allows you to upload files (send files to other computers on the Internet). Some FTP sites are private and require you to pay to retrieve or store information on them.

Communication services

Electronic mail (e-mail)

This is the most popular and widely used service on the Internet. It enables users worldwide to send electronic messages (text, sound, video and graphics) to one individual or group of individuals, and receive messages from others. E-mail is much faster than regular mail. It is free since you do not pay to send the e-mail, you only pay for Internet access from your ISP. It is convenient, since you can access your at anytime and from anywhere as long as your have Internet access.

Email addresses

To send and /or receive e-mail, each user must have an e-mail address and an email program. The address is unique to the user and consists of two parts separated by the @ (‘at’) symbol. The first part is the user name, which can be a real or made up name. The second part is the domain name (the location of the e-mail account on the Internet).

E.g. of an email address bradleyP@scarborough.sec.edu

For an email to be sent and received, the following must be in place:

• Mail server: this is the computer on the Internet that operates like the traditional post office- it receives incoming messages and delivers outgoing messages. It allocates a certain amount of storage space (called your mailbox). Users retrieve their mail by supplying their username and password.

• Mail client: this is a program that enables you to read and compose e-mail messages, send e-mail and access e-mail from the server.

Electronic Discussion Forums

Mailing Lists

An electronic mailing list is a group of people using e-mail to communicate their views on common issues or interests. You subscribe to become part of the group. Not all groups are open to everyone. Some allow only professionals in a certain field. When you become a member of a group, you can send messages with comments or views on some matter that is being discussed. A copy of your message is then sent to all subscribers on the mailing list. Some mailing list only let subscribers receive messages but not send them e.g. a mailing list that sends a joke a day.

Newsgroups

A newsgroup enables a group of people with common interests to communicate with each other. A subscriber to a newsgroup posts a message which can vary from a few lines to a whole article. The other subscribers read the message and may or may not choose to reply.

The main difference between newsgroups and mailing lists is the method of communication. Mailing lists use e-mail to communicate with subscribers. Messages are sent to a subscriber’s e-mail address. Newsgroups post messages on the Internet for all the users to access. For you to be able to read and post messages to newsgroups, your computer must have newsreader software.

Bulletin Board System (BBS)

This is an Internet facility much like a newsgroup. It is dedicated to the exchange of messages. Most bulletin boards serve specific interests groups and are often free, although some may charge a membership or user fee. Everyone with access to the bulletin board can post and view messages on topics covered the board.

Chat

Chat is a service used by a group of people who share the same interests and wish to communicate with each other interactively, in real time. Three different ways of chatting are:

1. Text-based Chat

Each user entering the chat room sees the comments being typed by other users in the chat room in real time. Everyone is notified when new users enter the discussion. Each user types his/her comments. They may also choose to talk to specific persons in the group. An example of a text-based program is ICQ.

2. Internet Relay Chat (IRC)

This type of chat allows you to talk with as many people as you like but they are grouped into channels based on the topics being discussed.

3. Instant messaging

This enables you to chat privately with another person, in real time. Here you do not enter a chat room but you speak directly to the person.

4. Multimedia chat

This allows users to communicate real time using microphone and a web cam. The users are able to see and hear each other.

World Wide Web (WWW)

The WWW also called W3 is part of the Internet. It consists of hypertext and hypermedia documents called web pages.

Web page

This is a collection of text and multimedia documents.

Website

A group of related web pages on the same web server.

Web server

A computer that stores and makes available hypertext and hypermedia documents.

Blogging

This is the act of distributing information over the web. A blog is an informal website consisting of time-stamped articles, or posts, in a diary or journal format, usually listed in reverse chronological order. Blogger needs blog software to create/maintain a blog.

Hypertext documents

A hypertext document is any document that contains hyperlinks to another document located on the same computer or on another computer on another part of the world.

Hyperlink

This is an element in a document (text or graphics) that allows you to move easily from one document to the next or to another position in the document.

Hypermedia

Hypermedia is the name given to documents that contains links to text, graphics, sound or video files.

Hypertext mark-up language (HTML)

This is a programming language used to create hypertext and hypermedia documents. HTML specifies how a web page is structured and how it looks when it is displayed in the browser. HTML is used to create the hyperlinks.

A computer that stores and makes available hypertext and hypermedia documents is called a web server, and a computer that requests web pages is called the client.

Hypertext transfer protocol

Hypertext transfer protocol (HTTP) is a set of rules that controls how data travels between the web server and client.

