4 Applications of ICT - markhunter.org - Paul Long text book... · A2 ICT 4 OCR @ A Level (G063) ... 4 – Applications of ICT Contents a. describe the advantages and disadvantages

A2 ICT 4 OCR @ A Level (G063) – Chapter 4 Published by paullong.net

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4 – Applications of ICT

Contents

a. describe the advantages and disadvantages of the following software-based training methods: online tutorials, computer based training, video conferencing .......................................... 3

Online tutorials ................................................................................................................................ 3

Computer based training ................................................................................................................. 4

Video conferencing .......................................................................................................................... 7

b. discuss the limitations of using ICT in society today and how advances in technology may overcome some of those limitations ................................................................................................... 9

c. discuss the use of networks of computers at work and at home .............................................. 14

d. describe how distributed database systems may be stored in more than one physical location using the following approaches: partitioned between sites (vertical and horizontal), entire databases duplicated at each site, central database with remote local indexes .............................. 18

Partitioned Databases .................................................................................................................... 18

Horizontal Partitioning ............................................................................................................... 18

Vertical Partitioning ................................................................................................................... 19

Replicated Databases ..................................................................................................................... 21

Central Database with Remote Local Indexes ............................................................................... 22

e. discuss the use of different types of distributed database systems ......................................... 24

Storage ........................................................................................................................................... 24

Database design ............................................................................................................................. 24

Local control ................................................................................................................................... 25

Queries ........................................................................................................................................... 25

Data availability .............................................................................................................................. 26

Backups .......................................................................................................................................... 27

f. explain security issues of distributed databases: interception of data, physical access to data, consistency and integrity of data and analyse methods of overcoming these issues ...................... 28

Interception of Data ....................................................................................................................... 28

Physical Access to Data .................................................................................................................. 28

Consistency and Integrity of Data .................................................................................................. 28

Centralised with Local Indexes ................................................................................................... 28

Vertically Fragmented Databases .............................................................................................. 29

Horizontally Fragmented Databases .......................................................................................... 30

Replicated Databases ................................................................................................................. 30

g. describe the components of an expert system (user interface, inference engine, knowledge base) and explain the advantages and disadvantages for a given application ................................. 34

What is an Expert System?............................................................................................................. 34

Components of an Expert System .................................................................................................. 34

Knowledge Base ......................................................................................................................... 35

Inference Engine ........................................................................................................................ 35

User Interface ............................................................................................................................. 36

Applications of Expert Systems ...................................................................................................... 38

h. describe the features of an effective management information system (MIS) and explain the advantages and disadvantages of its use ........................................................................................... 40



i. describe how MIS and expert systems can be used by organisations ...................................... 44

Management information systems ................................................................................................ 44

Expert Systems ............................................................................................................................... 45

j. discuss the range of services offered by digital television networks and the impact of these services on individuals, television companies and broadcasters ...................................................... 46

Game Show Participation ............................................................................................................... 46

Pay per view ................................................................................................................................... 47

Voting ............................................................................................................................................. 48

Choosing Camera Angles ................................................................................................................ 49

Interactive recording & live pause ................................................................................................. 50

Feedback Comments to TV Studio ................................................................................................. 51

3D ................................................................................................................................................... 52

Smart TV ......................................................................................................................................... 53

k. discuss the range of services offered by mobile communication services and the impact of these services on individuals and organisations ................................................................................ 55

Voice calls ....................................................................................................................................... 55

Video calls ...................................................................................................................................... 56

Caller display .................................................................................................................................. 56

Call waiting ..................................................................................................................................... 57

Voicemail ........................................................................................................................................ 57

SMS / MMS..................................................................................................................................... 58

Internet .......................................................................................................................................... 59

Push email ...................................................................................................................................... 59

l. describe the internal resources of an organisation: human, technological and premises ....... 61

Human ............................................................................................................................................ 61

Technological ................................................................................................................................. 61

Premises ......................................................................................................................................... 61

KNOWLEDGE REVIEW ........................................................................................................................ 63



a. describe the advantages and disadvantages of the following software-based training methods: online tutorials, computer based training, video conferencing

Software-based training methods are the use of software to train people. This is not restricted to training people to use computers or applications, but can also be used to train people to complete non-computer based tasks such as how to drive or how to use a telephone switchboard.

Online tutorials

Online tutorials usually include elements of multimedia (text, images, sound, animations, video) to show users how to complete a task. Sound can be used to read out instructions or give guidance. Pictures can be incorporated to show an item, its components or screenshots for learning software. Video can be used to show users how to complete tasks. Imagine trying to show somebody how to change gear in a car using a video compared with just using text. The use of multimedia therefore brings training software alive and stimulates users. Simple tutorials to show users how to use software consist of text and screenshots and can often include numbered lists to help users keep track of their progress.

Examples - simple tutorials Have a look at the tutorials for Vectorian Giotto which use text and images (screenshots). Compare the Vectorian Giotto tutorials with the ones for Kompozer which only use text.

If the training package is to show how to use a piece of software, then video screen captures can be used to explain how to use that software. Words and shapes can be added to the video screen captures to highlight certain parts of the interface.

Examples - video tutorials Have a look at some of the video tutorials at Teach-ICT and this tutorial about how to use Kompozer. Look at how a video tutorial can be used to teach people how to play the guitar. Imagine what this would be like with just text. Finally, a video tutorial can be used to help photographers create a simple flash bounce.

http://vectorian.com/help/tutorials/

http://www.charlescooke.me.uk/web/ugs02.htm

http://www.teach-ict.com/videohome.htm

http://www.youtube.com/watch?v=nuHN2VcZLnY&feature=watch_response_rev

http://www.youtube.com/watch?v=2RaXQKL-xbQ

http://cnettv.cnet.com/make-diy-flash-bounce/9742-1_53-50129131.html



Advantages Disadvantages

Multimedia methods such as pictures, animations, sounds and videos can be used to give more detailed explanations, especially when demonstrating tasks.

Trainees need to be motivated as there is not a tutor to monitor their progress.

Videos help to motivate some learners as the content is more stimulating that text and images.

Trainees will not have access to a tutor to ask questions if they get stuck.

Trainees can work at their own pace meaning that they are not held up by slower members of a class or are not left behind when they find tasks more difficult.

If all learning is delivered through online tutorials, the trainee may find the delivery style monotonous, particularly if they are auditory learners.

The tutorials are available to anybody at any time meaning that learners have flexibility about when and where to learn.

Trainees may leave learning to the last minute if they are not being monitored closely and therefore may miss deadlines.

Tutorials don’t have to be completed all at once. Learners can start and stop using them at any point and videos can be paused while learners try out techniques.

Access to a computer and the internet is required which may not always be available and my develop technical problems.

It takes a long time to produce multimedia tutorials and sometimes this can mean that they are out of date by the time they have been produced because new equipment or new software has been produced. Not all tasks will be covered by online tutorials meaning that learners will need additional support from elsewhere for certain skills.

Computer based training

Computer based training (CBT) is using the computer to assist with training. This training might be for students, employees or members of an organisation. You have already learned about how simple CBT can include video tutorials. CBT can be a complex piece of software that monitors the way in which the student learns and gives feedback to both the trainee and tutor. CBT software can include: Quizzes can be built that enable the user to interact. This means that instead of simply being presented with information, that the trainee becomes involved by having to answer questions, or match words to pictures or match phrases for example.

Task - quizzes Have a look at some online ECDL quizzes at Teach-ICT.

Logon whereby each trainee has a user ID and password so that their progress can be recorded. When the trainee returns to the software it will remember where the trainee had got to last time. The trainee can also see which modules they have completed so far.

http://www.teach-ict.com/ecdl/module_1/module_1tests.htm



Feedback to the trainee so that the trainee knows whether they have answered questions correctly or not. Some systems will make the trainee repeat a training module if not enough questions are answered correctly. The trainee can also see an overview of how they have done for each topic, including scores, so they can see where their strengths and weaknesses are. Pre-Assessment - some systems ask a number of questions in advance to work out what the trainee already knows so that the trainee only has to learn things they don’t know already. Feedback to the tutor so that the tutor can monitor the progress that each trainee is making. The tutor can monitor how long each trainee is spending on the CBT software, how many marks each trainee gets for each section and which trainees have completed or not completed particular training modules. The tutor can also identify questions which all trainees are finding difficult so that extra teaching can be delivered on that topic area. Target setting is where the trainee sets themselves targets to achieve and the software will determine how long it will take to achieve each of those targets and can therefore create a learning plan for the trainee to follow. Assignment setting is where a tutor can set an assignment to a group of trainees. The trainees will then be notified they have been set this assignment and the deadline. When they have completed the assignment they return it to the tutor. Some systems will automatically mark the assignment. The tutor will also be given a summary of who has completed the assignments and who has not completed the assignments.



Advantages to trainees Disadvantages to trainees

Interactive quizzes can be used to enable the trainee to interact with the software.

The trainee needs to be motivated as there is not always a tutor to monitor their progress.

Trainees can return to the place where they left off last time, saving them time trying to work out how far they had progressed.

The trainee may not have access to a tutor to ask questions to if they get stuck.

Trainees can monitor their own progress to see how much work they still need to do or where their strengths / weaknesses are.

If all learning is delivered through CBT, the trainee may find the delivery style monotonous, particularly if they are auditory learners.

Trainees receive feedback as to how well they are doing which can motivate them to continue learning.

Trainees may find it frustrating having to work through modules that they already know about, even if it is to learn just one small thing.

Trainees can complete pre-assessments so that they can save time by only having to complete the modules they need to.

Trainees may read through the training materials too quickly and not learn the material deeply enough.

Targets can be set so that the trainee can plan their learning pathway.

Trainees may leave learning to the last minute if they are not being monitored closely and therefore may miss deadlines.

Assignments can be set so the trainee knows what work has got to be done and when it has to be completed by.

Learners need ICT skills in order to access CBT.

The trainee can work at their own pace meaning that they are not held up by slower members of a class or are not left behind when they find tasks more difficult.

The advantages and disadvantages above are for trainees. Be careful and watch out for questions which may ask for advantages or disadvantages that are geared towards tutors rather than trainees. In an examination, you may be asked to give advantages and disadvantages for a particular group of people, for example the trainers. If this is the case, then do not give advantages such as “the trainee can receive feedback about their scores” as this is not an advantage to the trainer.



Advantages to tutors Disadvantages to tutors

The tutor does not need to plan or prepare learning materials which saves a lot of tutor time.

The tutor has to rely on training materials that somebody else has prepared and has to trust those materials are adequate.

If assignments are marked automatically then this saves the tutor a lot of time, enabling the tutor to analyse the results in more detail.

Some work cannot be marked by CBT software and so the tutor will need to mark this which can be difficult to do on-screen.

