12 Models and Simulations

Model vs Simulation A template of a physical object A mathematical model of a physical object Object modelled may be small or large (atom, solar system) Weather model A process / activity performed with a model It is a model with variables A collection of methods used to study/analyse the behaviour and performance of actual or theoretical systems Car crash

Simulation Modelling Simulation modelling means using a computer and mathematical formulas to imitate a real phenomenon. They look at ‘what if’ scenarios

Examples Models: Car dummy Drawing Diagrams Weather chart Financial model (using a spreadsheet) Simulations: Flight simulator Weather forecasting Games Car crash simulators

Components of a model Input values Variables Constants Constraints Rules Example: Economic model: unemployment= people able to work – people actually working

Advantages/Disadvantages + Cheaper than using real life scenarios E.g. car crash – cheaper than real cars and people Safer E.g flight simulator Can save time E.g. global warming simulations Can try different scenarios/situations Pilots: different weather conditions Making a nuclear reactor go critical - Powerful expensive computer hardware needed to run simulations Reality vs simulation Always a gap between the 2 Accuracy of rules Mistakes in variables or rules Some situations are hard to model (e.g. earthquakes) Some aspects can be open to interpretation. Some experts may disagree about the rules that apply

Hardware related to simulations Parallel processors – very powerful systems. Need to carry out many tasks ‘at same time’ Distributed processing More than one processor are used to run one application Can be different computers in a network