UNIT 21 Software Engineering
b iterationsor loop instructionsi.e. process these instructions repeatedly until or while a particular condition is true, or false (do... until... or do... while...). Program flowchartscan be used to show the sequence of instructions in a program and are sometimes used for designing parts of programs such as iterations. Pseudocodeis a method of writing a description of a computer program using a mixture of natural language and computer language code.
There are a large number of computer languages available for use by programmers. Each language is designed for use in solving particular types of problem and therefore has particular strengths and weaknesses. A systems analyst has to decide which language is most appropriate in each situation. Languages such as C++are particularly suitable for writing systems programs(programs that are used to control the basic functions of a computer system e.g. operating system programs). Languages such as Visual Basicand Pascalare easy to use and are particularly suitable for learning how to program. FORTRANis designed for solving engineering problems, COBOLfor writing business programs, Adafor military purposes, Prologand LISPfor working in artificial intelligence(an area of computing concerned with developing computer programs that perform tasks that can normally only be done
using human intelligence). Logois particularly suited for use by young children. Some languages such as HTMLand XMLare markup languagesrather than programming languages i.e. they use tag codes(labels) for marking text for use in programs such as Web browsers. Languages such as Javaand Perlhave a number of specialised uses including adding features to internet connections and webpages (hyperlinked documents).
Converting to new computer systems can be done in different ways. Each strategy has its advantages and disadvantages. These include:
a direct implementationwhere the old system is simply removed and the new system installed. In this strategy only one system is used at any one time but there is no fall back(alternative system that can be used if problems occur in the main system) if the new system does not operate properly.
b parallel implementationwhere the old and the new systems are both used at the same time until the users are satisfied that the new system is working properly
c phased implementationwhere the old system is gradually replaced by the new system, one part at a time
d pilot implementationwhere the new system is tried out in one section of the company to make sure that it works as required.
UNIT 22
People in Computing
INTRODUCTION
There is a wide range of jobs in computing and different titles are sometimes given to the same type of job. Jobs mentioned in this unit include:
• A Webmaster- a person who administers a Web server.
• A help-desk troubleshooter- a person who works as part of a telephone service that helps users solve problems that occur on computer systems.
• An applications programmer- a person who writes applications programs(computer programs designed to be used for a particular purpose e.g.
word processors, spreadsheets or database programs).
• A security specialist- a person who tests
the security of networks systems and
advises customers how to introduce and
maintain security policies including:
a setting up secure passwordsystems (secret codes used to control access to a network system)
b installing firewalls(a combination of hardware and software used to control the data going into and out of a network)
c keeping out hackers(skilled programmers who attempt to gain unauthorised access to network systems)
d dealing with viruses(programs written with the purpose of causing damage or causing a computer to behave in an unusual way).
• A systems programmer- a person who
specialises in writing systems software(a
program or set of programs that are used
to control the basic functions of a
computer system e.g. operating system
programs).
Being employed in any of these jobs requires the person to have particular formal
qualifications, personal qualities and technical skills. Qualifications mentioned in this unit include:
a Standard grades in Maths.This is a basic level school qualification in mathematics.
b HNC in Computing.This is a Higher
National Certificate in computing including the study of hardware(the physical components of a computer system) and software(programs and data). This is a college qualification that can usually be obtained by a period of part-time study.
c HND in Computing Support.This is a Higher National Diploma in installing, maintaining and troubleshooting(to find and fix faults in a system) computing systems and training users. This is a higher college qualification than an HNC but not as high as a University degree. It usually requires a period of full-time study.
An IT (Information Technology) support engineeris a professional who provides help for computer users by designing, building and maintaining information technology systems(systems and equipment such as computers for dealing with information). A support engineer might start out in their career by working on a help-desk(a telephone service for helping users solve problems that occur on computer systems).
An IT managermanages projects, technology and people. An IT systems manageris responsible for developing and implementing computer software that supports the operations of the business. Off-the-shelf systemsare ready-made systems that are purchased from systems suppliers. In-house systemsare developed by the employees of the company. A university degree is usually required but not necessarily
UNIT 22 People in Computing 10"
in computing science(the study of computers and their use). The best qualification for becoming a manager is experience.
A systems analyststudies systems in an organisation and decides how to computerisethem (change the system into one controlled by computers). They analyse requirements and report on options for using information technology(the study and practice of techniques or use of equipment for dealing with information).