The tutor can identify easily students who are not progressing quickly enough or who are struggling and intervene appropriately.

The tutor has to support trainees who are all learning at different stages and so has to have a lot of topics fresh in their mind at the same time.

The tutor can identify common areas of weakness so that extra teaching can be given on those topics.

As trainees may be working online at all times of the day, the tutor needs to be available to support the trainees if they have difficulties.

The tutor can easily see which students have completed modules and are ready to progress to the next stage or take formal tests.

Where the tutor has to assess the work themselves, this can take longer as they will not be assessing the same piece of work for a whole class but will be assessing lots of different pieces of work at the same time.

The tutor can easily set assignments for students to complete and will know when they have been completed or not.

Video conferencing

You will have realised from reading about video tutorials and CBT that learners often need access to a tutor. However, tutors may not be in the same geographical area as the learners. In these circumstances, video conferencing can be used to connect tutors with learners. You learned about video conferencing in chapter 3 on page 38 where you will have identified the equipment that is required to run a video conference. This included a camera that can capture moving images, a microphone, speakers and a display. This enables learners and tutors to see and hear each other live in real-time.

Example - video conferencing Schools use video conferencing to deliver lessons where there are not enough students in one school to justify the allocation of a teacher. A small group of schools will collaborate together to arrange for a single teacher to teach lessons by video conference to several schools. This helps schools retain and recruit students because they can offer more minority subjects. It also reduces the costs of delivering lessons.

Schools also use video conferencing to give students access to activities such as those provided by CLEO or JANET without the need to arrange an excursion.

Video conferencing can be used for distance learning where learners are using CBT for self-paced learning, but when they require access to a tutor they can use a webcam, microphone and speaker with their computer to seek help.

http://www.cleo.net.uk/index.php?category_id=262

https://community.ja.net/groups/janet-videoconferencing-content



During a video conference, the tutor can demonstrate techniques visually and trainees can ask the tutor questions or even show the tutor their problem. The tutor and trainee(s) can share a virtual whiteboard where they can write and draw to help with explanations and it is also possible to share the desktop which enables the tutor to take control of the trainee’s computer so that techniques can be demonstrated and problems solved in real-life situations.


Trainees can gain access to expert tutors, even if the tutor is located a long distance away. This distance could be international.

Equipment, which can be expensive, is required for a video conference to take place and the equipment can be prone to errors.

Groups of learners can collaborate together to receive learning at the same time by one tutor which can reduce the cost of lessons.

A decent bandwidth is required in order that the video conference can be conducted in real-time.

Trainees do not need to travel to find a tutor which saves both time and money.

If there are several trainees then it can be difficult for the tutor to manage a session where several of them may need to ask questions at the same time.

Specialised training which is rare can be provided because there is a world-wide customer base for training by video conference.

The quality of video conferences can be variable and it can often be difficult to hear people talking who are not right next to the microphone.

Questions - follow me 1) Explain how multimedia can enhance on-line tutorials. [4]

2) Explain the advantages to the tutor of feedback within computer based training. [4]

3) Explain the disadvantages to students of not having a tutor available when using computer-based training [4]

4) Describe a situation when video conferencing could be used for training. [2]

5) Describe two advantages of using video conferencing for training. [4]



b. discuss the limitations of using ICT in society today and how advances in technology may overcome some of those limitations

This section is asking you to look at two elements of ICT in society. Firstly, you need to consider the limitations of current uses of ICT. This means that a piece of technology exists, but it may not complete the task fully or to the best of its ability. Secondly, you need to look at how new technologies may overcome those limitations. It is impossible to identify all possible limitations of ICT in society and so some examples are given below.

Examples Limitations of ICT Potential advances in technology

A laptop can only be used for about 3 hours when not connected to the mains power supply meaning that it is not very suitable for camping holidays.

The development of larger solid state storage rather than hard disks will mean less battery power is required in the future. Solar powered cells may be produced that can be integrated into the lid of the laptop to charge the battery. Longer life batteries could be developed in the future.

Watching live television across the internet is not a very good quality and high definition is not possible due to current bandwidths.

Future developments of larger bandwidths (eg 100Mbps) to the home may provide the potential for higher quality and maybe high definition video to be streamed live across the internet, although contention ratios may still be an issue as well as the bandwidth available from the broadcaster.

Mobile phone screen size is currently too small to look at web pages effectively as the whole page cannot be seen at once without the font size being too small.

Fold up screens may be developed in the future meaning that a mobile phone’s screen could be folded away and then opened up when needed.

Wireless networks have difficulty penetrating walls and other structures meaning that some areas of buildings may suffer from weak connectivity.

Developments may take place with wireless networks with frequencies that are easily able to penetrate walls meaning that wireless networks can be extended to cover much larger areas.

Some people find the track pad on a laptop very difficult to use, and many of them do not include the use of a scroll wheel.

Laptops could include a scroll wheel or similar device. A mini wireless or Bluetooth ® mouse that could be slotted into the side of a laptop could be available to be used when required. Tablets already include touch screens.

Credit cards require the owner to remember a PIN (personal identification number) – this can be problematic if the owner has several PINs and passwords to remember.

Biometric identification may be used in the future which may mean that people would not even need to carry around a credit card as a person could simply present their finger or eye and this would uniquely identify the person meaning that authentication and authorisation are completed both at the same time. The person could then choose a method of payment from the virtual cards that they have available.



In an examination, you may be given a scenario where you may have to explain what the limitations of technology are and then go on to explain what advances in technology might become available in the future. You need to keep up to date with advances in technology by watching BBC Click and CNET TV, reading computer magazines such as PC Pro and reading online articles from companies like Engadget, CNET and Tech Radar. There are mobile phone apps for CNET TV and CNET UK (CNET Global) and an app called Appy Geek collates news stories from several technology sources. A summary of some limitations you are likely to need to discuss includes:

Battery power is limited for portable devices although technology is constantly improving. The physical size of the battery has to be restricted in order to keep devices portable and this means there are less cells available to provide power. Moving parts require more battery power and so hard disk drives which provide more storage also require more power whereas newer solid state devices (SSD) use up far less power and so are more suitable for portable devices such as tablets and mobile phones, but they are not capable of storing as much data. Some solar powered chargers are becoming available on the market. You should keep up to date with advances in technology that provide better power sources and lower power consumption. Bandwidth and connectivity restrict the amount of data that can be transferred at any one time or how far data can travel. Wireless networks, such as those offered by phone networks, are restricted in both of these ways. In November 2012, Everything Everywhere launched the first 4G network in the UK which overcame some of the bandwidth issues but only for those in major cities with expensive data plans. Mobile phone and WiFi signal strength are both restricted by distance and objects. You should keep up to date with advances in bandwidth for both wired and wireless networks and signal strength for wireless networks.

Example Read about the launch of 4G in the UK and how this has improved access to technology as well as the limitations that still exist.

Size does matter. Nobody wants a heavy mobile phone. That’s why the battery is small and restricted in terms of how many cells it contains and therefore how long it lasts. Only a limited amount of data can be shown on a screen at any one time. That’s why mobile phones are not really suitable for editing documents. However, advances such as holographic images and heads-up displays could mean that small devices could display large images in the future. Small keyboards, especially on-screen keyboards, are difficult to use causing mistakes to be made and slow data entry. Advances in voice recognition could negate the need for a keyboard although it could be rather embarrassing dictating a love message to a spouse while walking down the street. Mind reading technology in the future could solve this problem but could give some interesting results! You do not need to decide whether or not you believe the technology could ever exist in the future – you just need to have imagination and be able to dream the impossible. Equipment is also becoming more portable as storage, processors, memory, printed circuit boards and other devices become physically smaller. You should keep up to date with equipment that is becoming smaller and advances in technologies that enable large virtual displays.

http://news.bbc.co.uk/1/hi/programmes/click_online/

http://cnettv.cnet.com/

http://www.pcpro.co.uk/

http://www.engadget.com/

http://www.cnet.co.uk/

http://www.techradar.com/

http://crave.cnet.co.uk/mobiles/4g-what-you-need-to-know-50008963/



Examples - virtual displays Watch these videos about Google Glass and 3D holographic images which are futuristic plans that will soon be with us to overcome some limitations with current displays.

Processing power is the main contributor to speed and capability of equipment. The faster the processor, the faster a device will work and the more tasks it will become capable of completing. Some tasks, such as analysing human cells, can require so much processing power that they will take years to complete, even with thousands of distributed processors being used across the world. Processors are becoming increasingly more powerful, so much so that a device the size of a mobile phone today is more powerful than the largest computer servers 10 years ago. Advances in technology will continue to bring about faster and smaller processors. You should keep up to date with advances in processing chips.

Example - processor limitations Rosetta@home is conducting research to determine the 3-dimensional shapes of proteins that may ultimately lead to finding cures for some major human diseases. They use over one million computers to help with the immense analytics process.

http://www.youtube.com/watch?v=9c6W4CCU9M4

http://news.bbc.co.uk/1/hi/programmes/click_online/9393762.stm

http://boinc.bakerlab.org/rosetta/



Memory limits the amount of data that can be used at any one time

and the amount of data that can be stored. The amount of data that can be stored in RAM affects the overall speed of a computer,

particularly when lots of applications are being used at the same time. People are making more use of videos and photographs and want to store these which means that larger storage devices are

required. There is a strongly held belief that the more storage capacity that is provided to users the more they will use. Storage

devices are constantly increasing in capacity and solid state devices (SSD) are becoming cheaper with higher capacities. Maybe one day SSDs

will catch up with hard disk drives which will mean higher capacities in smaller devices with less power consumption. In a few years’ time you are likely to be able to carry in your pocket on a memory stick the same amount of data that your computer’s hard disk currently stores. You may have your entire video and photo library on your key ring. Advances in software that improve compression techniques are also important because the smaller the files are then the less storage is actually required meaning more data can be stored on existing hardware. You should keep up to date with increased storage capacities, new storage devices and improvements in compression. Hardware and software are a major limitation on the use of ICT in society. Often it can’t be done because the equipment (hardware) doesn’t exist or the software doesn’t exist – it is technically not feasible. New equipment is being invented all the time and new software is also being continually developed. What was not possible last year is often possible this year. You should keep up to date with advances in hardware and software.

Task - developments In groups or as a class, recall some developments in equipment and software over the last 10 years, such as 3D TV, that have changed the way ICT is used in society.

Examples - hardware and software Read about how a new smart glove will enable sign language users to sign to the computer and watch how augmented reality was used in the Ikea 2013 catalogue.

