Chapter 2 (how organisations use ICT

Question 1

What is a control system?

Answer 1

it uses microprocessors or computers to control certain physical conditions, either keeping them the same over a period of time or varying them according to pre-defined values and lengths of time.

Question 2

Give examples of Control systems.

Answer 2

1. air-conditioning systems
2. Refrigeration
3. Central heating systems
4. Car manufacture
5. Medical misapplication
6. Process control

Question 3

Describe how an Air-conditioning system works.

Answer 3

• The compressor compresses cool low pressure gas into high pressure gas
• As the gas then moves through the condenser outside the building , it cools into a liquid
  -the liquid flows through the piping and passes through an expansion valve causing to evaporate into a cold low-pressure gas
• as the liquid changes to a gas and evaporates it absorbs the heat from the inside of the building.
• A fan then blows air across metal fins that have been child as a result of the heat being absorbed.
  -this causes the room to cool down
  the gas continues to the compressor to continue this cycle

Question 4

How many sensors does air-conditioning systems have?

Answer 4

1. There are usually two temperature sensors that monitor the temperature off the refrigeration
2. pressure sensor that monitors the pressure of the refrigeration

Question 5

What is Batch Process Control?

Answer 5

This is used in processes where specific amounts of raw material are combined together and mixed for a certain period of time. Example is the manufacturing of food products such as ready packed meals

Question 6

What is Continuous Process Control?

Answer 6

This refers to a process that appears to be unending, for example the maintaining of temperature in confined surroundings. Like a refrigeration plant where it is necessary to maintain a constant low temperature using continuous process control.

Question 7

What is Discrete Process Control?

Answer 7

This is when specific items are produced. it is likened to an on/off or stop/start process. Example, manufacturing a car.

Question 8

What is PLC?

Answer 8

Programmable Logic Control

• it is what oversees process control
• PLC is a type of computer or microcomputer that is used for a single purpose.
• It is able to accept analogue and digital inputs, and a set of logic statements is used to compare the input with pre-set values.
• Depending on the result, it activates the out put device/

Question 9

what is process control?

Answer 9

Process control is the use of computers or microprocessors to control a process.

Question 10

How to program PLC?

Answer 10

Proportional-integral-Derivative (PID) algorithm.

Question 11

What is Embedded Web Technology (EWT)?

Answer 11

• EWT is a technology developed by NASA
• so experiments in outer space could be conducted by authorized personal anywhere in the world provided they had access to a computer and internet
• The technology combines the internet, world wide web and real time systems into one technology for controlling embedded systems.

Question 12

What are embedded systems?

Answer 12

Is an integration of microprocessors, input sensors, output actuators and the software needed to control them.
they can be built into any real time control system.

Question 13

What is video-conferencing?

Answer 13

Video-conferencing is the process where audio and video signals are transmitted simultaneously on a real time process where responses are real time and they are done using sophisticated hardware and software.

Question 14

what is Hardware needed for video-conferencing?

Answer 14

1. Microphone
2. Speakers
3. Projector
4. Headset
5. Web cam
6. Modems

Question 15

What is Software needed for video-conferencing?

Answer 15

1. Echo cancellation software
2. Web browsers
3. ISDN software
4. Ivisit
5. Skype
6. Acrobat connect Pro

Question 16

Advantages of using video-conferencing?

Answer 16

1. Saves money as there is no need to travel and pay for accommodation costs.
2. Meetings can be held at short notice.
3. Can make up for different time zones and can hold meetings at a convenient time to the user.
4. Can avoid travelling to dangerous parts of the country to attend meetings.
5. Meetings can be held with groups of different size.
6. Saves time also as there is no need to travel and reach for the meeting.

Question 17

Disadvantages of using video-conferencing

Answer 17

1. Loss of network signals can result in the process to be still.
2. Quality of images and sound depend on new innovative such as new hardware and software.
3. Is expensive to buy the required devices for setting up a video-conference.
4. People should be trained how to setup a video-conference.
5. Computer crimes such as eavesdropping and hacking can lead to information misuse.

Question 18

what are the different types of advertising?

Answer 18

1. Product advertising
2. Business advertising
3. Services advertising

Question 19

what is Product advertising?

Answer 19

is the advertising of a specific product.
product advertising is all about advertising one item: it may be a specific model of car, but not the whole range of cars the company might sell.
Advertising for the target audience.

Question 20

what is Business advertising?

Answer 20

it is advertising the business for it to become familiar with the people so as to make money.
the business needs to identify what type of customer they want to attract.

Question 21

what is Services advertising?

Answer 21

It is the advertising of a service rather than a product.

very similar to business advertising .

Question 22

What are sequential files?

Answer 22

In a sequential file records are stored one after the other, in order of which they were added to the storage medium, usually magnetic tape.

Question 23

what are random access files?

Answer 23

Random access is the quickest form of access. It does not matter whereabouts in the file the desire record is;it will take the same amount of time to access any particular record. Each record is fixed length and each has a key. the computer looks up the key and goes to the appropriate place on the disk access it.

Question 24

What is a relational database?

Answer 24

A relational database consists of a number of separate tables that are related in some way. Each table has a key field that is a field in at least one other table. Data from one table can be combined with data from another table when producing reports.

Question 25

What is the diagram for a New Master file?

Answer 25

Old master file Transaction file
\ \
Update
/ /
New Master file Reports

Key
Arrow in: \
Arrow out: /

Question 26

What are Payroll Systems?

Answer 26

They involve batch processing• The files are stored on two separate magnetic files• This obviously then means that there will be two types of data files involved

Question 27

What is a master file and a transaction file

Answer 27

1. Master file – containing data about the workers: i. Employee number ( This is used as the PRIMARY KEY; data is stored in order of this)
   ii. Name
   iii. Contact details
   iv. Rate of pay
   v. Pay received
2. Transaction File – is a temporary file; containing data that can change from month to month. I. Contains details of # of hours worked + any overtime + employee number. II. Details of any new worker or any worker whose details have been changed.

Question 28

What happens in a payroll system?

Answer 28

End of week/month: The master file is processed using the transaction file.
• BEFORE the processing, the transaction file needs to be put in the same order as the master file.
• Computer then calculates the pay of each worker use the # of hours worked and the rate per hour
• Payslips then printed along with error reports.