Page 1 of 90 Chapter 1: Types and components of computer systems Hardware: - General term for the physical components which make up a computer system (i.e Mouse/Keyboard) Software: - General term for programs which control the computer system Two types:1. Systems software: Those allow the computer to run properly such as the OS (Windows/IOS/Linux/etc...) 2. Application software: Those which allow the user to accomplish specific tasks (i.e spreadsheets/word processors/etc...) *Main components of a computer system 1. CPU (Central Processing Unit):- Part of the computer which interprets and executes the commands from software/hardware, as well as it does the mathematical operations in a computer. CPUs used to be made up of many parts, but due to modern improvements, the CPU has now become a microprocessor. CPUs are made out of two components:• Control unit : Controls input and output devices • Arithmetic Logical Unit: Carries out calculations and logical decisions • RAM:- Immediate storage (see later) 2. Internal Hard drive (HDD):- This is where applications software, operating system, and data files are stored. The reason behind why they are used is due to their fast data access and data transfer speed (to further learn about HDDs, check out the Chapter 3 summary) 3. RAM (Random Access Memory) & ROM ( Read Only Memory) :RAM: is an internal chip where data is temporarily stored while applications are running, Can be written to and read from ROM: is a memory used to store information which needs to be permanent (i.e BIOS). Can be only read from Page 2 of 90 -.: :- - .,.. _' .- - _,..,, RAM ROM Random Access Memory Data is temporarily stored Written to and read from Volatile Stores data/files which are currently in use Read Only Memory Data is permanently stored Read from only Non-Volatile Stores items such as configuration data *Other types of internal computer hardware 1. Motherboard: - Allows the processor and other computer hardware to function and communicate. It sort of acts as a “hub” for all the devices connected to the computer 2. Video Card:- Allows a computer to send digital data to a display device such as a monitor A video card has the following components:• Processing unit • Memory unit (RAM) • Cooling mechanism • Connection to a display unit 3. Sound Card: - Integrated circuit that allows a computer to produce sounds via a speaker/headphone. It also allows the user to record microphone This can happen through 2 ways:• • FM synthesis : Mimics different musical instruments according to built-in Formulas Wavetable synthesis: Relies on recordings of actual instruments *System Software 1. Compiler: - Computer program which translates HLL (Source code) to machine code (object code) 2. Linkers:- A program which combines a bunch of compiled files and joins them together to make 1 program ] 3. Driver:- Software which allows one or more hardware to communicate with the OS 4. Operating System:- Is the software running in the background of a computer system, and manages many of the basic functions (See later) 5. Utilities:- Programs that have been designed to carry out specific tasks (AntiVirus/Anti-Spyware/Backup of files/etc...) Page 3 of 90 *Application Software 1. Word Processor: Used to manipulate text documents (Essay, report, etc.), through a keyboard. It allows for many features, such as : (Creation/Editing/Saving of text, Copy and pasting, spell check and thesaurus, Importing images, Translation) 2. Spreadsheets: Used to manipulate and organize numerical data. It allows for features such as: (Use of formulas for calculations, ability to produce graphs, Ability to do if functions and modelling) 3. Database: Used to organize, manipulate, and analyze data. It allows for features such as : (Carry out queries and produce reports, add/delete/modify data) 4. Control & Measuring software : Allow computer or microprocessor to interface with sensors so that it can: (Measure physical quantities, control applications by comparing data with stored data or preset data) 5. Apps:- Type of software that runs on smartphones or tablets and includes: (Video and music streaming/GPS/Camera facility) 6. Photo editing software: Allow user to manipulate photographs stored on a computer, for example, you can: Crop/Change brightness/Resize/Combining pictures together/etc... 7. Video editing software: Allows the user to manipulate videos and produce an edited video, and includes: (Rearranging/Removing/Adding clips, Applying color correction/Creating transitions) 8. Graphics manipulation software: Allows bitmap and vector images to be changed, by alternating lines, curves, and text. *Types of computers 1. PC/Desktop computers: Refers to a general purpose computer which is made of separate components Advantages Disadvantages Spare parts tend to be standardized; resulting in lower cost Better specifications Large casing allows good wasting of heat build up Not particularly portable Can be complex/clutter up desk space Necessary to copy files if you want to do work somewhere else 2. Laptop computers: A type of computer where all the components are hooked up together in one single unit • Low weight • Low power consumption and long battery life • Does not generate too much heat Page 4 of 90 Advantages Disadvantages Very portable No trailing wires Can take full advantage of Wi-Fi Link into any multimedia system Easy to steal Limited batter life; need to carry charger Can be awkward to use peripherals Heat buildup not wasted as easily 3. Tablets: Relatively new internet-enabled, touch friendly, portable computers. Here, the tablet uses an on screen touch keyboard, and can connect to the internet using Wi-Fi or 3G/4G/5G Some features of the tablet are:• High-Definition Anti-Glare screens • Front and back cameras • Lightweight and long battery life • Bluetooth connection • Make use of backup storage facilities • Have a number of sensors to carry out multiple tasks (i.e Proximity sensor for detecting how close a tablet is to the ear) Advantages Disadvantages Fast switch-on time Portable Limited memory capacity Can be expensive to run if 3G/4G/5G is needed Typing on touchscreens can be awkward and slow Transferring apps/data has to be done using an implemented app store Don’t support as many file types as other computers Simple to use due to touchscreen Can use several standard apps Don’t generate any heat Can go on standby (stay connected but turned off) Recently, there has been a development of a “Phablet” which combines the features of a smartphone and a tablet together Page 5 of 90 4. Smartphones: Allow phone calls to be made as well as support functions such as apps due to having an implemented OS. They can connect to the internet through Wi-Fi or 3G/4G/5G Some features of the smartphone are:• Send/Receive E-Mails • GPS • Internet surfing capabilities • Calendar • Telephone banking • VoIP • Streaming of videos/music • Social network • Instant messaging Advantages Disadvantages Small in size and lightweight; makes them portable Can make phone calls and connect to the internet Can be used anywhere due to Wi-Fi capabilities Have hundreds of apps Reasonable battery life Small screens make it difficult to type and read Web browsing/Photographing can drain the battery rapidly Small memory size in comparison to other computers Easy to lose Slow data transfer rate 5. Smartwatches: Allow the user to wear a small-computer on their wrists, which allows the user to access the same features which the smartphone withholds. Some features of smartwatches are: • Internet connectivity • Ability to make phone calls • Messaging • Weather forecast • Fitness/Health programs • GPS Advantages Disadvantages Very convenient since notifications are delivered to the user’s wrist Very easy to use (Esp. for monitoring health and fitness) Large and bulky; making them uncomfortable Rather unattractive in their design Page 6 of 90 6. Mainframe Computers: Used for large and powerful computer systems, usually used to run commercial applications, where huge amounts of data need to be stored. Some features of mainframe computers are: • • • • • • Can have more than 1 CPU Have fast processing speeds Have multiple OS’ Huge amounts of storage capacity Huge internal memories Often operate through batch processing or time sharing *Emerging technology and their effect 1. Artificial Intelligence Biometrics: Artificial intelligence solves biometric problems such as the need to place your finger correctly so a device can read it. It learns from every scan a human does, and even if they change their look (i.e change their hair color, cut it, get cut), it’ll still recognize them due to what it has learned. 2. Vision enhancement systems: Used to enhance a person’s view of things, in two ways:• Low-Vision : Use video technology connected to headset so that the objects can be projected for the user • Night Vision: Visible and infrared light are amplified so that the image can be seen in apparent darkness 3. Robotics: Used in many factories (car factories), to weld car bodies, fit items such as windscreens, and do manual jobs (See chapter 5 summary) Applications such as drones can be used to scout military bases, or take a closer look at locations which experienced a phenomena Another application is the use of robotic arms in surgery, where it allows the surgeon to be more flexible and precise. 4. Quantum Cryptography: Science of making a message unreadable to any unauthorized user. Usually referred to as Encryption It uses photons and their quantum properties to produce an unbreakable cryptography system. It is used in Fiber lines to protect data and make it secure 5. Computer-assisted Translation: This type of translation goes some way to overcome word-to-word translation issues. It uses a particular type of translation method to decrease the effect of this issue. To do this, it uses two tools • • Terminology database: Linguistic database which helps the system learn from carried out translations Translation memories: Automatically insert already known translations for certain words. Page 7 of 90 6. Holography: Allows 3D images to be produces through the use of: Laser Light source/Interference of light/Diffraction/Light intensity recording Holograms are used in the following applications:• Engineering • Architecture • Simulations • Medical imagine • Cinema • Gaming • Advertisements • Holographic televisions and computer memories • Optical computers 7. Virtual reality: Artificial environment which allows you to get the feeling of reality through the use of goggles and helmets. Virtual reality is used in the following applications:• Military applications • Education • Healthcare • Entertainment • Fashion • Heritage • Business • Real estate • Engineering • Sport • Media • Scientific visualization Page 8 of 90 *CLI and GUI interfaces:1- GUI: - Graphical User Interface, allows the user to interact with the computer and operating system through a selection of icons and options. GUI interfaces usually use the WIMP technology (Windows, Icons, Menus, Pointer). 2-CLI:- Command Line Interface, allows the user to interact with the computer and operating system through typing a number of commands in order to allow it to perform tasks. Users usually need to learn a number of commands in order to use it efficiently. Interface CLI Advantages - User is in direct communication - User is not restricted to a number of options - Possible to alter the configurational settings GUI - No need to learn commands - More user friendly - Pointing device is simpler than typing in commands Page 9 of 90 Disadvantages - User needs to learn a number of commands - Commands need to be typed in - Commands need to be typed in correctly, or the task won’t be performed - Difficult to edit commands once typed in - Takes up more space than CLI - User is limited to icons only - Needs an operating system which uses up more memory Chapter 2: Input and output devices *Keyboards Most common input devices on computers, and have ergonomic keyboards for people who have a risk of RSI. Uses Advantages Disadvantages Input of data into app software Typing in commands Fast entry Can be difficult to use with limited arm movement Slow method compared to direct data entry Large space Easy to use Easy to do verification check 1. Concept Keyboard: uses icons and phrases instead of standard letters, usually used in food restaurants:• Fast data entry • Waterproof keyboard • Tamper resistant preventing people from keying in corrupt information 2. Numeric Keypads:- Used to enter numbers only Uses Advantages Disadvantages ATMS Faster than standard keyboards Very easy to carry around Small keys make it difficult to input data Order of numbers can sometimes be not intuitive Mobile phones POS Chip and PIN Fast data entry *Pointing Devices 1. Mouse: User can control the position of by moving the mouse, and double clicking to select items Uses Advantages Disadvantages Opening/Closing software Grouping/Moving files Faster way to choose options Difficult for people with restricted arm movement Easy to damage Image editing Very quick way to navigate between apps Doesn’t need large desk area Controlling position of pointer Page 10 of 90 If no flat surface is readily available 2. Touchpad: Pointing device in many laptops Advantages Disadvantages Same as mouse No need for mouse; aids portability Difficult for people with restricted arm movement More difficult to control a touchpad in comparison to mouse More difficult to do functions such as drag and drop 3. Tracker ball: controls the pointer on the screen by rotating a ball, used for people with limited hand and arm movement Uses Advantages Disadvantages Where users have disabilities Control room environments Luxury cars Doesn’t need fine control Not supplied with computers as a standard May need training before usage Easier to use than mouse More accurate in positioning More robust Less desk space needed than mouse *Remotes Used to control operations of devices remotely through infrared signals Uses Advantages Disadvantages Televisions/Satellite systems/DVD players/hi-fi systems Control multimedia systems Operated from any Reasonable distance Difficult for people with restricted arm movement Some processes (i.e chemical) can be hazardous Very easy to block signal due to walls Industrial applications to remotely control processes *Joysticks Have similar functions to that of the mouse and tracker ball, by gripping the handle, you are able to control the movement. Uses Advantages Disadvantages Video games Easier than a keyboard More difficult to control pointer in comparison to other devices Simulations More realistic than mouse *Driving wheel Similar to a joystick, allows you to simulate turning a wheel while driving Uses Advantages Disadvantages Video games Simulations Easier than keyboard or joystick Nearer to a real life steering wheel Expensive Too sensitive and has no feedback to improve it Page 11 of 90 *Touch screens The user can select options and icons by simply touching the part of the screen where the wanted item is located. Uses Advantages Disadvantages PDAs /Self-Service/Information systems ATMs/Point-of-Sale/Interactive white boards Computer-based training As an output device Fast data entry Limited options Easy method for choosing options User friendly Can lead to health problems *Scanners Used to enter information from a hard copy to the computer through a light source Uses Advantages Disadvantages Convert documents into formats of various software Scan in old documents and protecting original/keeping a copy. Scan photographs Images can be stored for editing Limited quality depending on the resolution Much faster and more accurate than re-typing the documents Fairly slow Possible to recover damaged docs Scan barcodes *Digital Cameras Are a replacement for traditional film cameras, and can have their files transferred through:- Memory card/Connection through USB port/Wireless (Note, the points in this table; if not clarified, will be a comparison between digital and traditional cameras) Advantages Disadvantages Produce better quality photographs Easier to upload photographs than scan them Saves money and environmentally friendly Memory card can store hundreds of photographs Need to be IT literate to use properly Some artistry lost, since you can modify pictures using software Resolution not as good as some expensive traditional cameras Images need to be compressed Page 12 of 90 Video cameras are used to take moving images at a speed of 25 MBPS Advantages Disadvantages Easier to manipulate video footage using specialist software High quality of images, which helps in editing Cost *Microphone Used to input and manipulate sound on a computer Uses Advantages Disadvantages Input sound in presentations Voice Recognition Software Faster to read text than to type it Possible to manipulate sound in real-time Use up a lot of memory Not as accurate as typing manually Sensor to pick up sound Improving safety in cars; no need to remove hands while operating the system VoIP *Sensors Analogue sensors detect data and have their data converted through an ADC (Analogue to Digital Converter), usually used in monitoring and control applications. Advantages Disadvantages More accurate More continuous readings Any necessary action will be accompanied with a warning or act Automatic Faulty sensors can give bad results *Graphics tablet Used to produce freehand drawings Uses Advantages Disadvantages Produce drawings Modify drawings Where written language has complex words In Computer-Aided Design Very accurate method of drawing Can record levels of pressure More expensive than pointing devices in addition to being expensive to produce Takes longer to produce than pen and paper Not very user friendly Damaged easily Page 13 of 90 *Webcams Connected directly to the computer to act as a camera Uses Advantages Disadvantages More personal way of having conversations Enable video conferencing Can be left on constantly Very limited features Allow people to keep contact with each other, without the need to travel Need to be connected to computers *Light pens Detect light changes are detected on CRT monitors Uses Advantages Disadvantages Selecting objects on CRT screens Drawing on screen Greater accuracy than touch screens Small Easy to use technology Lag problems Works with CRT monitors only Not accurate Dated technology *Direct Data entry devices 1. Magnetic stripe readers: - Used to read information off of magnetic stripes Uses Advantages Disadvantages Credit or debit cards Fast data entry Security devices to allow entry through gates Error free Data is lost if the stripe is damaged Doesn’t work from distance Secure and prevents access to restricted areas Not affected by factors such as oil/water/etc.. and does not have any moving parts Information is not human readable, which may be a disadvantage if the reader does not work 2. Contactless card readers: Allows customers to pay up to 25$ without entering their PIN through radio frequency:Advantages Disadvantages Faster transactions Do not need to worry about typing errors More expensive than normal cards A thief with a suitable reader can steal money from your card/money can be taken while customer is waiting in line Can take money twice if customer uses it as chip and PIN Retailers will not have access to customer’s info Uses number for transaction only, the information Transactions are limited on the card is encrypted Page 14 of 90 How the process of taking money from the card goes:1. 2. 