Newsletters and posters
Posters are typically produced following these steps:
Open a word processor, DTP (Desktop Publishing) or presentation software.
Create frames, boxes and text boxes.
Take photos if necessary using a camera.
Upload the images from the camera or from a CD/DVD, scan photos, or download photos from the internet.
Save the photos to a file.
Import or copy and paste the photos into the document.
Edit the photos and import from a file or type any text required.
Posters tend to be large sheets of paper wich are displayed on buildings, noticeboards or advertising hoardings.
Newsletters contain information about company employees or club members. The content might include:
Marriages, deaths and births of employees, club members or their families.
Advertising by outside companies.
News events, etc.
Brochures and flyers
Flyers are typically produced following these steps:
Open a word processor, DTP (Desktop Publishing) or presentation software.
Create frames, boxes and text boxes.
Take photos if necessary using a camera.
Upload the images from the camera or from a CD/DVD, scan photos, or download photos from the internet.
Save the photos to a file.
Import or copy and paste the photos into the document.
Edit the photos and import from a file or type any text required.
Brochures are used to avertise a company, product or service. While you can create a brochure using your computer, it is more professional to go to a brochure design company. They will have special paper and specialist software.
Publishing brochures and flyers:
They can be sent out to every household in a given area.
They can be put inside magazines and newspapers.
Generally, single sheet documents are referred to as flyers or leaflets and booklets are referred to as brochures.
This method of advertising requires the company to either develop their own websites or to pay another company to advertise on their website.
Sound, video and/or animation can be added.
Links to other websites/hyperlinks can be used.
Use of hotspots.
Buttons to navigate/move around the website leading to more information.
Hit counters to see how many people have visited the website.
Can be seen by a global audience.
Can't be defaced or thrown away.
It is much easier to update a website.
Websites can be hacked into and modified or viruses introduced.
Risk of potential pharming.
It is necessary for the potential customers to have a computer and internet connection.
Possible for customers to go to undesirable websites (either by accident or as a result of the pharming attack), this can lead to distrust from customers.
There is a need for the company to maintain the website once it is set up - this can be expensive.
Because it is a global system, it is more difficult to target the correct audience using website advertising.
Use of sound, animation and/or video effects which are more likely to grab the attention of the audience, and can also make the presentation easier to understand.
It is possible to have interactive/hyperlinks built into the presentation; this means the presentation could access a company's website or even key files stored on the cloud (such as video footage, images, spreadsheets and so on).
Use of transition effects allow a presentation to display facts in a key or chronological order.
The presentations can be interactive.
They are more fflexible; because of the links to websites and other external systems (e.g. the cloud), the presentation can be tailored to suit a particular audience.
There is a need to have special equipment which can be expensive.
Equipment failure can be a disaster when giving multimedia presentations.
Wherever the presentation is given there may need to be internet access.
There is a danger when using multimedia in presentations that the focus is on the multimedia presentation rather than the message.
It is very easy to make a bad presentation with too many animation effects and too much text or images.
Some of the features of this technology include:
Music samplers and mixers allow the original tracks that were recorded in the studio to be modified in any way that the producer wants.
Electronic instruments (like guitars and organs) can play back through electronic effects machines.
Synthesisers combine simple wave forms to produce complex music creations.
Electronic organs can mimic any other instrument.
The music score can be generated from the music itself using software.
Software can automatically correct music notes in a score.
There is no real need to understand music notation to write a music score.
Music notes are automatically printed out in the correct format.
Cartoons can simply be freehand drawings and then scanned in or can be computer-generated, possibly with the aid of a graphics tablet.
Cartoons can add humour to any form of communication and can be a very efficient and effective way to get a message across.
As with any form of communication, it is important not to offend anybody and also to make sure the cartoon doesn't become the "main feature" and the message becomes lost somewhere within the humour.
The use of mobile phones for communication
Mobile phones communicate by using towers inside many cells networked together to cover large areas. The towers allow the transmission of data throughout the mobile phone network.
Each tower transmits within itw own cell; if you are driving a car and get to the edge of a cell the mobile phone signal starts to weaken; this is recognised by the network and the mobile phone then picks up the signal in one of the adjacent cellss. If a person is making a call or sending a text to somebody in a different country then satellite technology is used to enable the communication to take place.
Mobile phones allow access to the internet on the move using either the cellular network or Wi-Fi "hot-spot".
