COMP 522 Modelling and Simulation model everything

Transcription

1 Fall Term 2004 COMP 522 Modelling and Simulation model everything Hans Vangheluwe Modelling, Simulation and Design Lab (MSDL) School of Computer Science, McGill University, Montréal, Canada Hans Vangheluwe Modelling and Simulation 1/32

2 COMP 522A: Modelling and Simulation... to study structure and behaviour... for analysis and design of complex systems... for different application domains: computer networks, software design, traffic control, software engineering, biology, physics, chemistry, management, implemented using Computer Science... focus on Software Aspects of Complex Systems Hans Vangheluwe Modelling and Simulation 2/32

3 A Variety of Complex Systems... Need to be modelled at appropriate levels of abstraction in appropriate formalisms Hans Vangheluwe Modelling and Simulation 3/32

4 Overview 1. What is Modelling and Simulation? 2. Which topics does COMP 522 cover? 3. What are the pre-requisites? 4. How is evaluation done? 5. What are the assignments about? 6. Where do I get the material covered in CS522? 7. What is the schedule? Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 4/32

5 What is Modelling and Simulation? Modelling: represent/re-use/exchange knowledge about system structure and behaviour Simulation: to accurately and efficiently emulate real behaviour Why? cost, danger,... what-if analysis? optimization (do it right the first time)! modelling and simulation based design Hans Vangheluwe Modelling and Simulation 5/32

6 Modelling and Simulation Based Design Hans Vangheluwe Modelling and Simulation 6/32

7 Modelling and Simulation in action: Training USC Institute for Creative Technologies Hans Vangheluwe Modelling and Simulation 7/32

8 Modelling and Simulation is Computer Science, Artificial Intelligence... is Numerical Analysis, Computer Algebra... is Systems Theory, Control Theory... is Operations Research... is Application Domain: Mechanical Engineering, or something more GENERIC? Hans Vangheluwe Modelling and Simulation 8/32

9 REALITY MODEL Real-World entity Base Model GOALS only study behaviour in experimental context System S within context Model M Model Base a-priori knowledge experiment within context simulate = virtual experiment Experiment Observed Data validation Simulation Results Modelling and Simulation Process Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 9/32

10 COMP 522 Concept Map Hierarchy of System Specifications is theory behind Causal Block Diagrams Formalisms time-less CBDs discrete-time CBDs continuous-time CBDs Discrete Event Continuous-Time Finite State Automata (FSA) Event Scheduling CSSLs Population Dynamics Petri Nets Statecharts Activity Scanning Process Interaction Forrester System Dynamics GPSS Modelica (multi-physics) DEVS Hybrid visualized using Animation Hans Vangheluwe Modelling and Simulation 10/32

11 Which topics does the course cover? 1. Formalism syntax and semantics. Causal Block Diagrams. 2. Hierarchy of System Specifications, Systems Theory. 3. Untimed Discrete Event Formalisms: (a) (non)deterministic State Automata. (b) Adding Concurrency and Synchronisation: Petri Nets (e.g., specifying network protocols). (c) Adding Hierarchy and Orthogonality: Statecharts (e.g., UML, specifying reactive software). 4. Timed Discrete Event Formalisms: (a) Timed Automata. (b) Event Scheduling. Hans Vangheluwe Modelling and Simulation 11/32

12 (c) Activity Scanning (AI). (d) Three Phase Approach. (e) Process Interaction for queueing systems (GPSS). (f) DEVS as a rigourous basis for hierarchical modelling. 5. Deterministic Simulation of Stochastic Processes: (a) Pseudo Random Number Generation. (b) Gathering Statistics (performance metrics). 6. Animation 7. Continuous-time Formalisms: (a) Ordinary Differential Equations, Algebraic Equations, Differential Algebraic Equations. (b) CSSLs: sorting and algebraic loop detection. (c) Forrester System Dynamics, Population Dynamics. (d) Object-oriented Physical Systems Modelling: Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 12/32

13 non-causal modelling, Modelica. 8. Hybrid (continuous-discrete) modelling and simulation. Assignments (5): cover these topics Project: For a formalism of choice (possibly construct your own): build a modelling and/or simulation environment. Using an existing modelling/simulation system: study a specific problem. Exam: mini-quiz during last lecture Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 13/32

14 Causal Block Diagrams (cfr. Matlab/Simulink) INDEP Plot DEP TIME 4.0 K 1.0 M 0.0 X0 1.0 V0 ^ 1 IC IC I O INDEP Print DEP Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 14/32

15 Petri Net model of intersection Hans Vangheluwe Modelling and Simulation 15/32

16 trafficdevs intersection animation Hans Vangheluwe Modelling and Simulation 16/32

17 GPSS model of a Telephone Exchange 12 FN1 Function: 1 LNKS 10 V2 2 R PH1 0 1 V1 PH 1 LNKS LR PH1 LR PH2 R PH1 2 V1 H S PH2 LNKS P1 NE P2 120 FN1 1 S PH1 Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 17/32