Search engines

To retrieve information on the Web you can use a search engine. A search engine is also called a web portal. It is a website that allows users to find information quickly and easily. Each search engine has a database (collection) of web documents. Some popular search engines are Yahoo, Excite, MSN, AltaVista, Lycos, Askjeeves and Google.

Uniform Resource Locator (URL)

This is the address of a website. It is usually in the format:

Protocol://Server/Path/Filename

e.g.

Pod-casting

This is a method for distributing audio files, known as pod-casts, using web feeds. Audio pod-cast files are stored on a website. A web feed is created for each pod-cast, or for a collection of pod-cast files. Users can subscribe to a web feed by clicking on an icon, and the pod-cast will be downloaded. If the pod-cast is part of a series then the new pod-casts will be downloaded automatically when they become available.

VoIP

Short for Voice over Internet Protocol. Services such as Skype allow you to use the Internet to have voice conversations. The calls are usually free. VoIP can be used on any computer that has Internet connection, a microphone and speakers. You can add webcams and see the person you are talking to. Some organizations combine the phone system with their LAN. This means that all internal phone calls are sent through the LAN using digital formats instead of analogue. In these cases the phones have additional features such as the ability to search telephone directories to contact other people in the organization.

Objective 4.4 Describe measures to secure data and maintain data integrity.

Computer crimes such as hacking, Internet Fraud, Industrial espionage and software piracy have increased the need for data security.

Data Security

This refers to the physical, hardware and software methods used to protect data from unauthorized access and corruption. Data security ensures that data integrity is maintained.

Data Integrity

This refers to the accuracy and completeness of data as it enters the system and its consistency after it has been processed. Data integrity can be compromised in several ways:

1. Human error (e.g. inaccurate data entry, accidental deletion, accidental changing of data)

2. Natural disasters (e.g. fires, floods and earthquakes)

3. Worms and viruses

4. Hardware malfunctions

5. Fraud

6. Malicious deletion or changing of data

Date Security Methods

Data security methods may be classified into two types: Physical access restrictions and Software restrictions.

Physical methods include:

1. Locks

2. Security guards

3. Burglar alarms

4. Monitoring systems using surveillance cameras

5. Biometric scans e.g. retinal and fingerprints

6. Burglar roofing and the reinforcement of doorways

7. Fireproof or waterproof safes and cabinets

8. Recovery procedures and backups stored at a remote (faraway) location

9. Distribution of work among more than one employee so that no one has sole control over the data.

10. Archiving: files no longer in use are backed-up for later use, if needed.

Software methods includes:

1. Passwords for the system or individual files

2. Access logs: records of system activities – what files are accessed, how often they were accessed and by whom.

3. Data Encryption: The scrambling of data during storage or transmission so it cannot be understood by someone who does not have the encryption key or software to convert it back to the original form.

4. Firewall: A program, hardware or a combination of both that filters information entering your network, from the Internet.

5. Anti-virus software: Software used to remove or deactivate viruses on storage devices such as diskettes, hard disks and memory sticks.

Prevention of and protection against viruses

• Install an anti-virus software package on your computer system.

• Do not use storage media (floppy disk, tape, CD, memory stick) from other computers in your computer. If you have to use them, make sure you run a virus scan first to remove any viruses.

• Do not open any e-mail attachments that contain an executable file: these are files with extensions such as .exe, .com and .vbs.

• Use operating systems such as UNIX which have security features that protect computers from some viruses.

• If you are using Microsoft applications, ensure that the Macro Virus Protection is turned on.

Backup and recovery procedures

A backup file is a copy of a file that you can use if the original file is damaged or not available. It must not be stored on the same storage medium as the original and it should be stored somewhere safe. Backups can be done for a single system or an entire network. There are two main types of backup:

1. Full backup: The computer or network can be set up so that it automatically makes a backup of everything on a regular basis. Most organizations backup the data on their networks every night, when users will not be trying to access it.

2. Incremental backup: Only the files that have been changed since the last backup is copied. Incremental backups are much quicker than full backups and can be done during normal work.

Backup files should be stored on a medium that:

• Makes fast copies

• Can be stored in a secure place away from the original

Common backup storage media are hard disks, CDs, USB drives or tapes. Digital tapes are a popular choice to store full backups, as data can be copied to tape very quickly. All backup tapes and disks need to be labeled very carefully with the date and time and stored in a

fireproof and water

Proprietary software

This is software that is owned by a commercial company and available to anyone to buy and use under license. It has a copyright owner who can exercise control over what users can do with the software. There are restrictions on use or private modification, or even restrictions on excessive copying or publishing of modified or unmodified versions. These restrictions are placed on it by its proprietors and its use, redistribution or modification is prohibited, or requires you to ask for permission.

