The ICT Lounge
 
Section 7.6:
Modelling Applications
 
Computers can be used to simulate different scenarios to work out all of the possible outcomes. This is called 'modelling'.
Key Concepts of this section:
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Understand how computers can be used to 'model' or 'simulate' real-life situations.
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Know some advantages / disadvantages of computer modelling.
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Be able to discuss different examples of computer modelling.

Examples of computer modelling include:

  • Flight simulators to help train aircraft pilots
  • 3D models of buildings and products to simulate how designs will look when built
  • Spreadsheet models to simulate profit/loss based on different levels of income.
Computer Modelling and Simulation
Key Words:
Modelling, Simulation, Prediction, Training, Design.
What is a computer model/simulation?
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Simulations aim to mimic (copy) real life systems in order to see the outcomes of different scenarios.

Another name for a computer simulation that mimics real-life situations is a 'computer model'.

Computer simulations can be created for a range of applications including:
What are computer models used for?
Prediction
Models can predict outcomes based on inputs we enter (e.g. spreadsheets)
Training
For example, allowing pilots or surgeons to learn their skills safely.
Design
Architects can produce very accurate 3D models of buildings.
 
Finance Simulation
Flight Simulation
Driving Simulation
3D Models

Advantages of using computer models/simulations
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Using computer simulations and models to mimic real-life situations can bring many advantages. Some include:
Crashing a plane in a flight-sim is safe.
 
Buildings can be perfected in a 3D model before money is spent on actual construction
 
Cheaper -
Modelling a situation is often much cheaper than carrying out the task for real. For example, architects can make and solve design errors on simulated buildings rather than waiting until the real thing is constructed before realising.

Safer -
Flight simulators mimic the skills needed to fly a plane. Novice pilots are likely to crash the plane whilst they are learning. This could be fatal if piloting a real aircraft. If a simulated plane is crashed, they just reload the simulation and try again.

Saves Time -
Simulations can produce results faster than the real thing. For example, global warming models can predict the temperature of the earth in 50 years time without actually having to wait that long.

Greater Range of Situations -
Simulations can be programmed to mimic a wide range of extreme situations. For example, pilots can be exposed to storms, volcanic ash clouds, high winds etc. In real life these conditions cannot be guaranteed.
Disadvantages of using computer models/simulations
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Disadvantages of using computer simulations/models include:
Some simulators require expensive hardware.
 
Accuracy -
Modelling a situation can never perfectly mimic real life. There will always be some difference between the model and reality.
Initial Expense -
Simulators require sophisticated hardware and software. For example, high powered processors and lots of RAM. The simulation software (program) can also be expensive.

Programmer Error -
If the simulation's programmer has made errors whilst creating the program, the simulation outcomes will be more inaccurate.
Examples of Computer Models/Simulations
The following examples discuss some computer models:
Flight Simulator (used to train pilots)
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These mimic the skills needed to pilot a real aircraft. there are two types of flight simulator:
  • PC/Laptop simulation designed to be used at home
  • Replica cockpit simulations which are large and expensive but feel more like the real thing.
Cockpit flight sim with realistic controls
 
PC flight sim for use in the home
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The simulator allows the pilot to practice the following flight skills:
  • Use of cockpit controls
  • Take off / Land
  • Navigation (following correct path to a destination)
  • Handling different conditions (high wind, storms, engine failure)
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At first trainee pilots will make mistakes and maybe even crash the plane. This doesn't matter because they can simply reset the simulation and try again. Nobody gets hurt.

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When the trainee gains enough experience in the simulator, they will be allowed to fly a real plane.
PLAY VIDEO TO
SEE AN EXAMPLE
OF A COCKPIT
FLIGHT SIM
 
Driving Simulation (entertainment, training and crash testing)
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These mimic the skills required to control vehicles such as cars, trucks, buses and trains.
Crash-Test simulators allow engineers to design
and build safer cars
 
Old methods of crash-testing required real cars and crash test dummies. This is much more expensive.
 
Some driving simulators are for entertainment
purposes like Test Drive Unlimited 2
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Uses of driving simulators as a training tool include:
  • Use of vehicle controls (steering wheel, accelerator, gears, clutch etc)
  • Practice driving maneuvers (emergency stop, reversing, parking etc)
  • Learning how to handle large trucks safely
  • Driving in hazardous conditions (snow, heavy rain etc)
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As with flight simulators, trainee drivers can build up a high level of confidence using the driving simulation before they actually begin to drive for real. Any mistakes or crashes are just 'virtual' and vehicles are not damaged or any people hurt.

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Some driving simulators are used to mimic the effects of high-speed car crashes on the driver and passengers.

This replaces the old method of using actual cars and crash-test dummies and is much cheaper and easier to set up.

Data taken from the simulation allows engineers to design and build safer cars. This is known as 'Computer Aided Engineering' (CAE).

PLAY VIDEO TO SEE AN EXAMPLE OF A TRUCK
DRIVER TRAINING
SIMULATOR
 
3D Models (buildings, rooms, mobile phones etc)
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3D models are created using special software called 'Computer Aided Design' (CAD).

CAD software can be used to create computer generated prototypes for a wide range of models including:
3D models can be rotated to see all angles
 
3D computer prototype of a room design
 
3D model of a torch design. Note how the model demonstrates how the torch is assembled
  • Buildings
  • Rooms
  • Products and gadgets (phones, mp3 players etc)
NOTE!
A prototype is an early stage design for the intended product.
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3D models are created on the computer and then shown to the customer so they can give the designer feedback. The designer then applies changes directly to the model.

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Creating and viewing 3D models on the computer offers advantages including:
 
Zoom -
Images can be zoomed into so that fine detail can be seen clearly
Rotation -
Images can be rotated through many different angles so that every aspect of the model can be seen
Cheaper -
Creating and modifying prototypes on software does not require expensive, physical materials (like plastic, wood, bricks etc)
Quicker -
CAD software allows prototypes to be created and modified by manipulating elements on a screen. This is much quicker than having to assemble and change plastic/wood based prototypes.
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Once the customer is happy with the prototype model, the product is manufactured using real materials. Everyone can sure that the final product is to an exact specification with no errors because the 3D model was perfected prior to production. This can save lots and lots of money.

NOTE!
Imagine manufacturing the actual products and then realising there were design errors. This would be a hugely expensive problem to fix!
 
Finance Simulation (business spreadsheet models)
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Spreadsheet models can be used to predict finance type outcomes based on mathematical values.

These predictions can show us things like.
  • Profit / Loss
  • Over budget / Within Budget
  • Answers to 'What If' questions (see below)
Spreadsheet programs such as Microsoft Excel are commonly used to create finance models
 
Spreadsheets also make use of charts/graphs to show changes to the model
 
NOTE!
Unit 14: Data Analysis of the course syllabus is all about spreadsheet modelling.
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Spreadsheet models can be used to answer 'What If' questions. For example - "What if I give my staff a 10% pay rise. Will I still make a profit?"

This is made possible with the use of 'formulae' which recalculate results based on new data entered.

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Running questions like this through the spreadsheet can help managers make 'informed decisions' and reduce the risk of overspending and reduced profits.
Picture Examples:
Spreadsheet model showing what net profit is if employees receive a 10% pay increase.
By increasing the employee pay by 40%, the model predicts that the business will lose money.
     
Spreadsheet models use formulae to calculate their predictions.