Prelim IPT - Tools for Information Processes PDF

Preview

Summary

Prelim IPT Topic 2 (HSC Score 94)...

Description

Information Processes and Technology – Information Systems in Context Collecting • information process involving deciding what to collect, locating it and collecting it • a range of hardware collection devices are used to collect different types of data (should be convenient to use, reliable and allow different types of data to be entered accurately) o pointing devices which controls an onscreen symbol called a cursor (useful choosing commands from menus, managing files and creating certain types of images) § mouse – small handheld device moved over a flat surface to control movement of cursor § trackball – like a mouse but the ball is on top instead of on the bottom § pointing stick – shaped like a pencil eraser and moves cursor by sensing direction and pressure applied to it § touchpad – a flat rectangular surface that senses movement of a finger § graphics tablet – input device that consists of a special electronic pad and stylus § joystick – consists of a small base unit with a rod which can be tilted in all directions § touchscreen – enters data by detecting touch of a finger § pen input – uses special hardware and software to interpret movement, use on screen o scanners which can electronically capture text or images such as photographs and drawings (converts images and text into digital data that can be processed by the computer, or printed, edited or merged into another document, quality is based on resolution of scanner and functionality of the scanner) § handheld – used for entering text and images that are less than a page wide, scanner is passed over the document § flatbed – looks like a small photocopier with document flat placed face up on scanning bed § overhead o digital cameras which can capture and store images in digital form rather than on film § photos are limited by amount of memory of camera, quality of lens and output device § main advantage is that making photos is inexpensive and quick as film doesn’t need to be processed § saved as JPG when compressed § price is based on functionalities such as zoom, megapixels, resolution and storage o video cameras which are used to create a video clip in either analogue or digital form § capture images and audio in succession which is converted into digital form using a video capture card § each frame of the video is interpreted as a bitmapped image o microphones which capture sound which is analogue data as it travels through the air in waves § digital audio is sound such which has been digitised using a sound card § music is digitised using MIDI (musical instrument digitising interface) § voices are digitised using a voice recognition technique which is restricted to low vocabularies o keyboards which consist of a series of keys in a standard layout used to enter text, numbers, instructions and commands § there are different keyboards designed for different needs • ATM – special keys to allow withdrawal of money § each keyboard has a different layout • order of keys is divided into different sections o alphanumeric – letters and numbers o cursor control – allow cursor to move o special – enter, tab, space, caps o function keys – allow instructions to be given to computer o optical recognition devices – uses a light source to read characters and barcodes § OCR which are scanners that read typed or written text • produces a digital image of the text • character recognition software matches images to shapes of individual characters • characters are stored in ASCII codes and can be used in word processing programs § barcode readers are used extensively in retail industries to input product identification at point of sale(used to keep track of stock movement) • laser of scanner reads barcodes • product information is stored on a central computer linked to the terminal point of sale computers • items scanned are entered quickly and accurately to find corresponding product information

Information Processes and Technology – Information Systems in Context •

•

•

•

software used for collecting includes the software that interfaces with hardware collection devices, usually classified as part of the operating system o operating software – the software that supervises and controls hardware § responsible for controlling all peripheral devices and contains specific software for each device § GUI allows user to give instructions using icons and menus to control hardware o application software – the software that allows users to carry out specific tasks and required functions Internet as a collection source o Allows people to access collected data stored on one computer from another o Websites present information on a topic o Allows data to be downloaded as text, graphics, animation, video, sound and software Non-computer tools are used as information technology is not always suitable for collecting data o Literature – printed texts such as books, reports, newspapers, journals § Can be accurate at time of printing but can become out-of-date as societal norms change o Surveys/interviews – collecting sample characteristics, attitudes, opinions of a population § Surveys can be delivered by mail, face to face or online § Interviews are meeting people face to face to verbally ask questions o Manually § Collected by recording on paper or a pre-designed table or form Social and ethical issues o Bias in where and what data is collected o Accuracy of data – data validation and verification to prevent error o Copyright and improper acknowledging or sourcing of data o Privacy and security of data o Ergonomic issues for participants entering large volumes of data