The use of internet telephony
One of the most common forms of internet telephony is Voice Over the Internet Protocol (VoIP).
VoIP is a method used to talk to people using the internet. VoIP converts sound (picked up by the computer microphone or special VoIP telephone plugged into the USB port of the computer) into digital signals that can be sent to their destination via the internet. One of the big advantages is that it is either free (if the talking is done computer to computer) or at a local rate to anywhere in the world when VoIP is used to communicate with a mobile or land line telephone rather than another computer.
Obviously, to work in real time this system requires a broadband ISP. The main problems are usually sound quality (echo and weird sounds are both common faults). Security is also a main concern with VoIP.
Another advantage of using VoIP is that a webcam can also be used so that it becomes a type of video chat.
Applications for publicity and corporate image publications
Business cards and letterheads
Business cards can be handed out to people as a form of personal advertisement. The use of IT (in this case, a website) has made this a much easier task. Business cards are less likely to be thrown away since they are seen as personal contact. It is also possible to include additional information on the reverse of the card - this could be further advertising of the company's products or it could be advertising another company.
Many of the advantages of having business cards are similar to the advantages of using headed stationery.
The same format used on the business cards can be adopted on a company letterhead. This helps to project a corporate image. As with the business cards, therse pages can be printed on high-quality paper using the same design/logo so it becomes very clear to the customer that the communication all comes from one company.
There are several advantages to a company in using corporate letterheads produced by a printing website:
Professionalism (gives a degree of credibility to the company)
Brand/company awareness (advertises the company by using the same designs on all products)
Legal reasons (it helps if there are any legal actions taken - legitimate documents using the company letterhead is regarded as proof of actual communication)
Advertising (the letterhead can contain many useful pieces of information to advertise the company)
Helps to make the company stand out (will tend to have more impact than a white sheets of paper with a typed company heading)
Can make the company appear larger than it is (this could give a degree of confidence to potential customers)
Data handling applications
Clubs and society records
Advantages of record keeping systems:
· Less office space would be required since no paper records would need to be kept.
· It would be quicker and easier to find details of a particular client/member of club/product.
· The system would be less expensive since it wouldn’t be necessary to employ somebody to do all the filing and searching.
· There would be fewer errors since no manual checking of paper files would need to be done.
· There would be a need to buy a computer and software to run the system.
· Time and effort would be required initially to transfer all the existing paper files to the database.
· School reports. Which data would this database need to store?
This type of application involves sensors constantly taking measurement data.
Because the data from the sensors are often in an analogue form, they have to be sent to an Analogue to Digital Converter (ADC) to turn the data into a digital format. This is needed because microprocessors and computers only understand digital data.
In measurement applications, the microprocessor simply reviews the data from the sensors and updates its files and sometimes gives a warning signal if the values are outside given parameters. The microprocessor will take no action to change any of the conditions during the measurement process.
They are set up to automatically gather data from the environment. They use sensors to measure: rainfall, temperature, wind speed, wind direction, air pressure, and humidity.
Measuring a patient’s vital signs in a hospital
Sensors read key vital signs (pulse rate, heart rate, temperature, blood pressure, respiration, etc.)
The data from the sensors is converted into digital using an ADC
The data is stored in the computer’s memory
The computer compares the data from the sensors with the values stored in its memory (these will be input by the nurse or doctor for a particular patient)
The results are output on a screen in the form of graphs and/or numerical readouts
An alarm is activated if any of the data is outside acceptable input values
The system continues to measure the patient’s vital signs until the computer is turned off
Measuring pollution in a river
The sensors are placed in at least 2 different positions so that a pollution comparison can be made
The data from the sensors is converted into digital using an ADC and sent to a computer
The computer stores the received data
The oxygen levels and acidity levels are compared to the historical data stored in memory and they are also compared to pre-set levels stored in memory
The oxygen and acidity levels from the different positions in the river are also compared to see if they are similar, this is used to see if the source of the pollution can be found
Advantages of using monitoring systems:
The computer wouldn’t forget to take readings
The computer’s response time is much faster
Doctors, nurses, scientists, etc. can all get on with other tasks whilst the measurements are taken automatically
Computers give 24-hour cover every day
The readings will tend to be more accurate
Readings can be taken more frequently if done by a computer and sensors
It could also be safer since whatever is being measured may have potential hazards (people falling into the river whilst attempting to take readings or a nurse looking after a patient who has a contagious disease)
Computers can produce graphs automatically for analysis of results
There is a potential cost saving as fewer staff are needed since the measurements are now done by computer (which results in a reduced wages bill)
Disadvantages of using monitoring systems:
The computer is unable to respond to unusual circumstances
Computer equipment and measuring software can be expensive to purchase and set up in the first place
A student doing an experiment, for example, will rely on the computer doing the measurement and analysis, it’s possible the student will not learn as much using a computer system
If the computer malfunctions or if there is a power cut, then the computer cannot be used, and there needs to be good backup procedures in place to cover this eventuality
Microprocessors in control applications
First of all, the start and end time are entered. Finally, the cooking temperature is selected.