People are a very big barrier to the use of ICT. Many people are unwilling to use ICT and some people lack the ability to use new technologies. This prevents mass rollout of technology that could be of great benefit to the majority but its use is prevented by a significant minority. Many people have a fear that technology will be used against them. This fear is usually fed by journalists giving damning reports about how technology could be used for cyber spying. This is one reason why fingerprint and retina scanning technologies are not seen as part of our everyday use. You should keep up to date with public opinion about ICT.

http://www.good.is/posts/smart-glove-voice-recognition-for-sign-language-users

http://www.youtube.com/watch?v=QQ8HNXtl7jQ&feature=youtube_gdata_player



Task - biometrics Read about how upgrades to the FBI biometrics capacities has sparked fret amongst privacy hawks in the USA and watch this video about India’s biometrics scheme.

Questions - follow me 1) Explain the limitations of entertainment systems within cars and how developments in

technology may overcome these limitations. [6]

http://news.cnet.com/8301-11386_3-57508562-76/privacy-hawks-fret-as-fbi-upgrades-biometrics-capacities/

http://www.bbc.co.uk/news/world-asia-india-16979875



c. discuss the use of networks of computers at work and at home Networks are explained more thoroughly in the Networks and Communications Chapter. This learning objective is expecting you to be able to discuss the use of networks. Therefore, you need to be able to consider situations in which networks could be used, both at work and at home, and then look at the advantages and disadvantages of using those networks. In an examination, you may be given a scenario that is new to you, but the general principles should be the same. Therefore, the scenarios below are only possible situations in which networks might be used at work or at home.

Example - family with children


Only one printer is required as it can be shared amongst the whole family.

Access to the world wide web means that the children may access undesirable material or spend too much time playing games rather than working.

The whole family can share an internet connection so they can communicate with friends, colleagues and research information for homework.

The children may spend too much time using instant messaging software through the internet meaning that there is less family social interaction.

All the computers can receive security and virus updates via the internet, increasing the protection from security threats.

The children may be bullied on social networks.

The laptop can be used anywhere within the house using a wireless access point.

Unless security is set up correctly, the wireless network could be used by other people in the street.

The parents can remotely monitor what the children are doing using their own computers.

A wired connection for the children’s connection could be difficult to install between rooms and the cable could be unsightly.

A family has three computers. One is used by the father, another is a laptop used by the mother and the third computer is shared between the two children. The family has a single ADSL connection connected to a wireless router. The father’s computer is near the router and so is plugged into the switch part of the router. The laptop is connected wirelessly. A wired connection is needed for the children’s computer.



Example - house rented by students


The students only have to pay for one broadband connection and can share the connection to the internet between them.

As they rent the house, they may not be able to run cabling throughout the house and it may be too large for a single wireless access point.

The students can work together and collaborate using the laptops in the same room if they have a wireless network.

They will not know who has printed which documents which could cause arguments as to who pays for replacement cartridges.

They can share files that they have produced, such as compositions, across the network.

If they connect all the computers through a cabled connection (for example in a single room), then there may not be enough ports on the switch / router.

As they are music students, they are likely to be using a lot of bandwidth to download music, and 2 Mbps shared between 5 people means they will suffer slow access to files on the internet.

In this scenario, five music students rent a house. Two of them have laptop computers and three have desktop computers. They share a 2 Mbps ADSL connection. They share a single printer.



Example - small business A small business has 4 desktop computers used by its staff. They have an 8 Mbps ADSL router with 4 switched ports for a LAN.

Example - large enterprise A large organisation with over 400 computers uses a network with both wireless connectivity for laptops and UTP cabling for desktops. They have a 20Mbps SDSL leased line connection to the internet.


The internet connection can be shared so that all employees can use email to communicate with other organisations.

The employees may use email and the world wide web for social reasons meaning that they are not as productive as they should be.

A peer to peer network can be set up so that files can be shared between employees meaning that they can work collaboratively.

Confidential files may be viewed by some employees who are not supposed to have access to them.

A colour printer and laser printer can be connected to two of the computers and shared across the network meaning that each computer will not need its own printer, saving the business money.

The computers that the printers are connected to must be always turned on in order for the printers to receive print jobs from other computers. This uses up electricity which adds to running costs.

All the computers can receive security and virus updates via the internet, increasing the protection from security threats.

The internet connection can be shared so that all employees can use email to communicate with other organisations.

The employees may use email and the world wide web for social reasons meaning that they are not as productive as they should be.


Backups can be made centrally meaning that employees are not responsible for their own backups saving the employees time and reducing the risk of lost work.

The amount of cabling needed for the organisation will be extensive with several kilometres of UTP cabling used – this will be expensive to install.

Software can be deployed automatically to each of the computers saving lots of technician time and thus saving salaries.

Specialist technical staff are required to manage the network which has additional salary costs to the company.

The computers can be set up to receive security updates and anti-virus updates from a central location on the network meaning that each user is not responsible for ensuring the updates take place. This reduces the risk of attack from hackers and viruses.

A large number of wireless access points will be required to cover the whole building as walls will get in the way. This has to be planned carefully to avoid interference from one wireless access point to another.

Printers can be shared and accounting software installed to manage how much printing each employee is allowed to do or to charge print jobs directly to departments. This will reduce the overhead costs.

Reliance upon the network means that a failure could leave all employees not being able to work productively.



Task - school network Describe the advantages and disadvantages to a school of networking its computers.

Questions - follow me 1) Identify 2 disadvantages of networking computers in a home. [2]

2) Describe 3 advantages of networking computers in a large organisation. [6]




d. describe how distributed database systems may be stored in more than one physical location using the following approaches: partitioned between sites (vertical and horizontal), entire databases duplicated at each site, central database with remote local indexes

Data stored in a database is usually stored in one location at one central computer – this is the sort of database you are most likely to be familiar with at school. Distributed databases store the data in more than one location across a local or wide area network. However, the user is usually unaware how a database is stored.

Partitioned Databases

A partitioned database has different parts of the data stored at different sites. No single site stores all the data as each site only stores part of the data. A “site” can be a server at a particular location or a single computer.

Horizontal Partitioning

With horizontal partitioning, data is separated across sites based upon records. Each site can search for its own records locally and can search for records stored at other sites using a global search.

Example - horizontal partitioning The table below represents a distributed database for an estate agency which has three branches in the midlands region:

In this example, the estate agency distributes its database horizontally by storing all the records about houses on sale in Boldmere, on the server in the Boldmere branch. Similarly, it stores all the records about houses on sale in Walmley, on the server in the Walmley branch and all the records about houses on sale in Erdington, on the server in the Erdington Branch. The database has a structure that looks like this:

HOUSE (Boldmere)

House ID

House Number

Post Code

HOUSE (Walmley)

House ID

House Number

Post Code

HOUSE (Erdington)

House ID

House Number

Post Code

If a member of staff in Walmley wants to search for information about a house in Boldmere, then the request for the data is sent from the server in Walmley to the server in Boldmere, and the resulting data is returned to the member of staff in Walmley.

House ID House Number Postcode Branch

ABC123 12 B73 5PW Boldmere

DEF456 29 B73 6TW Boldmere

GHI789 139 B73 4AP Boldmere

JKL123 22 B76 2LK Walmley

MNO456 4a B76 3BA Walmley

PQR789 10 B76 9BZ Walmley

STU123 12 B23 3WP Erdington

VWX456 18 B23 4SD Erdington

YZA789 79 B23 6PW Erdington



The data is stored like this:

Task - horizontal partitioning Design a horizontally fragmented database for a college where students studying Social Sciences and Sciences are based at Campus A, students studying English and Humanities are based at Campus B, students studying art subjects are based at Campus C and students studying maths and technology subjects are based at Campus D.

Vertical Partitioning

With vertical partitioning, data is separated across sites based upon fields. As with horizontal partitioning, each site can search locally for its own data and can also perform a global search to find data stored at other sites.

Example - vertical partitioning The table below represents a distributed database for an estate agency that has three departments. The three departments are concerned with houses, conveyancing and customers.

BOLDMERE





WALMLEY





ERDINGTON





House ID House Number

Postcode Branch Price Vendor ID

Surname

ABC123 12 B73 5PW Boldmere £285,000 9123 Smith

DEF456 29 B73 6TW Boldmere £315,450 2837 Jones GHI789 139 B73 4AP Boldmere £295,000 2891 Brown

JKL123 22 B76 2LK Walmley £295,000 3472 Adams MNO456 4a B76 3BA Walmley £289,999 2987 Burns PQR789 10 B76 9BZ Walmley £304,950 2372 Lloyd

STU123 12 B23 3WP Erdington £189,950 3092 Braid

VWX456 18 B23 4SD Erdington £210,990 3097 Cooper YZA789 79 B23 6PW Erdington £165,450 2891 Brown



In this example, the estate agency distributes its data vertically by storing all the fields to do with houses (House ID, House Number, Postcode, Branch) at the head office in Sutton Coldfield, all the fields to do with conveyancing (House ID, Price) at the conveyancing office in Boldmere and all the fields to do with vendors (House ID, Vendor ID, Surname) at the customer services office in Walmley. The database has a structure that looks like this:

HOUSE (Sutton Coldfield)

House ID

House Number

Post Code

Branch

CONVEYANCE (Boldmere)

House ID

Price

VENDOR (Walmley)

House ID

Vendor ID

Surname

As the customer services department is based in Walmley, each time they want to find information about a vendor, they only have to search the database stored on their own server. If a customer goes to the Walmley branch and wants to find out information about a particular house, then the request for the data is sent from the server in Walmley to the server in Sutton Coldfield and the resulting data is sent back to Walmley.

The data is stored like this:

Task - vertical partitioning Design a vertically partitioned database for a company which stores data about its employees. There are three departments that store the data – personnel, finance and sales.

SUTTON COLDFIELD











BOLDMERE

House ID Price

ABC123 £285,000

DEF456 £315,450

GHI789 £295,000

JKL123 £295,000

MNO456 £289,999

PQR789 £304,950

STU123 £189,950

VWX456 £210,990

YZA789 £165,450

WALMLEY

House ID Vendor ID Surname

ABC123 9123 Smith

DEF456 2837 Jones GHI789 2891 Brown

JKL123 3472 Adams MNO456 2987 Burns PQR789 2372 Lloyd

STU123 3092 Braid

VWX456 3097 Cooper YZA789 2891 Brown



Replicated Databases

Replicated databases are replicated (copied) in their entirety at each site within the network. Each site can search for any records locally without performing a global search.

Example - replicated databases In this example, records about accounts in a bank are all stored at every branch across the country.

This means that if a customer asks for their balance at a branch in Sunderland, then the information can be found at the server in Sunderland because it has an entire replica of the database. If the same customer asks for their balance at a branch in Newcastle, the information can still be found at the server in Newcastle because another replica is stored in Newcastle.