Organising • information process that is carried out arranges, represents and formats data for use by other information processes • Hardware o Keyboard – text is converted into binary using ASCII codes o Scanner/camera– bitmapping images o Microphone – sampling sound o Video camera – video and sound by sampling and bitmapping o Internet – download data from internet • Application software organises data o Database o Spreadsheet o Word processing o Photoshop o Audacity • Non-computer tools o Pen and paper – manual § Opinion: easier, faster and more flexible • Social and ethical issues o Data must be appropriate and complete o Poorly organised data à irrelevant information § Should be easy to understand by many people with appropriate headings and user friendly o Current trends in organising data § Internet, applications and cloud computing

Information Processes and Technology – Information Systems in Context Analysing • the interpretation of data and involves examining and ordering the data and giving meaning to it to become information • hardware o CPU § Speed of processor limits speed of response § Parallel processing allows for faster processing o Hard drive § Large amount of storage – needed to receive and retain data over time • Software – a range of software applications to analyse data o MS Excel - searching, what-if predictions, charts o MS Word - making characters into a document o MS Access - searching • Non-computer tools o Manual filing systems for searching o Calculator • Social and ethical issues o Unauthorised analysis of data o Incorrect analysis of data o privacy Storing and Retrieving • two step process for retaining data o stores saved data and information for later uses o retrieving obtains data and information that has been previously saved • hardware o motherboard § RAM • Temporary memory before, during and after analysing and processing • Can be lost due to power failure (volatile) § ROM • Permanent (non-volatile) storage which is added to computers during manufacturing o Removable storage § disk – CD-ROM, DVD, floppy disk, etc. § flash memory § hard drive § magnetic tapes • Accessing data o Direct access/random access § Data is indexed and specific files can be opened by double clicking § E.g. hard drives, CDs, USBs o Sequential access § Data is saved in a list so that all files must be searched through before reaching the desired file § E.g. tapes • software – to store data it needs to be formatted o backup software o file system software • non-computer tools o paper-based storage systems – folders, filing cabinets o microfiche – transparent film that holds thousands of pages of data o library – stores books of data and information • social and ethical issues o security of data – a series of safeguards to protect data (passwords, biometric security, firewalls, data encryption, backup) o unauthorised or illegal retrieval of data – hackers

Information Processes and Technology – Information Systems in Context Processing • manipulation of data by editing and updating it • hardware o CPU § Control unit – directs and coordinates the entire computer system § Arithmetic logic unit – part of CPU that carries out all arithmetic and logical calculations § Fetch-execute cycle – a cycle of events on a single instruction carried out by CPU • control unit fetches instructions • control unit decodes the instructions and makes data available to ALU • ALU performs operation on data • Control unit places result of operation into memory § Processing speed • Clock speed – number of electrical pulses per second and is often measured in MHz • Word size – number of bits processed at a time by CPU • Response time – amount of time taken for computer to respond to commands • CPU utilisation – amount of time the CPU is working • Bus capacity – capacity of wires on the motherboard that transmit data o Memory – parts of computer that holds data and programs before and after they are processed § RAM (Random Access Memory) – where data and instructions are held temporarily • Dynamic RAM – memory that is constantly refreshed and updated • Synchronous DRAM – type of DRAM synchronised with CPU • Static RAM – does not have to be updated or refreshed § ROM (Read Only Memory) - Holds data/instructions fixed at time of production • Programmable ROM –data/instructions to be entered by manufacturers and cannot be changed • Erasable programmable ROM – chips can be erased and reprogrammed • Types of processing o Centralised processing § controlled by central computer which performs all the processing § all data and resources is shared § used by big organisations o Distributed processing § Each terminal downloads data to process then sends it back to the server for storing § Consists of workstations connected to shared data and resources § Will continue to operate if some terminals are not functioning o Parallel processing § Simultaneous processing of instructions using multiple processors or CPUSs § Processing is faster but requires special software • Software o Text and numbers – edited by deleting, inserting, moving and copying o Images – edited using graphics tools by being positioned, cropped, resized and distorted o Video and audio – edited using digital video production software and audio • Non- computer tools o Documentation – written to explain detailed procedures or a series of steps for processing o Data flow diagrams – graphical method of representing a system using processes with inputs, outputs and storage o System flow chart – graphical method of representing both the flow of data and the logic of a system and documents essential details such as sequences and rules, etc. • social and ethical issues o bias – can be caused by biased data being collected, or the incorrect manipulation of data o ownership of data – once data is processed, who does it belong to o security of data – centralised processing is more secure as processing only occurs on one central computer