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Data privacy: This term refers to an individual’s rights to determine what information is stored about them and how that information will be used.

On the Internet, many companies collect personal information on their clients for a specific purpose. Because this information is valuable for businesses, sometimes it is stolen and/or sold to interested companies. Consequently, persons’ private information are used for purposes for which they were not intended. To protect individuals against this, data protection laws have been and are being developed in many countries. These data protection laws require that all data stored about an individual must be accurate and used only for the purpose for which it was collected. It also states that organizations must allow individuals to view whatever data is stored about them, and can request that it be amended if it is not correct.

Computer Surveillance

This involves accessing the storage mechanism of an individual’s computer, or monitoring an individual’s operation of a computer, without their knowledge. It can be done using both hardware and software methods.

Hardware Key logging or keystroke logging

This is a hardware method of computer surveillance. A key logger is a device that plugs in between your keyboard and computer and stores all data entered using the keyboard in its memory.

Spyware

This is software used for computer surveillance. It is secretly installed on a computer and covertly monitors the user’s actions without his or her knowledge. It saves its findings on the computer being spied on or transmits them to someone else. There are two types of spyware:

1. Surveillance spyware: This includes software key loggers, screen captures devices and Trojan horses. They are used by:

• law enforcement and intelligence agencies to solve and/or prevent crimes.

• Companies to monitor the use of their computer resources.

• Criminals to acquire passwords and credit card numbers.

• Private investigators hired to spy on individuals or organizations.

• Government agencies to spy on citizens.

• Parents to monitor their children’s use of the computer.

2. Advertising spyware: This is also known as adware, it is used to gather personal information about computer users or to show advertisements. Some record information such as email addresses, web browsing history, online shopping habits, passwords, etc. it is usually bundled with freeware (screensavers, emoticons, clipart) or shareware when unsuspecting users download it from the Internet

Electronic Eavesdropping

This is the act of secretly listening to the private conversation of others without their consent. It can be accomplished on phones, instant messages, VoIP, video conferences and fax transmissions. There are different methods used to eavesdrop, for example:

• The electronic radiation from computer equipment can be monitored and put back together into discernible information using with inexpensive equipment. The method can be applied to most computer equipment, but it is particularly effective with conventional (CRT-based) VDUs, situated in solitary locations close to the outer wall of your building. Because of this, it is important that the monitors of computers with highly confidential information be placed in areas that are not susceptible to this threat.

• Telephone/wire tapping is the monitoring of telephone and Internet conversations by a third party using methods such as hardwire tapping a outside telephone line, using a recording devices e.g. bugs on the phone or phone line or using wireless communications devices to remotely monitor conversations.

Propaganda

Many persons use the communication services (blogs, email, chat, twitter, etc.) over the Internet to spread propaganda. Propaganda is communication aimed at influencing the attitude of an audience toward some cause or position. It often presents facts selectively (thus possibly lying by omission) to encourage a particular way of thinking, or uses loaded messages to produce an emotional rather than rational response to the information presented. The desired result is a change of the attitude toward the subject in the target audience to further a political (biased) agenda.

Objective 4.6 Describe appropriate hardware and software to meet the particular needs of a given application;

Objective 4.7 Describe current and emerging technological trends;

Computer in Banking

In banking computers are used to:

• Process customer transactions (withdrawals, deposits, loans and bill payments)

• Process cheques

• Transfer funds (electronic fund transfer) from one account to another.

Automated Teller Machine (ATM)

This machine, together with a ATM card (debit card) allows you to perform a number of banking transactions (deposit and withdraw money, obtain balances, transfer funds and pay bills), 24 hours a day. The card has a magnetic strip which holds a code to identify the card-holder’s bank account. The card-holder enters a PIN (Personal Identification Number) to gain access to their account.

Cheque processing

Cheques are used to pay for goods and services. The amount of money to be paid to an individual or organization is printed at the bottom of the cheque using a magnetic ink character recognition (MICR) font. This money is deposited in the bank. If the cheque is presented at the bank where the cheque originated, payment can be received immediately. If the both parties have accounts at the same branch the cheque is cashed and the accounts of both parties are updated. If the cheque originated from a different bank, it is sent to a clearing house (In the Caribbean, the Central Bank). An MICR reader reads the information at the bottom of the cheque and the cheque is sorted according to its bank origin. Payments are made between the different banks and the cheques are sent to the original banks, where the information is read into the main computer so that the customers’ account can be updated.

