seminar on computer simulation and modeling the activity approach by:asamene.k
TRANSCRIPT
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Seminar on computer simulation and modeling
The Activity Approach
By:Asamene.K
EIT-M
School of electrical & computer engineering
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What Is Discrete-Event Simulation (DES)?
Discrete-Event Modeling Approaches
The activity approach
An activity based executive
The harassed booking clerk — an
activity based approach
Outline of Topics
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Discrete-event simulation Discrete-event system simulation is the modeling of the systemsin which the state variables change only at a discrete set of points in time. A system is modeled in terms of
its state at each point in timethe entities that pass through the system and the entities that represent system resources
the activities and events that cause system state to change. Discrete-event models are appropriate for those systems for which changes in system state occur only at discrete points in time.
Seminar on computer simulation and modeling
The Activity Approach
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Strategies of discrete event simulation
Activity-oriented simulationEvent-oriented simulationProcess-oriented simulation
Seminar on computer simulation and modeling
The Activity Approach
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The Activity Approach The activity-scanning approach uses a fixed time increment and
a rule-based approach to decide whether any activities can begin
at each point in simulated time.
the strict event-based approach its main beauty is its simplicity
Seminar on computer simulation and modeling
The Activity Approach
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The Activity Approach(continue) The programmer defines activities which arestarted when certain conditions are satisfied. In many cases, this type of simulation uses a simulated clock which advance in constant increments of time.
This type of model is used more often with simulating physical devices
Seminar on computer simulation and modeling
The Activity Approach
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The Activity Approach(continue)EXAMPLE 3.2 (Able and Baker, Back Again)
The events and activities were identified in Example 3.1.
Using the three-phase approach, the conditions for beginning each activity in Phase C are:
Seminar on computer simulation and modeling
The Activity Approach
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The Activity Approach(continue)With each advance, a list of activities is scanned, and those which have become eligible are started.
Simple in concept, but slow runtime on computers
Seminar on computer simulation and modeling
The Activity Approach
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Activity-Based executiveshas two phases:(1) Check the time cells (or event calendar) tofind the time of the next event. Move thesimulation clock to this time.
Seminar on computer simulation and modeling
The Activity Approach
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Activity-Based executives(continue)(2) Repeatedly scan through the activities, tryingeach test-head to see if that activity is now dueor able to occur. Continue the scan until nomore activities are executable at that time.This cycle is repeated until the simulation is over.
Seminar on computer simulation and modeling
The Activity Approach
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Activity-Based executives(continue)
Seminar on computer simulation and modeling
The Activity Approach
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the harassed booking clerk simulationthere would be six such activities:ArriveEndOfServiceCallEndOfTalkBegin ServiceBeginTalk
Seminar on computer simulation and modeling
The Activity Approach
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the harassed booking clerk simulation
Seminar on computer simulation and modeling
The Activity Approach
Conclusion
References Jerry Banks, John S. Carson, Barry L. Nelson, David M. Nicol , "Discrete Event System Simulation", 4th edition, Prentice Hall, 2005, ISBN 0131293427
DISCRETE-EVENT SYSTEM SIMULATION
Third Edition Jerry Banks John S. Carson II
Barry L. Nelson David M. Nicol
Seminar on computer simulation and modeling
The Activity Approach
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Seminar on computer simulation and modeling
The Activity Approach
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