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1.1 Basic Concepts of Input-Process-Output Cycle

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1 1.1 Basic Concepts of Input-Process-Output Cycle
A computer is a very powerful electronic machine A computer can: store a huge amount of data perform complicated calculations produce 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: Input Process Output Input-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. Input Enter data and commands into a computer via one or more input devices. Process The CPU works on the data according to the commands provided in the input stage. Output The computer shows the processed result on the output devices specified in the 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. Input Enter data and commands into a computer via one or more input devices. Process The CPU works on the data according to the commands provided in the input stage. Output The computer shows the processed result on the output devices specified in the 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 commands Should be provided to the computer in order to instruct the computer to complete a specific task Will 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 accurately Saved in the read-only memory (ROM) of many home appliances and machines Executed 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 boxes Old-fashioned sewing machines A mechanical music box and traditional sewing machine are examples of mechanical machines with stored programs.

10 1.2 Use of Stored Programs Stored programs
Found in traditional mechanical products: Mechanical music boxes Old-fashioned sewing machines A mechanical music box and traditional sewing machine are examples of mechanical machines with stored programs.

11 1.3 Difference between Data and Information
A collection of raw facts that are not organized Has no meaning on their own Information Data that has been organized Meaningful 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 devices Different types of data: Text Images Audio Videos

15 1.4 Types of Data Video Text Image Audio Different types of data

16 1.4 Types of Data Text Examples:
Characters Numbers Symbols Can be represented by certain character coding systems: American Standard Code for Information Interchange (ASCII) Unicode Big5 code

17 1.4 Types of Data Text Input devices for text entry: Keyboard
Handwriting board Scanner with optical character recognition (OCR) software Voice recognition system A handwriting board

18 1.4 Types of Data Text When 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 Character Big5 code Unicode Different character coding systems may have different codes for the same character.

19 1.4 Types of Data Image Examples:
Photographs Drawings Handwritten text Can 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 Data Image Common methods of producing a digital image

21 1.4 Types of Data Image Common devices that produce bitmap images:
Digital camera Mobile phone (with built-in camera) Scanner

22 1.4 Types of Data Audio Use of audio files in a computer: Record music
Speeches Any kind of audio signals in digital form Audio 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: WAV AAC MP3 22

23 Analogue audio can be digitized for editing, playback and storage
1.4 Types of Data Audio Analogue audio can be digitized for editing, playback and storage

24 1.4 Types of Data Video A sequence of images representing a scene in motion A 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 Data Video Analogue videos can be digitized for editing, playback and storage

26 Analogue videos can be digitized for editing, playback and storage
1.4 Types of Data Video Analogue videos can be digitized for editing, playback and storage 26

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 cycle The transformation can be either a manual or an automated process. In general, it consists of five interrelated components: Processes Purposes Personnel Technologies Data

28 1.5 Components of an Information System
Purposes Some of the most common reasons for implementing an information system: Automate an existing manual process Improve an existing system Fix system problems The current situation of a school library: Operate in manual mode Students 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
Purposes The purposes of a library system: Help students search for the books efficiently Help librarians track the status of a book efficiently Help teachers figure out which subjects are most popular Help in stocktaking at the end of each semester Automatically generate reports of overdue books 29

30 The library system of the Chinese University of Hong Kong
1.5 Components of an Information System Purposes The library system of the Chinese University of Hong Kong

31 1.5 Components of an Information System
Data The major component of an information system Examples: 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
Processes Work with data to achieve the purposes or objectives Some examples of processes: Generating bank statements Categorizing data Printing management reports All processes are combined together to form an information system.

33 1.5 Components of an Information System
Processes Processes of the food ordering information system in a restaurant: Receiving and transferring customer food orders Transforming order to kitchen format Generating customer receipt Aggregating goods sold and inventory data Producing management reports 33

34 1.5 Components of an Information System
Technologies An information system is a computer-based system that relies on technologies including: Hardware Software Network 34

35 1.5 Components of an Information System
Technologies Hardware Refers to all the physical components In a point-of-sale system, computer hardware includes: Monitors Keyboards Bar code scanners Printers Also covers any media used by machines, for example: ATM cards Credit cards Octopus cards

36 Point-of-sale terminal in a supermarket
1.5 Components of an Information System Technologies Hardware Point-of-sale terminal in a supermarket

37 1.5 Components of an Information System
Technologies Software A sequence of instructions which instructs the information system to perform specific tasks Two kinds of software that would be used in an information system: System software Application software 37

38 1.5 Components of an Information System
Technologies Software System software Manages computer resources such as hard disks, CPUs, files, the main memory and all devices that are used to control the computer An operating system: A part of system software Examples: Microsoft Windows, UNIX Application software Designed for users to perform specific tasks Database software: A type of application software Example: Microsoft Access Stores 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
Technologies Network Some 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 server 39