3. 4. Customer looks out for contactless symbol at POS Shop assistant enters amount to be payed Customer presents their card and holds it in front of the reader Terminal displays that money has been taken 3. Chip and PIN readers:- Similar to smart card readers, and has a space where the card can be inserted and a PIN is keyed in ( Only different than contactless in the way that a customer needs to input their PIN, and RF technology is not used) Uses Advantages Disadvantages Where payment is done through cards only More secure than other systems Need to be careful that PIN is not read by shoulder surfers More robust than other systems 4. RFID readers:- Used to read and capture information stored on a tag RFID Chips contain:- Microchip that stores data/Antenna used to receive and transmit data Tags are usually passive or batter powered. Either by using the reader’s Radio wave energy to give back the info, or have an embedded battery. Uses Advantages Disadvantages Livestock tracking Retail Admission passes Libraries No line of sight contact Robust and reliable Fast read rate Allows read and write operations as well as being able to read many chips at once Tag collision (signals overlapping) Easy to jam or interrupt Easy to hack into their signal More expensive than barcode systems 5. MICR:- system which can read characters printed in special ink, at the bottom of a cheque for example. Uses Advantages Disadvantages Primarily used to read bank cheques through batch processing Greater security than OCR/OMR because the characters cannot be altered No manual input; thus reducing errors Can still be read, regardless whether the characters are damaged or not Only a certain amount of characters can be read Page 15 of 90 More expensive than other methods 6. OMR:- Reads marks written in pencil or pen Uses Advantages Disadvantages Read questionaries’, multiple choice exams, etc… Fast way of inputting results of a survey More accurate than manual entry Forms need to be carefully designed Sometimes need to be checked manually which is time and money consuming More accurate than OCR 7. OCR:- Takes scanned text and converts it to computer-readable form Uses Advantages Disadvantages Processing passports and IDs Much faster than manual entry Has difficulty reading handwriting Reduction of errors Not a very accurate technique Comparison between OCR and OMR OCR OMR Possible for customers to extend answers Can read handwriting- but can also cause errors Converting printed documents to editable formats Requires complex recognition system Fewer instructions needed Problems recognizing all handwritings Limited to choices in each question Relies on detecting marks on the page only Reads position of marks; ideal for MC exams Requires complex forms; but recognition is simpler More instructions needed, but is easier and faster More accurate 8. Barcode Readers:- Read information off of a barcode in POS terminals through barcode scanners Uses Advantages Disadvantages Supermarkets and shops Libraries to keep track of loaned books Safety function to check that electrical equipment is regularly checked Faster than manual entry Less mistakes Expensive to admin Not foolproof Automatic stock control/Improve safety Tried and trusted Easily damaged 9. QR codes can contain more information than a barcode, and due to the development of smart phones, they can be easily scanned through the embedded app. They can contain multiple items, ranging from telephone numbers, to offers, and even locations. Page 16 of 90 *Output devices 1. CRT Monitors: - Least expensive type, and make use of an electron gun firing against a phosphorus screen Uses Advantages Disadvantages Primary output display device for computers Used with light pens Angle of viewing better than most TFT monitors Work with light pens in CAD and CAM. Rather heavy and can cause safety hazards Run very hot and can cause fires if no ventilation is present Consume more power than modern monitors Flicker; cause headaches and vision problems 2. TFT monitors: - Usually the screen for laptop computers, makes use of pixels controlled by microprocessors Uses Advantages Disadvantages Primary output device for laptop computers and other types Integral part of laptop computers Lightweight and don’t pose the same hazards as CRT Viewing angle is critical to obtain a clear image Less glare than CRT and less radiation as well Consume less power than CRT and don’t produce as much heat Definition might be worse than CRT 3. LCD/LED Monitors:To display output on the screen, it uses a form of backlit technology, as well as diodes to make combinations of Red Green and Blue. There are many reasons why these kinds of monitors are replacing CRT screens:• Reach maximum brightness immediately • By giving a white light, they sharpen the image • Produce a brighter light, which improves definition • Much thinner • Last almost indefinitely • Consume little power and produce little heat In the future, manufacturers will be able to make OLED screens, which eliminates the need for making LCD screens. What this does is that it allows the screen to be bendable, meaning that the viewing angle is improved. This also means that the user will be more comfortable since they can suit the screen’s shape to their needs. If this technology is moved on to phones, they will have the ability to bend around your wrist making them less lose-prone. Page 17 of 90 There are many advantages for this technology:- (In comparison to LED/LCD) • Thinner, lighter, and more flexible • Layers can be made of plastic instead of glass • Give brighter light • Do not require backlighting • Can be made into large thin sheets • Very large field of view 4. Multimedia projectors: Used to magnify and project images on a screen that they receive from a computer Uses Advantages Disadvantages Training presentations Enables many people to see the same image Avoids the need for more than 1 computer Images can be fuzzy Ad presentations Home Cinema systems Expensive to buy/set up Setting them up can be complex 5. Laser printers: Produce very high quality hard-copy outputs at a very fast rate. Usually, they rely on a buffer where data is stored before printing Uses Advantages Disadvantages Where low noise is required Where high quality, fast printing is needed Fast Can handle great amounts of printouts Consistently high quality Fast only when several copies are being made Color printers can be expensive Produce ozone and other organic compounds Cartridges last for a while 6. Inkjet Printers: Used to produce good quality hard copies, but at a slower rate due to having large buffers Uses Advantages Disadvantages Where low output volumes are required Where high quality is required for one page 3-D types of them are used to produce prototypes High quality printouts Slow output with several copies Cheaper than laser Can’t do large print jobs Lightweight Printing can smudge Don’t produce ozone/organic compounds Can be expensive if used frequently 7. Dot Matrix Printers: impact printers, where a print head presses against inked ribbons Uses Advantages Disadvantages Noisy environments Used in environments where it is a problem for other types of printers Page 18 of 90 Very noisy Multi part stationary Where impact printers are valued Carbon copies can be produced Cheap to run and maintain Cost more than inkjet initially Slow and has poor printing quality Easy to use if continuously required 8. Speakers: - Connected directly into a computer to produce the sound at a higher volume from the computer itself Uses:• Output sound in presentations • Playing sound files • Audio output for on-screen text 9. Actuators:- are devices which take orders and signals from a microprocessor and convert them into a type of act. Motors Uses Automatic washing machines/central heating systems/glasshouses Control of robot arms Computers; to control fans/disk drives Buzzers Lights Uses Security lights Glasshouses Heaters Uses To tell operator when cooking process is done in cookers/microwave ovens Burglar alarm systems Uses Automatic washing machines Controlling temperature in ovens Control heating in central heating systems Temperature in glasshouses 10. 3-D Printers:- Used to produce solid objects that actually work by placing layer over layer until the object is completed Some of its features • Have various types, sizes, and shapes • Use additive manufacturing (aka they put layers over each other) • Also use subtractive manufacturing to carve the object • Direct 3-D printing Uses inkjet technology • Binder 3D is similar to normal 3D, but with two passes instead of one (dry powder then solid form) • Newer technologies use lasers and UV-Light Page 19 of 90 Fields where 3-D printing can be used:• Making prosthetic limbs • Making items which allow reconstructive surgery • Aerospace, in making aero planes • Fashion and art • Making parts for objects (usually cars) which are no longer in production Process for making a solid object in 3D printers 1. 2. 3. 4. Design is made using CAD software Finalized drawing is imported into a software which prepares it for printing 3-D printer is set-up to allow object to be made Object is made layer by layer, and can range from minutes to hours depending on the thickness 5. Object is removed from the printer, and prepared to wash away the excess materials from it Advantages Disadvantages Can manufacture any solid product the user wants easily Allows rapid prototyping Potential to make items which do not stick to others’ copyright If it falls in the hands of wrong people, production of items can lead to dangerous and illegal activities Potential for job losses in the field of manufacturing Convenient since it’s less costly than labor work Benefits the medical side of the world Parts for machinery no longer need to be readily available Page 20 of 90 Chapter 3: storage devices and media *Data backup and access Copying of data and transferring it to a different medium in case a problem happens to the main storage device or the main files. (Ex. Storing server data on magnetic tape) *Reasons of backing up data:• • • Safeguard data to save it from failure of data Safeguard data from hackers (corruption/deletion) In case files need to be used somewhere else Note: Data can still be effected by viruses even if backed-up *Serial access: - Accessing each record until the wanted record is found • • • When updating files; the original file is called the master file The additional data added to the master file is called the transaction file The updated tape is the new master file Here’s how the process goes:• • • • Transaction File is stored in the same order as the Master File The file is added to the master file to make a new master file The two records are compared and if there are new files on the transaction file, then they are compared and the new files are transferred Process is repeated until a new updated master file is made *Direct access: - Computer calculates where it should store the data and moves to the data through its calculations, making the process much faster *Magnetic Storage Media 1. Hard Disk Drive: - fixed hard drives are in all computers, and are the main storage device for storage. Uses Advantages Disadvantages Store OS/systems software and working files Storing applications which need fast retrieval In real-time systems Very fast data transfer rate Easily damaged if correct shutdown isn’t carried out Many moving parts Very large memory capacities Read/Write operations can be pretty noisy File servers for network computers Page 21 of 90 2. Portable HDDs Uses Advantages Disadvantages As backup systems Very fast data access time/data transfer rate Easily damaged if dropped or subjected to strong magnetic fields Transfer data between computers Large memory capacity Method of transferring data between computers 3. Magnetic Tapes: - Very thin strip of plastic coated with magnetic layer which is a set of 1s and 0s. It uses serial access causing it to be nearly useless in real-time Uses Advantages Disadvantages Batch processing processes (clearing of cheques, utility billing) Back-up media Generally less expensive in comparison to HDDs Slow data access time Robust technology In long term archiving of data since they are known to be stable Fast data transfer rate Huge data storage capacity Another tape is needed when updating data Affected by magnetic fields *Optical storage media CDs and DVDs are optical storage devices which are read and written to by laser light. The thin layer of metal alloy is light sensitive, and uses organic dye to store data. Three types of CDs/DVDs: - R( Write once only)/ROM(Read from only)/RW(Read from and written to many times DVDs have dual layering, and a red laser is uses to read the second layer through fractions of millimeters Page 22 of 90 1. CD-ROM/DVD-ROM:- Read only, cannot be written to Uses Advantages Disadvantages CD-ROM used to store Hold more data than music/files/software/games floppy disks DVD-ROM stores films/more sophisticated files/software Both used in applications where there is a need to prevent deletion of data Have slow data transfer rate/data access rate Less expensive than HDDs 2. CD-R/DVD-R:- Recordable only once then become ROM Uses Advantages Disadvantages Home recordings of music Store data for later use or transfer to another computer Cheaper than RW Only recorded once Once burned, they are similar to ROM Not all CD players are able to play them 3. CD-RW/DVD-RW:- Rewritable media and do not become ROM Uses Advantages Disadvantages Record television programs Data can be added to at a later stage Can be written over many times Can use different file formats Relatively expensive Possible to accidentally rewrite data CCTV systems 4. DVD-RAM:• Use number of concentric tasks • Allows simultaneous read and write operations • Allow numerous read and write operations • Can be written to and read from many times Uses Recording devices Camcorders to store movies Advantages Long life Very reliable- have built in verification Disadvantages Not compatible as R/RW formats Expensive Fast access and large storage Can read and write data at same time Superseded by new technology Page 23 of 90 5. Blu-Ray disks:- Fundamentally different to DVDs in the following ways:• A blue laser is used to read data instead of a red one • Blu-Ray stores data by 5 more times than DVDs • Disks do not suffer from birefringence (rays refracting and reflecting causing errors to happen) • Come with secure encryption systems Uses Advantages Disadvantages Home video consoles Storing and playing back movies Data storage or backup Camcorders can use it Store high-definition movies Fast data transfer rate Fastest data access speed Come with secure encryption systems Expensive Encryption problems Fewer movie titles on blu-ray Note: Optical storage media are proving to be obsolete, since data can be stored on harddisks or streamed (like movies). *Solid State Storage Are rapidly taking over HDDs due to the following reasons • • • • • • • • • 1. No moving parts so they are thinner All data is retrieved no matter it’s storage location Do not depend on magnetic properties, but on the movement of electrons inside it More reliable Lighter Don’t have to get up to speed Lower power consumption Much cooler than HDDs Faster data access Memory sticks:- Store several gigabytes and are connected through USB ports Uses Advantages Disadvantages Transferring files between computers Compact/Portable Can’t write-protect data Security device to prevent piracy Robust Easy to lose No need for additional software Not affected by magnetic fields User can corrupt data they remove it incorrectly Page 24 of 90 2. Flash memory cards:- Use EEPROM Uses Advantages Disadvantages Storing photos on cameras Mobile phone memory cards In MP3 players to store music Back-up source in computer held devices Compact Expensive per gigabyte of memory Have a finite life Can be easily removed Very robust Lower storage capacity than HDDs Page 25 of 90 Chapter 4: NETWORKS AND EFFECTS OF USING THEM Networks: A Network is two or more computers or other electronic devices connected together so that they can exchange data. Network allows computers to share files, resources. A computer that is not connected to a network is known as Stand-alone computer. Network connections are created using cables (wires), radio signals or by satellite links. Using a computer connected to a network, allows us to: • Easily share files and data. • Share resources such as printer, scanner and internet connections. • Communicate with other network users (email, video conferencing, chatting, etc). • Store data centrally (by using server) for ease of access and backup. • Keep all of our settings centrally we can use any work station (PC). If we use a computer connected to the internet, we can: • Make use of online services such as e-commerce (shopping), e-banking, etc. • Get access to a huge range of information. • Access forms of entertainment (games, music, videos, etc.) • Join online communities (e.g., Facebook, MySpace, etc.). What are the disadvantages of a Network? Using a computer connected to a Network means that: • • • • • • The computer is vulnerable to hackers. If the network breaks, many tasks become very difficult to perform. Your computer can more easily be attacked by a virus. We have to be careful about revealing personal information. We have to be careful to avoid suspect websites that might contain malware. We have to be aware that information found on the internet is not always accurate or reliable. Explain the following terms. Client: Client computers are the normal computers that user can use it to get their work done. Server: Servers are special, powerful computers that provide services to the client computers. The services are: • Providing a central, common file storage area. • Sharing hardware, such as printers. • Controlling who can or cannot have access to the network. • Sharing internet connections. Servers are more expensive than normal computers. In a small network, one server might provide all of these services. In a larger network, there might be many servers sharing the work. Page 26 of 90 There are three types of Networks: • • • LAN – Local Area Network WLAN – Wireless Local Area Network WAN – Wide Area Network Local Area Network or LAN : Is usually within one building or not over a large geographical area. A LAN consists of a number of computers and devices, e.g., printers, which will be connected to hubs or switches. Advantages • The sharing of resources (such as expensive peripherals and application software). • Communication between users. • A network Administrator to control and monitor all aspects of networking. • E.g., changing password, monitoring internet, etc. Disadvantages • • • • • Easier spread of viruses through the whole network. The development of queues for printer, which can be frustrating. Slower access to networks, such as internet. Increased security risk as compared to stand alone computers. If the main server breaks down, in must cases, the network will no longer function. Wireless Local Area Networks or WLANs Similar to LANs, but there are no wires or cables. They provide wireless network communication over very short distances (a few metres) usually radio or infra-red signals instead of cables. Devices known as access points are connected into the wired network, at fixed locations. Because of the limited range, most commercial WLANs need several access points, to permit uninterrupted