# Computer Igsce Revision

Topics: Mathematical model, Computer simulation, Computer graphics Pages: 5 (822 words) Published: December 2, 2012
r 1. Simulation:
* Studying behavior of a system by using a model that represents real life/ * Uses a lot of mathematical representation
* results can be predicted e.g. flight/other simulator,

2. Why do some real life applications need to be simulated first before actual implementation? It is used for modeling difficult situations and complex applications such as hazardous chemical reaction, computer games, traffic control lights, flight paths and medical situations.

3. A simulation using a mathematical model is being used to forecast the weather one week in advance.

(a) (i)State what data are gathered for this model.
* pressure
* temperature
* humidity
* wind speed/direction
* historic data

(ii) Explain how the data are gathered for this model.

* sensors
* satellites
* airline pilots send in information
* meteorological/weather balloons/station
(b) (i)Describe how the simulation can predict the weather for the next seven days.

* information from sensors/satellites sent to computer * data compared to stored information
* which contains known weather patterns
* predictions made based on these comparisons using expert system

(ii) Describe in what format the predicted weather can be shown.

* produces weather maps showing isobars, etc.
* computer can show weather changes graphically/by animations

4. (a) How could a computer simulation be used by a supermarket to reduce queuing at checkouts?

* count people at the check-outs
* allows optimum number of check-outs to be open
* run computer model with differing scenarios

(b) The supermarket has decided to fit sensors at the shop entrance to count people coming in and leaving.

(i)What type of sensor would be suitable to detect people?

* infra-red sensor
(ii) How could the supermarket use the information obtained from these sensors? * safety reasons (in case of fire, for example)
* how many check-outs to open
* check on how many customers use s/market at different times * feed information into simulation/model

(c) The supermarket has decided to fit information screens at various locations for customer use. These information screens do not use keyboards.

(i)Give one example of a suitable input device.

* trackerball
*
(ii) What information could be made available to supermarket customers?

* special offers/goods on sale
* map of supermarket/where things are
* prices of goods
* services available (e.g. insurance)

(iii) Give one advantage of using this system rather than displaying signs and notices around the supermarket. * quick to update
* could allow interaction with customers

5. A road system is to be operated using computer-controlled traffic lights. Sensors are used as part of the control system.

(a) The movement of traffic throughout the road system was first simulated on a computer.

Describe what data would need to be collected and how it would be used in the simulation.

* (count) number of vehicles at various times of day/at different positions/in different directions * put data into computer and try out different scenarios
* look at effect of accidents/break downs
* look at effect of heavy traffic
* determine optimum timings of lights
* effect of emergency vehicles/public transport

(b) Give two advantages of carrying out a simulation first before introducing a new system.

* less expensive (must be qualified)
* much safer prevents accidents/traffic problems through incorrect lighting times * can try out many scenarios first (to give optimum settings) * much faster than doing actual “experiments” on real lights

(c) Describe how the sensors, traffic lights and computer interact to control...