Information Processes and Technology – Information Systems in Context Transmitting and Receiving • transfer of data and information within and between information systems • types of transfer o serial – one bit at a time through a single line § less chances of error due to no space for bit-swapping but causes slow transmission o parallel – one bit at a time through multiple lines simultaneously § quicker transmission but allows for more errors over long distances • direction of data flow o simplex – allows transmission in one direction only (e.g. automated emails, input devices to computer, radio and TVs) o half-duplex – allows transmission in two directions but only one at a time (e.g. walkie-talkies) o full duplex – allows transmission in both direction • hardware o expansion cards o bus – pathway of wires and connectors that provides a link between input, storage process and output devices o computer (modem) modulates digital data into analogue data which travels through cables to another computer which demodulates the data from analogue to digital form § works with radio transmission towers when transmitting data over long distances • Networks o Peer to peer network – two computers directly linked o Local Area Network – connects computers within an organisation o Metropolitan Area Network – connects LANs together for a larger organisation o Wide Area Network – internet connection • Social and ethical issues o Accuracy – need to come from reliable sources, or obtained from cross-referencing o Acknowledgment o Security/privacy – permission to transmit o Email etiquette o Development of internet (WAN) allows for online businesses Displaying • Presenting output from an information system to meet a given purpose (text, images, video, audio) • Hardware o Screens – a display surface that provides immediate feedback about what a computer is doing § CRT Monitor • Images are produced by firing a beam of electrons onto the inside of the screen which is coated with phosphor starting from the upper left corner, moving left to right and top to bottom in a zigzag pattern called a raster scan • Raster scan is REFRESHED or repeated to maintain the image produced as the phosphor only displays colour for a short time. Non-interlaced monitors refresh up to 72 times per second. Interlaced monitors scan odd lines then repeat with even lines but this causes the monitor to flicker § LCD monitor • The cooled liquid crystals is placed between two polarising sheets of glass which polarise light at different angles so that one pane blocks vertically vibrating waves of light and the other blocks horizontally vibrating waves of light Electricity passes through the liquid crystals turning it "on" and "off" by twisting and untwisting the • liquid crystal structure. When the crystals are switched off or twisted, light is rotated by the crystal and can flow through the polarising glass and light up a sub pixel (RGB)

Information Processes and Technology – Information Systems in Context Plasma Monitor • Each subpixel is an individual plasma lamp that is switched on and off electronically using plasma • Each lamp of a pixel is coated using a different phosphor to produce different colours when exposed to light or electrons in electricity • Allows for thinner screen and faster switching of colours • Expensive, heavier and more fragile, uses more electricity to change colours of pixels, lamps can burn out after an image is exposed for too long § LED • Uses an array of light-emitting diodes placed behind an LCD display and the light diffuser is used to form a uniform amount of light across the screen • Opacity of a pixel is controlled through and electric field which applies a portion of light for pixel that needs to be displayed Printers – a device that represents data on paper, producing a hard copy § Impact printers – make image on paper using some sort of physical contact § Non-impact – make image using some other method (laser and inkjet) § Quality of output is called resolution • Dot matrix printer o Cheap o ink was wet after printing o Low resolution o Loud • Inkjet printer o ink head sprays fine droplets of ink onto paper o Quieter o Higher resolution o Printer and cartridges are cheap but only print up to 200 pages each • Laser printer o Laser attracts powdered ink onto paper o Highest quality printer o Cartridges can print up to 1500 pages per cartridge but is expensive • Plotter o Large scale printer that is used for architectural or digital designs o High quality drawings such as maps, charts and building plans §

o

Speakers – outputs sound § Audio is converted and stored as digital data through devices such as a microphone § Voice synthesis – artificial production of human speech Software features for displaying o Formatting – spacing, tables, charts o Reporting and mail merge Non-computer tools o Storyboard – series of frames each representing a different action or screen image o Paper and pen to write and draw output Social and ethical issues o Visually impaired o Current trends § Keep audience engaged by using current technology § Compatibility between different systems o Offensive material – for different ages and cultures § Parental control, country regulations, firewalls o Communication skills o

•

•

•...