wireless communication. The access point receives and transmits data between the WLAN and the wired network structure. Advantages • All computers can access the same services and resources. E.g., printers, scanners, internet access, etc. • There is no cabling to individual computers and devices so safety is improved. • The system is more flexible since, users can move their laptops from their desks. • Adding new computers and devices is a very easy task and costs are reduced, since no extra cabling is needed. Disadvantages • • • Security is a big issue, since anyone with a WLAN enabled laptop or computer, can access a network if it can pick up a signal. There may be problems of interference, which can affect the signal. Data transfer is slower than LAN. Page 27 of 90 Wide Area Network (WAN): A Wide Area Network is formed by a number of LANs being connected together through either a router or modem. Some companies setup private WANs. This is expensive but comes with an advantage of much enhanced security and speed. It is common to use an Internet Service Provider (ISP) for connections to the internet and communicate through this network system. Advantages • A WAN is a network that extends over a large area. • WAN can be connected using optical fibre cable, satellite link, radio signals, etc. Disadvantages • Very expensive. • Limited access. • Data access slows down if spread over huge area. Write the difference between LAN and WAN. LAN LAN is confined to a very small area. Usually located in a single building. Uses cables, wireless, infra-red which are usually queued by the organization. We can restrict or block any websites. WAN WAN covers wide geographical areas. E.g. Between cities, countries and even continents. Usually located between many buildings and countries. It uses wireless, satellite links, which are globally organized. WAN has very fast speed. Bluetooth (Personal Area Network): Bluetooth is a wireless network technology designed for very short range connections (just a few metres). The idea of Bluetooth is to get rid of all those cables, that connects our computer to peripheral devices such as printers, mouse, keyboard, etc. Bluetooth devices contain small, low power, radio transmitters and receivers. When devices are in range of Bluetooth devices, they detect each other and can be connected. With this system, it is possible to create small home networks. The range is however quite small (about 10 metres). Typical uses of Bluetooth • • • • • • Connecting a wireless keyboard to a computer. Connecting a wireless mouse to a computer. Using a wireless headset with a mobile phone. Printing wirelessly from a computer or PDA. Transferring data or music from a computer to a MP3 player. Transferring photos from a cell phone or camera to another device. Page 28 of 90 Wi-Fi: • Wi-Fi refers to any system, where it is possible to connect to a network or to single computer through wireless communication. E.g., Laptop computers which are Wi-Fi enabled can connect to devices like printer, keyboard, etc. Wi-Fi system rely on some form of ‘AP’ (Access Point), which uses radio frequency technology to enable the device to receive and send signals. It is not a short form of wireless Fidelity. It is a trademark name for any product which is based on IEEE 802.11 standard. Wi-Fi hotspots are places where you can access Wi-Fi (free or paid). They exist in public places such as airports, hotels, internet cafes’, etc. It is possible to log on to free Wi-Fi unless they are protected by password. Software exists which can be loaded in a laptop which then searches for non-protected Wi-Fi system. The practice of driving around in a car looking for these unsecured Wi-Fi hotspot is known as war driving and possess a security risk. • • • • • • • • • Networking Hardware (Devices): Modem Modem means modulator and demodulator and is a device which converts a computers digital signal into analogue signal and digital to analogue signal and transmission over existing telephone lines. Modems are used to allow computers to connect to network over long distances using existing telephone networks. Dial-up modem operate at the speed of about 60 kilobits per second, which is very slow. Modern broadband operate at 11,000 kilobits per second. Hub Hubs are hardware devices that can have a number of devices or computers connected to them. Its main task is to take data which receives through one of the ports and then send out this data from all of the ports. Each computer or device will receive the data, whether it is relevant or not. Hub is used at the centre of star topology. Hub is a dumb device, if it receives a message, it sends it to every computer on the network. This means that hub-based networks are not very secure. Page 29 of 90 Switch Switch is like a hub. It is a device which connects number of computers together to make a LAN. The use of a switch is at the centre of star topology. The switch has cables plugged into computers to connect to a network. A switch is a more intelligent device than a hub. If it receives a message, it checks who it is addressed and only sends it to that specific computer. Because of this, networks that use switches are more secure than those that use hubs, but also a little more expensive. Switch only sends packets of data to the computer, it reduces the amount of data on the network, thus speeding up the network. Bridges Bridges are used to connect LANs together. When one of the LAN sends a message, all the devices on the LAN receive the message. This increases the amount of data flowing on the LAN. Often a large LAN is divided into a series of smaller LANs. If a message is sent from one computer in a LAN to another computer in a different LAN, then the message needs to pass between the LANs usng the bridge. A bridge therefore, usually has only two ports in order to connect one LAN to another LAN. Router Routers are hardware devices that read the address information to determine the final destination of the packets. Each computer linked to the internet is given a number which is called Internet Protocol address (IP address). This address is like 123.456.7.89 and is unique for each device. When data is transferred from one network to another, the data is put into packets. The packets contain details of the destination address of the network it is intended for. Computers on the same network have the same first part of the IP address and this is used to locate a particular network. Can be used to join wired or wireless networks together. Page 30 of 90 Firewall Is a device or a piece of software that is placed between your computer and the rest of the network (where the hacker is). If you wish to protect your whole LAN from the hacker on the internet. You would place a firewall between the LAN and internet connection. A firewall blocks un-authorised connections being made to your computer or a LAN. Normal data is allowed through the firewall, e.g., Emails, Web pages, but all other data is blocked. Inetrnet: The internet is the world wide collection of networks which allows a user to send and receive emails, chat or browse the World Wide Web (WWW). WWW or web is the part of the internet which the user can access by using web browsers. A web browser is a software that allows a user to access and interact with web pages and files on the web. Web Page Web pages are documents on a computer screen which may consist of text, pictures, sound, video, etc. Web Site Web site consists of many of the web pages linked together. A web is made up of millions of websites and web pages. e.g. www.google.com The web site shows the hyperlink to allow user to navigate between web pages. These hyperlinks are often shown as Blue underlined text or sometimes a small hand appears under a picture or under some text indicating that link to web pages or web sites. Web browsers use URL (Uniform Resource Locator) to retreive files. URL’s are a standard way of locating resources on the internet. They are usually a set of four numbers. The URL indicates: Protocol://site address/Path/Filename where • • Protocol is usually HTTP Site address consists of host computer name, domain name, domain type and the country name. o Computer name is usually www o Domain name is name of website o Domain type is commonly one of the following o .com, .org, .net, .mil, .gov o country name .in, .uk o file path is a URL of the web page o file name is the name of the document Page 31 of 90 Thus, full url could be: http://www.cie.org.uk/exams/ict.pdf Accessing the Internet: An ISP is a company that provides access to the internet to the user and usually a paid service. When a user registers with an ISP, an account is set up and they are given login details which include username and password. There are three common ways of accessing the internet offered by service providers. • • • Dial up internet access Cable internet access DSL (Digital Subscriber line) Dial up internet access: It is the slowest internet connection (60 kbps). The user connects to the internet via telephone lines by dialing one of the number supplied from the ISP. ISP contracts are usually for hours per month of internet access time and additional charges are incurred if this is exceeded. A big disadvantage is that if the telephone line is tied up while a dial up modem is in operation. Cable internet access Local cable television operators give a user access to the internet through their own cable network using a cable network model. DSL – Digital Subscriber Line The fastest download speed can be obtained by using DSL broad band connection (about 11,000 kbps) This is often offered through wireless interface which requires an access point and a router. Broadband has the advantage of always being on because it does not tie up the telephone line. Intranet: An intranet is the name given to a private network that provides similar services to the internet like email, messaging, web page, etc. Intranet is a computer network based on internet technology that is designed to meet the internal need for sharing information within a single organization or company. However, these services are only for the users of intranet, they are private not public. Businesses and other organizations often have intranet, for use by their employees Page 32 of 90 Advantages: • It is safer since there is less chance of external hacking or viruses. • It is possible to prevent employees accessing unwanted websites. • Companies can ensure that information available is specific to their needs. • It is easier to send sensitive messages that will remain within the company. Typical uses of intranet • • • • Internal emails and instant messaging between the workers. Company’s workers or employees can view internal web pages only. E.g., Company’s calender, Company’s strategies, etc Sharing of internal documents Difference between internet and intranet: Internet The term internet comes from the phrase ‘International Network’. Covers topics of global interest It is difficult to block certain web sites from internet. Can be accessed from anywhere provided user has an ISP account. Will not give full protection against hackers and viruses. Information cannot be stored on local server. Intranet The term intranet comes from the phrase ‘Internal restricted access network’. Used to give local information relevant to the company. Possible to block certain internet web sites using intranet. An intranet requires password entry and can only be accessed from agreed points. An intranet is behind the firewall which gives protection against hackers and viruses. Information used in intranet is stored on local servers which makes it more secure from outside agencies. Page 33 of 90 Network Issues and Communication Policing of the internet/Reliability and desirability of websites/Security issues These were all discussed in chapter 10, please refer to that summary in order to revise these concepts. Authentication Authentication is usually used to verify that data comes from a trusted and secure source. Some of the forms of authentication are:• Digital certificates • Biometrics • Magnetic stripe In many applications, RFID chips and tags can be used to authenticate data, here’s an example of how it occurs in passport control:- Passport page containing data such as photo and name is placed on the reader Microchip on the page is read by the RFID and so is the facial image Photograph and data read are compared to those stored on the central database Owner of passport looks at camera, which takes a photograph of them Ways of preventing and minimizing risk of viruses 1- Antivirus software:Running antivirus in the background on a computer keeps checking for virus attacks, and has the following features and tasks:• • • • • • Checks software/files before they are run on a computer Compares possible viruses with those in the database Checks software for types of behavior which could indicate Any detected viruses are placed in quarantine and deleted or stay there until the user chooses to do so Need to be kept up-to-date, since new viruses are always discovered Full system checks need to be done weekly, to make sure no viruses are dormant Page 34 of 90 2- Avoiding viruses on the internet Always look out for HTTPS in the URL or a green lock before accessing a website. In addition, when someone gives you a URL, copy and paste the address rather than clicking on a hyperlink, as to avoid spam. Lastly, don’t open suspicious attachments in E-Mails. 3- Viruses from Hardware devices Always scan the device you are plugging into the computer before using it. In addition, don’t plug any device you get into the computer, because it can be infected with a virus. Data protection acts These acts are usually set by governments to protect citizens from their data being incorrectly or inaccurately stored. In many countries, failure to abide by these acts can lead to a fine, and sometimes an imprisonment There are a number of ways to prevent data from being unlawfully taken:• • • • • Don’t leave personal info lying around on desks Lock filing cabinets at the ending of the day Do not leave data on an unattended computer monitor Use passwords and IDs Make sure that info sent online is not sensitive There are main principals for DPA, some of them are:• • • • • • • • Data must be lawfully obtained and processed Data can be processed for stated purposes only Data must be relevant and adequate Data must be accurate Data should not be kept longer than needed Data must be processed with the subject’s rights Data must be kept in a secure place Data should not be transferred out of the country Faxing and Emails There are two basic ways of faxing: 1- Physical faxing Machines:In this way, a document is sent through a fax machine to another, by inputting the receiver’s fax number and telephone line number. This can be a slow process if the line is busy, or many documents are being sent. 2- E-Faxing (or E-Mail):Usually, E-Mailing would mean that an account’s address is used and a message with content and/or attachments is sent to the address. Afterwards, the recipient will log into the account and read the message Traditional faxing More likely to be intercepted, since the document needs to be printed out Signatures on fax printed documents are legally accepted Poor Quality of documents Telephone line being busy can delay the document Can be slow if more than 1 document needs to be sent Emails More secure No need to print the document Much better quality of document and can be modified Can send and receive documents anywhere with ISP Much easier to send to multiple recipients Access to an Email is more likely than a fax machine Page 35 of 90 Video Conferencing Is a form of communication that uses both video and audio, and is done in real-time. Usually used in face to face conversations, especially in companies Here a few things to consider before starting any video conference:• • • • • • Agree a time and place for the conference Delegates should log in to the conference beforehand Conference needs to be set-up beforehand Webcams should be placed in correct positions Microphones should be placed between all delegates, so everyone is heard Important for one person to be the main contact, so that it could go smoothly Here are the peripherals needed to run a video conference Hardware Webcams Large monitors/Display Microphones Software Webcam/Microphone drivers: So that audio and video can be correctly transferred to other delegates Coder-Decoder/Compression-Decompression: the first one is used to code and decode the data sent over, while the second is used to compress and decompress the data so it can travel Echo-Cancellation software: Allows communication to occur in real-time, and synchronizes all the communication together Speakers There are some issues with video conferencing:• • • • • • • Lag Jerking of images Can be very expensive to set up and maintain Time zones can cause an issue Training people to use the program is expensive and time consuming Can be demotivating for employees who want to travel Relies on good internet connection However, there are some advantages for video conferencing: • Much easier to access documents of work, since delegates are at their workplace • Possible to hold them at short notice • Reduces costs of Travelling/Accommodation/Need to travel away from work for 2-3 days • Can be safer, since delegates might need to travel to insecure places Audio Conferencing Usually, audio conferencing can be done through a telephone line or VoIP. As for VoIP, it can be done using the drag and drop feature, and needs a solid and strong internet connection. Users who do not have internet can also join using their telephone numbers. Here is the process of audio conferencing:-Contact an audio conferencing provider for organizer’s PIN and participant’s PIN -Give the PIN to each participant -at the start of the conference organizer types in his PIN -Each participant dials the number and enters the PIN Page 36 of 90 Web Conferencing Web conferencing uses the internet and the WWW to permit a conference to take place in real-time. Usually, it is used in the following applications:• Business meetings to discuss new ideas • Presentations • Online education and training There is one requirement, which is high speed and stable internet. The organizer controls who can speak and at which times, while the delegates have the Some of the features of web conferencing are:• Slide presentations can be posted during the conference • Possible to draw on a whiteboard using the mouse/keyboard • Possible to transmit images while the conference is going on • Documents can be shared by uploading them on the website, before the start of the conference • Can communicate through audio/video/instant messaging Page 37 of 90 Chapter 5: The effects of using ICT *Effects of ICT on employment • Manufacturing:- Robots replaced humans in many areas, especially things like welding car bodies and spraying metal items • Shop work :- Online shopping has decreased the need for high street branches • Banking:- Introduction of ATMs/Online banking decreased the need for high street branches • Office work:- Databases/Spreadsheets/Word processors have taken over the office tasks which needed staff to perform *Negative effects (AKA job losses):1. Office work:- Robots and ICT have decreased the employment in Administration/Human resources/Payroll • • • Word processors: - Since documents are now much easier to edit and modify, less employees are needed for such a job. In addition, they are now stored in an electronic format which removes the need for space, and can be saved on external servers known as cloud storages. This means that wages decrease, and less space is needed for file cabinets. Spreadsheets: - Payroll has become much easier to do, since macros or functions can be used. This makes calculations, especially for wages, much easier to do, since if you change a variable, the record will change with it. In addition, graphs can be made to compare and see progress. Lastly, conditional formatting, sorting, and using functions can all show differences (For example, marking badly preforming students in red) Database: - Human resources have become much easier ever since the implementation of databases, since cross-searches can be done much easier, and files can be easily opened. In addition, data such as personnel, can be updated much easier through forms and reports. This has led to a decrease in employees in the field of human resources. Page 38 of 90 2. Manufacturing: - Robots have decreased employment in spraying bodies with paint, fitting body parts, fitting windscreens. Through that, factories had to obtain the following skills: - Maintenance, quality control, design, and development of robots. Marketing and training of other workers Advantages Higher productivity More consistent results Disadvantages Expensive to setup/maintain Need to be reprogrammed for new tasks Work non-stop If an error happens, it’ll keep on happening Don’t get bored Cannot think for themselves Don’t go on strike *Positive Effects (AKA new jobs) Some advantages that sparked due to ICT being implemented in offices are:• • • More pleasant (less noise) offices Safer places to work in Much tidier due to less files and cabinets Some jobs have increased in employment, while others were freshly obtained, after the implementation of ICT in offices:• • • • • • • Network managers/Computer technicians Website designers System analysts Programmers (for applications) Computer engineers Computer programmers (For system applications/OS) Delivery drivers Page 39 of 90 *Effects of ICT on working patterns:1. Part-Time working: - Usually, this is when someone works less time than the normal staff during one week. A lot of teens or university students do this to obtain some money to help them during their studies. 