Volume 1

Programs: A sequence of commands No commands ->  PC wont function Data: collection of raw facts and have no meaning on their own. Information: data that has been organized. -> meaningful + useful for decision making 

Stored Programs:  controlled by a small circuit board (microprocessor + ROM) +ve do automatically, repeatedly and accurately.  e.g. oven,rice cookers, music box, old-fashioned sewing machines

Data: collection of raw facts and have no meaning on their own.1. Text: characters, numbers symbolsExample of character coding system (Big5, Unicode,ASCII)Text entry: keyboard ,scanner with OCR software, voice recognition system, handwriting board2. Image: Photographs, drawings and handwritten text  Bitmap : digital representation of a collection of pixels of an image Produce Bitmap images: digital camera, mobile phone, scanner 3. Audio: music, speeches (WAV, ACC, MP3) Analogue audio->stream (by sound card) Entry : microphone 4. Video: Scene in motion (AVI,MPEG)Analogue video signals-> digital video files(by video capture card)Entry: webcam

Information system: Forecasting, planning, coordination, control, decision-making, operational activies in an organizationData->Information : Input-Process-Output cycle1. Purposes (improvement, fix system problems)2. Data3. Processes 4. Technology (hardware,software,network)5. Personnel (end users + Information system specialists)a. Systems Analyst: research, planning, implementation of information system. b. Programmer: Covert system design from (a) -> program codesc.Technician: Manage the information systemd. Network Manager: monitor the availability and performance of the communication between systemse. Data entry operator: Enter data

Information Process:1. Data Collection (Collect Raw material)2. Organization (Data-logging, accuracy checking, categorization)3. Storage (Store organized data)4. Processing (Process stored data)5. Analysis (Extract useful information)6. Transmission (Send inform)7. Presentation (show information in different medias)

Information Age:1. Last quarter of the 20th century2. Computers become essential tools to control information3. Information spreads widely and rapidly4. Low cost to access up-to-date informationKnowledge-based society A. Computers: producing, manipulating, storing, distributing knowledgeB. Communication Networks: high transmission speed + wide coverage at low cost.C. People:Must be information literate-Use information ethically and legally-Question the information source.-Access information effectively and efficiently

Data Input and sources of Errors :1. Data source error 2. Transcription error: 1 -> l / o- > 03. Transposition error:  61->16Garbage-in-garbage-out (GIGO) : Erroneous data produces inaccurate information. -ve waste human resources + produce useless information

Data Control:Data Validation: (F4 CRT)                                   Data verification:  inputted data = source document  Field Presence check                                    1. Input Data twice Field length check                                          2. Double data entry (2 users are involved) Fixed value check (M/F) Format Check (abc@gmail.com) Check digit (e.g. Parity check)Additional parity bits is attached to the end of the data1011 0 (check odd)1011 1 (check even) Range check (0-100 marks) Type check (char then input char)

Data Hierarchy1. Field (smallest unit of data)2. Record3. Table4. Database 

Key Field:A field that can be used to uniquely identity one specific record from other records. e.g. ID card no.Database Management System (DBMS) Manage the database structure store, organize and retrieve data e.g. Database server: MySQL, Microsoft SQL servere.g. Small office and personal use: Microsoft Access

File Access Modes:Sequential Access Mode: Uses: data back up/recovery of data files +ve very cheap in price, high portability -ve long  and unpredictable seek time   e.g. Magnetic tape                                          

Direct Access Mode: Uses: storage medium for secondary storage  +ve High reliability, speed and capacity, predictable and shorter seek time (8-20ms) -ve low portability, more expensive than magnetic tape  e.g. Floppy, DVD-RAM

Denary: daily lifeBinary : data representations and manipulationsHexadecimal: for computer to communicate with programmers Bit: A single binary digit. Byte: Smallest addressable unit in a microprocessorKilobyte: 2^10Megabyte 2^20Gigabyte 2^30Terabyte 2^40Word: natural unit of data used by computerword length/word size e.g. 16,32,64 bits

Unsigned binary number e.g. 1111=15 Signed binary number1. Sign-and-magnitude 1111= -7       0111=72. Two's complement1001=-7     0111=7original:                  0000 1101=13one's complement:  1111 0010=-13Two's complement:  1111 0011=-13

Overflow Erro

Overflow ErrorWhen fixed digits, results outside the range that the digits can represent.