Account Number

Surname Forename Balance (£)

JKL123 Adams Frank -25

STU123 Braid David 300

GHI789 Brown Jonathan 50

YZA789 Brown Jonathan 10298

MNO456 Burns Joanne 39

VWX456 Cooper Martin 250

DEF456 Jones Michael 2039

PQR789 Lloyd Susan 258

ABC123 Smith Wendy 5827



Central Database with Remote Local Indexes

A central database is only stored in one single location but has indexes at each site. The index is used to improve search times for data because each site can search for a record’s location at its own site and then simply request that record from the location at the central database. The index will contain the key field that can be searched and the address of the record in the central database.

Example - central database with remote local indexes The data for the bank might only be stored at the head office in Durham. However, indexes exist at each site so that the search for data can be speeded up. Instead of sending a request to the head office to search the database, the local site can search its own index which will give the result of the address of the data being searched for. Then the request is sent to head office for the record directly from that address.

A bank clerk in Newcastle requests data for account number PQR789. The index stored in Newcastle is searched and the software is told the record can be found at address position 8. The server in Newcastle sends a request to Durham for the record at address position 8 and that record is sent to Newcastle.

LOCAL INDEX IN NEWCASTLE

Account Number

Record Address

ABC123 9

DEF456 7

GHI789 3

JKL123 1

MNO456 5

PQR789 8

STU123 2

VWX456 6

YZA789 4

DATA STORED AT HEAD OFFICE IN DURHAM

Record Address

Account Number


1 JKL123 Adams Frank -25

2 STU123 Braid David 300

3 GHI789 Brown Jonathan 50

4 YZA789 Brown Jonathan 10298

5 MNO456 Burns Joanne 39

6 VWX456 Cooper Martin 250

7 DEF456 Jones Michael 2039

8 PQR789 Lloyd Susan 258

9 ABC123 Smith Wendy 5827

Other indexes may exist at each site too, such as those sorted by surname or post code.



Questions - follow me 1) Identify 3 methods of distributing databases. [3]

2) Describe how data can be distributed using horizontal partitioning. [2]

3) Describe the difference between horizontal and vertical partitioning. [2]

4) Describe how local indexes can be used with a centralised database? [3]



e. discuss the use of different types of distributed database systems In an examination, you may be asked to discuss the use of distributed database systems. This may refer to one particular type (eg partitioned) or to distributed databases in general. You will need to consider both the advantages and the disadvantages of each type of distributed database system. Security and updates with regard to data integrity are discussed in the next section of this chapter.

Storage

Partitioned database Replicated database Centralised database with local indexes

Less storage space is required at a central location as the database is partitioned across multiple sites meaning that storage can be utilised from other servers. This increases the overall capacity for storage. However, this does mean that storage must be available at the local servers.

Far more storage space is required as the whole database is stored at each site. This can be very expensive as each server at each site will need to have large hard disks as well as complex setups such as RAID configurations.

Storage is only required in the central location for the centralised database. However, this will need to be high quality storage that is capable of allowing multi-user access to data and therefore will not be cheap. Similarly, very powerful processors will be required for the central server. The local indexes stored at each site will be small as they will only contain the secondary keys and record addresses.

Database design


The design of the distributed database is very complex and requires highly trained specialists to create and maintain the database structure.

The same issue of complex database design and maintenance applies to replicated databases as it does to fragmented databases, although the design issues are different in nature.

The design of a centralised database is quite straight forward as it follows normal relational database design. The only complex parts are the local indexes that need to be stored at the local sites, but these are no more complex than local indexes for a relational database



Local control


Each site has local control of its data meaning that it can customise the database to its own requirements. However, unless this is done in a controlled manner, it could result in data becoming unavailable or not provided in its correct format to other sites.

Each site has local control of its data as with fragmented systems. As each replica is stored at each site, it is possible for the replica of the database to be customised, including adding extra fields or tables that are useful to the local site.

As the database is stored centrally and managed centrally, no other sites have any control over the configuration of the database. This can be an advantage because it means that the database configuration is maintained and therefore its integrity is maintained, but it also means that local sites cannot customise the database to their own needs.

Queries


Local queries for data that is stored at the local site are much quicker than if the query had to be sent to a central server. In the estate agency example used earlier, this means that information about houses in the local area can be found very quickly. However, if information about houses in a different area is needed, then the global query will be slower than the local query as data will need to be sent across various communication links.

As all data is stored at the local site all queries are much quicker than sending requests to a central server. There is no fragmentation as the whole database is replicated at each site and so there is no difference between local and global queries as global queries are performed locally on the replica of the database.

Where a local index exists for data that is searched for, then the query should be quite fast as the processing will be performed upon the index at the local site and then the data retrieved directly from its record location at the central site. However, if an index does not exist for the data being searched for, then the query will be performed at the central location which means that processing will be slower as it will have to take its turn with all the other tasks being performed on the central server. The time taken to send the request for data across the external communication link and for the data to be sent back using the external communication link will be slower than local queries.



Data availability

B

C

D

A

Partitioned database Replicated database Centralised database with

local indexes

Imagine data being stored at each of the locations B, C and D above. If the link between A and C breaks, then C may seem to be isolated. However, C can continue to work locally with its local data whether it be horizontally or vertically fragmented. Whilst it cannot get data from B or D, it can still perform local queries which means that the network break down is not a complete disaster. Similarly, sites A, B and D can still access data from all the other sites except site C so the disruption to these sites is lessened.

As each site stores a complete replica of the database, each site can continue to work independently of the rest of the organisation as it can still find data from its own replica. However, it does mean that any updates to the database can be problematic as the updates cannot be distributed to the other replicas whilst the link is broken. Even when the communication links are available, the data may not be up to date. Updates to data may be carried out every few hours or every few minutes. A balance has to be found between the importance of having up to date data and reducing the amount of traffic across communication links. Therefore, a replicated database is not suitable for real-time systems such as flight booking systems where data must always be up to date. However, it is very suitable to a system where immediate updates are not crucial, for example in supermarket stock control systems. As each site has its own replica of the database, more than one user can view the data at the same time as a user at site B can be viewing data on site B’s replica and the same time as a user at site D is looking at exactly the same data on site D’s replica.

In a centralised database, all the data is stored at a single site – in this example all the data is stored on server A. If the communication link between C and A breaks down, then site C becomes isolated from the rest of the network and no data can be retrieved at site C. If the server at site A breaks down, then none of the sites in the whole network will be able to access any data. As the data is only stored in one location, then data will always be up to date and there are no potential conflicts which may compromise integrity. This makes this type of database suitable where real time data is required such as ticket reservation systems.

X



Backups


As the data is fragmented to several sites, backups cannot be taken centrally. Therefore a backup system needs to be in place at all sites and this must be managed at each site too, including detail such as swapping tapes, storing tapes off-site and testing that backups have worked by attempting test restores.

Each replica acts as a natural backup to the database as there are various copies replicated throughout the system. Therefore, backups are not necessary at each site. However, backups do still need to be taken at least at one of the sites in case data becomes corrupted across the whole system and the database might need restoring to a previous time.

As the data is only stored in one central location, then it is essential that a fail-safe backup system is created that includes:

changing tapes daily

tape rotations so that data can be recalled from several weeks ago

off-site storage of backup tapes

daily testing that backups can be restored

Task - advantages and disadvantages Highlight the advantages in green and disadvantages in red for each consideration and for each type of distributed database in the tables above.

Questions - follow me 1) Compare the storage implications for partitioned and replicated databases. [2]

2) Compare local and global query processing for partitioned databases. [2]

3) Describe how data still be accessed by a site using a replicated database when the communication link for the site is lost. [2]

4) Explain the benefits of having local control to data. [2]

5) Explain why backups are not necessary in a replicated database system. [2]



f. explain security issues of distributed databases: interception of data, physical access to data, consistency and integrity of data and analyse methods of overcoming these issues

As with databases stored at a single location, it is important to ensure that data within a distributed database system is kept secure from hackers.

Interception of Data

With fragmented and central databases with local indexes, there is a lot of data moving around communication links between the sites, which increases the risk of interception (eg hacking) of data. Therefore, high quality encryption techniques are required. Encryption does not prevent data from being intercepted, but it renders it useless because it cannot be understood. Replicated databases do not involve as much data movement between sites, although there are still updates that are required. It is highly unlikely that an entire database would be sent across a communication link and so although data can be intercepted, it will only be parts of the database that are intercepted and not the whole database. This is still not an acceptable security breach though.

Physical Access to Data

With fragmented and replicated databases, each site stores data and therefore security to prevent unauthorised access must be in place at every single site, resulting in an increase in security costs:

physical security

user level security

anti-virus software

firewall

anti-spyware software

encryption With central databases with local indexes, the index does not store information of any value and therefore the security listed above only needs to be at the central site.

Consistency and Integrity of Data

Data must be accurate and up-to-date. Distributed databases add to the potential problems that can cause data to become out of date or inaccurate. It is important that all data in any database is input correctly and for this reason validation and verification methods should be used along with setting up referential integrity. These topics can be revised from chapter 4 of AS ICT 4 OCR @ A Level. Distributed databases store data in several locations and it is the fragmentation and duplication of data that can cause problems with consistency and integrity. If data is changed in one location, then it must also change in all the other locations that it is stored at.

Centralised with Local Indexes

With a centralised database with local indexes, all the data is stored in one single place and updated in one single place. The only changes that occur at the local sites are the updates of the indexes which are fairly straightforward to perform and can be done at regular intervals.



Vertically Fragmented Databases

With vertically fragmented databases, sets of fields are kept in their entirety at a site. The data is linked to other fields through a common primary key. If the primary key is changed at one site, then it is essential to ensure that the primary key is also changed at other sites.

Example - integrity of vertically partitioned databases Imagine this scenario for an estate agency. The House ID PQR789 needs to be changed to PQP789. It is changed at Sutton Coldfield:

The vendor has agreed to drop the price of the same house to £299,950. This change is made in Boldmere and there is no problem:

The Sutton Coldfield branch returns an error stating that the house could not be found. (It was changed to PQP789 so PQR789 no longer exists).

This error has occurred because when the primary key was updated in Sutton Coldfield, the change was not made at Boldmere or Walmley meaning that the integrity (truthfulness and correctness) of the data was compromised. It is therefore necessary that any changes to the primary key in one fragmented part of the database are also made to the other fragmented parts of the database.

SUTTON COLDFIELD







PQP789 10 B76 9BZ Walmley




BOLDMERE

House ID Price

ABC123 £285,000

DEF456 £315,450

GHI789 £295,000

JKL123 £295,000

MNO456 £289,999

PQR789 £299,950

STU123 £189,950

VWX456 £210,990

YZA789 £165,450

A customer goes to the Walmley branch and asks for the price of property PQR789. They are told it is £299,950 (found from the Boldmere branch). They then ask for the address so they can go and see it. The Walmley branch server sends a request to the Sutton Coldfield branch for the details of house PQR789.

