IGCSE IC Chapter 6 Section 2

1. 6.2 Modelling Applications

2. OBJECTIVES
▹ Computer modelling including finance,
bridge and building design, flood water
management, traffic management,
weather forecasting
▹ Advantages and disadvantages of using
computer modelling rather than humans

3. STARTER
Imagine that the Traffic police department wants
to build a new Traffic signal.
How can they ensure that the signal they design
works well, does not cause traffic congestion in
other roads, and helps manage the flow of traffic
equally in all roads?

4. WHAT is a Computer
model ?
It is a computer-generated
simulation which would
replicate/simulate the functions
of a real system.
It is designed to behave just like
the real-world system.

5. Advantages of using models?

6. To save costs and time
by testing a system
before you build it.
e.g. Creating bridges
On many occasions it is
safer to use a computer
model
e.g. chemical processes
Computer modelling allows
you to try out various
different scenarios in
advance.
It is nearly impossible to
try out some tasks in
advance in real life
because of the high risk
involved or the
remoteness (for example,
in space, under the sea, in
nuclear reactors, when
crash testing cars, etc.).
Advantages of use Computer Models?
It is often faster to use a
computer model than do
the real thing

7. Disadvantages of using models?

8. A model is only as good
as the programming or
the data entered; the
simulation will depend
heavily on these two
factors.
Although building the real
thing can be expensive,
sometimes computer
modelling is also a very
costly option, and the two
costs need to be
compared before deciding
which to use.
People’s reactions to the
results of a simulation may
not be positive; they may
not trust the results it
produces
Disadvantages of use Computer Models?

9. Where is computer modelling used ?

10. Personal
finance
Bridge and
building design
Flood water
management
Where we used Computer
Models?
Traffic
management
Weather
forecasting

11. WHAT are the types of Modelling
Applications ?

12. Type of Modelling Application
Personal
Finance-
Spreadsheets
• Business can use spreadsheets models to forecast future profit
or loss.
• Due to the use of formulas business can adjust certain values to
see automatic changes in potential revenue.
Bridge and
Building
Design
• A computer model of a bridge can be used to test the design
• Bridges have to be able to survive extreme weather conditions.
It is obvious not practical to build a real bridge and then wait
to see if it falls down in a storm. Instead, a computer model of the
bridge is created and tested in virtual storms
• If the model breaks, it can be quickly and cheaply re-
designed and re-tested.
• Bridges can also be tested to see if they can cope with heavy
traffic..
Flood Water
Management
• Computer models are used to predict water levels, water flows
and potential flood depths.
• Flood water management uses computer modelling to perform a
risk assessment to identify sources of potential flooding, the
extent of flooding and how any mitigation or protection measures
could work

13. Type of Modelling Application
Traffic Lights
Simulation
• A traffic light simulator looks at the flow of traffic (data captured
from sensors).
• The simulator will adjust the lights to best control the flow of
traffic.
Weather
forecasting
• Uses a variety of sensors to measure rainfall, temperature,
wind speed, wind direction, air pressure, humidity.
• Data is continuously gathered, input into a model, which
then predicts the weather
• Continuous improvement is made

14. Sample Past paper question
?

15. Example of Traffic light simulation
How and what data needs to be collected?
Data needs to be collected by watching traffic for a long period of time at the Y-junction.
This is best done by using induction loop sensors which count the number of vehicles at
each junction. Manual data collection is possible, but is prone to errors and is difficult to
do over an 18-hour period per day
The following data is an indication of what would need to be collected:
 the number of vehicles passing the junction in all directions
 the time of day needs to be recorded along with a vehicle count
 how many vehicles build up at the junction at different times of the day
 data should cover weekends, bank holidays, etc. as this can alter how the
data needs be interpreted
 how long it takes a vehicle to clear the junction
 other data needs to be considered (for example, pedestrian crossings)
 how long it takes the slowest vehicle to pass through the junction
 consider other factors (for example, left turns, right turns, filtering, etc.).

16. Sensors in the road gather data and count the
number of vehicles at the junction.
This data is sent to a control box or to a computer
(it will need to be converted first into a form
understood by the computer).
The gathered data is compared to data stored in
the system
The control box or computer ‘decides’ what action
needs to be taken.
Signals are then sent out to the traffic lights to
change their timing if necessary
Example of Traffic light simulation
How the system would work in real life

17. Example of Weather forecasting
Weather modelling is often shown in animated format where cloud,
rain, sun and wind are projected on top of a map of the country and
shown in real time

18. Which of the school values did you use today?

19. CLASS TASK WORKSHEET –QUESTION 1

20. CLASS TASK WORKSHEET – ANSWER 1

21. CLASS TASK WORKSHEET –QUESTION 2

22. CLASS TASK WORKSHEET – ANSWER 2

23. Plenary

24. Plenary