2. Flexi-Time working: - With this working pattern, an employee can choose when and sometimes where they work. So long an employee completes a full day’s working hours, the time and place do not matter. However, this requires an office to be ready at all times 3. Job-Sharing: - With this working pattern, the full week’s working hours are divided between two employees (part-timers). Both do the same work, but one picks up where the other left 4. Compressed hours: - In this working pattern, employees work the same amount of hours, but over a smaller amount of days. For example, an employee could work 40 hours in 4 days instead of 5 days. Advantages which these working patterns resulted in:• Avoids rush-hour commuting • Leads to a more contented staff; which won’t quit as easily • The above point leads to less retirement, so the manager won’t have to spend time interviewing • Flexi-Time allows longer opening hours • Job-Sharing means that more people will have the same skill • Compressed hours lead to staff being more focused • Varied working patterns can give more flexibility during busy times or when some of the staff are sick Page 40 of 90 *Microprocessor controlled homes Microprocessors fall into two different categories:1. Labor saving devices: - Automatic washing machines/Microwave ovens/Cookers/etc.. 2. Devices related to the home: - Alarms/Heating and conditioning systems/Entertainment systems/etc.. Here are some advantages/disadvantages towards the use of microprocessor devices which can change a person’s lifestyle Advantages Disadvantages No need to stay at home to do manual tasks Can lead to unhealthy lifestyles due to dependence on ready food Can lead to people becoming lazy No longer need to stay home while food is cooking/laundry is being washed Give more leisure time for a person Possible to control devices while out of the house through using a smartphone Alarms (Especially safety ones) can give people a sense of security Smart fridges/freezers can lead to healthier lifestyles People can become less fit if they just lay around doing nothing There is a potential loss of household skills On the other hand, here are some advantages/disadvantages which don’t necessarily affect a person’s lifestyle Advantages Disadvantages Save energy since they can turn themselves off and are much more efficient Easy to program devices to do tasks (for example, putting a picture of a QR code for a certain product will automatically select it’s cooking program) Leads to a wasteful society; can be expensive to repair these devices People who don’t like using electronic devices can find them complex Leaving devices on stand-by can waste energy Page 41 of 90 Chapter 6: ICT APPLICATIONS *Communication Applications There are several communication applications that make use of ICT technology: Flyers, Posters, Brochures and Newsletters: Flyers and posters are very easily created using some of the commonly available software like Word Processing and Desktop publishing. Flyers and posters often contain photos which may have been taken or downloaded from the internet. The following outlines the steps that are generally followed to make a document on a computer: 1. 2. 3. 4. 5. 6. 7. Open one of the software as mentioned above Create frames, boxes and/or text boxes Take photos, if necessary using a camera Upload the images from the camera/cd/DVD or downloaded photos from the internet Save the photos to a file Import or copy and paste the photos into the document Edit the photos and import from a file or type any required text Brochures are generally used to advertise a company or its products. While these can be prepared on a normal computer and printed on a laser printer, it is advisable to go to a specialist company who use specialized computer and print the outputs on glossy paper resulting in a better final product. Brochures could be offered to a specific audience by distributing them in a pre-studied area or to a much more general audience by inserting them into newspapers and such, the downside is that they might be thrown away if they didn’t catch the reader’s eye. Single sheets of a document are called as flyers or leaflets and booklets or multiple sheets of documents are called are brochures. Posters are usually much larger and displayed on buildings, noticeboards or advertising hoardings. Newsletters are produced by companies or clubs using the methods mentioned above. They generally contain local information which is read by company employees or club members. The content is specific to the organization and may contain: 1. 2. 3. 4. advertising by other companies fundraising events or their successes by employees or club members news events, like certain achievements by that organization marriages, deaths and births of employees or their family members, club members Page 42 of 90 Websites: With the advent of the internet, companies tend to advertise in the virtual world rather than on paper through the development of their own website or advertise on another company’s website. Using the first option would mean hiring web designers and developers or go to a company specialized in doing this kind of work. Add to it there are costs involved for purchasing the hardware and software to develop the website, storage of the website, prevent the sight from being hacked by employing IT security experts. However, the biggest advantage of a website is that the company gets worldwide audience and there is no need to keep spending on paper, delivery of the leaflets and flyers, etc. There are pros and cons to both these options and it is company which has to take a call what suits best for them Advantages Disadvantages Sound/video/animation can be added It becomes necessary for the customers to have a computer and internet connection. Can’t be defaced or discarded away There is a risk of the websites being hacked and modified or viruses and Trojans introduced Can be seen by a global audience There is a possibility for customers to go to undesirable websites (due to accident or as a result of hacking) which can lead to distrust among customers Links to other websites/hyperlinks can be made As it is a global system, it is very difficult to target the right audience by advertising on the website Buttons to navigate or move around the website which provides more information The website needs to be maintained once it is set up, which can prove to be expensive Hit counters which provide how many people have visited the website with details of cities, countries from where the hits have come Use of hotspots It is very easy to update a website and immediately it is visible to the global audience Page 43 of 90 Multimedia Presentations: Any presentation that uses animation, video, sound or music are generally more interesting than a standard presentation done on slides or paper. The presentations are produced using one of the many commercial software applications available in the market and then using a multimedia projector the whole audience is able to see the presentation. Advantages Disadvantages The use of transition effects allows a presentation to display facts in a logical manner. It is possible to make them interactive or hyperlinks built into the presentation, which means that the presentation could access the company’s website or even key files stored on the cloud. The presentation can be interactive. Whenever the presentation is given it is necessary to have internet access. One needs special equipment which can prove to be expensive for many companies. Use of sound and animation or video effects are more likely to grab the attention of the audience. Moreover, this makes the presentation easier to understand. As links to websites and other external systems like is possible, the presentations can be tailored to suit a particular audience. Equipment failure can prove to be disastrous when giving multimedia presentations Often the presentation can turn out to be bad if it contains too many animation effects and/or too much text or images. When using a multimedia presentation, there is a danger that the focus is on the medium i.e. on the multimedia presentation itself rather than the facts or message which you want to convey. Paper Based Presentations: It is always possible to produce presentations in a hardcopy format rather than the system just described. Advantages Disadvantages The recipients can read the presentation at any time as per their convenience and will always have a permanent copy There are no special effects like sound, video, animation, etc. Disabled people don’t have to go to the venue to see the presentations There are printing costs for paper, ink, etc. Moreover, it is possible to print it out in braille for the benefit of blind people The presentation needs to be distributed through some method Page 44 of 90 Music Scores: The generation of music and the production of the music scores can now be done by computer systems with the appropriate software. Some of the features of this technology includes but not limited to: 1. Electronic instruments like guitars and organs can be played back through electronic effects machines 2. Music samplers and mixers allow the original tracks that were recorded 3. 4. 5. 6. 7. 8. earlier to be modified in any way one wants Synthesizers combine simple wave forms to produce complex music creations Electronic organs can mimic any other instrument The music score can be generated from the music itself using software Software can automatically correct music notes in a score There is no real need to understand music notation to write a music score Music notes are automatically printed out in the correct format. Cartoons: Animations can be created using computer software and hardware. With 3-D animation, objects are designed on a computer and a 3-D skeleton or framework or basic structure is produced. The parts of the skeleton are moved by the animator using key frames (these frames define the starting point and ending point to give a smooth animation effect). The difference in the appearance of the skeleton on these key frames is automatically calculated by the software and is known as tweening or morphing. In the final stage, using a technique called rendering, a realistic image is made. Cartoons can also be freehand drawings and then scanned or computer generated. Further, just like any form of communication, cartoons should not offend anybody and at the same time, it is necessary to make sure that cartoons don’t become the main feature so that the actual message is lost. Mobile Phones: Mobile phones communicate by using towers inside many cells networked together to cover large areas. The towers allow the transmission of data throughout the mobile phone network. Each tower transmits within its own cell; if you are driving a car and get to the edge of a cell, the mobile phone signal starts to weaken. This is recognized by the network and the mobile phone then picks up the signal in one of the adjacent cells. If a person is making a call or sending a text to somebody in a different country then satellite technology is used to enable the communication to take place. Mobile phone technology can now be used by computers and tablets. A plug-in-device (using one the available USB ports) or SIM (Subscriber Identity Module) card allows the computer to connect to the mobile phone network. This then allows access to the internet. Page 45 of 90 Advantages 1. The phone can be used to make phone calls from any location within the cellular network. 2. It is easier to keep in contact with co-workers at the office no matter where you are. 3. There is no need to look for an operational public telephone in an emergency. 4. It is possible to conduct business or personal phone calls on the move. As they allow text messaging: 1. It is quicker and less expensive than making phone calls 2. They employ predictive texting where the system completes a word from the first few letters keyed in e.g. Key in ‘compl’ and the phone completes the word as ‘complete’. This allows the system to remember frequently used words – together they increase typing speed 3. Text messages can be sent at any time of the day or night even if the recipient’s phone is switched off. Mobile phones allow access to the internet on the move using either the cellular network or a Wi-Fi ‘hot spot’. Internet Telephony: The most common form of internet telephony i.e., having a telephone conversation via the internet is Voice over Internet Protocol (VoIP). VoIP is a method to talk to people using the internet. The sound which is picked up the computer microphone is converted into discrete digital packets in VoIP and sent to their destination via the internet. The biggest advantages of VoIP is that it is either free (if both parties use computers to converse) or charged at a local rate to any call in the world (when VoIP is used to communicate with a mobile or land line instead of a computer). Of course, you will need a broadband connection to work in real time. The main problem is sound quality in the form of echoes and strange sounds. Security is also a concern with VoIP, just as it is with other internet technologies. One of the big advantage of VoIP is using it can be used as a video chat using the built-in webcam. While this may not be a very sophisticated way of video chat, it is much cheaper as it uses the computer’s built-in microphones, speakers and webcams. However, if you want to improve the video quality, use an expensive webcam, which connects to the computer’s USB ports. Page 46 of 90 Business Cards and Letterheads: Many IT companies offer to produce business cards and letterheads to any design. The user connects to an appropriate website and they will give a number of business card templates. The user chooses a template and keys in data such as: • Name of the company • Contact details • Image wanted on the business card The final version of the business card is then shown. The customer places their order and the business cards are printed and delivered. Business cards are handed out to people as a form of personal advertisement. The use of IT (in this case, a website) has made this a much easier task. Business cards are less likely to be thrown away since they are seen as personal contact. It is also possible to include additional information on the reverse of the card – this could be further advertising of the company’s products or it could be advertising another company. The same format used on the business cards can be adopted on a company letterhead. This helps to project a corporate image. As with business cards, these pages can be printed on high quality paper using a laser printer. Flyers and brochures can be produced using the same design/logo so it becomes clear to the customer that all the3 communication has come from one company. There are various advantages to a company in using corporate letterheads produced by a printing website: 1. Legal reasons (it helps if there are any legal actions taken – legitimate documents using the company letterhead is regarded as proof of actual communication). 2. Can make the company appear larger than it is (this could give a degree of confidence to potential customers). 3. Professionalism (gives a degree of credibility to the company) 4. Helps to make the company stand out (will tend to have more impact than white sheets of paper with a typed company heading). 5. Brand/company awareness (advertises the company by using the same designs on all products). 