The microprocessor checks the set time against the current time and when they are equal, the cooker/oven heating elements are switched on. Once the cooker/oven starts the cooking process, the microprocessor then constantly checks the end time against current time, when they are equal, the cooking process is stopped.
The microprocessor checks the temperature data sent from a sensor and turns the heating element on if the value is less than the pre-set value chosen by the user. If the temperature is greater than or equal to the pre-set value, then the heating element is switched off by the microprocessor.
Once the cooking process is finished, the microprocessor sends a signal to a beeper to make a beeping sound to indicate that the cooking cycle is completed.
Central heating systems
There are many types, let’s take a look at a central heating system that uses a boiler.
o The required temperature is keyed in and this is stored in the microprocessor memory (pre-set value)
o The temperature sensor constantly sends data readings to the microprocessor
o The sensor data is first sent to an ADC to convert the analogue data into digital data
o The digital data is sent to the microprocessor
o The microprocessor compares this data with the preset value
o If the temperature reading is greater than or equal to the preset value then no action is taken
o If the temperature reading is less than the preset value, then a signal is sent:
o To an actuator (via a DAC) to open the gas valve to the boiler
o To an actuator (via a DAC) to turn on the water pump
o The process continues until the central heating is switched off
Chemical process control
Let’s say that a chemical process only works if the temperature is above 70℃ and the pH level is less than 3.5. A heater is used to heat the reactor and valves are used to add acid when necessary to maintain the acidity. How are the sensors and computer used to control this process?
o Temperature and pH sensors read data from the chemical process.
o This data is converted to digital using an ADC and is then sent to the computer.
o The computer compares the incoming data with pre-set values stored in memory. If the:
o Temperature is less than 70oC, signal is sent to switch on the heaters.
o Temperature is greater than or equal to 70oC, a signal is sent to switch off the heaters.
o pH is greater than 3.5, then a signal is sent to open a valve and acid is added.
o pH is less than or equal to 3.5, then a signal is sent to close this valve
o The computer signals will be changed into analogue signals using a DAC (Digital to Analogue Converter) so that it can control the heaters and valves.
o This continues as long as the computer system is activated.
Glasshouse environment control
Which sensors could be used here?
Let’s see how the humidity sensor would work.
o The humidity sensor sends a signal to an ADC which (after converting the data from analogue to digital) then sends the signal to the computer.
o The computer compares this digital value with a pre-sent value stored in memory.
o If humidity is greater than the pre-set value, the computer sends a signal to a DAC to operate the motors to open windows thus reducing the humidity.
o If humidity is less than the pre-set value, the computer sends a signal to open valves to spray water into the air.
o If the reading is the same as the pre-set value, then no action is taken.
o The control process continues as long as the system is switched on.
FORWARD x Move x cm forward
BACKWARD x Move x cm backward
LEFT d Turn left through d degrees
RIGHT d Turn right through d degrees
REPEAT n Repeat next set of instructions n times
ENDREPEAT Finish the repeat loop
PENUP Lift the pen up
PENDOWN Lower the pen
A computer model is the creation of a model of a real system in order to study the behaviour of the system. The model is computer generated and is based on mathematical representations.
The whole idea is to try to find out what mechanisms control how a system behaves. This then makes it possible to predict the behaviour of the system in the future and also see if it is possible to influence this future behaviour.
Advantages of computer models: save money, can help find a solution more quickly and can be considerably safer.
Examples: spreadsheets to control personal finances, flight simulators, population growth, modelling queues at checkouts, training drivers, running chemical and nuclear plants, crash testing of cars, weather predictions, etc.