Credit Cards

Credit cards are similar to debit cards. They give you access to funds in your credit account. When the credit card is swiped in a business to pay for goods or services, the card’s magnetic strip is read and the information on the strip is transmitted to the credit card company. A check is performed to determine if sufficient funds are available, before payment can be transferred to a merchant’s account. If there is not enough money available, the transaction is denied or declined. The transaction is verified by the card-holder signing a receipt. Paying for an item in this way uses Electronic Funds Transfer (EFT). The balances in both the merchant’s account and your account are updated.

Smart Cards

Smart cards contain wafer-thin memory chips embedded in the card. This chip can store more information than magnetic strip cards, and the information can be updated. Smart cards are more secure than debit or credit cards. The magnetic strips on the backs of debit and credit cards can be altered or forged, but this is much more difficult with a smart card chip. These chips can hold information for cell phone accounts, debit and credit cards or any other financial services.

Home and Internet Banking

This form of banking gives you the convenience of doing transactions anytime and from home or anywhere there is Internet access. You can check your accounts, order cheque books, pay bills, transfer funds and apply for loans via the Internet.

|Hardware requirement |Software requirement |

|Mainframe computer with networked terminals |Accounting and financial software |

|Printers (character, line and page) |Database software |

|Character: for printing transactions on passbooks | |

|Line: for printing duplicate copies and statements | |

|Laser: for printing reports | |

| |Word processing software for preparing documents |

|Cheques encoders and writers (MICR) |Security software (e.g. intrusion and forensics for detecting and |

| |tracing unauthorised access) |

|ATM machines |Networking software for WAN |

|Magnetic card readers |Video conferencing |

|Currency counters |Internet access software |

| |E-mail software |

Computers in Business

In business, computers are used create bills (invoices), monitor inventory (stock control), in point–of-sale systems (store checkouts), in accounting (profit and loss accounts), in marketing (promotion of merchandise), e-commerce and telecommuting.

Stock Control

Computers and its related technology is used to keep track of stock inventory. For example, when an item is purchased in a store it is swiped over a barcode reader. The reader sends a message to the stock computer to update the record of that particular item – decreasing the stock by one.

The reverse occurs when items are added to stock and scanned by a reader in the warehouse. This system allows companies to set up their system to automatically re-order a quantity of an item. When the number of items sold diminishes to a point where the stock is at a low level – the designated reorder level – the system can warn the stock manager to re-order.

E-commerce

Electronic commerce consists of buying, selling, marketing and servicing of products and services over computer networks. It also includes the transfer of funds in the buying process. There are two types of e-commerce:

• B2C or Business to Customer (where businesses retail their supply goods and services over the Internet to individual private consumers).

• B2B or Business to Business (where businesses supply other businesses with products and services that are required in the operations of that business).

Telecommuting

This is also called teleworking. It is working from home and communicating with colleagues and customers using computer facilities – modem, telephony, e-mail, teleconferencing and faxing. Telecommuting can be part-time or full-time.

|Hardware requirements |Software requirements |

|POS terminals |Inventory software |

|Barcode readers |Payroll software |

|Mainframe or minicomputers with networked terminals and cash registers |Accounting and financial software |

|Printers (character, line, laser, thermal for printing statements, reports, bills) |Word processing software |

|Magnetic card readers (for the reading of credit cards, debit cards) |Video conferencing software |

| |Internet access software |

| |E-mail software |

Computers in Education

Computer-Assisted Assessment (CAA)

This is the use of computers to assist in the marking of examination scripts, such as multiple choice papers.

Computer –Assisted Learning (CAL) and Computer – Aided Instruction (CAI)

This is the use of computers and appropriate computer software to allow students to learn at their own pace, and/or create a more interesting learning environment in which teaching material is presented.

There are three basic forms of CAL/CAI:

• Drills and practices: This is where students are repeatedly given a range of questions from a data bank, especially to practice skills and concepts that require repeated practice e.g. vocabulary work or mastering rules in mathematics. These questions have an exact right or wrong answer and are therefore very easy for the computer to mark.

• Tutorials: These are self-paced, self-instructional programs that guide the student through new material, acting as their tutor. Students can repeat a lesson as often as they like if they do not understand the material. The lessons can also be adjusted depending on the level of the student’s ability – the tutorial may even test the student’s ability at the start, and adjust the tutorial accordingly.

• Simulations: These use multimedia (sound, text, video and graphics) to demonstrate a realistic-looking and sounding outcome, based on a specific scenario. For example, a simulation may show you what happens when you mix two chemicals together in a test tube (e.g. bubbles, changes in colour, production of gas etc.). Simulations provide the opportunity for individuals to learn in a safe environment, without wastage of material or high – risk situations.