6. Advertising (the letterhead can contain many useful pieces of information to advertise the company). Page 47 of 90 Data Handling Applications Data Handling Applications are beneficial where data is input and stored in computer, processed, and finally output into the desired form. Data handling is useful for searching, editing, backup, security, sorting, transport, etc. Survey Results: Surveys are often used and collected by business organizations to find the requirements of the people and to know if the people are satisfied with their service. Surveys are often carried out on paper and are filled by shading the circles or ticking boxes. This data is then analyzed by scanning them with an Optical Mark Reader (OMR). When the data is inside the computer, it can be used for sorting searching, analyzing and finding results. The benefits of using a computer to handle survey data are: • • • • Lesser errors Efficient and fast Saves time and money Fast result analysis Address List: Address lists are used to store details about friends, family, relatives or business contacts. Some of such details stored in address lists are: • Name • Address • Telephone numbers • E-mail address • Pin code Modern address lists are stored on computers or mobile phones and have a couple of advantages like: • • • • Seamless editing Groups can be created Easy searching Back-ups can be initiated Page 48 of 90 Vendors Records: Vendors sell things like, drinks, chocolates, crisps and other snacks to school children. Like any other shop, a tuck shop needs to keep a track of records such as income, expenditure, stock-level, etc. Before the introduction of computers, vendors records were kept on paper, and were called Account’s ledger. Such kind of paper-based records had several drawbacks such as: • They were challenging to update • Difficult to back up • They can be easily damaged • Manual entry errors are possible • Now a day, spread sheets are used to store shop account records. The advantages of using spreadsheets to do so are: • • • • Easy editing Easy to back up Calculation can be carried out by formulas Charts and graphs can be created Clubs and Society Records: Clubs and societies have many members. Records need to be kept about these members for details such as: • Membership number • Name • Address • Telephone Number • E-mail address • Membership subscription status. etc. Advantages of using vendor records: • • • • • Easy editing Easy searching Back-ups can be controlled and created Security Mail merge can be used Record Keeping: Records can be kept using a spreadsheet or a database. Advantages Disadvantages Less office space would be required in the shop since no paper records would need to be kept It would be quicker and easier to find details of a particular book or find out whether or not it was in stock The system would be less expensive since it wouldn't be necessary to employ somebody to do all the filing and searching There would be fewer errors since no manual checking of paper files would need to be done. There would be a need to buy a computer and software to run the system Time and effort would be required initially to transfer all the existing paper files to the database. Page 49 of 90 Measuring Applications What are the measurement or measuring applications? These types of applications involve use of various types of sensors and other hardware like microprocessors. The sensors that are used generally take light intention, rate of rotation, temperature, etc. As the data is usually in analogue form, they are sent to an Analogue to Digital Converter (ADC) to turn the data into digital format. This conversion is necessary as microprocessors and computers only understand digital data. The term analogue means the data varies constantly and has no discrete values. For example, the height of mercury in a thermometer to represents temperature. The term digital refers to discrete data which is made up of binary values 0 and 1. However, when you to need control devices like pumps, heaters, valves, etc., the data or signals (i.e. a series of 1s and 0s) from the computer needs to be converted back to an analogue form (e.g. electric signals) using a Digital to Analogue Converter (DAC). After conversion of the data, the data is sent to microprocessor where it is processed. However, in measuring applications, microprocessors are programmed to only review the data from the sensors (often comparing it to the data which is stored in memory) and update their files and sometimes giving a warning signal if the values are outside the given parameters. The microprocessor do not take any action to change any of the data or conditions during the measurement process. Common examples of measuring applications are: • • • • • Measuring a patient’s vital signs in a hospital Monitoring of pollution Weather stations Burglar alarm systems Scientific experiments (e.g., taking light intensity). Weather Stations: Weather stations are generally setup to automatically gather data from the environment. They are mostly unmanned and use a variety of sensors to measure: • Temperature • Wind speed • Rainfall • Humidity • Barometric pressure (air pressure) • Wind direction The data is gathered 24 / 7 (i.e. 24 hours a day, 7 days a week). This data is then used by weather forecasters to help predict the weather for the next few days or even take a more long-term view by looking at past and current weather patterns. Page 50 of 90 Measuring a patient’s vital signs in a hospital Using a computer to measure the key vital signs of a patient in a hospital, can be seen in the following steps: • • • • Sensors read key vital signs such as heart rate, temperature, blood pressure, respiration, pulse rate, etc The data from the sensors are converted into digital format using an analogue to digital converter (adc) The data is stored in the computer’s memory The computer compares the data from the sensors with the values stored in its memory (these are usually fed in advance either by the nurse or doctor for a given patient) The results are displayed on a screen in the form of graphs and/or numerical readouts An alarm is activated if any of the data is outside acceptable input values The system continues to measure the patient’s vital signs until the computer is switched off. Measuring Pollution in a River: • • • The below steps show how a computer can be used to measure pollution in a river: • • • • • • • The sensors are placed in at least two different positions to do a pollution comparison at various points The data from the sensors are converted into digital form using an adc and sent to a computer The computer stores the data received The acidity levels and oxygen levels are compared with the historical data stored in computer databases and they are also compared with preset levels stored in the databases. The oxygen and acidity levels from the different positions in the river are also compared to see if they are similar. This sometimes help to find the source of pollution. The data stored in the computer can now be transferred either by copying this to a CD/DVD/USB media and taken away for further processing and analysis or the computer can be connected to a LAN/WAN network or internet and transmit the data back automatically to the monitoring station. Other types of sensors such as light sensors (to check whether there are solids or chemicals in the water blocking out light) or temperature sensors (to check the temperature of water at different points which might disturb the marine life in the river), can also be used. Advantages Disadvantages The computer’s response time is very fast (which is very important in the hospital monitoring system). If the computer malfunctions or if there are frequent power cuts, then a computer cannot be used. Due to this, there should be proper backup procedures in place to over this eventuality. The computer cannot respond to unusual circumstances. A student doing an experiment using a computer for measurement and analysis, may not learn as much using a computer system. The initial cost to setup the measuring software and computer is usually very high. The computer does not forget to take readings. The staff can carry on with other tasks whilst the measurements are being taken automatically and precisely. The readings are generally more accurate than when taken manually. There is a huge cost saving the in the long run, as lesser staff are needed since the measurements are now being done by computer (which in turn reduced wage bill). It could also be safer to use sensors since whatever is being measured may have potential hazards. Computers can be programmed to produce graphs automatically. Computers can measure data 24 hours X 7 days without tiring out. Leading to more frequent readings Page 51 of 90 Microprocessors in Control Applications Use of Microprocessors in Control Applications: In control applications, sensors and a microprocessor or a computer are used. Sensors send data to the microprocessor or computer which then compares the incoming data to stored values or data entered earlier. An Analogue to Digital Converter (ADC) may be needed before the microprocessor or computer can process the data. The microprocessor/computer will check whether the incoming data is outside the given parameters and will take any necessary action. For example, a temperature sensor sends data to a computer which will then check whether the temperature is greater than the preset or stored value. If the temperature is greater than the pre-set value, the computer will send a signal to switch off a heater. If the temperature is less than the pre-set value, the computer will send a signal to switch on a heater. Thus, the microprocessor/computer takes some action which affects the input value it receives. By doing this, the microprocessor/computer is controlling the application. Describe the working of an Automatic oven/cooker An automatic cooker/oven has temperature sensors and a number of controls to set the cooking time (i.e., when to switch the cooker/oven on and off). First of all, the start time and end time (or the actual cooking time) are entered. Finally, the cooking temperature is selected. The microprocessor checks the set time against the current time and when they are equal, the cooker/oven heating elements are switched on. Once the cooker/over starts the cooking process, the microprocessor then constantly checks the end time against the current time (the end time may be a pre-set value entered by the user or it may be a value calculated by the microprocessor, based on the cooking time entered); when they are equal, the cooking process is stopped. The microprocessor checks the temperature data sent from a sensor and turns the heating element on if the value is less than the preset value chosen by the user. If the temperature is greater than or equal to the preset value, then the heating element is switched off by the microprocessor. Once the cooking process is finished, the microprocessor sends a signal to a beeper to make a beeping sound to indicate that the cooking cycle is completed. Describe the functioning of Central Heating Systems In the example shown below, a gas supply is used to heat water in a boiler. A valve on the gas supply is controlled by a microprocessor and is opened if the heating level needs to be increased. A water pump is used to pump hot water around the central heating system whenever the temperature drops below a preset value. Working of this system: • • • • • • • • • The required temperature is keyed in and this is stored in the microprocessor memory (this is called preset value). The temperature sensor constantly sends data readings to the microprocessor. The sensor data is first sent to an ADC to convert the analogue data into an digital format. The digital data is sent to the microprocessor. The microprocessor compares this data with the preset value. If the temperature reading is less than the preset value, then a signal is sent: to an actuator (via a DAC) to open the gas value to the boiler to an actuator (via a DAC) to turn on the water pump The process continues until the central heating is switched off Page 52 of 90 Describe Chemical Process Control: A certain chemical process only works if the temperature is above 70° C and the pH (acidity) level is than 3.5. Sensors are used as part of the control system. A heater is used to heat the reactor and values are used to add acid when necessary to maintain the acidity. • • • • • • • • • Temperature and pH sensors read data from the chemical process This data is converted to digital format using an ADC and is then sent to the computer The computer compares the incoming data with the preset values stored in the memory if the: Temperature is less than 70°C, a signal is sent to switch on the heaters Temperature is greater than or equal to 70° C, a signal is sent to switch off the heaters pH is greater than 3.5, then a signal is sent to open a value and acid is added pH is less than 3.5, then a signal is sent to close this value The computer signals will be changed into analogue signals using an DAC so that it can control the heaters and values This continues as long as the computer system is activated. 4. Describe how microprocessors/computers are used to control a Glasshouse environment Control: There are about five sensors to control a glasshouse environment namely humidity, moisture, temperature, pH and light. Due to this, it is a quite a complex problem. For simplicity, let us consider only the humidity sensor. This sends signal to an ADC which then sends a digital signal to the computer. This compares the input with the stored or preset values and decides what action needs to be taken. If the humidity is greater than the pre-set value, the computer sends a signal to a DAC to operate the motors to open windows thus reducing the humidity. If it is less than the pre-set value, the computer sends a signal to open values to spray water into the air. If the reading is the same as the preset value, then no action is taken. The control process continues as long as the system is switched on. On similar lines, the other four sensors work. The table below gives a list of possible sensors that might be used in various applications which involve measurement of control. Sensor type Temperature Moisture Oxygen/Carbon dioxide Motion pH Proximity/distance Light Infra-red Acoustic Pressure Possible applications used in the control of central heating systems used in the control of measuring temperatures in a chemical process measuring/used in the control of a glasshouse environment measuring moisture levels in any process (e.g., in the production of electronic components) environment monitoring (e.g. measuring the oxygen content in a river to check for pollution) measuring carbon dioxide levels in a glasshouse detecting movement (as in virtual reality interface devices measuring acid/alkaline levels in a river (pollution monitoring) used in a glasshouse to measure soil acidity used to measure acidity in a chemical process these tend to be another name for sensors such as infra-red, motion, etc., measuring the light levels in a glasshouse measuring for light levels in a dark room (photography) used with automatic doors detecting an intruder by the breaking of an infra-red beam allows microprocessors to count items picking up sounds (e.g. footsteps when used in a burglar alarm system) detecting liquids or solids moving in pipes/check for blockages in pipes detecting intruders in a burglar alarm system counting vehicles as they pass over a bridge Page 53 of 90 Modelling Applications Describe Modelling Applications: A computer model is the creation of a model of a real system in order to study the behavior of the whole system. The model is computer generated and is based on mathematical representations. The idea behind developing the model is to try to find out what mechanisms control how a system behaves. This makes it possible to predict the behavior of the system in the future and also see if it is possible to influence this future behavior. Computer models are used because they can help find a solution more quickly and can be considerably safer while at the same time saving money and time. Traffic Light Simulation: A set of traffic lights are to be modelled at a Y-junction: In this computer model, it is necessary to consider: How and what data needs to be collected? The success (or failure) of a computer model depends on how realistic the model is. Hence, data needs to be collected for a considerable period of time by watching traffic at the Y-junction. This is best done by using induction loop sensors which count the number of vehicles at each junction. Collecting data manually is possible but is prone to errors and is also difficult to do over an 18-hour period per day (for example). The type of data that would need to be collected or considered for collection would be as follows: A count of the number of vehicles passing through the junction in all directions at all differing times of the day The day of the week (weekends, bank holidays, public holidays, etc., can alter how the data need to be interpreted) • • • • How long it takes a vehicle to clear the junction How long it takes the slowest vehicle to pass through the junction Whether there are any pedestrian crossings, etc., nearby Whether there are other factors which might affect the junction (e.g. Left turns, right turns, filtering, etc.). How the computer model is carried out? Data from the above list is entered into the computer database and the computer model is run. Once the designers are satisfied that it simulates the real situation accurately (i.e., by comparing results obtained with actual traffic flow from a number of data sets), then different scenarios can be tried out. For example: • Increase the number of vehicles stopped at part of the junction and then change the timing of the lights to see how the traffic flow is altered • Increase or decrease traffic flow in all directions • Consider how emergency vehicles affect traffic flow at different times of the day • Vary the timing of the lights and see how the traffic flow is affected. How the system would work in real life? • • • • • Sensors in the road gather data and count the number of vehicles at the junction. This data is sent to a control box or to a computer. The gathered data is compared to data stored in the system (the stored data is based on model predictions which were used to optimize the traffic flow). The control box or computer ‘decides’ what action needs to be taken. Signals are sent out to the traffic lights to change their timing if necessary. Page 54 of 90 Why are computer models done (in general terms)? • • With computer models it is much easier to try out various scenarios in advance. Time scales are reduced by doing a computer model rather than the real thing (some applications would take before a result is known e.g. climate change calculations, population growth, etc.). • They are less expensive than having to build the real thing (e.g., a bridge!). • On many occasions it is safer to run a computer model (some real situations are hazardous e.g., chemical processes). Other examples of computer models include: training pilots and drivers, running chemical and nuclear plants, crash testing of cars, financial modelling, weather predictions, population growth and modelling queues at checkouts. Manufacturing Applications Describe the use of computers in Manufacturing Manufacturing uses ICT (i.e., automation) in a number of areas to improve productivity, reduce costs, improve consistency and to make factories safer and more environmentally friendly. One of the most common forms of automation is the use of robots. Robotics Robots are used in many areas of manufacturing, from heavy work to delicate operations. For example, welding bodywork on cars, manufacturing of microchips, paint spraying of car bodies, automatic warehouses and manufacturing electrical goods. Control of robots is either through embedded that is built-in microprocessors or linked to a computer system. Programming of the robot to do a series of tasks is generally done in two ways: The robot is programmed with a sequence of instructions which allow it to carry out the series of tasks (e.g. spraying a car body with paint). Alternatively, a human operator manually carries out the series of tasks; this can be done in two ways. Here let’s assume, an object is being painted using a robot arm. The robot arm is guided by a worker when spraying the object; each movement of the arm is stored as an instruction in the computer OR The worker straps sensors to his own arm and sprays the object; each movement is stored as a set of instructions in a computer; the sensors send back information such as position relative to the object; arm rotation and son on – this information forms part of the instructions stored in the computer. Whichever method is used, once the instructions have been saved, each series of tasks can then be carried out by a robot arm automatically. Each instruction will be carried out identically every time (e.g. assembling