Character Coding system1. ASCII  / EBCDIC (for Reference)consists of 7 bits = 128 characters2. Big 5 code    GB code (4 bytes)    Traditional     Simplified 3. Unicode:Represent all the existing languages 100 000 characters Code points: Representations of Unicode Variable in length -> 1-4 bytes  Most frequently used characters are put at the front of the coding system.

GraphicsBitmaps: (BMP, JPEG,GIF)Collection of color dots called pixels arranged in rows and columns.Pixel: smallest picture element that can be shown on screen. (affected by  color depth )Resolution: No. of pixels per inch in a bitmap image (ppi)+ve suitable for digital photographs and scanned pictures-ve file size increases rapidly when more bitmap objects when resolution increases. Vector Graphics:composed of a number of shape, line or string of text. Shape + location defined by math formulas. +ve re-scale and modify wont affect the quality        file size doesn't grow rapidly when more vector objects drawn tgt-ve not suitable for representing images with complicated patterns 

AudioDigitized data of audio signals (WAV: uncompressed, WMA,MP3) Bit Resolution: No. of bits used to represent the amplitude of  an audio signal Sampling rate: no. of samples taken each seconds No. of  sound track (Stereo audio 2/ mono audio 1) Size = sample rate * bit resolution * time * no.of sound track

VideoSequence of full-motion images tgt with sound tracks (AVI :uncompressed)                                                        ( Compressed: MPEG-1,MPEG-2, WMV) Frame size No. of horizontal + vertical pixels  Frame rate No. of frames/ s Duration play time Compression method changing the content/ way of representation of vdo frames Color depth : No. of bits used to represent a pixel

Analogue dataContinuous signals are measured (photos taken with film camera)+ve Accuracy of information (depending on sampling technique )-ve impossible to hv absolute replication-ve High rate of transmission error-ve low efficiency on data storage  (VCR, magnetic tape,sequential)-ve low data analysis Digital dataInformation is represented in discrete form+ve easy to hv error-free to hv absolute replication+ve low rate of transmission error+ve high efficient on data storage (DVD,direct acess)+ve High data analysis (reused/processed easily)-ve low accuracy of information 

Digitizatio

DigitizationSampling : Obtaining discrete sample data -> analogue signal (Digital Analogue Converter DAC)Quantification: convert attribute of sample data ->digital code (binary code) (Analogue Digital Converter ADC)VideoAnalogue video (e.g. Video Cassette records, TV broadcast)TV tuner card receive TV signals.Analogue TV signals -> digital images + audioReal time Video Using Charge-coupled devices

Office AutomationComputer hardware and software are widely used to accomplish tasks.Exchange+ Manage  information +ve Increase Productivity+ve Better Data management+ve Better communication+ve Reducing company expenses Application softwareOrganize raw data -> useful information1. Word processor (Microsoft Word, Google Docs)    Create, modify, format, print documents 2 .Spreadsheet (excel, Google spreadsheets)   Organize calculate chart, present data on spreadsheet) 3. Presentation software (PowerPoint, Google Dos)   Create multimedia elements for presentation4. Communication Software (Outlook)   Manage appointment calendars, emails5 .Image editing software (Photo Impact, Photoshop)   Create and modify images

Factors which affect office effectivenessEquipment  Cost is within budget New system is compatible with existing one Level of technical requirement Tailor-made for the user Time required for system implementation is controlled PeopleExtensive + well-organized training programs -> proper and effect operation of the office automation system

Basic activities on data:  users access data stored in central repository Application (data analysis, digital image modification, document production, report generation ) Storage Hard disk Storage of data and software CD-ROM Files back up/transfer Magnetic tape system backup Memory card 'portable Exchange (e.g. Video conference and groupware stored)  Management (e.g. DBMS,Task scheduling systems)  Task scheduling systems: monitor & manage various project through timelines

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