Computer Managed learning (CML) or Computer Managed Instruction (CMI)

CML or CMI are administrative tools used in education to organize students’ data and timetables and in libraries to manage indexes.

Referencing Information (Research)

Online Library

Computers are a popular means of sourcing information, especially when connected to the Internet. Online libraries allow individuals to stay at home and access most of the information they need relatively quickly and easily. Online libraries carry information from books, magazines, journals, articles and newspapers around the world from both academic and commercial publishers. They maybe subject-specific, e.g. medical libraries or law libraries, or general libraries that cover a wide range of subject areas. Some require you to register and subscribe to their service by paying either a monthly or annual fee. Members are given a password and a user name to allow access. Others do not charge a fee; however , for some books and articles your access is limited to the abstracts and summaries.

Electronic Encyclopedias

Traditional encyclopedias are now also available on CD-ROMs or online. The advantages of these are:

• They can be updated regularly; new information can be added.

• The electronic versions need less storage space than the printed encyclopedia.

Distance Learning

This involves classes being conducted via the Internet, an extranet or intranet, satellite broadcasting, interactive television and CD-ROM. It includes:

• Web-based Learning (WBL)

• Tele-collaboration, which means using global computer networks in teaching/learning environment to connect students all over the world. Learners can collaborate or work together on projects through the use of e-mails, synchronized chat, threaded conversations and other forms of electronically mediated conversation

• Virtual classrooms, which is an online learning environment designed to carry out some of the roles of a physical school/classroom. They are used in home schooling.

|Hardware requirements |Software requirements |

|Computers (stand alone and networked) |Word processing for creating documents |

|Printers (laser, inkjet and sometimes character printers) |Web and video conferencing software |

|Devices for disabled learners e.g. concept keyboards, voice |CAI/CAL software for a variety of subjects and levels (simulations, |

|synthesizers |drills and tutorials) |

| |Database software for managing student records |

| |Spreadsheets for grading students’ marks |

| |CML software for creating timetables, etc. |

Computers in Industry (engineering and manufacturing)

In engineering and manufacturing computers are used to:

• Direct assembly line operations

• Perform simulations

• Design, draw and manipulate engineering, architectural, product, graphic and textile designs.

Computer Aided Design (CAD) and Computer Aided Design and Drafting (CADD)

This includes the hardware and software used to draw, manipulate and design engineering and architectural designs, electronic products and even clothing designs. They allow adjustments, updates and duplications of designs to done easily on the computer. CADD systems allow designers to create three dimensional (3D) objects that can be easily manipulated, rotated and viewed from many angles. The CAD package contains basic elements such as points, lines, circles, shapes and solids, from which all CAD drawings are constructed. Additionally, the computer keeps track of design dependencies, so that when a value is changed all other dependent values are automatically changed. A high-resolution graphics monitor is needed to show the details of drawings done with a CAD package. Some advantages of using CAD are:

• The length of time it takes to draw a design is reduced.

• It is easier to make changes or update the original design.

• Duplicates of the design are easy to produce, to distribute to various interested parties or other parts of the company

Computer Aided Manufacturing (CAM)

These systems are used to control manufacturing plant equipment and production equipment e.g. in a car manufacturing plant or a factory that makes microprocessors for computers. CAM translates the design into the actual product, such as moulding a bottle or spoon. Many CAM systems use robots and sensors along with computers in the manufacturing process. The advantages of CAM include:

• Faster production of parts and products, therefore meeting customer demand.

• The ability to control and maintain the quality of the product better, so that it is produced more consistently.

Computer Aided Engineering (CAE)

These systems analyses engineering designs, simulating varying conditions to determine in advance whether the design is likely to work. For example, an aeroplane manufacturer might be able to simulate the forces of a hurricane wind on a plane wing using a CAE computer, or an engineer might be able to simulate the stresses applied to a bridge.

|Hardware requirements |Software requirements |

|Robots |CAD and CADD software for design and drafting |

|Sensors |Specialized software to control machines |

|Mainframes, minicomputers and microcomputers |CAE or Simulation |

|Printers and plotters (for printing drawings) | |

|Light pen and digitized tablets | |

|Monitors (high-resolution) | |

Computers in Artificial Intelligence (AI)

In AI computers are used to:

• Control robots

• Produce expert systems

Robotics

Robotics is the use of computer-controlled machines in place of humans to perform repetitive and dangerous tasks. They are normally found in industry or assembly lines. For example, in the automotive industry robots are used for welding, paint spraying, assembling and loading. They are used to perform high precision tasks, which they can perform with fewer errors than humans. They do not get sick, complain or take strike action. Robots are also able to operate in extreme environments where it might be difficult or impossible for human beings to operate.