parts in a mobile phone) giving a consistent product. Robots are often equipped with sensors so they can gather important information about their surroundings and also preventing them from doing ‘stupid things’ e.g. stopping a robot spraying a car if no car is present or stop the spraying operation if the supply of paint has run out, etc. Robots are very good at repetitive tasks. However, if there are many different tasks (e.g. making specialist glassware for some scientific work) then it is often better to still use human operators. Page 55 of 90 Advantages They can do boring, repetitive tasks leaving humans free to do other more skilled work (e.g., quality control or design work). They can work in environments harmful to human operators. Higher productivity (don’t need holidays, etc.). They can work non-stop (24/7). Greater consistency (e.g., every car coming off an assembly line is identical). They are less expensive in the long term (although expensive to buy initially, they don’t need wages). Disadvantages The initial set up and maintenance of robots can be expensive. They find it difficult to do ‘unusual’ tasks (e.g. one-off glassware for a chemical company). They can cause higher unemployment (replacing skilled labor). Since robots do many of the tasks once done by humans, there is a real risk of certain skills (such as welding) being lost. Because robots are independent of the skills base, factories can be moved anywhere in the world (again causing unemployment). School Management Systems Describe School Registration Systems The traditional way to record the registration and attendance of a student is to complete daily registers. This is very time consuming since it is required a 10-minute session at the beginning and end of each day. It is also prone to error if a student’s name is missed at some point during the registration process. However, it is now possible to automate this process using computers and related software. Two methods are given below: Method 1 Issue each student with an ID card. This contains a magnetic stripe on the rear of the card. The student name and the unique student ID is written on the back of the card. The student has to sign the card. The magnetic stripe contains the name of the school, the name of the student, the student’s date of birth and unique ID (registration) assigned to the student. Each morning the student has to swipe the ID card through a magnetic card reader on arriving at the school. The data read would identify the student and the time and date the student entered the school’s premises. This data would now be stored in a database. On leaving the school, the ID card has to swiped again. This would now record the leaving time and date in the database. This would give a very comprehensive record of when the student attended the school and the number of hours the student attended. It would also be more secure method in the event of, say, a fire. The school would now be able to account for every student currently showing as being present on the school premises. Using the paperbased system, a student could register then just go home – with this ID card system, the student’s attendance would be known at all times. There are further subtleties that could be used such as (1) use of a PIN to stop another student swiping in with the wrong card (2) use of GPS tracking so that the exact whereabouts of a student would be known. This would require the addition of a chip on the ID card so that the tracking system could identify them. At the end of a term (or school year), the database could be interrogated and it would give an accurate attendance record for the student. Page 56 of 90 Method 2 A second method could make use of biometrics. Each student would have their fingerprints taken. Their personal details like date of birth would be stored in a database. When a student enters the school premises, he/she would be asked to put his/her hand on a scanner which would read his/her fingerprints. Since each student would have unique fingerprints, this system would be very secure. The date and time of entering or leaving the school would also be accurately recorded in the database. Advantages It is much easier to ‘clone’ (i.e., to make copies) of ID cards than it would be copy fingerprints (not impossible but very difficult). Fingerprints are unique, so it would be impossible for a student to sign in pretending to be someone else (with magnetic cards, a student could give his card to a friend and ask him/her to sign in for him/her) – this gives more accurate data and improved security. ID cards could be easily lost – fingerprints are ‘part of you’ so can’t be lost. ID cards could be affected by magnetic fields (e.g., by being placed close to a mobile phone) which would stop them from working. Disadvantages It would take a long time to collect the initial fingerprints for every student in the school. There are ‘invasion of privacy’ issues and some parents may object to having the fingerprints of their children stored in a database. If a student cuts a finger, the fingerprint may not be identified by the system (which would prevent entry to the school). The equipment needed to take and read fingerprints is more expensive than magnetic stripes reading equipment. 2. Describe use of Computer systems to evaluate student performance Teachers can evaluate the performance of students using a spreadsheet. The teacher enters the marks of students in a spreadsheet for a number of subjects. Using a spreadsheet has the following advantages: • • • • • • graphs and charts can be produced to show how the students compare to each other graphs and charts can also be used to show student progress over a given time period, use of ‘rolling averages’ or trend lines can be used to monitor changes in performance. it is also possible to use ‘conditional formatting’ to show which students are performing badly (e.g. by highlighting the results in red) or well (e.g., by highlighting results in green) using functions, such as sorting or averages, allows the teacher to quickly see which students are doing particularly well and how they compare against the class average it also allows the teacher to easily see how they are performing against each other students in the same subjects it is also very easy to import data into a report, e.g., summarising a student’s performance over the academic year. 3. Explain the use of Computers and softwares for preparing Exam timetables, subject timetables and teacher substitution Timetables are often required for the following: • exams scheduling (both internal and external) • subject scheduling • producing cover/substitution plans for teachers who are absent. For example, at the start of a new academic year, a student may be given their own personal timetable covering their subject allocation. Page 57 of 90 Timetable for: Tom Alter 112 678 234 Summer term 2016 Monday Tuesday Wednesday Thursday Friday 09:00-10:30 History Maths Geography Science Geography 10:45-12:15 Science Geography Maths History History 12:30-13:30 lunch lunch lunch lunch lunch 13:30-15:00 Maths History Science Geography Maths 15:15-16:45 Geograhy English Science Sport time Art/Music Many factors have to be taken into account when producing timetables for each student: availability of rooms for each subject availability of teachers number of hours for each subject making sure double lessons appear for certain practical subjects but ensuring this doesn’t happen with others subject clashes (e.g. a student wishing to do German from a group containing History, German and English finds this clashes with their Art/Music lessons and so they have to take Geography instead of German). Timetables are also produced so that students know when to sit an exam. This allows them to schedule their work correctly. The main advantages of using software to create timetables is that it is quicker and less prone to errors than the older paper-based systems. It is also easier to try ‘what if’ scenarios to ensure the most efficient use of time. Likewise, timetables can be produced to cover classes when teachers are absent. This is often done using the main timetable software since each teacher is allocated a class or non-contact time for each of the teaching periods. In the above example, a teacher would have either a class or a ‘free period’ for each 1.5hour session. The main subject specialty of each teacher is also stored so that a subject specialist can be used to cover for absent teachers. Page 58 of 90 *Booking Systems • Theatre and Cinema booking process 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. • Customer clicks on wanted performance Date/Time is typed in Required number of seats is typed in Seating chart is displayed on the screen User highlights the seats Database is searched to check for availability Total price and number of seats is shown Seats are set to be temporarily unavailable Customer enters personal details Payment method is selected Seats are booked under customer’s name Final details and check is presented E-Mail sent to the customer with tickets to print Database is updated with transaction Seats become permanently unavailable Flight booking systems Advantages Disadvantages Prevent double booking Setting-up/Maintaining these systems can be expensive Needs access to a computer with reliable internet connection Harder to cancel bookings Impossible to book seats if servers are down Immediate feedback Always available Special offers can be attached to the customer’s EMail Easier to browse seating plans Can temporarily reserve seats Difficult to book what you exactly want/can lead to mistakes Difficult to build a personal relationship with travel agents who might give you free upgrades Reduces post costs, and allows impulse bookings Allows use of modern tablets and smartphones for bookings *Banking applications • Automatic Teller Machines (ATM) Sequence of what happens at the ATM:- 1. 2. 3. 4. 5. 6. 7. 8. Customer puts card into ATM PIN is entered using the keypad Customer selects cash option Number of amounts are shown Customer chooses an option (Amount) Customer asked if they want a receipt Card is returned Money is deposited Page 59 of 90 • Sequence of what happens at the bank’s computer 1. 2. 3. 4. 5. 6. 7. Contact between ATM and computer occurs PIN is checked to see if it’s correct Card is checked to see if expiry date has been passed/if card was reported stolen Customer’s account is checked to see if sufficient funds are available Card is checked to see if the daily limit for transactions has been passed Transaction confirmed Customer’s account is updated with new balance Data that’s inputted/read by customer/ATM 1. 2. 3. 4. 5. 6. 7. 8. Account number Sort code Expiry date Amount to withdraw PIN Card limit Choice of language Receipt required (Y/N) Advantages/Disadvantages of ATM Advantages Disadvantages No embarrassment of not having sufficient funds When getting cash late at night may be susceptible to mugging Machine may be out of order/run out of cash Can only be given denominations in the machine Limit to the amount that can be withdrawn Less time spent queuing Can get money any time of day or night Own bank may be further to travel to than the nearest ATM Can use most ATMs/does not have to be own bank • Internet Banking As online banking and shopping increases, the effect on society is getting larger and larger, but this impact has pros and cons. below is a comprehensive list of advantages/disadvantages for online shopping and banking:Advantages Disadvantages Reduces costs of travel Can look for cheaper products; thus reducing time and price Disabled/Elderly can access shops without the need to travel Can be done at any time People can have more time to do other tasks People find it less embarrassing to ask for loans online There are long queues at banks Shops save money by employing less employees Isolation/Lack of socialization due to no communication Health risks due to lack of exercise Security issues Fraudulent websites Necessary to have a computer/stable internet connection Only possible to see pictures, and not products themselves High street shops are closing Easier to make errors/incorrect transfer of money Page 60 of 90 Effects on companies due to online banking/shopping:- • • • • • • • Can save costs since companies need to employ less workers Increased customer base Increased costs; more employees needed in despatch department (however, this can even out with the first point) Increased costs due to setting up and maintaining the website Very little to no customer-employee interaction Decreased abundance of robberies Less security staff needed; decreased costs • Telephone banking process 1. 2. 3. 4. 5. Customer keys in account number PIN is requested Customer is presented with various options Customer chooses the wanted option Customer can: Check their balance/Talk with representative/Pay bills or transfer money The advantages/disadvantages of telephone banking are similar to that in online, and only differ in the fact that you can talk to someone, and there is no need for an internet connection. However, it can be slower. • Chip and PIN This system uses both a chip and a PIN with credit cards, as well as a magnetic stripe system. The way it operates is as follows. (Note: this example relates to a fast food restaurant):1. PIN entered using keypad 2. Card checked for validity 3. PIN is read from chip and compared to keyed in PIN 4. If they are the same, transaction completes. If they are different, transaction is terminated on 3rd try 5. Restaurant contact customer’s bank 6. Their account is checked for sufficient funds 7. If the validity check proved wrong/sufficient funds are not available, transaction is terminated 8. Otherwise, transaction is completed 9. Authorization code sent to restaurant 10. Price of meal is deducted from the customer’s balance 11. Same amount of money is added to the restaurant’s balance 12. Receipt is produced as proof Page 61 of 90 • Process of clearing of paper cheques 1. 2. 3. 4. 5. 6. Cheque is sent to centralized clearing center by receiving bank Cheque is passed through reader/sorter machine (the amount and code line are read) Data is converted into an encrypted format (IBDE file), which has a digital signature Receiving bank delivers cheque to exchange center Exchange center gives cheque back to paying bank Paying back sends cheque to its own clearing center, which checks for the digital signature then processes it through their sort/read machine. 7. Paying bank checks if their client has sufficient funds to pay for the object, as well as if it is signed, dated, written, and is genuine 8. Based on the information, the paying bank chooses whether they should send the cheque unpaid or not. This should be done on the morning of the next day 9. A cheque can be returned unpaid because: A. Client does not have sufficient funds B. Cheque was not signed/dated/written correctly C. It is fraudulent • Process of clearing of digital cheques (The same process is followed as above, but with these differences) 1. Details of the amount and payee are sent electronically 2. The sort code, account number, unique coding number or UCN is encoded as text 3. The check details and encoded MICR are read using OCR and stored • Electronic Funds Transfer This allows money transfer instructions to be directly sent to the receiving bank, without the need of clearing centers. However, actual money is not transferred, and the process is fully electronic Page 62 of 90 *Expert Systems • • • • • • • • Experts are interviewed Data is collected Knowledge base is designed Rules base is designed as well as a rules base Explanation system is developed Input and output screens are designed Expert system is trusted with known situations Experts are interviewed to test and give feedback Advantages Disadvantages Provide consistent answers and are not affected by emotion Lack of common sense Never forget to answer Lack of emotion can be a disadvantage at times Less time consumption Errors in knowledge base will lead to a wrong solution More precise Expensive to set-up/maintain Less costly Need to train operators so they can use it correctly Allows people all around to access expertise which they couldn’t’ve other wise Here’s an example where expert systems can be used: - (oil prospecting) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Interactive screen appears System asks questions about geological profiles Operates types in/answers System asks questions based on the previous answer Inference engine compares answers with knowledge base through the rules base System suggests probability of finding oil Indicates the probability for the depth The system explains how it reached its conclusions It will make predictions about the deposits inside the rocks It will then produce a map, containing concentrations of minerals Page 63 of 90 *Computers in medicine In medicine, computers can be used for the following tasks:• • • • Keeping records Monitoring patients Diagnosis using expert systems 3-D printers in surgeries Patient/Pharmacy records In hospitals, accessing a patient’s record can be the difference between life and death, so it is very important to keep them up to date, in addition, pharmacies are able to prescribe the correct medications through them. Here are some types of information which a patient’s record might contain:Unique ID Blood group Name Known allergies Address Doctor Date of birth Current treatment Gender Current diagnosis Medical history Additional info Monitoring Patients Connecting a computer to a patient means that they can be monitored all the time, and can give doctors and nurses valuable information about the patient’s current state. Some of the items a computer can monitor are:- Hear rate Body temperature Respiration Blood sugar level Brain activity Blood pressure Blood temperature Oxygen level 3-D printers in medicine • • • • 3-D printers can help doctors by taking pictures of the organs of the patient, then show what exactly is wrong. Then, the doctor can proceed to show the patient their problem, and help them fix it. 3-D printers are being used to print out prosthetics, such as hands or legs, to help people without these organs. They can cost as little as 100$, and function very similarly to an actual hand. However, this field still has a long way to go. 3-D printers are being used to make tissues, such as cells, skin layers, bone tissue, and even heart grafts. They use biological materials and put them in the form of layers. Lastly, 3-D printers are being used to make medical equipment, which can take a long time to make in the traditional way. Thus, it also reduces the costs needed to make these equipment. Page 64 of 90 *Computers in libraries Many libraries now use computers to treat customers. Usually, two files would be analyzed each day, being the Borrower’s file and the book’s file:- Book’s File Barcode Book title Author’s name Date published Unique book ID Borrower’s ID Borrower’s File Borrower’s ID Borrower’s name Borrower’s details Barcode of borrowed book Unique book ID Process:1. 2. 3. 4. 5. 6. 7. System calculates due back date based on date the book was taken Book file and borrower’s file are linked and updated Due back date is saved in borrower’s file System sets a reminder Computer reads record of book file daily and compares it to borrower’s file Letter or E-Mail is sent if the due back date is near or exceeded Process is repeated *Computers in Retail (barcode stock control) Barcodes are usually used at EPOS terminals, and in stock control to update data through purchases. Barcodes can also be used in the following fields as well:- 1. 