WALMLEY

House ID Vendor ID Surname

ABC123 9123 Smith

DEF456 2837 Jones GHI789 2891 Brown

JKL123 3472 Adams MNO456 2987 Burns PQR789 2372 Lloyd

STU123 3092 Braid

VWX456 3097 Cooper YZA789 2891 Brown



Horizontally Fragmented Databases

With horizontally fragmented databases, each record is kept in its entirety at a single site and therefore it is only updated at that one site. There are no potential conflicts with the data being updated elsewhere.

Replicated Databases

This is where there is most potential for the integrity of the data to be compromised because all the data is duplicated. If data changes in one replica, then it will be different in all the other replica until it is updated. Imagine the scenario below where there are two replicas of the database. In reality there would be more, but for the purposes of this example, only two are used.

Example - integrity of replicated databases A bank stores data in a replicated database with replicas in Durham and Newcastle. David Braid started the day with £300.

David needs to withdraw another £250 from Durham but he has no overdraft limit. Therefore, he is told he cannot withdraw the money. But he knows his salary has been paid in so cannot understand what has gone wrong.

David Braid withdraws £250 from his bank account in Durham. The balance therefore changes from £300 to £50 in Durham. Replica B is now out of date and thus the integrity of the data has been lost. David’s salary of £2,500 is then paid in to his account in Newcastle giving him a balance of £2,800 (£2,500 + £300).

REPLICA A IN DURHAM

Account Number











REPLICA B IN NEWCASTLE

Account Number



STU123 Braid David 2,800










In order to resolve the inconsistency issue, updates need to regularly take place between the replicas. Let’s imagine these take place every 4 hours. We can see what might happen below:

Joanne is OK because her name was only changed once. Susan is happy because she started with £258, deposited £300 (£558 so far) and withdrew £100 and so should only have £458. But the bank have lost £100 because the update from Newcastle to Durham was replaced by the update from Durham to Newcastle and has therefore been lost.

Susan Lloyd started the day with £258. Susan deposits a cheque for £300 in Durham at 1pm giving her a new balance of £558 (£258 + £300). Joanne Burns goes to her branch in Durham with her marriage certificate asking for her name to be changed to Joanne Oakley. Whilst Sue is out shopping in Newcastle, she realises she has no cash, so withdraws £100 from the cash machine. It only took her 2 hours to get to Newcastle and so no updates have taken place yet. Therefore, according to Newcastle her balance is £158 (£258 - £100).

REPLICA A IN DURHAM

Account Number






MNO456 Oakley Joanne 39






Account Number



STU123 Braid David 2,800








REPLICA A IN DURHAM (updated from Newcastle)

Account Number



REPLICA B IN NEWCASTLE (updated from Durham)

Account Number




Newcastle sends its updates across the network first. Durham therefore receives this updated data from Newcastle. Now Durham sends its updates across the network. Newcastle therefore receives this updated data.



Task - replicated database update problem Martin Cooper starts the day with £250. He withdraws £50 from Durham and £100 from Newcastle. Assuming the update takes place from Durham to Newcastle first, identify what Martin’s balance should be and what it will actually be due to the problem with updates. Using the tables in the example above, explain how the problem occurs.

The DDBMS (Distributed Database Management System) needs to be able to resolve these conflicts. It can do this by sending out transactions (changes) to the data rather than the results of changes to the data. If this had happened, then the following updates would have been sent:

Example - transaction updates

TRANSACTIONS FROM NEWCASTLE

Account Number


PQR789 -100

REPLICA A IN DURHAM

Account Number



PQR789 Lloyd Susan (558 – 100 = ) 458


TRANSACTIONS FROM DURHAM

Account Number


MNO456 (Change to) Oakley

PQR789 +300


Account Number





PQR789 Lloyd Susan (158 + 300 = ) 458


Newcastle sends its transactions (changes) across the network first. Durham therefore receives this transaction. Durham updates its database replica to show this data. Durham then sends its transactions across the network. Newcastle therefore receives these transactions. Newcastle updates its database replica to show this data.



Task - transaction updates Frank Adams starts the day with an overdraft of £50. He gets paid £250 from his employer in Durham and withdraws £200 from Newcastle. Assuming the update takes place from Durham to Newcastle first, identify what Martin’s balance should be and explain how transaction updates ensure that his balance is correct.

Questions - follow me 1) Describe three security implications of using distributed databases? [6]

2) Explain why encryption is required with fragmented databases? [2]

3) Explain how the integrity of data can be compromised within a replicated database system. [2]

4) Explain how the integrity of data could be maintained within a replicated database system. [2]

Question%20Templates/4f%20-%20Question%20Template.docx



g. describe the components of an expert system (user interface, inference engine, knowledge base) and explain the advantages and disadvantages for a given application

What is an Expert System?

An expert system, also known as a knowledge based system (KBS) is a computer program made up of knowledge and rules that can be used to diagnose a problem. Expert systems are used for decision making and recommending particular courses of action. The system will try to replicate the role of the human expert. It is called an expert system because the knowledge and rules are all defined by experts in a particular field. A popular expert system is that used by NHS Direct on their website. Experts (doctors) will have collated their knowledge about illnesses and the symptoms of those illnesses and identified the rules that state which symptoms lead diagnose which illnesses. A true expert system will:

be able to make decisions based upon uncertain data (eg “don’t know” answers from a user)

be limited to a particular subject or area of expertise

give advice based upon the answers given by the user

explain the reasoning behind its decision

Task - printers and faxes Click on Start then devices and printers (or printers and faxes) on your computer (if you are using Windows). Right click a printer and select printer properties (not properties in Windows 7). Click on Print Test Page. When asked if the page printed, answer “Troubleshoot…”. Make up a problem and answer the questions. Eventually you will be given a diagnosis. This is a basic expert system.

Example - expert systems Explore some of the expert systems from these web pages:

Diagnosing why a car won’t start – this example explains the reasoning behind its decision

Exsys Corvid expert system demos – a variety of demonstrations of expert systems

Components of an Expert System

There are three main components of an expert system.

Knowledge Base

Inference Engine

User Interface

http://expertise2go.com/webesie/car/Car.htm

http://www.exsys.com/demomain.html



Yes No

Does the phone

switch on?

Is the battery

inserted?

Yes No

Answer: Insert the

battery and turn

on the phone.

NoYes

Charge the battery

then try again.

Ask questions

about the battery

being used in

another phone

Has the battery

been charged?

Knowledge Base

The knowledge base consists of the factual knowledge and the rules gathered by knowledge engineers using methods such as interviewing experts.

Examples - knowledge Examples of knowledge are:

the VAT rate is 15%

a mobile phone needs a battery or power lead to work

a human has 2 hands

Examples - rules Examples of rules are:

if the product is food, then VAT should not be applied

if the battery not inserted, the phone will not turn on

if the phone is plugged in, the phone should turn on

if a patient has a cut on their hand but bleeding can be controlled by putting a finger on the cut, then anti-septic cream and a plaster should be used

Inference Engine

The inference engine is the software that makes the decisions based upon the answers given by the user and the knowledge and rules stored in the knowledge base. It will also decide which questions the user should be asked next based upon the previous answers given. If the answers given by the user are uncertain, the inference engine will ask other questions to try to eliminate possible diagnoses. It will then identify a diagnosis and give a reason for the diagnosis. At a basic level, an inference engine uses a decision tree that might look like this.

Task - decision tree Expand upon the decision tree by asking questions about the battery being used in another phone and see if you can get to a diagnosis as to whether it is the handset or the battery that is faulty.

Mobile Phone Decision Tree.vsd

Tasks/Task%20-%20Decision%20Tree.docx

Examples/Mobile%20Phone%20Decision%20Tree.vsd





User Interface

The user interface is the part of the expert system that asks the user the questions and then gives an answer with a diagnosis. The screenshot below shows part of the print trouble shooter in Microsoft Windows. You can see how instructions are given and then questions are asked as part of the user interface.



The screenshot below shows the user interface of NHS Direct Self-Help where questions are being asked about the type of cough that an adult has:

Once the user interface has asked all the questions and used the inference engine to determine the diagnosis, a diagnosis will be given to the user. This is part of the diagnosis given by the NHS Direct Self-Help system:



Task - NHS Direct Visit http://www.nhsdirect.nhs.uk/en/CheckSymptoms and try the self-help guide.

Extension task Extension – try out these basic examples of expert systems and then identify the knowledge and rules in the source code.

Applications of Expert Systems

So far, you have seen three uses of expert systems which are:

medical diagnosis

mobile phone fault diagnosis

printer troubleshooting Here are some other examples of how expert systems might be used in the real world:

Fault diagnosis for a car engine – a car mechanic can plug in a laptop computer into the engine management system and it will run various tests. Based upon the results of the tests, it will identify what the fault is with the engine. During the tests, the mechanic may be asked certain questions about sounds and emissions.

Broadband Internet Service Provider (ISP) fault diagnosis – when you phone up your ISP to report a fault, the operator is likely to be using an expert system. The operator will ask the questions that the expert system tells them to ask you and will input the answers you give. The expert system will then suggest possible solutions that could be tried out and if none of these work, then a diagnosis will be given. The results of all the tests will be stored.

Social services can use expert systems to determine what benefits are due to a claimant. All the answers that the claimant puts on the forms are input into a computer and the expert system will then determine the benefits that are due and will give a reason why those benefits apply.

Her Majesty’s Revenue and Customs expect some tax payers to file a ‘tax return’. The tax payer answers lots of questions using an on-line form. The inference engine will then determine which taxes are due based upon the answers given and calculate the amount of tax due. The user interface will then respond to the tax payer by explaining how the tax was worked out.

Extension task Follow through this introduction to expert systems, making notes about:

consulting with experts

what makes a good expert

reasoning

problem selection

knowledge engineering

http://www.nhsdirect.nhs.uk/en/CheckSymptoms

http://www.lpa.co.uk/wfs_dem.htm

http://expertise2go.com/e2g3g/tutorials/ESIntro/



Questions - follow me 1) Identify the three components of an expert system. [3]

2) Describe the purpose of each of the components of an expert system. [3]

3) Give an example of knowledge and of a rule for somebody claiming income support (the knowledge and rule do not have to be correct). [2]

4) Describe two things that an expert system should be able to do. [2]

Question%20Templates/4g%20-%20Question%20Template.docx



h. describe the features of an effective management information system (MIS) and explain the advantages and disadvantages of its use

A management information system (MIS) is designed to organise information within an organisation in such a way that it can be used to produce useful information to the management of the organisation. Managers don’t need to see all of the data that exists within an organisation, but will need to see summaries of data in the form of charts and reports. A MIS organises data and creates links between sets of data that are inter-related. For example, your attendance at lessons is related to your attendance at school. An MIS can relate this data and produce summaries of which students were in school but did not attend a lesson. A common misconception is to think that a MIS is solely computer based. A MIS needs a human information manager to ensure that the right type of data are collected in order to produce the information that managers require. The information manager will also produce standard reports that can be used by managers to see summaries of the information. Managers at different levels within an organisation need different types of information and it is important that a MIS can provide information that is useful to all levels of management. Management information systems can provide information that will help managers with tasks such as:

monitoring budgets to see how actual expenditure is comparing to planned expenditure

identifying trends in sales for different products and at different times of the year

gathering intelligence about other organisations

identifying information about demographics and the types of customers that buy the products

monitoring cash flows within the organisation

analysing the effectiveness of a market campaign, eg did sales go up during the marketing campaign

monitoring labour input into the production process and overall productivity per employee In order to generate this information, data needs to be collated from one or more databases. The two major features of a MIS are therefore to collate data and produce reports. The information produced by a MIS will help managers to make strategic and tactical decisions. It is important to note that the MIS does not make those decisions, it just provides the information. Another major feature of a MIS is its ability to inter-connect various systems within an organisation and generate reports based upon data from those systems. A MIS that inter-connects various sub-systems is often known as an Executive Information System (EIS). Each sub-system will in itself produce reports that can help with tactical decision making, but the EIS will gather together information that will help with strategic decision making for the whole organisation.