Expert Systems

These systems provide a vast knowledge database of information in specific fields such as medicine, mathematics, engineering, geology, computer science, business, law, defense and education. Expert systems or knowledge-based systems make decisions based on the results of questions put to the user; the program analyses input data and provides answers at the level of an expert in the particular field. By looking at various possibilities the computer makes the best informed decision. These systems perform the function of a human expert consultant in a particular field, providing support for decision making. They can also ‘suggest’ alternatives or other issues to be considered.

Expert systems consist of two parts: the knowledge base and the inference engine. The knowledge base contains a large volume of information in a particular field e.g. a medical expert system knowledge base contains a vast array of information about different types of diseases, symptoms and possible treatments. The inference engine complements the knowledge base; it analyses the input data using ‘reasoning’ methods along with the knowledge base, to arrive at a conclusion. It also provides the user with an explanation of how it arrived at its conclusion, by showing the concepts that were used.

|Hardware requirement |Software requirement |

|Robots |Software to control machinery such as robots, process, sensors |

|Sensors |Virtual reality software |

|Voice recognition and voice synthesis systems that include |Voice recognition and voice synthesis software |

|microphones and speakers | |

|Virtual reality (VR) systems that include special clothing, |Expert systems |

|head gear, data gloves, joysticks and handheld wands | |

Computers in law enforcement

Computers are used in law enforcement to:

• Maintain criminal databases

• Examine forensic evidence

• Communicate with other departments and agencies

• Provide electronic surveillance

• Control traffic systems

• Provide assistance to officers through easy access to information

• Computerize many of the traditional office tasks

• Prepare reports

• Equipment inventory

• Tracking parolees

• Transmitting, exchanging and obtaining information from other police officers

Security cameras

These can act as a visible deterrent to a criminal. Sometimes they are hidden in order to catch criminals in action. They can capture video footage of a crime in progress and the images can be used to identify the criminals. Most cameras today are linked to computer systems which can store and process the raw data.

Biometric identification systems

Biometrics refers to the science of identifying an individual through their body characteristics, such as face geometry, hand geometry e.g. fingerprints, iris or retinal scans, veins and voice patterns. All these forms of identification can be input into a computer system set up for security purposes. Two of the most commonly used methods are:

• Fingerprints obtained from a crime scene can be matched against a database of known criminals’ fingerprints to identify a suspect. The patterns are stored and analyzed by computer.

• Computer-assisted facial image identification systems use computers to identify a person from an image captured through a surveillance camera or photograph.

Profiling

This involves the use of software by the police to compose a picture of an alleged criminal based on the description of a witness. The picture can then be compared to those stored in criminal databases. This method reduces the cost of police stations having a traditional sketch artist. It also allows the image to be sent electronically over the Internet to other police departments.

Traffic control

Computerized traffic light systems control traffic flow using a specific sequence of lighting managed by the computer. These sequences are adjusted throughout the day depending of the flow of traffic. The systems use a sensor in the road to detect traffic flow. They then process this data, adjusting the traffic lights as necessary to promote the maximum flow of traffic at different times of the day. The data from the sensors is sent via wire-based or fibre-optic cables to the processing computer.

Electronic surveillance

Wire-taps, email and online communication interception, location information ( e.g. determining where you are from calls going to your cell phone) and communication analysis (e.g. monitoring when and where credit cards are used) are all forms of electronic surveillance. Such surveillance can help police track criminals’ movements and activities.

|Hardware requirements |Software requirements |

|Robots (bomb detection and disarming) |Database management software |

|Security cameras and electronic surveillance equipment |Biometric identification software such as DNA, voice analysis, |

| |facial image identification and fingerprinting identification |

| |software |

|Biometric identification systems | |

|scanners | |

|Mainframes and minicomputers |Profiling software |

|Printers |Statistical analysis software |

Computers in medicine

Computers are used in medicine to:

• Monitor patients’ vital signs

• Maintain databases of patients, diseases and drugs

• Aid in detecting and diagnosing diseases

• Assist in generating case-sensitive advice through the use of expert systems

• Helps doctors to collaborate with colleagues and administer treatment over the Internet.

• Perform research

Patients’ Records

Electronic patients’ records help doctors provide medical care. Records of patients’ health history, as well as their personal information, can be easily accessed if this information is computerized. This is especially helpful when a patient’s records exist in several different institutions. Computerized records can reduce the time spent looking for a patient records in the case of emergency. It also makes it easy to detect trends in diseases.

