Presentation on theme: "1.1 Basic Concepts of Input-Process-Output Cycle"— Presentation transcript:
1 1.1 Basic Concepts of Input-Process-Output Cycle A computer is a very powerful electronic machineA computer can:store a huge amount of dataperform complicated calculationsproduce the calculated results on different media
2 1.1 Basic Concepts of Input-Process-Output Cycle The process of a computer task can be divided into three stages:InputProcessOutputInput-Process-Output cycle
3 1.1 Basic Concepts of Input-Process-Output Cycle In our daily lives, many activities involve the Input-Process-Output cycle.Input-Process-Output cycle
4 1.1 Basic Concepts of Input-Process-Output Cycle For a computer, the Input-Process-Output cycle usually involves operations and hardware.InputEnter data andcommands into acomputer via one ormore input devices.ProcessThe CPU works onthe data accordingto the commandsprovided in the inputstage.OutputThe computer showsthe processed resulton the outputdevices specified inthe input stage.The Input-Process-Output cycle in a computer process
5 1.1 Basic Concepts of Input-Process-Output Cycle For a computer, the Input-Process-Output cycle usually involves operations and hardware.InputEnter data andcommands into acomputer via one ormore input devices.ProcessThe CPU works onthe data accordingto the commandsprovided in the inputstage.OutputThe computer showsthe processed resulton the outputdevices specified inthe input stage.The Input-Process-Output cycle in a computer process
6 1.2 Use of Stored Programs Programs Computers themselves will not function if no command is given.A program:A sequence of commandsShould be provided to the computer in order to instruct the computer to complete a specific taskWill be fetched by the computer and the commands will be executed one by one
7 1.2 Use of Stored Programs Stored programs Enable computers to do tasks automatically, repeatedly and accuratelySaved in the read-only memory (ROM) of many home appliances and machinesExecuted by the microprocessor to control the operations of the machines.
8 1.2 Use of Stored Programs Stored programs A modern microwave oven has stored programs to decide the appropriate temperature and cooking time for the food.A modern video recorder records TV programmes automatically according to the recording schedule preset by users.
9 1.2 Use of Stored Programs Stored programs Found in traditional mechanical products:Mechanical music boxesOld-fashioned sewing machinesA mechanical music box and traditional sewing machine are examples ofmechanical machines with stored programs.
10 1.2 Use of Stored Programs Stored programs Found in traditional mechanical products:Mechanical music boxesOld-fashioned sewing machinesA mechanical music box and traditional sewing machine are examples ofmechanical machines with stored programs.
11 1.3 Difference between Data and Information A collection of raw facts that are not organizedHas no meaning on their ownInformationData that has been organizedMeaningful and useful for decision making
12 1.3 Difference between Data and Information Data is processed into information.
13 1.3 Difference between Data and Information Data is processed into information.
14 1.4 Types of Data Text Audio Images Videos Data can be converted into digital forms with the help of appropriate input devicesDifferent types of data:TextImagesAudioVideos
15 1.4 Types of DataVideoTextImageAudioDifferent types of data
16 1.4 Types of Data Text Examples: CharactersNumbersSymbolsCan be represented by certain character coding systems:American Standard Code for Information Interchange (ASCII)UnicodeBig5 code
17 1.4 Types of Data Text Input devices for text entry: Keyboard Handwriting boardScanner with optical character recognition (OCR) softwareVoice recognition systemA handwriting board
18 1.4 Types of DataTextWhen we enter text data with an input device, the text data is transformed into binary codes.The binary codes can be further processed or stored in a computer.Chinese CharacterBig5 codeUnicode日學天Different character coding systems may have different codesfor the same character.