2. 3. 4. 5. 6. Library book system Administration systems Passports/ID cards Burglar alarm Equipment checking systems Automatic stock control Page 65 of 90 Due date Process of stock control:1. Barcodes are attached to items 2. Each barcode is linked to a stock file, where it acts as the primary key 3. Customer reaches EPOS terminal 4. Barcodes are scanned/keyed in manually 5. Barcode is searched for in stock file 6. Once barcode is found, the record is associated 7. Price of item is found and displayed 8. Stock level is reduced 9. Procedure is repeated 10. Customer gets an itemized bill, and if they have a loyalty card, computer updates it 11. Computer updates file with all the daily takings *Automatic Plate Number Recognition Systems These systems are used to read number plates off of cars, in the following process:1. Sensor detects car approaching, and sends a signal to the microprocessor to capture a picture 2. An algorithm is used to isolate each character on the number plate, then OCR is used to reach each character single-handedly 3. After all of this occurs, the barrier is raised and the car is allowed to go through, while the machine gives them a ticket 4. When the car comes back from the park, the user inserts the ticket 5. The system activates again, and if the plate number is similar to that stored earlier, it will allow them to go through the gate *Monitoring and tracking systems Monitoring or tracking a person There are many reasons behind why someone would be tracked, some of them are:1. The person might be an offender who was recently released from prison, and their whereabouts have to be known at all times 2. The person might be old, so they are tracked for safety 3. The person may be competing in a marathon, and their whereabouts or position need to be known, so that the finish time can be recorded 4. An ankle monitor can use an RFID chip, which are tamper proof, to see if a person has stepped out of their designated space or tried to remove the monitor. This is commonly used with people who have committed crimes which are not prison-worthy, or they are put on a rehab Page 66 of 90 Employee call monitors A call monitor can allow a manager to listen to their employee’s calls, for the following reasons:1. Improve employee performance 2. Allows the manager to supervise the call 3. As a training tool 4. Allows security-concerned companies to monitor all calls 5. To make sure employees represent the company well There are 3 types of call monitors, which are:1. Monitor: Allows manager to listen to the call 2. Whisper: Allows manager to listen and talk to employee only 3. Barge: Allows manager to listen and be heard by both employee and the receiver *Satellite systems GPS systems and satellite navigation Is used to determine the exact location of kinds of transport. The system uses at least 3 satellites, and a sat-nav system to measure the distance between the vehicle and the location, as well as giving instructions to reach the destination. Advantages Disadvantages Driver does not have to look at maps Can give false info if not up-to-date Removes errors Road closures such as car accidents might cause problems System can warn driver about Loss of satellite signals can cause problems Estimated time for arrival If you key in incorrect locations, the system will respond with incorrect info Gives you the fastest route Can give useful info about information of petrol stations Page 67 of 90 GIS systems:GIS allows the user to create queries, edit, and analyze map data. GIS allows for the following: • • • Amalgamation of information into easily understood maps Performance of complex analytical calculations and then present them in form of maps Geographers, scientists, and engineers are able to see the data in several different ways. Uses:• • • Emergency services use them to send personnel to the closest emergency center Biologists and environmentalists use GIS to protect animal life Teachers can use it in geography/science/engineering lessons Media Communication Systems:Usually, satellites are used in multimedia such as televisions, where data is sent through a radio wave frequency to the satellite, and the satellite takes it then converts it to a different frequency and relays the data back to the location it was sent from. Cables would cost too much, due to the long distances, so satellites are used instead Page 68 of 90 Chapter 7: system life cycle *Why a system analyst is brought When a system is regarded inadequate for the task, a system analyst is brought in to review the current system and suggest a number of improvements. *Analysis 1. 2. 3. 4. 5. 6. Research the current system and collect data Describe the current system Identify the problems Agree the objectives and identify then interpret the requirements with the customer Produce a cost-benefit analysis and identify software/hardware needed Produce a data flow diagram Note: Stage 2-6 are identified as a feasibility study:1. Terms of reference A. Objectives B. Boundaries C. Constraints 2. Description of the current system A. Identify the problems B. Project the costs 3. Criteria A. Essential requirements B. Desirable features 4. Proposed solution A. Development plan B. Cost-Benefit Analysis Data flow diagrams Helps by showing data, inputs, outputs, their requirements, and types of data stored. DFDs are used to describe:• The need to identify inputs/outputs • The need to identify current problem • Need to identify user and customer requirements • Hardware/Software specifications Page 69 of 90 Methods of research Description and name Observation: Watching personnel using the existing system and finding out the problem Advantages • • • Questionnaires:- Distributing forms to see how the staff do some of the work • • • • Interviews: Involves one-toone sessions between analyst and employee • • • Looking at paperwork: Analyst looks at already existing paperwork and figures out the problem • • • Can be answered quite quickly Inexpensive method Recipients remain anonymous Gives quick analysis of data Motivates interviewee to give honest answers Analyst can extend the question Analyst can modify the question as the interview proceeds Allows unique info to be obtained Can see how the system operates • *Design • • • • • • • • Disadvantages Gives reliable data Possible to get an overall view of the system Inexpensive method Make data capture forms Design screen layouts Design outputs in the form of screen/printed displays Produce system flowcharts Design validation rules Agree on file structures Produce program flowcharts Design a test plan Page 70 of 90 • • • • • • • • People will be uncomfortable being watched Workers will do things that they don’t usually do, to impress the observer/give a good image Number of returned forms is usually low Questions will be inflexible No immediate way of clarifying weird/vague answers Time consuming Relatively expensive Interviewee cannot remain anonymous Time consuming Relatively expensive Paper based forms Have a heading to make purpose clear Make it clear where the person should answer Make use of text boxes Make use of character boxes (surnames, telephone numbers, etc..) Make use of printed text boxes for easy input of date of births Make use of tick boxes to make limited choices easier Make sure there is sufficient space for writing Use clear fonts and clear text colors Computer based form Make use of text boxes Make use of on-screen help Make use of drop-down/combo boxes Make use of radio/tick boxes to make limited choices easier Have automatic validation of data Include navigation buttons Have double data entry boxes (verification purposes) Note: Always make sure of the following 1. 2. 3. 4. Size of all fields are matching to their outputs All instructions are clear Full screen is utilized Colors and fonts are clear System flowcharts Show how data flows through the system and how decisions are made. They use special symbols for each kind of command (output, input, etc..), and view an overall view of the proposed system, in addition to showing how the system is supposed to work. Page 71 of 90 Verification: A way of preventing errors while preventing data, through its two types:1. Double entry : Data is entered twice using two people at a time 2. Visual check: The person types in the data, and then compares it to the source of the data to see if there are any mistakes Validation: A process where data is checked to see if it meets a certain criteria Validation check Description Examples Range check Checks if the data is within acceptable values. A person age should be in the range 0 to 150 Length check Checks if the input data contains the required number of characters If the field is six inputting 5 will be an error Character/type check Checks if the input data does not contain invalid characters A person height should only contain digit Format check Check that the data in a specific format In the form dd/mm/yyyy Limit check One of the limits is checked Input data >10 Presence check Checks if the data is actually present and has not been missed out The field can not be left empty required field. Consistency check Checks if fields corresponds with each other If Mr has been typed into a field title then the gender must contain M Check digit Looks at an extra digit which is calculated from the digits of a number then put on the end of the number If two digits has been transposed during input. • An incorrect digit have been entered Example: barcode Lookup check Checks whether the data entered exists and is stored in a table M or E or F Page 72 of 90 • Data dictionaries: Used to find and show suitable data types based on the data in the document. Designing a strategy plan:1. 2. 3. 4. Make sure it meets the customer’s requirements Remove any bugs Make sure it produces the correct, already known, output Check if the software doesn’t crash under certain conditions *Development 1. At this stage, if there are any files contained, then their structure has to be finalized and tested to make sure it is robust and ready. 2. Make sure to adopt certain techniques so that the data can populate in the correct form. In addition, data which is unwanted is to be trapped, while wanted data HAS to be transferred from paper based to electronic form 3. Of course, the system has to have a user interface. At this point, the interface’s inputs and outputs have to be thoroughly tested to make sure they are working. For example, you need to see how the inputs will be placed on the screen, and how they will be presented as outputs. Finally, the interface should be checked to see if it is user friendly. Testing strategies In most systems, data is developed in modular, where it is broken down to small parts, and each part is tested separately to make sure it works. After all files have been tested, they are combined together to see if the system functions correctly. This strategy allows each file to be modified and rebuilt on its own, so that when one part crashes, the whole system is not affected. Page 73 of 90 Categories of test data:• Live: Data which is tested and it’s outputs are already known • Abnormal : Data out of the range (Ex. 101 when the range is 0-100) • Extreme: Data on the boundaries of the range (Ex. 100 when the range is 0-100) • Normal : Data that is within the range and not on boundaries (Ex. 2 when the range is 0-100) *Implementation Method Description Advantages/Disadvantages Direct New system is implemented overnight and old system is wiped out Parallel Old and new system run together Pilot One branch or office takes the new system Phased Only part of the system is introduced, and is continued if the pervious part proves to work Can be disastrous if system fails Immediate benefits Reduced costs (less workers needed) Less likelihood of malfunction (system would’ve been tested) Old system can be relied on Gradually trains staff Expensive (more workers needed) Time consuming (data needs to be inputted twice) Only one branch is affected if system fails Can train staff in one area only (less costly/less time consuming) Less expensive than parallel If one part fails, you only have to go back one step More expensive than direct VERY time consuming Possible to insure the system works properly before expanding *Documentation Technical Documentation (made to help analysts/people who made the system) contains:• • • • • • • • • Program listing Programming language Flowchart/algorithm List of variables File structure Purpose of the system/program Input format or example Output format or example Hardware requirements Page 74 of 90 • • • • Software requirements Sample runs/test runs Known bugs/possible errors Validation rules User Documentation (made to help the user figure out the program) contains:• • • • • • • • • • • • • • • • • How to load software/install/run software How to save a file How to search How to sort How to print How to add records How to delete/edit records Purpose of the system/program Input format or example Output format or example Hardware requirements Software requirements Sample runs Error messages Error handling Tutorials Troubleshooting guide/Contact details/help line/FAQ Why is technical documentation made:• • • To help programmers maintain system To help programmers update a system To help programmers upgrade a system *Evaluation Ways of evaluating a system:• • • • • Compare the final solution with the user requirements to ensure that requirements have been met Identify any limitations of the new system so that system works without problems Identify any further improvements to the new system Analyze feedback from users of the new system to see how well they are coping with the new system/ to see how well the new system works and so that user’s needs are taken into account. Compare test results from the new system with the old system Page 75 of 90 Chapter 8: Safety and security *Physical Security Health Aspects Risk Cause Back and Neck pain Sitting for long periods in the -Regular Breaks same position -Foot rests -Sit in correct posture -Use tilted screens Continuous use of keyboards -Use ergonomic equipment and mice -Use your wrist properly while working -Sit in correct posture -Use voice activated software Staring at a computer screen -Insure there is no screen for too long/Incorrect lighting flicker -Switch to LCD monitors -Anti-Glare screens -Test your eyes regularly Incorrect Lighting / Flickering / -Anti-Glare Reflections screens/Windows -Regular breaks -Test your eyes regularly Laser printers -Proper ventilation -Isolate printer -Use other types of printers RSI Eyestrain Headaches Ozone Irritation Ways of minimizing Safety Aspects Risk Ways of minimizing Electrocution -Use RCB -Check insulation on wires -Don’t allow food near computers -Check equipment -Cable Ducts -Cover wires/Tie them to walls -Use wireless connections -Use sturdy tables/desks -Use large tables/desks -CO2 Extinguisher -Don’t cover equipment vents -Maintain electrics used in hardware -Good ventilation -Don’t overload sockets -Change to low-voltage hardware Trailing wires Heave equipment falling Fire Page 76 of 90 *Electronic Security Some ways of staying safe while browsing the internet:• • • • • • • • • • • • Do not broadcast your info to unknown people Do not send photos of yourself Maintain your privacy settings Make sure the websites you visit are secured Use websites recommended by teacher Open E-Mails from known sources Be Vigilant (keeping careful watch for possible danger or difficulties.) Block suspicious people Use a nickname/Keep private data secrete Never enter private rooms Never arrange to meet people on your own/Always tell an adult when your meeting someone Use appropriate language and respect people Some risks of going online:• • • Violence Predators/Cyber bullying/Cyber attacks Use of webcams/Use of voice masking technology *Safety of Data (EXTREMELY IMPORTANT) Some examples of security “risks”:• Hacking (Gaining unauthorized access) • Phishing (Sending an unsolicited E-mail containing malicious info) • Smishing (Phishing through SMS) • Vishing (Phishing through a phone call) • Pharming (Installing malicious code on a user’s computer) • Spyware (Installing a software which spies on the user) • Virus (Malicious code which copies itself and destroys the system) • Spam (Sending an unsolicited message repeatedly) Page 77 of 90 Risk Consequences Ways of prevention Hacking -Identity theft -Deletion/Corruption/Editing of data -Firewall -Strong passwords -Intrusion detection software -Using passwords/IDs -Personal data can be gained -ISPs/Web browsers filter out phishing emails -Fraud/Identity theft -Being cautious -Do not click on executable attachments (.exe/.bat/etc..) -Personal data can be gained (Credit card -Anti-Spyware software details when using a fake website) -Be alert/Look for clues -Fraud/Identity theft -Gives access to all data entered by -Anti-Spyware keyboard -Be alert/Check for clues -Other spyware can be installed -Use an on screen keyboard when entering important info -Can cause computer to stop functioning -Anti-Virus software - Deletion/Corruption/Editing of data -Do not use software from unknown sources -Do not open suspicious attachments -Can cause computer to ‘crash’ -Denial of services -Use a spam filter and set the protection to a high -Clogging up inbox level -Can lead to other risks like viruses -Block images in HTML messages -Look out for already checked checkboxes -Do not sign up to commercial mailing lists -Do not reply to unsolicited messages Phishing Pharming Spyware Viruses Spam *Moderated and Unmoderated Forums • When a forum is moderated, an administrator (or a number of administrators) monitor the forum, and delete any unwanted posts or hateful comments • This allows the forum to be safer, since the administrator can remove spam and inappropriate, rude, or offensive posts • Essentially, the internet is an unmoderated forum, but there are some rules that most social discussions go by. *Cookies • • • • Small files that are stored on a user’s computer Contains custom settings Generate an anonymous user profile, which contains NO personal info Remove need to store massive amounts of data by web servers Page 78 of 90 *Additional security levels 1. Firewall • • • • • • • Examines traffic between computer and network Checks if data meets a certain criteria, and filters it out if it doesn’t Records all incoming/outgoing traffic Can prevent hackers/viruses Cannot prevent individuals from using modems to access internal networks Cannot control carelessness Can be disabled on stand-alone computers 2. Security protocols A. SSL: Protocol which allows data to be sent and received SECURLY over the internet. HTTPS shows the user that SSL is being used on that specific website B. TLS: Is a similar more recent type of security which provides: Encryption, Authentication, and Data Integrity; in a more effective way than SSL. TLS is designed to prevent third party hacking through two ways: -Record protocol: Can be used with or without encryption -Handshake protocol: Allows the user and website to authenticate each other, in addition to using encryption techniques. It is a fact that TLS separates the handshaking process from the record protocol TLS can be improved through new authentication techniques and session caching (see later). C. Session Caching: TLS sessions require a lot of computer time to process, so session caching is used to remove the time needed to open a TLS session. From there, a new session can be opened, or an already existing one can be modified. 