Control of robots is either through embedded microprocessors or linked to a computer system. Programming of the robot to do a series of tasks is generally done in 2 ways:
1. The robot is programmed with a sequence of instructions which allow it to carry out the series of tasks (e.g. spraying a car body with paint)
2. Alternatively, a human operator manually carries out the series of tasks. Let’s say the task of a robot arm is to paint an object:
a. The robot arm is guided by a worker when spraying the object; each movement of the arm is stored as an instruction in the computer.
b. The worker straps sensors to his own arm and sprays the object; each movement is stored as a set of instructions in a computer; the sensors send back information such as position relative to the object, arm rotation, and so on – this information forms part of the instructions stored in the computer.
Advantages of using robots in manufacturing applications:
o They can work in environments harmful to human operators.
o They can work non-stop (24/7).
o They are less expensive in the long term.
o Higher productivity (don’t need holidays, etc.)
o Greater consistency (e.g. every car coming off a production line is identical).
o They can do boring, repetitive tasks leaving humans free to do other more skilled work (e.g. quality control or design work).
o They find it difficult to do unusual tasks (e.g. one-off glassware for a chemical company).
o They can cause higher unemployment.
o Since robots do many of the tasks once done by humans, there is real risk of certain skills (such as welding) being lost.
o Because robots are independent of the skills base, factories can be moved anywhere in the world (again causing unemployment).
o The initial set-up and maintenance of robots can be expensive.
School management systems
School registration systems
Method 1: each student could have a magnetic stripe ID card containing information such as: school name, student’s name, date of birth, ID number. Each morning the student would swipe his ID card through a magnetic card reader. The data read would identify the student and the time and date they entered the school’s premises. This data would be stored on a database. On leaving the school, the student would swipe the ID card again. This would record the leaving time and date on the database. One disadvantage is that the student could give his ID card to another student to swipe it for him.
Method 2: using biometrics. The student’s personal details plus fingerprints would be taken and stored on a database. Every morning the student would put his hands on a scanner which would read his fingerprints.
Advantages of using biometrics:
o Fingerprints are unique, so it would be impossible for a student to sign in pretending to be someone else; this gives more accurate data and improved security.
o ID cards could easily be lost, fingerprints are part of the body, so can’t be lost.
o ID cards could be affected by magnetic fields (e.g. by being placed close to a mobile phone) which would stop them working.
o It is much easier to clone (copy) ID cards than it would be to copy fingerprints.
Disadvantages of using biometrics:
o It would take a long time to collect the initial fingerprints for every student in the school.
o The equipment needed to take and read fingerprints is more expensive than magnetic stripe reading equipment.
o If a student cuts a finger, the fingerprint may not be identified by the system (which would prevent entry to the school)
o There are “invasion of privacy” issues and some parents may object to having the fingerprints of their children stored on a database.
Teachers could use spreadsheets to track the students’ performance.
Exam timetables, subject timetables and teacher substitution
To produce timetables one needs to take into account:
o Availability of teachers.
o Availability of rooms for each subject.
o Subject clashes.
Number of hours for each subject.
Theatre and cinema booking systems
o The user types in the url of the theatre booking system website.
o The user clicks on the performance they wish to see.
o A date and time is typed in.
o The required number of seats is also entered.
o The seating display in the theatre is shown on the screen.
o The user selects his seat by highlighting the actual seat on the screen display and then clicks CONFIRM to
go to the next part of the process.
o The database is then searched to check the availability of the selected seat.
o If the seat is available, the total price is shown plus the seat number.
o If the customer is happy with this, he selects CONFIRM on the screen.
o The seat is now temporarily set at NO LONGER AVAILABLE.
o The customer then enters his personal details or indicates that he is a returning customer (in which case the website will already have his details)
o The payment method is then selected and payment made.
o The theatre seat is then booked in the customer’s name.
o The final details are again shown on the screen.
o An email is sent to the customer which he can print out as proof of purchase.
o The database is finally updated with the transaction and the seat become no longer available.
Flight booking systems
Advantages of online booking systems
o They prevent double-booking (which could happen in paper-based systems)
o The customer gets immediate feedback on the availability of seats and whether or not their booking has been successful.
o The customer can make bookings at any time of the day.
o The customer’s email address allows the booking company to attach “special offers” to them and inform them of such offers automatically.
o It is usually easier to browse the seating plans (particularly on flights) to choose the best seats available at the price.
o It is possible to “reserve” a seat for a period of time – this allows a customer to make up their mind before finalising the booking of the seat.
o Very often there are no printed tickets which save postal costs and also allow impulse bookings only a few hours in advance.
o Online booking allows the use of modern smartphone and tablet apps technology; the customer is sent a QR code which contains all the booking information necessary (this QR code is stored on the smartphone or tablet and only needs to be scanned at the theatre or cinema on arrival). This removes the need to print out tickets and the possibility of forgeries.