18 Process Interaction DEV: GPSS SIMULATE * * GPSS/H Block Section (the model) * * * MANUFACTURING SHOP - MODEL 1 * Time unit = 1 minute * GENERATE 5 Create parts ADVANCE 4,3 Inspect TRANSFER.1,ACC,REJ Select rejects ACC TERMINATE 1 Accepted parts REJ TERMINATE 1 Rejected parts * * GPSS/H Control Statements (the experiment(s)) * START 1000 Run 1000 parts END Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 18/32

19 Population Dynamics, System Dynamics uptake_predator loss_prey Grazing_efficiency prey_surplus_br predator_surplus_dr Predator Prey 2 species predator prey system Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 19/32

20 Trajectory trajectories 600 predator prey Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 20/32

21 What are the pre-requisites? COMP 251 (data structures and algorithms), COMP 302 (programming languages and paradigms), COMP 350 (numerical computing).... or equivalent (see me). Note: all assignment/project programming in Python no prior knowledge required, read Tutorial at Hans Vangheluwe Modelling and Simulation 21/32

22 How is evaluation done? 65% on 5 assignments (more than 10% per assignment!!). 30% on the project (work, correctness, presentation). 5% on a mini-quiz during the last lecture. Together, assignments, mini-quiz and project cover the entire course. Hence, there is no final exam. Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 22/32

23 Assignment/project rules of the game? Completely in HTML form: requirements, design, code, discussion. Submit via WebCT. All coding in Python (where appropriate). Assignments in groups of 2, project in groups of maximum 3. Original work, some presented in class. Respect deadlines (or do more work to compensate). Alternate subjects may be proposed. Hans Vangheluwe Modelling and Simulation 23/32

24 Need help? Use the discussion forum in WebCT Come and see me Monday 10:00-18:00 in MC328 See the TA (Marc Provost) Wednesday 11:30-13:00 in MC202 Talk to me after class or make an appointment Assignments/projects are never fully specified! Give feedback! Hans Vangheluwe Modelling and Simulation 24/32

25 Undergraduate or Graduate course? Challenging course (work load) graduate flavour (independent thinking) some of the highest grades ever were obtained by ugrads Hans Vangheluwe Modelling and Simulation 25/32

26 What are the assignments about? 1. A Causal Block Diagram simulation tool. 2. Petri Net model and analysis. 3. Statechart model and software synthesis. 4. GPSS (process interaction) model of a queueing system. 5. A DEVS model of a traffic system. Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 26/32

27 What are the project subjects? Model/simulate a particular application (e.g., traffic, biology) Build a modelling/simulation/animation tool for a particular formalism Suggestions are welcome! Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 27/32

28 Where do I get the material covered in CS522? Class presentations/notes online in PDF format. Some handouts during the term. Links and references for background info. Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 28/32

29 The schedule (tentative) All lectures and tutorials are held 8:00 9:30 in Trottier Wednesday 1 September Course Introduction Friday 3 September Causal Block Diagrams time-less Monday 6 September Labour Day, no class Wednesday 8 September Causal Block Diagrams discrete-time Friday 10 September tutorial: AToM 3 internals Monday 13 September Causal Block Diagrams continuous-time Wednesday 15 September The Modelling and Simulation Process Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 29/32

30 The schedule (tentative) Friday 17 September A Hierarchy of System Specification Monday 20 September A Hierarchy of System Specification Wednesday 22 September State Automata Friday 24 September demo: model-based complex systems design Monday 26 September Petri Nets (basics) Wednesday 28 September Petri Nets (analysis) Friday 1 October presentation: projects Monday 4 October Statecharts (intro) Wednesday 6 October Statecharts (semantics) Friday 8 October tutorial: DCharts in AToM 3 Monday 11 October Thanksgiving Day, no class Wednesday 13 October Statecharts (applications) Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 30/32

31 The schedule (tentative) Friday 15 October The Event Scheduling World View Monday 18 October The Process Interaction World View Wednesday 20 October GPSS Friday 22 October tutorial: GPSS World Monday 25 October no class Wednesday 27 October no class Friday 29 October no class Monday 1 November GPSS Wednesday 3 November GPSS Friday 5 November DEVS (atomic) Monday 8 November DEVS (coupled) Wednesday 9 November DEVS (simulator) Friday 11 November tutorial: PythonDEVS Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 31/32

32 The schedule (tentative) Monday 14 November Animation Wednesday 16 November Continuous-time models (causal) Friday 18 November Population Dynamics Monday 21 November Forrester System Dynamics Wednesday 23 November Modelica: OO Modelling of Physical Systems Friday 25 November work on project Monday 29 November work on project Wednesday 1 December Project Presentations Friday 3 December Project Presentations Hans Vangheluwe hv@cs.mcgill.ca Modelling and Simulation 32/32