3. Encryption • Primarily used to protect illegally accessed data. • Uses a secret key, which can alter the characters in a message making them unreadable. • The recipient can only access the data if they have the same key • Encryption Key : Used to encrypt the message making it meaningless Decryption key : Used to decrypt the message to return it to its original form • Cypher text : The form of an encrypted message Plain text: The form of a decrypted message Page 79 of 90 4. Authentication • Used to verify data which comes from a secure/trusted source • Digital Certificates contain: A public key, and a private key. One which is known to the public, and the other which is known to the user only. • Digital certificates are attached to show that the info comes from a trusted source. Digital certificates Contain:123456- Email address Digital certificate owner Serial number Expiry date Public key Authority of digital certificate • Passwords are a number of letters and numbers used to secure data from being stolen. • Strong passwords should contain: Uppercase/Lowercase letters, Numbers, signs, etc... • A maximum number of tries is allowed before the user is blocked out • Passwords should be regularly changed There are many reasons why a Credit Card may experience Fraud:1. User may be tricked to enter their credit card details through :Phishing/Pharming/Hacking/Spyware 2. Breaking of passwords 3. Visiting a fake website and entering your details 4. Using wireless internet access with no password 5. Carelessness of the user (leaving personal info without anyone monitoring it) 6. Hacking of the organization/bank which withholds the info of the credit card Simple precautions a user can take to avoid Credit Card fraud:1. 2. 3. 4. 5. 6. 7. 8. Use varied and complex passwords Check accuracy of bank accounts Provide personal info to secure sites with HTTPS Do not provide personal info to unsolicited messages Do not open suspicious attachments Delete spam messages Report suspicious activity to the credit card company Download software from trusted websites Page 80 of 90 5. Biometrics Biometric technique Advantages Disadvantages Fingerprint Scan - Very intrusive - Can make mistakes if the skin is damaged Signature Recognition Retina Scan - Most developed biometric technique - Very high accuracy - Easy to use - Small storage requirements - Non-intrusive - Requires very little time to identify - Low-cost - Very high accuracy - Can’t be replicated Iris recognition - Very high accuracy - Less than 5 seconds needed to verify Face recognition - Non-Intrusive - Inexpensive - Non-intrusive - Less than 5 seconds needed to verify - Inexpensive Voice recognition Page 81 of 90 - Problems may arise if users do not sign with the same name - High error rate - Very intrusive - Slow to verify scans with stored ones - Expensive to set-up/maintain - Very intrusive - Uses a good amount of memory - Expensive to set-up/maintain - Affected by lighting or change of facial characteristics - Can be replicated through recording - Low accuracy - A change in a person’s voice can make it malfunction Chapter 9: Audiences *Audience Appreciation: There are many factors to consider when presenting something specific while appreciating the audience, here are some of them :1. Age: Young children like animations and pictures, while adults may like something more informative and formal. 2. Experience of the audience: - For example, a group of school teenagers would expect a different presentation than that for a group of directors or managers. 3. Expectations of the audience: - If you’re advertising a new product, a car for example, adults would expect a presentation about the car’s features and comfortability, while children would be more interested in the car’s looks and speed. 4. Knowledge of the audience: - For example, Physics graduates would expect a different approach that Chemistry graduates during a presentation about Science. To achieve the best presentation possible, research must be done in order to reach a conclusion about the audience you’re presenting to. There are 3 different methods which researching can be done: 1. Interviewing a small group of the audience, and asking them questions 2. Distributing questionaries’ to find the background of the group 3. Carrying out market research and doing in-depth analysis *Factors of a presentation Language • No vulgarity • No Inappropriate language • Technical terms should be used with experienced audiences only Multimedia • Sound/Video/Animation will catch the attention of the audience • Do not overdue the effects • Loud music will interest young audiences • Complicated info should be explained with graphs Length • Always be understanding when referring to examples (i.e. do not refer to meat in front of vegetarians • Asking the audience questions and getting them to participate is always good, but do not do it for those who do not want to Examples Interactiveness Page 82 of 90 • Long presentations only work if they are interesting and engaging • Young audiences will get quickly bored and become restless Always make your speech matching to the factors listed below: 1. How old are the audience 2. How skilled are the audience (dependent) 3. Do the staff have any problems (Disabilities, ethical problems, religious problems, etc...?) Note: Go to pages 163,164, and 165 for an example about Audiences. *Copyright and privacy Whenever purchasing a copyrighted software (on a CD for example), it is illegal to:1. Make a copy of the software and sell it as your own or give it away 2. Use the software multiple times on different networks (unless specified you can do so) 3. Use coding of the software in your own software 4. Rent out a software package without permission 5. Use the name of the software on other software without agreement Software privacy has been a big problem on the internet, so companies have taken extra steps to stop copies from being used after they’ve been sold:1. The user will need to put in a PRODUCT KEY in order to use the software 2. The user will need to AGREE to certain conditions and rules, which if disobeyed, will cause the user to face major consequences 3. Original packaging comes with a sticker saying that it is illegal to copy the software. 4. Some software will not work without the CD-ROM/DVD-ROM/Memory Stick being plugged in 5. Some software will only run if a dongle is plugged in. *Legal/Moral/Ethical/Cultural implications:Word Legal Moral Ethics Culture Definition Covers the law, whether or not it is punishable by the law Governs personal interactions, and is usually determined by the person concerned Governs professional interactions; such as behaviors or acts a group or society practices Attitudes, values, and practices of a certain society or group All of these factors differ, for example, anything that the law prohibits is deemed illegal, and punishable by the law itself. As for moral acts, these depend on the person, and not on the Page 83 of 90 law or on a group, however, culture can get in the way. What may be immoral to many people, is permitted in some cultures, and vice versa. For example, cows are usually slaughtered for their meat, however, in India, cows are a very sacred animal. There is a very thin line between immorality and illegal acts. For example, giving information from your company to its rival is deemed immoral, but is not necessarily illegal *Policing of the internet Arguments For Arguments Against Prevents illegal material from being posted Material published is already available on other sources Would be difficult to enforce rules on a global scale Would go against freedom of information and speech Many comments posted are already illegal, and rules already exist to deal with them Many things are offensive only to a minority of people Can shield people from having to discover information with serious consequences Would prevent children and other vulnerable groups from unwanted material Would stop incorrect info from being published Page 84 of 90 Chapter 10: Communication *Constraints of communication using E-Mail:A. Laws • Many countries require users to obtain permission before sending E-Mails • Never send an E-Mail with a misleading subject title • If you are sending as a company, a valid postal address MUST accompany • • • • the message Many countries DO NOT allow companies to harvest (collect) E-Mail address lists Privacy policies must be made clear to a company’s subscribers Companies must provide subscribers with a way to unsubscribe from their EMails Companies and individuals must have clear ways for the user to opt-out (Exit) B. Acceptable Language • You can LIE but only within an acceptable range • Obscene images/Offensive/Exploitive/Profane/Abusive messages (etc..) are not allowed • Illegal materials and matters are not to be discussed in E-Mail messages Note: In many countries, the above constraints are VERY strict, and will be met with huge consequences if they are ignored. C. Copyright Even though they are E-Mails, copyright still applies to them. You may think that the forward button is just a simple click, with no consequences, but that is not always the case. Many companies are very strict about the copyright policies of their attachments and messages. You are not supposed to forward a message unless you or the recipient are responsible for doing so. Other than that, forwarding of copyrighted messages is PROHIBITED, and will be met with great consequences. D. Security and password protection It is very important that E-Mails stay secure through passwords and encryption, because if one’s E-Mail is hacked, a ton of information (Sometimes personal) can be leaked. Some ways of keeping your password safe are:1. Use strong passwords (i.e. k7O9-J5E7X) 2. Change passwords on a regular basis 3. Use a spam/junk folder to remove spam and keep it isolated 4. Run up to date Anti-Spam/Anti-Virus software on your computer Page 85 of 90 *Netiquette • • • • • • • • • • Don’t be abusive Don’t send spam Be clear in your messages Remember that your posts are read by everyone, so be understanding Check spelling and grammar ALWAYS Respect people’s privacy and do not discuss delicate matters Forgive people for their mistakes Do not use CAPITAL letters, as they may be viewed as screaming Do not plagiarize Do not use to many Emoticons It is important to note that these points can show who you are as a person to the general public, and give a first impression to anyone unknown to you. Usually, sticking to these rules will give a good first impression about yourself. *Spam Spam E-Mails are any unsolicited messages that are sent to you, and can range from being annoying to being extremely dangerous, depending on the weight of the situation. There are many disadvantages behind spam, with some of them being:• • • • • Uses up people’s time Generally annoying Uses up bandwidth, and slows down the internet connection Can have viruses attached Clogs up the inbox Spam doesn’t only affect computers, but can also reach out to mobile phones, through SMS spam or ‘Spasms’ , which charge the user a specific amount of money every time they receive a message, which can greatly increase the bill. *Purposes of an E-Mail group • • • Easier to send multiple E-Mails to the same addresses if they are all grouped under the same name. Companies/Marketers can group people up in specific groups, so when a certain sale comes, they can send it to that specific group. (For example, they can group up people who like sport equipment, and send them messages when Sport equipment is on sale) Although this is a disadvantage for the general public, spammers are able to group people up and send spam to thousands of people, in addition to saving time Page 86 of 90 • Companies set up E-Mail groups to ensure everyone is invited to their meetings, and no one misses out. *The internet the internet has enabled people to do many different things, some of them being: Send and receive E-Mails, Transfer files, Chat online, Browse the WWW. It is important to note that the WWW is only part of the internet, and while you use a web browser to open web pages, the browser only allows you to access the WWW which is based on the HTTPS. *Intranets Is a computer network based on internet technology, but designed to meet internal needs for organizations/companies/private groups/etc... This means that it is not available to the general public, and is protected by a FIREWALL Intranets are only accessible to:1. People from the company itself 2. Members external to the company, who have been given various levels of access Reasons for adopting an intranet, instead of basing your network on the internet:1. 2. 3. 4. 5. Safer – Less chance of hacking/catching viruses Information available will be specific for the company’s needs Easier to send sensitive messages Offer better bandwidth – There are less connection limits than with the internet Possible to create Extranets to extend intranets, but give them the same advantages as intranets Difference between Internet and Intranet Internet Intranet International network Covers topics of global interest Internal Restricted access Gives local information relevant to the company Very easy to block certain websites Resides behind a firewall which protects it from malicious code Privately accessed It is difficult to block websites More difficult to place protection since it is on a global scale Publicly accessed *Cloud Storage Data is stored on an offsite server, in many different servers. This is done so that when a server is repaired, the data would stay there. This is known as Data Redundancy Types of Clouds:- Page 87 of 90 1. Public Cloud :- Customer and provider are from different companies 2. Private Cloud :- Customer and provider are integrated and act as a single entity 3. Hybrid Cloud: - Combination of the two previous clouds, where some data resides in the private cloud, and less sensitive data resides in the public cloud. Advantages Disadvantages Data is accessed at any time Some of its security aspects are not very strong Needs strong and fast internet connection to access properly Can be costly if large space is needed Potential fail of a cloud storage company is always possible – can lead to major losses No need for the customer to carry an external storage device Provides the user with data backup Allows recovery of data in case the storage device fails Offers almost unlimited storage capacity *General internet terms HTTP(S): Rules of communication which must be obeyed when transferring data over the internet. If the S or a green padlock is beside it, this means that the source is secured. Web Browsers: Allow the user to view webpages by translating the HTML code from websites and showing the results They can have the following features:1. 2. 3. 4. 5. Home page Favorite websites/pages History Can go backward and forward Have hyperlinks which allow users to navigate between web pages They use URL (Uniform Source Locator) to access websites and retrieve data. URLs consist of: - (protocol://website address/path/filename) • • • • Protocol : HTTPS Website address -Domain host : WWW -Domain name : Name of the website -Domain type : (.org, .ac, .gov, .com, .net, etc...) -Country codes (sometimes given) : (.uk, .us, .de) Path : Web page Filename : The item on the browser FTP: File Transfer Protocol, used when transferring files from one computer to another on the internet. ISP: Internet Service Provider, provides users with access to the internet by allowing them to set up an account with a user name and password Page 88 of 90 *Blogs/Wikis/Social networking sites Blogs: an author writes their opinion about a certain topic, and may provide links to certain websites to support his conclusion. Users can then comment on the blogs, and give their opinions as well It is worth knowing that blogs are NOT IMMUNE from the law. Some features of a blog:• • • • • Updated regularly Organized in reverse chronological order (newest to oldest) Public Come from one author Other users cannot edit blogs MicroBlogs are similar to blogs, but are much shorter and more frequent. They are similar to posts on social media, especially apps like Twitter or Facebook. B-Blogs are similar to blogs, but used by businesses to promote their product Wikis: - Web pages which can be edited by any user through any browser. Usually used to give information about a certain topic (i.e. Wars and their dates) Some features of a Wiki:• • • • • Anyone can edit/delete/modify Can contain more than one author Page can be organized however an author wishes Can be easily edited using a browser Allows large documents to be seen by many people Social Networking Sites:- Applications which focus on building online communities, and allow users to share photos, videos, music, hobbies, favorite eating places, etc... Some features of Social Networking Sites:• • • • • • Provides free web space Each member has their own private and public profiles. Possible to upload content such as text messages, photos, videos, etc… Can write on each other’s walls Give free instant messaging and video chatting Possible to email other members of the community Page 89 of 90 • • Possible to invite people to become friends Members have control over who can access their private data *Search engines Allows you to search up data, without knowing the URL. They use words entered in a box, and look them up in their knowledge base then do a cross search. The more specific your search is, the less hits you’ll get. Once information is found, it can be saved in the following ways:• • • • Favorited Adding hyperlinks to a document Using “print screen” Copy and pasting it Advantages Disadvantages Info is up to date and easier to find Vast, limitless amounts of info Fast and Easy Can find info at the comfort of your home without the need to travel Free of charge Makes learning more interesting Anything can be posted on a webpage Risk of accessing inappropriate websites Easy to be distracted when surfing the net Can cause information overload Huge risk of plagiarism Loses research skills Information is not always easy to find, because if the user is not specific with their search, it may lead to information overload. In addition, some websites are placed at the top of the search results, and are given the greater priority compared to others. Why can information be unreliable on the internet? • • • • There is no guarantee that the info is unbiased or accurate Anybody can make a website and write whatever they want to Material on websites does not have to be checked by others Information can be out of date leading to it being irrelevant How can you evaluate the reliability of information? • • • • • • • • • • Anybody can set up a website, so make sure to be aware Some commercial websites will be biased If the advertising is related to its own product, a website will be unreliable Use the Domain of a website (especially .ac and .gov) to evaluate reliability Compare the information with books See if responsible bodies endorsed the site If the website has links to reliable/unreliable websites If a website has testimonials, it can be reliable If it hasn’t been updated in a while, it’ll be unreliable If the author has good credentials, it’ll be reliable Page 90 of 90