19 1.4 Types of Data Image Examples: PhotographsDrawingsHandwritten textCan be inputted into a computer by a scanner.Can be converted into a rectangular grid of colour dots (known as pixels).Each colour dot is represented by a string of binary codes in a computer.The digital representation of a collection of colour dots of an image is known as a bitmap image.19
20 Common methods of producing a digital image 1.4 Types of DataImageCommon methods of producing a digital image
21 1.4 Types of Data Image Common devices that produce bitmap images: Digital cameraMobile phone (with built-in camera)Scanner
22 1.4 Types of Data Audio Use of audio files in a computer: Record music SpeechesAny kind of audio signals in digital formAudio signals can be captured into a computer by means of a microphone.The analogue audio signals are converted to a stream of digital audio signals by a sound card.The computer is able to edit and store it or reproduce the audio with speakers.Popular file formats for digital audio files:WAVAACMP322
23 Analogue audio can be digitized for editing, playback and storage 1.4 Types of DataAudioAnalogue audio can be digitized for editing, playback and storage
24 1.4 Types of DataVideoA sequence of images representing a scene in motionA digital video file consists of a stream of digital data that contains both video and audio.A web cam can capture video and audio (with its internal microphone) into a digital video file.A video capture card can convert analogue video signals from external sources into digital video files.Both digital video cameras and digital cameras can capture and record video in a digital form and store them as digital computer files.Digital computer files can be transferred across computers without the need of any further conversion.24
25 Analogue videos can be digitized for editing, playback and storage 1.4 Types of DataVideoAnalogue videos can be digitized for editing, playback and storage
26 Analogue videos can be digitized for editing, playback and storage 1.4 Types of DataVideoAnalogue videos can be digitized for editing, playback and storage26
27 1.5 Components of an Information System Basically a system that accepts data as input and transforms it into information as output via the Input-Process-Output cycleThe transformation can be either a manual or an automated process.In general, it consists of five interrelated components:ProcessesPurposesPersonnelTechnologiesData
28 1.5 Components of an Information System PurposesSome of the most common reasons for implementing an information system:Automate an existing manual processImprove an existing systemFix system problemsThe current situation of a school library:Operate in manual modeStudents need to come to the library and search for books on the bookshelves.If a student wants to borrow a book, the librarian will write down a record of it in a logbook.Teachers sometimes need to check the logbook to see which subjects are most popular.28
29 1.5 Components of an Information System PurposesThe purposes of a library system:Help students search for the books efficientlyHelp librarians track the status of a book efficientlyHelp teachers figure out which subjects are most popularHelp in stocktaking at the end of each semesterAutomatically generate reports of overdue books29
30 The library system of the Chinese University of Hong Kong 1.5 Components of an Information SystemPurposesThe library system of the Chinese University of Hong Kong
31 1.5 Components of an Information System DataThe major component of an information systemExamples:In a payroll information system, data can be employees’ names, salaries or grades.In a multimedia information system, data can be digital images or digital videos.After the information system has collected the data, the data will be stored in a main database.A main database is a structured collection of records or data that are stored in a computer system so that they can be retrieved by query languages.
32 1.5 Components of an Information System ProcessesWork with data to achieve the purposes or objectivesSome examples of processes:Generating bank statementsCategorizing dataPrinting management reportsAll processes are combined together to form an information system.
33 1.5 Components of an Information System ProcessesProcesses of the food ordering information system in a restaurant:Receiving and transferring customer food ordersTransforming order to kitchen formatGenerating customer receiptAggregating goods sold and inventory dataProducing management reports33
34 1.5 Components of an Information System TechnologiesAn information system is a computer-based system that relies on technologies including:HardwareSoftwareNetwork34
35 1.5 Components of an Information System TechnologiesHardwareRefers to all the physical componentsIn a point-of-sale system, computer hardware includes:MonitorsKeyboardsBar code scannersPrintersAlso covers any media used by machines, for example:ATM cardsCredit cardsOctopus cards
36 Point-of-sale terminal in a supermarket 1.5 Components of an Information SystemTechnologiesHardwarePoint-of-sale terminal in a supermarket
37 1.5 Components of an Information System TechnologiesSoftwareA sequence of instructions which instructs the information system to perform specific tasksTwo kinds of software that would be used in an information system:System softwareApplication software37
38 1.5 Components of an Information System TechnologiesSoftwareSystem softwareManages computer resources such as hard disks, CPUs, files, the main memory and all devices that are used to control the computerAn operating system:A part of system softwareExamples: Microsoft Windows, UNIXApplication softwareDesigned for users to perform specific tasksDatabase software:A type of application softwareExample: Microsoft AccessStores records or data in a computer system and organizes them in a structured way by using tables
39 1.5 Components of an Information System TechnologiesNetworkSome information systems may not only be used in a single computer.They may be used in a group of computers interconnected via the Internet or the intranet.An online cinema information system using network technologies:A server is set up at the head office.This server is connected to a database server.Customers can use a web browser to submit a ticket-ordering request to the server39
40 1.5 Components of an Information System PersonnelA major component of all information systemsThey use, develop or manage an information systemTwo types of roles:End usersInformation system (IS) specialists40
41 1.5 Components of an Information System PersonnelEnd usersUse an information system or an information productInformation system (IS) specialistsDevelop or manage information systemsUsually from the information system department which deliver IT services to an organizationExamples:Systems analystsProgrammersTechniciansNetwork managersData entry operators41
42 1.5 Components of an Information System PersonnelInformation system (IS) specialistsSystems analystResponsible for the research, planning and implementation of the information system according to the requirements defined by end usersAnalyze the cost, study the feasibility, design the system using any new technologies and estimate the time frame of the implementationProgrammerResponsible for converting the system design developed by the systems analysts into program codes42
43 1.5 Components of an Information System PersonnelInformation system (IS) specialistsTechnicianResponsible for managing the information system such as performing the backup of the system and monitoring its resource usagesNetwork ManagerResponsible for monitoring the availability and performance of the communication between computer systemsData Entry OperatorResponsible for entering data into the information system before end users can use it43
44 1.5 Components of an Information System PersonnelInformation system (IS) specialistsTechnicianResponsible for managing the information system such as performing the backup of the system and monitoring its resource usagesNetwork ManagerResponsible for monitoring the availability and performance of the communication between computer systemsData Entry OperatorResponsible for entering data into the information system before end users can use it44
45 1.6 Information Processes The information life cycleThe processes of transforming data into useful informationNormally there are seven information processes:Data collectionPresentationOrganizationTransmissionStorageAnalysisProcessingAn information life cycle
46 1.6 Information Processes Data CollectionThe activity of collecting raw data from the outside world so that it can be put into an information systemMethods:Personal interviewsTelephone interviewsQuestionnairesExperimentsThe InternetThese methods can be used separately or combined together.