40 1.5 Components of an Information System
Personnel A major component of all information systems They use, develop or manage an information system Two types of roles: End users Information system (IS) specialists 40

41 1.5 Components of an Information System
Personnel End users Use an information system or an information product Information system (IS) specialists Develop or manage information systems Usually from the information system department which deliver IT services to an organization Examples: Systems analysts Programmers Technicians Network managers Data entry operators 41

42 1.5 Components of an Information System
Personnel Information system (IS) specialists Systems analyst Responsible for the research, planning and implementation of the information system according to the requirements defined by end users Analyze the cost, study the feasibility, design the system using any new technologies and estimate the time frame of the implementation Programmer Responsible for converting the system design developed by the systems analysts into program codes 42

43 1.5 Components of an Information System
Personnel Information system (IS) specialists Technician Responsible for managing the information system such as performing the backup of the system and monitoring its resource usages Network Manager Responsible for monitoring the availability and performance of the communication between computer systems Data Entry Operator Responsible for entering data into the information system before end users can use it 43

44 1.5 Components of an Information System
Personnel Information system (IS) specialists Technician Responsible for managing the information system such as performing the backup of the system and monitoring its resource usages Network Manager Responsible for monitoring the availability and performance of the communication between computer systems Data Entry Operator Responsible for entering data into the information system before end users can use it 44

45 1.6 Information Processes
The information life cycle The processes of transforming data into useful information Normally there are seven information processes: Data collection Presentation Organization Transmission Storage Analysis Processing An information life cycle

46 1.6 Information Processes
Data Collection The activity of collecting raw data from the outside world so that it can be put into an information system Methods: Personal interviews Telephone interviews Questionnaires Experiments The Internet These methods can be used separately or combined together.

47 1.6 Information Processes
Data Collection Collecting data through a personal interview

48 1.6 Information Processes
Organization Collected data must be organized into certain formats so that it can be further processed. The data can be represented in: Text Images Audio Videos Ways to organize data: Putting data into paper-based forms or electronic forms by its category Inserting data into related database tables or spreadsheets Grouping images to create an animation 48

49 Stages of data preparation
1.6 Information Processes Organization Data-logging Keep track of incoming data. Manual validity check Check for completeness. Check whether the contextual information is included. Check whether the answers are reasonable and legible. Data categorization Divide 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
Storage Organized data must be stored in storage media so that they can be retrieved for processing later. Two kinds of storage media: Non-digital media Paper Files Digital media CD-ROMs DVDs Hard disks Floppy disks Magnetic tapes 50

51 1.6 Information Processes
Storage Most 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
Processing Different kinds of processing: Data processing Sorting Searching Merging Calculating Word processing Image processing Video processing Audio processing 52

53 1.6 Information Processes
Processing An 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 Processes Processing A photo can be processed by using image editing software – Paint.NET.

55 1.6 Information Processes
Analysis Analysis is performed on the processed data to extract useful information. An analysis method: using spreadsheets to create models to produce statistics or trend analysis Analyzed 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
Transmission The process of sending information from one computer system to another A 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 Processes Transmission Transmitting purchasing orders on an online supermarket web site

58 1.6 Information Processes
Presentation Information can be presented through different media: Audio Video Screen displays Printed outputs 58

59 1.6 Information Processes
Presentation Various ways of presenting information: Tables Charts Lists 59

60 1.6 Information Processes
Presentation Various ways of presenting information: Tables Charts Lists 60

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 century With 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 Age What 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 Age Living in a Knowledge-based Society A society employs knowledge, information technology and communication systems to all citizens Knowledge is the major asset in a knowledge-based society. Factors to determine the success of a knowledge-based society: Communication Networks Computers People 64

65 1.7 Information Technology and the Information Age
Living in a Knowledge-based Society Computers Essential equipment for producing, manipulating, storing and distributing knowledge Must be prevalent in the society Communication Networks Should be of high transmission speed and wide coverage at low cost Examples: Telecommunication networks Broadband services The Internet Media broadcasting networks 65

66 1.7 Information Technology and the Information Age
Living in a Knowledge-based Society People Must be information literate in order to handle the vast amounts of information encountered every day An information literate should be able to: determine the nature and extent of the information needed access information effectively and efficiently question the information source use information effectively to accomplish a specific task convert information from one form to another desirable form using information technologies create new knowledge from collected information through analytical processes with IT software use information ethically and legally 66

67 1.7 Information Technology and the Information Age
Living in a Knowledge-based Society People The 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 Society People The knowledge and skills required for effective use of IT changes from time to time. Lifelong learning has become imperative. 68


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