Executive Information System (EIS)

Accounting MIS

Financial MIS

Manufacturing MIS

Marketing MIS

Human Resources

MIS



In summary, the main features of an effective MIS include:

collation of data

production of reports

inter-connection of sub-systems Other features of an effective MIS include:

appropriate analysis it is essential that a system is analysed properly so that it meets the needs of the

organisation, but most importantly a MIS must meet the requirements of management. Managers at various levels within an organisation must be involved in the analysis and design of a MIS to ensure it meets their needs. The life-cycle of a MIS can be 2 to 4 years.

information focussed on management the information produced by a MIS must be targeted towards managers. The

information needs to be suitable to enable managers to make decisions rather than just operational information.

modularisation information needs change over time and so an effective MIS should be modular so

that it can be built upon in the future. This flexibility enables new reports to be created and new methods of collating information to be put into place.

Task - school MIS Find out what sort of data is collected by your school’s MIS and what sort of information is used by managers and leaders within your school. Ask managers at different levels what sort of information they require and what decisions it helps them to make:

classroom teachers

year heads

department heads

senior leaders

Tasks/Task%20-%20school%20MIS.docx



Example – universal flight information system Read this overview of UFIS-AS and this breakdown of the sub-systems within the UFIS. Notice how the systems are integrated and provide different types of management information for each of the operational areas of an airport.

http://www.airport-technology.com/contractors/traffic/ufis-airport/

http://www.ufis-as.com/products/




Provides managers with up-to-date information for tactical and strategic decision making.

Not all sub-systems will necessarily be compatible and there may be problems integrating data from some sub-systems.

Information can be collated from several sub-systems and summarised.

An effective MIS takes several years to develop and to use properly.

Information overload is minimised by providing summary information that is necessary for decisions rather than detailed information that is difficult to interpret.

Not all information required to make decisions can be provided by a MIS. Data about competitors and other external influences will need to be gathered and summarised separately.

Managers can forecast future trends and make decisions which could save an organisation money or increase profits.

The information provided to managers is only as good as the data that is input at the operating level. Garbage in means garbage out (GIGO).

Decisions can be made quickly because summary information can be made readily available.

It is expensive to purchase or develop a MIS and expensive on-going support will be required because a MIS is a complex software and data management tool.

Activities within the organisation can be monitored and inefficiencies can be identified enabling managers to re-deploy resources.

Business and organisational environments change and that will mean that the way a MIS works will also need to change leading to additional development costs.

Performance of departments and individuals can be monitored and if necessary changes can be made to working practices.

Due to the complexity of a MIS, managers (or information managers) will need training in how to generate reports.

Questions - follow me 1) Describe three features of an effective management information system. [6]

2) Using examples, describe two advantages of using a management information system. [4]

3) Describe two disadvantages of using a management information system. [4]

Question%20Templates/4h%20-%20Question%20Template.docx



i. describe how MIS and expert systems can be used by organisations

Management information systems

Information is only useful if it is then used to make decisions. Management information systems provide information that can then be used to decide on appropriate courses of action based upon the information provided. The MIS does not make the decisions itself – it just provides the information. It is then up to managers to make the decisions. Information reports can be produced at regular intervals so that managers can decide how to react to the current information, or managers can request unscheduled reports when they feel that there may be a problem that needs solving. Looking at each of the types of information that could have been provided above, these types of decisions might be made by managers:

Example – MIS decision making

Information provided by MIS Decisions to be made

The marketing department has already spent 90% of its budget in September.

Senior management need to ensure that the marketing department cut down on expenditure as there are another 6 months of the financial year left to go. Plans need to be put in to place to ensure value for money is being achieved by the marketing department.

More nappies are being sold during April and May than other months and there was a shortage towards the end of May.

Production managers need to decide whether to increase production during these next year in time for April and May. Marketing managers need to decide whether to repeat marketing campaigns that took place during those months.

Babies’ dummies produced by a competitor have been selling for 80% of the cost of the company’s own dummies but are of a similar quality. Sales of dummies have not changed.

Sales managers need to decide whether to maintain or reduce prices as it seems competitor’s lower price is not having an effect. They will probably request further reports over the next couple of months to monitor the situation more closely.

The number of children born in Somerset increased by 20% during 2013.

Production managers need to consider increasing the amount of products that are produced for children of applicable ages over the next few years.

During the last 2 months, the amount of money available in the company’s current account has ranged from £1,500 to £384,000.

Finance managers need to consider whether the current account needs extra funds adding to avoid it going overdrawn and interest being charged. They also need to consider how a smaller deviation in funds could be maintained.

A marketing campaign for the company’s brand name took place during June and July. A 1.5% increase in sales was noticed during July, 2% in August and 0% in September.

The marketing managers need to compare the cost of the marketing campaign to the increased profits due to the increases in sales. Consideration then needs to be made as to whether or not to repeat the marketing campaign.

Employees in the dummy assembly department have been making dummies at the rate of 25 per hour on average. One employee has only been making 10 dummies per hour.

The production manager needs to consider re-training for the employee, or whether to terminate their employment.



Expert Systems

As expert systems contain expert knowledge and rules, questions can be asked of the expert system and a solution will be suggested by the expert system with reasoning. This enables decisions to be made. Hypothetical questions can be asked and the expert system will give answers as to what the likely outcome will be. This is effectively modelling where “what-if” questions can be submitted to the expert system which will simulate the effect of the data and give a diagnosis or solution based upon that scenario. Some examples of how an expert system could be used to make decisions include:

Example - expert system decision making

The difference between expert systems and management information systems when it comes to decision making is that management information systems provide the information and the manager must make the decision, whereas an expert system suggests what the decision (solution) might be.

Task - NHS Direct decision making Consider the NHS Direct Self-Help guide introduced earlier in the chapter. How might this be used by a patient for decision making?

Questions - follow me 1) Describe how a management information system (MIS) might be used to help a construction

company decide whether to build a new block of flats. [6]

2) Describe how an expert system might be used to help a construction company decide whether to build a new block of flats. [4]

Scenarios Decisions to be made

Answering questions about the type of person you are, what you like doing and what you are good at. The expert system suggests a future career.

You decide whether to follow that future career, or try putting in other information such as different things that you like doing.

Entering suggested prices for a product, quantities that can be produced and information about the local demographics. The expert system suggests how many products are likely to be sold.

How many products to make and what price to sell for. Different production quantities and selling prices can be experimented with.

A gas engineer enters symptoms regarding a gas leak at a house. The expert system suggests what might be causing the leak.

The gas engineer has to decide how to fix the problem based upon the suggestion given.

Question%20Templates/4i%20-%20Question%20Template.docx



j. discuss the range of services offered by digital television networks and the impact of these services on individuals, television companies and broadcasters

When answering questions linked to this learning objective, you will need to consider the impact to a specific group. Individuals are the viewers that watch programmes and use services on digital television networks. Broadcasters are the companies that distribute the programmes such as cable TV broadcasters (eg Virgin), satellite TV broadcasters (eg Sky and Freesat) and radio waves broadcasters (eg Freeview). Television companies are the organisations that make the programmes and own the TV channels (eg Channel 5).

Game Show Participation

Some game shows allow viewers to take part by answering the questions along with contestants. This can be achieved either by the viewer answering the questions using the internet or by using multiple choice options with the remote control for the set-top box. Impacts

Individuals Television Companies Broadcasters

The viewers feel part of the game show and will be more interested as they are participating.

If this is popular with the viewers then the television companies are likely to receive more revenue from advertisers if there are more viewers.

If the digital set-top box is used for answering the questions, then the broadcasters have got to ensure the facility is available which could be costly; for satellite and radio wave broadcasters this will also involve the need for a telephone line to send back the viewer responses.

It can be very frustrating if the viewer has answered lots of questions and then the wrong button is pressed meaning all the answers are lost.

The television companies have got to set up the facility to receive viewers’ answers and to give feedback which could be costly.



Pay per view

This is a facility whereby viewers can pay to watch a particular programme. These programmes are usually sporting events or movies but can include other special events or programmes. The viewer can book the programme in advance or at the time of viewing and will then be charged when their next bill arrives. Impacts


Viewers will have to pay for each programme that they watch and may build up a large bill without realising the potential total cost.

The television companies may receive extra income by allowing customers to buy a particular event or programme.

Broadcasters have got to make the facility for pay per view available which could be costly.

Viewers can watch individual events such as a football game without paying the full subscription costs for a channel such as a sports channel.

The television companies may lose out on revenue for their subscription channels as customers will only buy the programmes they are interested rather than a whole package of channels.

Broadcasters have got to have a facility whereby payments can be made for pay per view programmes.

Some programmes such as films can be watched at any time rather than specified start times meaning that the viewer can arrange their viewing around their life rather than the other way around.

Broadcasters have got to put encryption and other security in place to ensure that the programmes can not be hacked.

A high bandwidth is required, particularly if viewers are allowed to watch a programme at any start time rather than a specified start time.



Voting

This feature allows viewers to vote as part of participating in a television programme. This could include voting for their favourite performer in a competition, or voting for somebody to be removed from a reality television show or voting for their preferred ending to a television programme. The voting facility can be made available in different ways:

dialling a telephone number or sending a text message

using a website

using the interactive feature of the set-top box. Impacts


The telephone numbers and text message numbers are often premium rate numbers which can be very expensive to the viewer.

Using premium rate numbers will significantly boost revenue for the programme makers – imagine two million people voting at £1 per vote.

If the interactive feature of the set-top box is being used, then the broadcaster will have to make this facility available which could be costly to implement; for satellite and radio wave broadcasters this will also involve the need for a telephone line or internet connection to send back the viewer responses.