Disadvantages of online booking systems
o The setting up and maintenance of online booking systems is expensive.
o All customers using this service need access to a computer and a reliable internet connection.
o It is often more difficult to cancel the booking and get your money back using online systems.
o If the server is down for maintenance or if the system breaks down, it becomes impossible to book seats by any method (a temporary paper-based system can’t be used because of the risk of double-booking occurring).
o If the websites are not well designed, it can be difficult to make exactly the booking you want or can lead you to make mistakes; this is a particular issue with flight bookings where correcting an error can cost the customer an additional fee.
o Booking online does not allow you to build a personal relationship with the travel agent who might offer free upgrades or special offers which may not be available to online bookings.
Automatic teller machines (ATMs)
Sequence for withdrawing cash
o Customer puts card into ATM. Behind the scenes, contact is being made with the customer bank’s computer.
o PIN is entered using the keypad. Such PIN is checked to see if it is correct.
o A number of options are given:
o Change PIN
o See account balance on screen or printed out.
o Pay in cheques
o Receipt required?
o Get a mini statement
o Pay a bill
o Make a money transfer
o Withdraw cash
o The customer selects the cash option.
o A number of cash amounts are shown.
o Card is checked to see if card expiration date is exceeded or card is reported stolen.
o The customer accepts one of the options or types in a different amount.
o Customer’s account is accessed to see if they have sufficient funds, and to see if the daily limited has been exceeded.
o The customer is then asked if he wants a receipt.
o The card is returned.
o Money is dispensed.
o Customer’s account is updated.
Disadvantages with ATMs:
o They are often in places where theft can take place at night.
o Bogus ATMs can be set up to gather information about the card and retain the card.
o Some banks charge customers for the use of ATMs.
Internet banking and online shopping
Advantages of online shopping and banking:
o There is no longer a need to travel into the town centre thus reducing costs and time-wasting; it also helps to reduce town centre congestion and pollution.
o Users now have access to a worldwide market and can thus look for products that are cheaper; this is obviously less expensive and less time consuming than having to shop around by the more conventional methods; they will also have access to a much wider choice of goods.
o Disabled and elderly people can now access any shop or bank without the need to leave home which is of great benefit to them; it helps to keep them part of society since they can now do all the things taken for granted by able-bodied people.
o Because it is online, shopping and banking can be done at any time on any day of the week, this is particularly helpful to people who work as the shops/banks would normally be closed when they finished work.
o People can spend more time doing other things e.g. going shopping to the supermarket probably took up a lot of time; by doing this online people are now free to do more leisure activities.
o Many people find it less embarrassing to ask for a bank loan using the internet rather than enduring a face to face discussion with bank staff.
o There are often long queues at the banks or checkouts at the shops, so internet banking saves time.
o The shops and banks save money by not having as many staff working for them or hiring of high street premises. These savings are often passed on to customers in the form of lower interest rates, cheaper goods or higher rates on interest for savers.
Disadvantages of online shopping and banking:
o There is the possibility of isolation and lack of socialisation if people stay at home to do all their shopping and banking.
o There are possible health risks associated with online shopping or banking because of a lack of exercise; if people physically go shopping then they are getting some exercise.
o Security issues are a major concern (e.g. hacking, stealing credit card details, etc.) as are viruses and other malware.
o Accidentally using fraudulent bank or shopping websites is always a risk and this is linked to security issues.
o It is necessary to have a computer and to pay for the internet to take part in online shopping and banking.
o Unlike high street shopping, it is only possible to see a picture of the goods, which might not portray the exact colour of a dress for instance (nor can you try something on to see if it fits) before buying them; you also have to wait several days for the goods to arrive; returning goods is also expensive.
o High street shops and banks are closing because of the increase in online shopping or banking and this is leading to ghost towns forming.
o It is easier to make errors with online banking and transfer money incorrectly to different accounts.
