modelling application

Modelling application:
is a simulation that create model. This model is based on mathematical representations. This system can predict the behaviour in the future. A computer models have a advantage that can save up money, safer, also find solution more quickly. There are 2 examples traffic light simulation and model for showing the profit and loss.

Tuck shop simulation:
This simulation can show you the profit and loss of a price. This modelling uses the mathematical form.

Traffic light simulation:
This simulation is more complex. Example of traffic light is a Y junction. The data need to watch traffic for a long period of time at the Y junction.They use sensors to count the number of vehicles that passes through at each junction.This is the following data what do you need to collect:
the number of vehicles passing the junction in all directions
the time of day for the vehicle count
how many vehicles build up at the junction at different times of the day
how vehicle movements change at weekends, bank holidays, etc.
how long it takes a vehicle to clear the junction
how long it takes the slowest vehicle to pass through the junction
the movements made by vehicles (e.g. left turns, right turns, filtering, etc.)
additional environmental factors, such as whether there are pedestrian
    crossings nearby.

Carrying out the simulation:
data from the above list entered to the computer and simulation run. The simulation are compared to the real/ actual traffic light. once the designers are satisfied that it simulates the real situation accurately, then the different scenarios can be tried out. for example:
vary the timing of the lights and see how the traffic flow is affected
build up the number of vehicles stopped at part of the junction and then changethe timing of the lights to see how the traffic flow is affected
increase or decrease traffic flow in all directions
how emergency vehicles affect traffic flow at different times of the day.

Using the simulation:
The simulation can see the flow of the junction, if the red light need to be slower time that it needs, the computer can change the timer as the people control it.
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 may need to be converted
first into a form understood by the computer.
The gathered data is compared to data stored in the system. The stored data is
based on model/simulation predictions which were used to optimise the traffic flow.
The control box or computer ‘decides’ what action needs to be taken.
Signals are sent out to the traffic lights to change their timing if necessary.

Why simulations are used:
to build a real thing need a long time to build but if you use a simulation, you don't need to wait a long time to build it. if you don't like what you are building on your simulation, you just need to delete it.

Batch processing:

A number of task are all collected together over a period of time. Can only be done where there are no timing constraints. Cannot straight away respond. Can be process when the computer is not busy or less busy. Include billing.

Real time processing:

An example of online processing. Booking seats in theatre, flight. Needs to be fast in order to prevent double booking. The booking uses the ATM.

Real time process control:

An example of online processing. Involves sensors and feedback loops. Update in real time. Can see the temperature, data.

Driving simulations:

We use driving simulations for making driving license. Driving simulations used if you cannot drive a car and you want to learn how to drive, usually you use driving simulation car. Driving simulation car is a car if you are driving/ learning, example you ecidentaly want to crush a wall, the car can instantly stop.

Driving simulation use real time process control.