Patient Monitoring Systems

These help doctors monitor and treat patients – either at home or in hospital intensive care – by providing 24 hour service. These are computerized systems that monitor a person’s vital signs, such as blood pressure, temperature and heart rate, using sensors attached to the patient. The system records the information at specific intervals and may sound an alert in the event of a dangerous abnormality in the readings.

Computer-aided Detection and Computer-aided Diagnosis

• Magnetic Resonance Imaging (MRI) uses magnets to create two and three dimensional images of tissues such as the brain. The images are processed by computers for analysis by doctors. This helps to detect strokes, tumours, infections and even haemorrhages.

• Computer Axial Tomography (CAT) scanning: A CAT scanner is an X-Ray tube that takes as many as 30 pictures per second as it rotates around the patient. The computer reconstructs a three dimensional view of parts of the patient’s body from the pictures taken. This aids in the diagnosis of brain diseases, tumours and so on.

|Hardware requirements |Software requirements |

|Mainframes, microcomputers and supercomputers |Database management software |

|Sensors (heart rate, temperature, pressure) |Patient monitoring system software |

|Printers/plotters |Expert systems |

|Magnetic Resonance Imaging (MRI) systems |Imaging software |

|Computer Axial Tomography (CAT) scanning (X-ray tubes) | |

|Monitors (high resolution | |

Computers in Entertainment

Computers are used to:

• Record, synthesize, edit and distribute music

• Create and play computer games

• Create animations and special effects in movies

Music and Sound

The natural sounds of most musical instruments have been digitized into electronic versions and can now be played from a single instrument such as a keyboard. When the keyboard is connected to a computer you can record, play back and enhance music. Software can be used to edit sound and music clips, and these clips can be inserted into other pieces of music.

Another application of computers in music is distribution. Popular music can be downloaded to cell phones and MP3 players from the Internet, for a relatively small fee.

Movies and animation

Computers are used in movies to create computer generated images (CGIs) e.g. The Matrix, Star Wars, Finding Nemo, etc. Animations are now part of many popular movies. Anima software allows persons without much computer skill to develop an animation from beginning to final product.

Games

Computers are used to play games for both entertainment and education e.g. Nintendo, Game Boy, Marble Blast and Bookworm.

Current and Emerging Technological Trends

In addition to robots, expert systems, CADD, CAE, CAM, and telemarketing another emerging technological trend is teleconferencing.

Teleconferencing

A teleconference is a meeting or conference held via a telephone or network connection between participants in remote cities or work sites. Many types of teleconferences exist, with the simplest form involving the use of a speaker phone at each location to conduct an audio conference. More sophisticated teleconference meetings involve the exchange of audio, video, and data. The term teleconference can also refer to a live event that is transmitted via satellite to various locations simultaneously.

Objective 4.8 Assess the impact of Information Technology on job skills and careers;

The Effects of Computers on Employment

The effects of computers have been both good and bad – there has been job loss, job creation and changes in job skills.

Employees in the computerized workplace should be able to:

Office Employees

• Prepare and edit documents using word-processor

• Calculate and analyse numerical data using a spreadsheet program

• Store, edit, receive and query records in a database

• Use computerized accounts for processing customer and company accounts

• Send and receive faxes

• Use web browsers and know how to send and read e-mail

Teachers

• Use word-processors to prepare exercises and notes

• Use presentation software to make demonstrations

• Use the Internet for research purposes and teach students how to do so

• Teach students how to use the multimedia, simulation or tutorial software designed to aid learning

• Use spreadsheets applications to record and calculate students’ marks

• Assemble the main parts of a computer and do simple troubleshooting

Engineers

• Use CAAD software, simulation software and in some cases graphics plotters

• Design computer-based process control systems

Medical personnel

• Use computer-controlled devices to monitor a patient’s condition

• Use expert systems for the diagnosis and treatment of illnesses

• Store, edit and retrieve a patient’s record using database management software

• Use specialized equipment for performing operations

Musicians

• Do sound sampling

• Record sounds

• Do music synthesizing

• Edit songs and add special effects

Movie Industry

• Use animation software

• Use graphics editors

• Use custom-written special effects software

• Operate robots to imitate dangerous animals etc.