The viewer feels like they are participating in the programme and are able to have an influence upon the outcome.

If viewers are voting for a preferred ending to a television programme, then either two endings need to be produced and recorded, or a live performance needs to take place.

If the viewer’s vote is not part of the winning vote, then the viewer could be very frustrated by the outcome.

The television company is at the complete mercy of the voting viewers who may not be the majority of the viewers. This means that an unpopular decision may be made.



Choosing Camera Angles

Some programmes allow the viewers to choose which camera angles they want to watch or which games they want to watch for a sporting event. For example, in a reality TV show, viewers could choose to watch a particular room within a house or for a football game, viewers could choose to watch a birds-eye view, a particular player or the director’s cut. For sporting events such as Wimbledon, viewers could choose which games they want to watch. Impacts


Viewers get a choice meaning that they do not have to rely upon the director to show them the best parts of a programme – they can choose the parts they prefer to watch.

The television companies have got to ensure that all the camera operators involved are constantly shooting a good picture as the director cannot switch to a different camera if the viewer has chosen a particular camera.

Normally the broadcaster would only broadcast the director’s cut (ie the final programme), but more bandwidth will be required to broadcast the extra camera pictures.

Viewers may miss something exciting within a television programme if they are watching a particular picture and the exciting event happens on a different camera angle.

If this is popular with the viewers, then more viewers will subscribe to the channel increasing revenue and more advertising revenue will raised.

Broadcasters have got to ensure that advertisements are all shown at the same time, whichever camera picture is being watched.

The viewer can choose to watch replays of parts of sporting events, such as tries in a rugby match meaning that if they missed them, they can choose the replay viewing option.

In live programmes, the television company has got to ensure that all content being shown from all cameras is appropriate rather than just the director’s cut. For example, if a streaker was to run across a cricket pitch then this would need to be blocked meaning that more moderators are required.



Interactive recording & live pause

Using a digital set-top box, the viewer can pause live TV. This means that the set-top box immediately starts to record the programme on a hard disk and when the viewer resumes watching the programme, the programme is played back from the disk rather than live and the programme will also continue to record. Viewers can also record television programmes. This can either be done when the programme is broadcast, or the

viewer can use an electronic programme guide (EPG) to select programmes in advance that they would like to record. Some EPGs allow viewers to set a ‘series link’ which means that all programmes in the television series will be recorded without having to select each one individually. The EPG will usually include a schedule for at least 7 days in advance and programmes can be viewed across the screen in a table format with times in one direction and channels in the other direction. By selecting a programme, viewers can see a synopsis of the programme, choose to record it or change to that channel if it is showing at the current time. Impacts


This facility usually incurs a monthly charge which adds to the total bill for digital television.

Television companies that use advertising as part of their revenue may lose revenue if people are not watching programmes live as these viewers can skip the advertisements.

Broadcasters need to ensure that the EPG is regularly updated.

Viewers won’t miss part of a programme if they answer the telephone or answer the door as they can pause the programme and return to it after the telephone call. If more than one programme is being shown at once, viewers can record one of them whilst watching another meaning they won’t miss one of the programmes.

This type of feature is attractive to viewers who are therefore more likely to buy digital television with more channels which will result in more revenue for the television companies.

Set-top boxes that include hard disks with the ability to play and record at the same time need to be produced. With strong competition between broadcasters, this may be costly if no monthly charge is made to the viewer.

Viewers do not have to be at home to watch a programme as they can set up recording in advance using the EPG and then watch the programmes at a time convenient to them. Viewers are less likely to miss a programme with a series link feature.



Feedback Comments to TV Studio

Viewers can interact with a television programme by feeding back comments on live shows. The viewer can send a text message and it may be shown scrolling along the screen. Viewers may be able to phone in to the show and their comments may be read out or they may be able to talk themselves on the show. E-mails can also be sent which may be read out. Set-top boxes could be used by the viewer to send a comment to the TV studio if the facility is available. Impacts


The telephone numbers and text message numbers are often premium rate numbers which can be very expensive to the viewer.

The television companies will need to moderate any messages that are sent in to ensure that they are not offensive or libellous.

If the interactive feature of the set-top box is being used, then the broadcaster will have to make this facility available which could be costly to implement; for satellite and radio wave broadcasters this will also involve the need for a telephone line to send back the viewer responses.

Viewers may have a very strong opinion on a topic and will feel relieved if they can share this opinion with other viewers.

Thousands of comments may be received and it may be very difficult to find the best comments to include on the programme.

There are likely to be lots of viewers feeding back and so most viewers will be frustrated that their comment has not been included in the programme.

In documentary style programmes, the programme makers are less likely to be accused of bias if they include a variety of opinions from viewers.



3D

3D televisions have been around for a few years now although they have only recently started to become commonplace. In order to watch 3D TV, viewers either need passive glasses (no battery required and suitable for any passive 3D TV) or active glasses (battery required and only suitable for one make of TV). Every viewer will need a pair of 3D glasses. In 2012, the BBC broadcast a 30 minute summary of each day’s Olympics in 3D as well as the opening and closing ceremonies. Sky broadcast some sporting events in 3D but there is still very little content available in 3D although quite a few films are available on Blu-ray to hire.

Impacts


Viewers get a richer viewing experience because they can see objects at distances and close up.

TV programmes need to be created in 3D using cameras with two lenses in order to keep up with competitors. This comes at a higher cost.

Broadcasters need to have sufficient bandwidth available in order to broadcast 3D programmes because each frame size is much larger.

With passive 3D TVs, viewers can use special 3D glasses that only cost about £1 a pair but with active 3D TVs, each viewer needs an electronic pair of glasses that can cost over £25 each.

It’s possible to convert 2D programmes to 3D but this requires editing programmes frame by frame which is very time consuming and very costly.

Broadcasters need to make available set-top boxes that are capable of receiving 3D content which means replacing existing HD boxes.

There are some reports of viewers suffering nausea after watching 3D programmes.

3D televisions are much more expensive than standard TVs and there is not enough content available for many viewers to justify the additional cost.



Smart TV

Smart TVs are televisions that are connected to the internet. Some may use WiFi and some may require a wired connection. A smart TV will provide a collection of apps that can be used to access content across the internet, or within a home network. Examples of apps include:

BBC iPlayer to catch up on past programmes from BBC channels

YouTube to watch videos and live broadcasts over the internet

Film Trailers to watch trailers for films that are on at the cinema or available on DVD/Blu-ray

LoveFilm/NetFlix to watch streamed films by paying a subscription fee

Photos/music/video to access content on devices on the home network

Impacts


Smart TVs require an internet connection. If the viewer has wireless then this can be achieved relatively simply, but if a cable connection is required then it will need to be installed.

If viewers spend more time watching online content and less time watching traditional television programmes then there will be a loss of advertising revenue for television companies.

Broadcasters need to develop new ways of transmitting television such as through the internet in order to keep up with competition and not to be left behind. A wireless internet connection may

not be strong enough or due to contention with other devices in the home there may not be enough bandwidth meaning that a wired connection is required. Broadband suppliers can limit the amount of data that can be downloaded each month and this cap could be easily reached if downloading lots of television content.

TV companies need to make their programmes available through apps so that viewers can watch programmes on demand as otherwise customers will watch competitors’ programmes.

Broadcasters may find that there is less demand for their services such as cable TV or satellite because viewers can choose internet TV and this can cause a loss of revenue. The viewer is able to watch films

spontaneously rather than having to decide in advance to rent one on DVD or Blue-ray. The viewer can view home videos or photographs from the comfort of their lounge and share them with family and friends in a group viewing.

TV companies have to develop apps for a variety of platforms as there is no standard platform for smart TV and this uses up a lot of development time and thus cost.

The viewer can watch online content including film trailers from the comfort of their lounge without having to use a laptop or go to a PC.



Task - digital television If you have digital television at home, experiment with the set-top box or television to see what other facilities are available, including digital teletext. Complete the table below for each facility.

Questions - follow me 1) List seven services available on digital television. [7]

2) Identify two advantages of pay per view to the individual viewers. [2]

3) Identify two impacts to broadcasters of enabling viewers to choose camera angles. [2]

4) Identify one disadvantage to a television company that provides viewers with the facility to vote for their favourite performer. [1]

5) Describe three features of an electronic programme guide. [6]

Impacts


Tasks/Task%20-%20digital%20television.docx



k. discuss the range of services offered by mobile communication services and the impact of these services on individuals and organisations

Mobile communication services could include 2-way radios, Citizen Band, satellite phones, emergency service radios and other methods of communicating on the move. For this chapter, OCR’s focus is on mobile communication services are the services offered by mobile phone companies. In the UK, these services are currently offered by EE, O2 and Vodafone. This is not about the services offered by a mobile phone. It is about the services offered by the mobile communication service, or mobile phone operator. Therefore, these are some things that are not services offered by the mobile phone operator:

apps camera NFC (near field communication) Bluetooth WiFi

The services offered by mobile phone operators include:

voice calls video calls caller display call waiting voicemail SMS / MMS internet access push email

Voice calls

Mobile phones were originally designed for making and receiving phone calls. You can see from these images how mobile phones have

developed since 1978 when analogue cellular networks were first introduced commercially in America. Mobile operators charge for calls or users can have a monthly contract with an allowance of calls. Monthly contracts usually last 12-24 months and tie the

user in to a fixed rate and phone for that time period. Going over the monthly allowance can become expensive. Calls using pay as you go phones are charged per minute. When ‘roaming’ (using the phone abroad), calls are very expensive and it also costs money to receive calls. Text messages also cost when roaming but the worst problem is data charges which are extortionate with some mobile operators charging £1 per MB when roaming.



Video calls

Many mobile phones now include the facility to make video calls. When making a video call, the caller and recipient can see each other as well as hear each other. It is necessary for both the caller and the recipient to have the facility in order to make a successful video call. It is also necessary for both parties to have a 3G or 4G signal. If the call is successful, each participant will see a full-screen picture of the other participant and a small picture of themselves. Video calls are not part of any monthly allowances and can be quite expensive. Many mobile phone users have taken advantage of alternative voice over IP (VOIP) services such as Skype and FaceTime to make video calls. These are not services offered by the mobile phone operator but are instead apps that run on the phone across a 3G or 4G internet connection and therefore use the data allowance instead of the user being charged for the call. Some mobile operators block VOIP because it means they are losing out on revenue from actual video calls.

Caller display

When receiving a telephone call, the recipient can see the number of the person calling. The recipient can then decide whether or not to accept the call. If a set of contact names and numbers has been set up and the caller’s number is in the address book, then the recipient will be able to see the name of the caller. Many mobile phones will even give different ring tones based upon the person who is calling and most will allow the display of a photograph for each contact. The transmission of the number is the service provided by the mobile operator; the additional facilities of looking up a name, photograph or ringtone are provided by the mobile phone.

