Transcript CS 450 – Modeling and Simulation

CS 450 – Modeling and Simulation
Dr. X
Topics
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System Analysis
Arrival process
The Queue
The Server
The simulation
Single Server Queue
Single Server Queue
Arrival
Server
System Analysis
• Needs Analysis – why?
– Queue size
– Idleness
– Wait time
• Original System – what?
– Web server
– Buffers
– Requests
System Analysis
• Observable elements
– Queue size
– Request arrival
– Request departure
• Data
– Interarrivals
– Service time (interdepartures)
– Number of packets in buffer
Events?
Input data
• Arrival times
• Other?
Output data
Conceptual Model of SSQ
Arrival Process
• Mean
• Standard Deviation
• Distribution!!
How do we figure out a and b?
How do we figure out a and b?
Histograms
Histograms
Normal distribution
Uniform Distribution
Converting uniform to exponential
How the SSQ works
Event Scheduling
References
• The Guide to Computer Simulations and
Games, By Katrin Becker and J.R.Parker, Wiley
(Chapter 6)
• Computer Simulation Techniques: The
Definitive Introduction, by Harry Perros,
http://www4.ncsu.edu/~hp/simulation.pdf
(Chapter 2)
CS 450
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