Mass Media Personnel

• Use a word-processor to produce and edit articles

• Scan photos with a scanner

• Use desktop publishing to design advertisements

• Use the Internet for research and communication

• Take photographs with a digital camera

Law Enforcement Personnel

• Knowing how to use a scanner to scan photographs of criminals

• Knowing how to use computers for fingerprint matching and DNA analysis

• Knowing how to use database management software to store and retrieve data

• Knowing how to use statistical analysis software

Loss of Jobs

Because of automation, some jobs have become extinct. Many jobs previously performed by humans are now being performed by computers or computer technology. Automated assembly lines e.g. car production plants, can perform many assembly jobs more efficiently and effectively than humans. As a result, significant job losses have occurred in production lines over the world.

Automation has also been used to replace humans where the jobs are boring, monotonous or dangerous. Dangerous or potentially hazardous jobs, such as handling chemicals are now often done by robots instead of humans. In other cases, job losses have occurred because jobs previously requiring two or more persons to do them are now being done by just one person with a computer.

Job Creation

Even though computers have caused job loss, it has also created millions of new jobs. Some jobs have been created as direct result of computerization in areas such as research, design, manufacturing, programming, maintenance, communication, education, consultation, marketing and security.

Computers have also made jobs more accessible to the disabled person.

Change in Job Skills

Because of the introduction of computers in the work place, many workers now need new skills or upgrading of old ones. Many jobs now require basic computer knowledge and thus workers require retraining e.g. office secretaries are now being asked to use word processors instead of typewriters; draughtsmen and architects are now required to produce drawings and designs using CAD software.

Changes in Work Patterns

Computers have changed the way people do their jobs. People can work from anywhere, outside of normal working hours, using their laptops i.e. telecommuting. Teachers can send homework to absent students via e-mail, after normal school hours. A police officer can access and retrieve information from their police car instead of having to return to headquarters.

Objective 4.9 Describe the roles of various personnel in computer-related professionals;

Roles or duties of a Programmer

• Discuss program specifications with the systems analyst

• Write programs

• Test programs for correct operation and intended results

• Debug programs

• Document programs

• Update, repair, modify and expand existing programs

N.B. System programmers write systems software, such as programs to monitor and control peripherals. Their roles are the same as a programmer.

Roles or duties of a Systems Analyst

• Plan and conduct studies to determine if an existing system needs to be upgraded or if a new system has to be put in place

• Hold discussions with managers and users of the system to determine their exact needs

• Gather facts about, and analyze the basic methods and procedures of, current information systems

• Design new systems, integrate existing procedures into new system specifications as required and assist in the implementation of new designs

• Make recommendations for the acquisition and purchase of hardware and software, if necessary

• Test and debug the new system

• Create documentation for the system

• Assist in training employees to use the system

• Evaluate the performance of the system over a period of time to see if it is performing as expected

Roles or duties of an IT Manager

• Plan, co-ordinate, manage and staff the data processing department

• Communicate with, motivate and lead a number of highly skilled people

• Be aware of the latest developments in the IT field

• Read reports on the system’s performance and develop strategies to improve it

• Meet users and members of other departments to discuss problems encountered with the system or new projects for computerization

• Prepare budget projections for the department

Roles or duties of a Database Administrator

• Interact with managers and users to ensure that the database is accomplishing what they need

• Meet with users to make modifications to the database whenever there are changes in the company’s operation

• Ensure that the database is performing at its optimum at all times to meet the needs of its users

• Develop policies and procedures to ensure the security and integrity of the system

• Select and maintain database management software

• Co-ordinate database design

• Establish backup and recovery procedure in case of failure or loss of data

• Establish a data dictionary that records company-wide data definitions and standards

• Co-ordinate the data collection and storage needs of users

Roles or duties of a Network Administrator

• Plan and design the network

• Oversee the installation of the network’s hardware and software

• Test the network to ensure it is functioning properly

• Set up user accounts and arrangements for access

• Ensure that staff are trained to use the hardware and software that form part of the network

• Monitor the network’s performance to ensure it is working at its optimum

• Troubleshoot and solve problems on the network

• Set up systems to ensure compliance by users of the network

Roles or duties of a File Librarian

• Maintain and protect the company’s programs and data

• Catalogue and store magnetic tapes and disks

• Supply magnetic tapes and disks to authorized users

• Clean and inspect storage media

• Keep records of the disks and magnetic tapes stored

Roles or duties of a Computer Engineer

• Design, develop, test and supervise the manufacture of components and peripherals

• Assemble and test new designs for overall effectiveness, cost reliability and safety

• Maintain and repair computer hardware sold to clients

Roles or duties of a Computer technician

• Assemble and service computer equipment

• Find and fix computer problems

Roles or duties of a Software Trainer

• Train people to use computer hardware and software

• Develop training manuals

• Examine and mark examination scripts

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