However, some callers withhold their number which means that the recipient will not know who is calling. Many organisations also withhold their number. The recipient then has to decide whether to take the call or not without the knowledge of who is calling.

Task - caller display Add a photograph to one of your contacts and see what happens when they next call you. Find out how to setup a different ringtone for a single contact or group of contacts.



Call waiting

When a mobile phone user is actively on a call, it is possible that somebody else may call the phone. If this happens then the recipient will hear a beep and will be presented with three options:

reject new incoming call

hang up current call and accept new call

put current call on hold and accept new call

Voicemail

Voice mail is a service offered by mobile operators. If a recipient is on another call or does not want to answer the phone or has their phone turned off, then a message can be left on their mobile operator’s voice mail service. This message is stored by the mobile operator and can be accessed by the recipient at any time. Facilities included within a voicemail system include:

delete or store multiple messages

forward the message to another voice mail inbox, including being able to add an extra message to explain why it has been forwarded

have different greetings depending upon whether the phone is engaged or not answered

retrieve the message from another phone by dialling in to the voice mail system and using a PIN (personal identification number)

have the voicemail forwarded to the user by email either as an attachment or as text by voice recognition

Voicemails are usually free to retrieve although this is not the case when the recipient is in a foreign country. Sometimes messages can be missed because there is only a small symbol indicating the presence of a voicemail and this could be problematic if the message is important.



SMS / MMS

SMS (short message service) is the ability to send and receive text messages using a mobile phone. The messages can only contain text characters and are limited to 160 characters, although it is possible to send groups of messages as if they were a single message. Groups of messages are usually limited to a maximum of 3 messages and this will be 459 characters. This is less than 3 x 160 because extra user data header (UDH) information needs to be sent in order to concatenate (join) the messages for the recipient. Text messages can be useful when somebody needs to send some information to another person but does not have time for a conversation. They can also be used to send information to another person who can then view that information when they are available; in other words, it is not necessary for the two parties to be available at the same time. Text messages are very popular because most mobile operators allow an unlimited number of messages to be sent each month and therefore customers use texts

rather than phone calls because the texts are free of charge. Text messages are charged when roaming. Text messages have been used as a method of bullying which is particularly a problem with pay as you go phones where the owner of the phone may not be identifiable. Some people believe that text messages are not good for the English language because people use ‘txt spch 2 write their msgs’. Other people believe that this is fine as long as it is restricted to text messages. Sending lots of text messages can also result in repetitive strain injury (RSI). Multimedia messages (including images, sound and video) can be sent using MMS (multimedia messaging service). This means that mobile phone users can take a photograph, record some audio or film a short video clip and send it to a friend or colleague. MMS will not work on a standard GSM signal and is dependent upon the phone having a GPRS, 3G or 4G signal which may not always be available. Further to this, the multimedia file size that can be sent can be limited by the network operators or mobile phone manufacturers. Some network operators will only allow sending and receiving a maximum of 300Kb, 600Kb or 1.2Mb which limits what phone users can send. Even if a large MMS can be sent, there is no guarantee that it can be received if it is too large for the recipient’s network operator.

Task - text message RSI Read these articles about RSI:

text message RSI from BBC health

advice regarding text message RSI – try out some of the recommended exercises

Extension: read more details about different types of RSI affecting the hands

http://news.bbc.co.uk/1/hi/health/5063364.stm

http://www.theregister.co.uk/2006/02/22/text_injury/

http://www.hemp-eaze.com/apps/blog/show/19081995-texting-thumb-and-rsi-injuries-helped-with-hemp-eaze



Internet

It’s quite rare to find a phone that does not have some kind of access to the internet. The mobile operator will provide internet access through GPRS, 3G and 4G networks. Once a mobile phone has access to the internet then many apps can use the internet service. These apps may include a web browser, email client, social networking, rail timetables or anything that requires data from the internet. The apps are not the service provided by the mobile operator. The service provided by the operator is the connection to the internet. Data can be charged at a rate per MB or phone users may have a monthly contract which includes a data allowance. These allowances are not particularly large (typically 250MB – 1GB) but they are designed for mobile use rather than home use. Some mobile operators offer ‘unlimited’ data, but there are always ‘fair use’ policies in place which mean that the data is not really unlimited but will still have restrictions. When using data abroad the data charges can be astronomically high and so phone users have to be careful to setup their phone to disable data roaming. It’s also possible to use a mobile phone to ‘tether’ an internet connection. These means sharing the internet connection with other devices. Most phones do this by creating a Wi-Fi hotspot from the phone that other devices can connect to and then use the phone’s internet connection. If this is done then users need to ensure that they don’t download too much data on connected devices such as laptops, especially as some software such as on demand TV (eg iPlayer) can download large files in the background automatically. It’s also important to set up encryption on the hotspot so that other users cannot see the data and also so that other users cannot access the hotspot without a passkey. Some mobile operators block tethering across their network because they want their customers to purchase a 3G or 4G dongle to access the internet instead. These are devices that connect a portable device (eg laptop or tablet) to the internet through a mobile phone network. Customers usually pay a monthly fee for a data allowance.

Task - mobile internet Use http://www.uswitch.com/broadband/mobile_broadband/ to compare mobile internet deals.

Push email

Many email systems use a system called ‘polling’ whereby the email app on the phone will regularly check (poll) for new emails on the mail server. This uses up data each time the check is made and it also means that emails are not received until the next poll. RIM introduced a system of push email for mobile phones for Blackberry devices which meant that emails were actively pushed to the phone so that no polling was necessary. This means that emails are received instantly and there is no need to keep using up data allowances to check for new emails. This can become intrusive when lots of emails are arriving and users cannot ‘escape’ from work although it is possible to set up active schedules for receiving emails. Users also need to remember to disable data roaming when abroad otherwise they will incur data charges each time an email is pushed to their phone. Since RIM introduced this system, other email services such as Gmail, Hotmail and Microsoft Exchange also use the push system. This relies upon both the mobile phone operator and the mail server providing a push service.

Tasks/Task%20-%20mobile%20internet.docx

http://www.uswitch.com/broadband/mobile_broadband/



Questions - follow me 1) Describe three services provided by mobile communication services. [6]

2) Describe one advantage of video calls. [2]

3) Describe two disadvantages of SMS/MMS. [4]

4) Describe two advantages of push email. [4]

5) Discuss the use of internet services provided by mobile communication services. [9]

Question%20Templates/4k%20-%20Question%20Template.docx



l. describe the internal resources of an organisation: human, technological and premises

Human

Human resources are the people that use and maintain a system. They are either employed by the organisation or contracted to do particular tasks. Some tasks that may be carried out by human resources include:

entering data into a system – eg entering details of orders received by post

maintaining the computer systems – eg an ICT technician

programmers who develop new software or produce web pages

managing people within an organisation – eg a personnel director

managing the finances within an organisation – eg a finance director who would use spreadsheets and other financial modelling software

researchers who find out about and develop new products with new ideas

Technological

This consists of electronic or equipment with moving parts within an organisation. It could include:

computers, peripherals, servers and communications links

CAM (computer aided manufacture) machines – eg lathes

EPOS (electronic point of sale) machines – eg tills

arcade games

Premises

These are the buildings, offices and other property owned by an organisation. People and equipment need somewhere to be situated and that is known as accommodation. The location of the premises can be important. Shops need to be accessible to public transport and cars; manufacturers prefer out of town business parks where rental costs and council taxes are cheaper; car parks that are underground are expensive to build but take up less ground space. Premises could include:

offices for people to work in – some may be private offices for managers, whilst other offices may be open plan for general employees

factories for machinery and workers

retail outlets (shops) to sell products

a car park



EXAMPLE A church would include the following internal resources:

Human

A vicar who is responsible for organising services, the welfare of their congregation and a vision for the church’s future.

A curate who is training to be a vicar and will support the vicar in the pastoral care of the congregation.

An administrator who is responsible for the administration of the church including taking bookings for rooms, dealing with enquiries, receiving correspondence and providing information.

A youth worker who is responsible for organising events for young people and for their pastoral care.

Church Wardens who are responsible for the accommodation and organising services in the vicar’s absence.

Congregation who are the people who worship at the church and will carry out various tasks voluntarily within the community.

Technological

A computer and printer connected to the internet for the administrator to use.

A laptop computer for the vicar to use whilst at the church or in their office at the vicarage.

Projectors and LCD screens for showing the words to worship songs and the liturgy.

Microphones for singers, readers, vicar and curate.

Speakers, amplifier and mixing desk to enable the congregation to hear what is being said and sung.

Premises

The sanctuary where the congregation meet to worship.

A lounge where the congregation meet to drink, eat and chat.

A kitchen for making drinks and preparing food.

Toilets for members of the congregation to use.

An office for the administrator.

A vicarage for the vicar to live in with his family.

Task - school resources Identify some of the internal resources within your school or college.

Questions - follow me 1) Identify 3 examples of internal resources. [3]

2) Describe two different human resources that might be required to work within a bank. [4]

3) Apart from computers, describe a technological resource that might be required by a retail outlet. [2]

4) Describe the type of premises that might be required by an estate agency. [2]

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KNOWLEDGE REVIEW

Test - follow me Frank has just retired and has decided to use his spare time to learn about new technologies and to invest his lump sum payment in buying some new gadgets.

1) (a) Describe how Frank might make use of an expert system if he feels ill. [4]

(b) Describe two components of an expert system. [4]

2) A television company is going to provide digital television services to its viewers.

(a) Discuss the impact on the television company of providing digital television services. [7]

(b) Discuss the impact on Frank of Pay Per View and being able to pause live television. [7]

Frank passed on his ball bearing manufacturing company to his son Melvyn. Melvyn has been told that it would be a good idea to invest in a management information system (MIS).

3) Describe two ways in which Melvyn could use a MIS. [4]

To help Melvyn to learn to use the new MIS, software based training methods will be used.

4) (a) Describe four advantages to Melvyn of using software based training methods. [4]

(b) Describe two disadvantages to the trainers of using software based training methods. [4]

5) Describe three different types of internal resources within Melvyn’s company and give an example of each. [6]

Melvyn has decided to upgrade the ICT systems at the ball bearing company.

6) Describe how the ball bearing company could make use of mobile communication services for their sales staff. [6]

7) Describe three advantages to the ball bearing company of installing a local area network. [6]

The ball bearing company will be opening two new factories. They have decided to use a partitioned database at each of its factories to store details about employees.

6) Discuss whether a horizontally partitioned database or a central database with local index should be used. [9]

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Documents

4 Applications of ICT - markhunter.org - Paul Long text book... · A2 ICT 4 OCR @ A Level (G063) ... 4 – Applications of ICT Contents a. describe the advantages and disadvantages