Modeling and Simulation

Dr. X

Simulation Design

• Event Advance• Unit Time Advance• Activity Based

Event advance design

• System changes when event occurs• Each event is associated with a clock• Master clock advances based on event time

Event advance

Future event list

• Contains events• Event has the following fields:– Type– Time– Other?

• Performance considerations:– Add event– Remove event– Find next event

Unit-time advance design

• Master clock is advanced in fixed increments of time

Selecting time unit

• Problems:– Inaccuracies– Speed

Implementation

• Compare master clock with future event list time

Activity based design

• Event driven: event changes system state• Activity driven: system model is a collection of

activities of services• Machine oriented models• SSQ:– Interarriving– Being served– Waiting for service

SSQ Activity based

What to do on Wednesday• Besides being sad that we are missing class…• Look for open source simulation software in the areas of your interest:

– Biology– Physics– Chemistry– Business– Engineering– Computer science– Games simulations– other?

• Download and run the software• Think about your project: can you design something similar? How?• Write a paragraph of ideas that you have for your project

Suggestions of free Simulation Software

• Minskyhttp://sourceforge.net/projects/minsky/

• Open Source Physicshttp://www.compadre.org/osp/index.cfm

• PALhttp://www.adrianboeing.com/pal/engines.html

• OpenModelicahttps://www.openmodelica.org/

• SimPyhttp://simpy.readthedocs.org/en/latest/

• PHEThttp://phet.colorado.edu/en/simulations/category/new

• Roboworkshttp://www.newtonium.com/

• WeBotshttp://www.cyberbotics.com/