A software engineer/designerproduces the programs which control the internal operations of computers. They use program libraries(sets of programmed functions that are made available for use by any program) to produce programs. They also design, test and improve programs for a variety of purposes including computer-aided design and manufacture(the production of technical designs and the production of goods using machines controlled by computers).
A computer services engineering technicianis responsible for installation, maintenance and repair of computers and peripherals(associated equipment). They install, test, troubleshoot, upgrade(add components to improve the features or performance of a system) and carry out routine maintenance on hardware, ranging from personal computers(a computer designed to be used by one person at a time) to mainframes(the largest and most powerful type of computer, usually operated by a team of professionals).
A network support personor computer engineermaintains the link between PCs(personal computers) and workstations(powerful desktop computers used by power users for work that requires a lot of processing e.g. graphic design) connected in a network(a number of computers and peripheral devices connected together). They use telecommunications(technology
concerned with communications over long distances), software, electronic skills and knowledge of networking software to troubleshoot systems. This may involve work with the controlling software, on the wiring, printed circuit boards(the electronic boards that hold the components of a circuit and connect them together), software or microchips(small integrated electronic circuits) on a file server(a powerful network computer that stores computer files and makes them available to users on a network), or on cables either within or outside the building.
An applications programmerwrites applications programs(computer programs designed to be used for a particular purpose e.g. wordprocessors, spreadsheets or database programs).
A systems support personis an analyst programmer(a person whose job is a combination of systems analysis and computer programming) who is responsible for maintaining, updating(bring up to date i.e. change into the latest version) and modifying the software used by a company. Some specialise in systems software(software that handles the basic operation of the computers). This involves use of machine code(computer language that consists entirely of a combination of Is and Os) and specialised low-level computer languages(computer languages, such as machine code or assembly language, that is closer to the form that a computer understands than to that of a human language). They may sort out problems encountered by users including amending an area of code(text of a program or part of a program using a computer language) in the software, retrieving files and data lost when a system crashes(fails suddenly and completely, usually referring to the failure of a hard disk).
UNIT 23
Recent Developments in IT
INTRODUCTION
An electronic newspaperis an electronic device that connects to the Internet and displays news items on a display screen.
A channelis a path for the transmission of data.
A gigabit per secondis a communications speed of approximately one thousand million binary digits every second.
A fibrerefers to a strand of glass fibre used in fibre optics cable which carries data using the reflection of laser light
Visual computer personalitiesrefers to digital images with human characteristics that are used as an interface between the user and a computer system.
A hydraulic chairis a chair that has moving parts that are operated using fluid pressure.
VR gamesare virtual reality gamesi.e. computer games that use a simulated three-dimensional environment that surrounds the user and is generated by a computer.
An intranetis an internal network webpage system that operates using the same protocols(agreed communication standards) as the Internet.
The Internetis the connection of computer networks across the world.
A wearable health monitoris a computerised medical device built into clothing so that it can be worn by the user to take measurements of certain aspects of the user's health.
A robotis a mechanical device controlled by a computer.
A terabitis a unit of storage capacity equal to approximately one million million binary digits.
Optical fibreis the glass fibre used in fibre cable that carries data using the reflection of laser light.
A robotic petis a mechanical device in the
form of a pet animal, such as a dog, that is controlled by a computer.
Robotic devices within blood vesselsrefers to computer-controlled mechanical devices that are small enough to be inserted into human veins and arteries that carry the blood around the body.
Artificial brain implantsrefers to computerised devices that are designed to be inserted into the human brain.
Avatarsare animated graphical icons used to represent real people in cyberspace(the combination of all the data on all the computer networks throughout the world, accessed using the Internet).
Roboticsis the study of robot systems.
Barcodesare sequences of vertical parallel lines used to give items unique identification numbers.
Radio-frequency tagsare badges attached to products that emit radio-frequency signals to provide information about the product.
Computerised(operated or controlled using a computer) versions of common household items, such as fridges and washing machines, are becoming available. These devices have touch-sensitive display screens and can be connected to the Internet to enable email(electronic mail) and browsing(moving from webpage to webpage using a Web browser program) using Web protocols(agreed standards for communicating using the Web) such as WRAP(web-ready appliance protocol). These devices can be operated by remote control(at a distance) and can communicate with each other through the house ring main(the common, main electrical supply circuit). Computerised fridgescan use radio-frequency tags to keep track of the items in the fridge, suggest menus or provide a shopping list.
Wireless network systems(network