The customer calls the bank using a telephone. The steps are:
o The customer keys in their account number.
o They are then requested to enter a four-digit PIN or selected numbers from their PIN.
o The customer will then hear various options, which might include:
o Press 1 for your balance
o Press 2 to carry out a money transfer
o Press 3 to pay a bill
o Press 4 to talk to one of our representatives
o The customer chooses one of the options.
Advantages of telephone banking: there’s no need to have a computer and it’s possible to talk to an actual human being.
Disadvantages: can be much slower than internet banking (there may be a long queue before you talk to somebody) and the options can be a little more complex to navigate.
Chip and PIN
When paying for items using a chip and PIN card, a form of electronic funds transfer (EFT) takes place. Suppose a customer pays for his meal in a restaurant:
1. The PIN is entered using a keypad.
2. The card is checked to see if it is valid (check on expiry date, whether stolen or not)
3. The PIN is read from the chip on the card and is compared to the one just keyed in.
4. If they are the same, then the transaction can proceed. If this is the third attempt at entering the PIN, then the transaction is terminated.
5. The restaurant’s bank contacts the customer’s bank.
6. A check is made on whether they have enough funds.
7. If the card is not valid or there aren’t enough funds available, then the transaction is terminated.
8. If everything checks out OK, then the transaction is authorised.
9. An authorisation code is sent to the restaurant.
10. The price of the meal is then deducted from the customer’s account.
11. The same amount of money is then added to the restaurant’s bank account.
12. A receipt is produced as proof of purchase.
Clearing of cheques
Suppose John uses a bank called Hodder Bank and he pays a cheque for $50 to a company called H&S Ltd who bank with the Smith Bank. How is the H&S bank account credited with $50?
The cheque is sent by the Smith Bank to a centralised clearing centre. The cheque is processed by the clearing centre by passing it through a reader/sorter machine. This machine automatically reads the amount on the cheque and the code line (containing the account number, sort code and cheque number)
All the cheques are then sorted using their sort codes (unique six-digit numbers that are used to identify each bank or building society), ready for sending to an exchange centre.
The data from the cheque which has been read is then converted into an encrypted file known as Inter-Bank Data Exchange (IBDE) file. Every IBDE is signed with a digital signature so that the receiving bank can be sure that the data hasn’t been tampered with.
Later, Smith Bank delivers the cheque to an exchange centre. The exchange centre then passes the cheque back to the paying bank (Hodder Bank in this case) which then sends it to its own clearing centre.
At the paying bank’s clearing centre, the digital signature is first checked and then the cheque is passed through its own reader/sorter machine to make sure the data matches with that on the IBDE file. It also sorts the cheques into branch order (using the sort code).
Later on, Hodder Bank checks to see if John has enough money in his account to cover the cheque, and also that it has been signed, dated and written correctly to cover the cheque, and also that it has been signed, dated and written correctly and is genuine. Based on this information, Hodder Bank decides whether to pay John’s cheque to H&S Ltd or return it unpaid to the Smith Bank.
If John’s bank decides not to pay the cheque to H&S Ltd, his bank will send the unpaid cheque back to the Smith Bank by special courier.
The decision to return a cheque unpaid must be made on the morning of the day after exchange so the cheque can be returned straightaway to Smith Bank if necessary. A cheque may be returned unpaid for a number of reasons:
o The customer has not got enough money in his account.
o It has not been signed, or written correctly.
o The cheque is fraudulent.
Electronic funds transfer (EFT)
EFT is a system that allows money transfer instructions to be sent directly to a bank’s computer system. No actual money is transferred. When is an EFT made?
Expert systems mimic the expertise and knowledge of an expert in a particular field. Examples: diagnosing an illness, diagnostics (faults in a car engine, a circuit board), prospecting for oil and minerals, tax and financial calculations, strategy games (chess), identification of plants, animals, road scheduling for delivery vehicles.
How to set up an expert system
o Experts in the field are interviewed.
o Data is then collected from these experts.
o A knowledge base is first designed and then created.
o The rules base is then designed and created and an inference engine is also designed and created.
o An explanation system is also developed.
o The user interface is designed and created.
o The expert system is tested.
o Experts are interviewed about how effective it is before the expert system goes out on general release.
