This document discusses various types of models, simulations, and their uses. It describes models as mathematical representations that predict real-world systems based on past data. Simulations interactively recreate experiences for learning, using models and user input. Examples discussed include population growth, chemical reactions, flight simulators, and economic models. Advantages are listed as avoiding risks to equipment and people while allowing repeated testing; disadvantages include incomplete representations of reality and high costs.

1. Chapter 23 1
Modeling
 A model is a program which has been
developed to copy the way a system
works in real life.
 It uses mathematical formulas and
calculations to predict what is likely to
happen based on data recorded about
what actually did happen in the past.
 A modeling is a set of equations
which describes the behavior of
process

2. Chapter 23 2
Model Builder
 You can develop and evaluate your own models or
use the models that have already been set up to
simulate a real life
 Models include
 Population growth
 Supply and demand
 Chemical reactions
 Nutrient cycle
 Carbon cycle
 Nitrogen cycle

3. Chapter 23 3
Expert System & Expert Builder
 Expert System
 Expert system are programs
that mimic the intelligence of
human expert in a specific
field of knowledge.
 Could be set up to give
medical advice.
 The computer is given a base
of knowledge from the expert
and then given the rules for
processing.
 Computer ask the questions
similar to those the expert
would ask and then comes to
similar conclusion.
 Expert Builder
 That enables you to
construct logical diagrams of
your knowledge .
 This software helps you to
understand a problem more
clearly

4. Chapter 23 4
Simulations
 A simulation is a software package that recreates
or simulates a complex phenomena,
environment, or experience in order to provide the
user with a better understanding.
 A simulation is interactive, and relies upon
decisions made by the user, often in ‘real time’.
 Simulation uses computer modelling in order to
work.
 The difference between a model and a
simulation is that a simulation also uses
something physical to mimic the system.

5. Chapter 23 5
Simulations
 Examples
 Thrill ride simulator somewhere like Disneyland.
 Another form of simulation is Virtual Reality.
 Experiments in chemistry
 Airline training
 Traffic lights Systems
 Nuclear physics experiments
 Common uses of simulations include:
 Computer games.
 Flight simulators.
 Economic models.
 3D Engineering simulations.

6. Chapter 23 6
Computer games
 Computer games are simulations of various
types of experience.
 They have five elements:
 Graphics (often 3D and sometimes incorporating Full
Motion Video [FMV]).
 Sound (including music and sound effects).
 An interface (usually the keyboard or a joystick but
also including the graphics, the menu, and the Artificial
Intelligence [AI] incorporated into the game’s
programming).
 Game play (including fun and length of playability).
 Scenario (the background to the game and any
information or understanding that the player gathers
during play).

7. Chapter 23 7
Flight simulators
 Flight simulators are used to train pilots
how to fly.
 They can also be used to test new
aircraft before they are actually flown for
the first time.
 Flight simulators are expensive to buy
but are much cheaper than actual aircraft.
 A landing simulation with ice on the
runway, thick fog and only one of the four
engines working would really test the
pilot’s ability

8. Chapter 23 8
Economic models
 Economic models are used by governments
and businesses to see what would happen if
changes occurred in the economy.
 For example, the government might want to
see what would happen if they changed the
level of tax on fuel – Would prices increase?
Would road haulage companies go out of
business?

9. Chapter 23 9
3D Engineering simulations
 3D Engineering simulations can be
used to design new products (e.g.
cars) or to test existing products
(e.g. Nuclear power stations, oil
refineries, aircraft) in ways that
would be too expensive or too
dangerous to do in real life.
 Simpler versions can also be used
to help people to sell products (e.g.
new kitchens), where potential
buyers want to see what the
finished product will look like.

10. Chapter 23 10
Advantages of Models
 No equipment is damaged
 People aren't put in any danger
 Expensive prototypes don't need to be built
 Time can be sped up or slowed down
 Models can be run and re-run over and over
 Modifications can easily be made and re-
tested quickly

11. Chapter 23 11
Disadvantages of Models and Simulations
 The results depend on how good the model is and
how much data was used to create it in the first
place.
 Models and simulations can't ever completely re-
create real-life situations.
 Not every possible situation may have been
included in the model.
 The equipment and software are expensive to
purchase.
 Staff need to be trained how to use the software
and equipment.