47 1.6 Information Processes Data CollectionCollecting data through a personal interview
48 1.6 Information Processes OrganizationCollected data must be organized into certain formats so that it can be further processed.The data can be represented in:TextImagesAudioVideosWays to organize data:Putting data into paper-based forms or electronic forms by its categoryInserting data into related database tables or spreadsheetsGrouping images to create an animation48
49 Stages of data preparation 1.6 Information ProcessesOrganizationData-loggingKeep track of incoming data.Manual validity checkCheck for completeness.Check whether the contextual information is included.Check whether the answers are reasonable and legible.Data categorizationDivide the raw data into different groups.Sort the raw data into a specific order for facilitating subsequent data entry procedure.Stages of data preparation
50 1.6 Information Processes StorageOrganized data must be stored in storage media so that they can be retrieved for processing later.Two kinds of storage media:Non-digital mediaPaperFilesDigital mediaCD-ROMsDVDsHard disksFloppy disksMagnetic tapes50
51 1.6 Information Processes StorageMost of the information systems use database software to store data.Database software uses direct access devices such as hard disks as storage media.Financial data of a company can be backed up in magnetic tapes.
52 1.6 Information Processes ProcessingDifferent kinds of processing:Data processingSortingSearchingMergingCalculatingWord processingImage processingVideo processingAudio processing52
53 1.6 Information Processes ProcessingAn example of information processing in a human resource management system:Photos given by employees may be in a different format or size other than the system requires.The photos may need to be processed by image editing software.Sorting (data processing) on employee names may be necessary to speed up data search.53
54 A photo can be processed by using image editing software – Paint.NET. 1.6 Information ProcessesProcessingA photo can be processed by using image editing software – Paint.NET.
55 1.6 Information Processes AnalysisAnalysis is performed on the processed data to extract useful information.An analysis method: using spreadsheets to create models to produce statistics or trend analysisAnalyzed information can be presented in graphs or charts.For the food ordering system of a restaurant:The database is analyzed to find most popular foods.The staff is then informed to purchase more of these foods.55
56 1.6 Information Processes TransmissionThe process of sending information from one computer system to anotherA common protocol must be used to communicate between different systems.The Internet:It uses TCP/IP for data communication.Data in different systems may be in different formats.Extensible Markup Language (XML) provides a common data format for different information systems.56
57 Transmitting purchasing orders on an online supermarket web site 1.6 Information ProcessesTransmissionTransmitting purchasing orders on an online supermarket web site
58 1.6 Information Processes PresentationInformation can be presented through different media:AudioVideoScreen displaysPrinted outputs58
59 1.6 Information Processes PresentationVarious ways of presenting information:TablesChartsLists59
60 1.6 Information Processes PresentationVarious ways of presenting information:TablesChartsLists60
61 1.7 Information Technology and the Information Age The rapid development of information and communication technology presents us with a large amount of information every day.It not only makes the Internet an information enriched network but also a platform providing numerous web-based services.Our society has now moved into the Information Age.61
62 1.7 Information Technology and the Information Age What is the Information Age?Refers to a period beginning in the last quarter of the 20th centuryWith the advancement of distribution of information by telecommunication networks and especially the Internet, information spreads widely and rapidly.People can access all kinds of up-to-date information easily anywhere and anytime at a very low cost.62
63 All kinds of up-to-date information can now be easily obtained. 1.7 Information Technology and the Information AgeWhat is the Information Age?All kinds of up-to-date information can now be easily obtained.
64 Communication Networks 1.7 Information Technology and the Information AgeLiving in a Knowledge-based SocietyA society employs knowledge, information technology and communication systems to all citizensKnowledge is the major asset in a knowledge-based society.Factors to determine the success of a knowledge-based society:Communication NetworksComputersPeople64
65 1.7 Information Technology and the Information Age Living in a Knowledge-based SocietyComputersEssential equipment for producing, manipulating, storing and distributing knowledgeMust be prevalent in the societyCommunication NetworksShould be of high transmission speed and wide coverage at low costExamples:Telecommunication networksBroadband servicesThe InternetMedia broadcasting networks65
66 1.7 Information Technology and the Information Age Living in a Knowledge-based SocietyPeopleMust be information literate in order to handle the vast amounts of information encountered every dayAn information literate should be able to:determine the nature and extent of the information neededaccess information effectively and efficientlyquestion the information sourceuse information effectively to accomplish a specific taskconvert information from one form to another desirable form using information technologiescreate new knowledge from collected information through analytical processes with IT softwareuse information ethically and legally66
67 1.7 Information Technology and the Information Age Living in a Knowledge-based SocietyPeopleThe knowledge and skills required for effective use of IT changes from time to time.Lifelong learning has become imperative.67
68 1.7 Information Technology and the Information Age Living in a Knowledge-based SocietyPeopleThe knowledge and skills required for effective use of IT changes from time to time.Lifelong learning has become imperative.68