Advantages of expert systems:
o They provide consistent answers and are not affected by emotional reasoning.
o They never forget to answer a question when determining the logic.
o Using expert systems reduces the time to solve a problem.
o They indicate the probability of the given solution being accurate or correct.
o The potential of saving money exists since there is less need for specialists.
o Allows areas of the world access to expertise which they couldn’t normally afford.
o They tend to lack common sense in some of the decision-making processes.
o Whilst lack of emotional reasoning is an advantage, it can also be a disadvantage in areas such as medical diagnosis.
o Errors in the knowledge base can lead to incorrect decisions being made.
o They are expensive to set up.
o Needs considerable training to ensure the system is used correctly by the operators.
Computers in medicine
Patient and pharmacy records
Using expert systems to diagnose patients
Using 3D printers in medicine
Surgical and diagnostic aids: a 3D printer can reproduce a solid object showing the exact internal organ of the patient. The doctor can then show the patient exactly what is wrong and then show them what procedures are required. Some 3D printers produce hard nylon objects which are used in certain pre-surgical planning. If a patient has suffered a bone break, for example, surgeons can physically test and position screws and plates in the £D bone nylon prior to the surgery taking place. This reduces the chance of any errors when the actual procedure is carried out.
Prosthetics: 3D printers are used to print out false arms, hands and legs.
Tissue engineering: the procedure involves making biological materials by diffusing cells into a bio-compatible scaffold. The bio-printed tissue is then put into an incubator and the cell structure held within the scaffold grows to form actual cellular tissue.
Design of medical tools and equipment.
Computers in libraries
1. Two files exist: Book file (this contains records with fields such as: barcode, book title, author date published, etc.) and Borrower’s file (which contains records with fields such as: borrower’s ID, name, address, barcode of books borrowed, date due back)
2. When a borrower takes out a book, the barcode is scanned. The system automatically calculates the due back date.
3. The borrower’s library card contains a unique barcode which is then scanned. The book file is linked to the borrower’s file and both files are updated to indicate which book has been borrowed and when it is due back. The date the book is due back is saved in the borrower’s file. The system therefore knows when to send out a reminder to the borrower of the book if the return date of the book is exceeded.
4. On a daily basis, the borrower’s file is interrogated by the computer to see which books are overdue for return.
Some library systems use magnetic stripes on the borrower’s cards rather than barcodes.
Computers in the retail industry
Automatic stock control system using barcodes
A barcode usually consists of 4 parts: a country code, manufacturer’s code, product code and a check digit. The check digit is a form of validation which is used to make sure no errors occurred during the reading of the barcode.
How barcodes are used to automatically control stock levels in a supermarket:
o Barcodes are attached to all items sold by the supermarket.
o Each barcode is associated with a stock file which contains details such as price, stock levels, product description (the barcode will act as the primary key in the file/table)
o A customer takes their trolley to the EPOS (Electronic Point of Sale) terminal once they have completed their shopping.
o The barcode on each item is scanned at the EPOS. If the barcode can’t be read, then the EPOS operator has to key in the number manually.
o The barcode is searched for on the stock file record by record until a match is found.
o Once the barcode has been found, the appropriate record is accessed.
o The price of the item is then found and sent back to the EPOS together with a product description.
o The stock level for the item is found in the record and is reduced by 1 and the new stock level is written back to the file.
o If the number in stock of the item is less than or equal to the minimum number in stock, then the computer automatically orders a batch of items.
o Once goods have been ordered the item is flagged on the file to indicate an order has been placed; this now prevents a re-order of the product.
o When new goods arrive, the barcodes on the cartons will be used to update the stock files; also any flags associated with these goods will be removed.
o The above procedure is repeated until all the items in the customer’s trolley have been scanned.
o When all the items have been scanned, the customer is given an itemised bill showing a list of everything they have bought.
o The computer also updates the files containing the daily income.
o If the customer has a loyalty card, the system will also update their total points.
MICR, OCR, OMR, RFID
Check Unit 2. All these are input devices.
Automatic Number Plate Recognition (ANPR) System
How ANPR is used in a car park to enable entry and exit to be automatically controlled by a computer system:
A sensor detects a vehicle and sends a signal to a microprocessor to instruct a camera to capture an image of the front of the vehicle.
An algorithm is used to locate and isolate the number plate from the image taken by the camera. This algorithm also takes into account the size of the number plate and any damage or orientation. The brightness and contrast of the number plate is first adjusted (this ensures that the characters can be clearly read). Each character on the number plate is then segmented. Each character is then recognised using optical character recognition (OCR) software. The characters are converted into a string of editable text by the software. This text is then stored on a database.
Once all this has happened, the car park barrier is raised and the motorist is issued with a ticket. The ticket shows the date and time entering the car park.
When the motorist returns to the car park, they insert their ticket into a machine which calculates the car park charges. The payment is registered on the database. The motorist then drives to the exit barrier and the ANPR system again reads the number plate and checks its database. If the number plate is recognised (and payment has been made), the exit barrier is raised.
Monitoring and tracking systems
Monitoring a person
Reasons: the person may be an offender who is released from prison on the understanding that their whereabouts is known at all times. An elderly person may need to be tracked to ensure their safety. It may be necessary to track somebody taking part in a marathon to determine their position and their time to complete the race.
Example of monitoring a person: an ankle monitor makes use of RFID technology by inserting a microchip into the device which is strapped to the ankle.
It sends out (at timed intervals) radio frequency signals. These signals contain the person’s location and other data. They are tamper-proof devices and automatically alert the authorities if an attempt is made to remove the monitor from the ankle.
The monitor sends out RF signals which are picked up by a device in the person’s home. This unit uses either landline or mobile phone networks to relay the information back to a computer in a control room. If the person isn’t at home at an agreed time, an alert is sent to the control room. GPS monitoring is also used so that the person can be tracked outside their home. CCTV cameras are also used to monitor people in streets and shopping malls in case of crime or any suspect activity.
Employee call monitors
It allows managers to listen to employee’s telephone calls. Reasons:
To improve the employees performance.
Allows the manager/supervisor to join in a call where necessary.
Can be used as a training tool.
It allows a company who are concerned about security to monitor all calls.
If the workforce moves around, it can be used to make sure they correctly represent the company whilst out of the office.
There are 3 types of call monitoring: monitor, whisper, barge.
Global Positioning Satellite (GPS) systems and satellite navigation
GPS systems are used to determine the exact location of transports such as, airplanes, cars, ships…
Satellites surrounding the Earth transmit signals to the surface. Computers installed in the mode of transport receive and interpret these signals. Knowing their position on the Earth depends on very accurate timing. Each satellite transmits data indicating its position and time. The computer on board the mode of transport calculates its exact position based on the information from at least 3 satellites.
Advantages of GPS:
The driver doesn’t have to consult paper maps, so it is far safer.
It removes errors (can warn drivers about one way streets, street closures, etc.)
The system can warn the driver about the location of speed cameras.
The system can estimate the time of arrival.
It is also possible to program in the fastest route, route to avoid towns, etc.
The system can also give useful information such as location of petrol stations.
If the maps are not kept up to date, they can give incorrect instructions.
Unless the system is sophisticated, road closures, due to accidents or road works, can cause problems.
Loss of satellite signals can cause problems.
If an incorrect start point or end point is keyed in the system will give incorrect information.
Geographic Information System (GIS)
It is a computer system that allows us to map, model, query and analyse large amounts of data according to their location. GIS allows users to create interactive queries, analyse spatial information or edit map data. The technology combines maps with computer graphics and databases.
GIS enables the following:
o Amalgamation of information into easily understood maps.
o Performance of complex analytical calculations and then presentation of the results in the form of maps, tables or graphics (or a combination of all three)
o Geographers, scientists and engineers are able to see the data in several different ways in order to see patterns and relationships.
o Emergency services use GIS to send the closest emergency personnel to a location.
o Biologists and environmentalists use GIS to protect animal life and plants in certain vulnerable areas.
o Teachers can use GIS in their geography, science or engineering lessons.
Media communication systems
There are many media used to send and receive information, such as fibre optics, copper cable, Wi-fi and satellites.
Satellites contain antennas, transponders (to allow receiving and sending of data), solar panels and propulsion (to ensure the satellite is in the correct orbit at all times).
Signals are converted to analogue and then beamed to the satellite from a satellite dish on Earth. The signals are delivered by carrier waves which consist of radio waves. Each signal has its own frequency and bandwidth (the larger the bandwidth the more data can be transmitted).
Once the data reaches the satellite it is then resent to Earth. The satellite usually boosts the signal before sending it back to Earth. Often the frequency is changed to prevent the signal received being confused with the signal sent.
The satellite system is used to transmit data from one part of the planet to another. Due to the often great distances, cables would be too costly and there is also the problem of signal deterioration over long distances.
Satellites systems are used to transmit television, telephone and internet data around the world.