Lecture 23 april 11 2002
This presentation is the property of its rightful owner.
Sponsored Links
1 / 26

Lecture 23 – April 11, 2002 PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on
  • Presentation posted in: General

Lecture 23 – April 11, 2002. Semester end questions More about Bond agents Models and languages supporting concurrency Petri Nets. Final Exam and Project. The final exam will be Thursday April 25, 7:00 – 9:00 PM in this class room.

Download Presentation

Lecture 23 – April 11, 2002

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Lecture 23 april 11 2002

Lecture 23 – April 11, 2002

  • Semester end questions

  • More about Bond agents

  • Models and languages supporting concurrency

  • Petri Nets


Final exam and project

Final Exam and Project

  • The final exam will be Thursday April 25,

    7:00 – 9:00 PM in this class room.

  • The class project is due on Monday April 22 at 9 AM. See http://www.cs.ucf.edu/~dcm/Spring02Class/Projects.html for a description of the format and contents of project.


Office hours during the last weeks

Office Hours during the last weeks

  • I will be out of town Sunday April 14 till Saturday, April 20.

  • I will be available on

    • Tuesday, April 24, 3 – 6 PM

    • Thursday, April 15, 4- 7 PM


Final exam

Final Exam

  • Open book

  • Comprehensive

  • Two hours

  • 4-6 problems


Final project presentations

Final project presentations

  • Tuessday – April 16:

    • 7:00 – 7:20 David Aihe

    • 7:20 – 7:40 Kiran Anna

    • 7:40 - 8:00 Temitope Alo

    • 8:00 - 8:20 Xin Bai

  • Thursday – April 18

    • 7:00 – 7:20 Wafa Elgarath

    • 7:20 – 7:40 Shan Natarajan

    • 7:40 – 8:00 Sudipta Rashit

    • 8:00 - 8:20 Vivek Singh


Final project presentations1

Final project presentations

  • Friday – April 19 CS 232 (Seminar Room)

    • 9:00 – 9:45 John Anthony

    • 9:45 – 10:30 Brian Hill

    • 10:30 – 11:15 Mathew Lowerey

    • 11:15 – 12:00 Aniruddha Tumalla


Agent transformations

Agent transformations

  • Trimming.

  • Splitting.

  • Joining.


Place transition nets

Place/Transition nets

  • In 1962 Carl Adam Petri introduced a family of graphs, called Place-Transition, P/T nets to model dynamic behavior of systems.

  • P/T nets, are bipartite populated with tokens, that flow through the graph.

  • A bipartite graph is one with two classes of nodes; arcs always connect a node in one class with one or more nodes in the other class.

  • In the case of P/T nets the two classes of nodes are places and transitions; arcs connect one place with one or more transitions or a transition with one or more places.


P t nets

P/T nets

  • Enabling and firing of a transition

  • Weight of flow relations (arcs).

  • Marked P/T net

  • Preset and postset of a transition/place.

  • Modeling choice and concurrency.

  • Confusion – symmetric and asymmetric

  • Marked graph –concurrency but no choice

  • State graph graph – choice but no concurrency

  • Inhibitor arcs – modeling priority


P t nets1

P/T nets

  • Marking  state

  • Finite/infinite capacity nets

  • Strict/weak firing rules

  • Extended P/T nets – P/T nets with inhibitor arcs.

  • Modeling exclusion.


Properties on p t nets

Properties on P/T nets

  • Marking independent properties of P/T nets – structural properties

  • Marking dependent properties of P/T nets.


State machines

State machines

  • Finite state machines can be modeled by a subclass of L-labeled P/T nets called state machines (SM) with the property that

  • In a SM each transition has exactly one incoming and one outgoing arc or

  • This topological constraint limits the expressiveness of a state machine, no concurrency is possible.


Marked graphs

Marked graphs

  • In a marked graph each place has only one incoming and one outgoing arc thus marked graphs do no not allow modeling of choice.


Confusion free choice and extended free choice p t nets

Confusion; free-choice and extended free-choice P/T nets.

  • When choice and concurrency are mixed, we end up with a situation called confusion.

  • Symmetric confusion means that two or more transitions are concurrent and, in the same time, they are in conflict with another one.

  • In an extended free-choice net if two transition share an input place they must share all places in their presets. In an asymmetric choice net two transitions may share only a subset of their input places.


Marking dependent properties

Marking dependent properties

  • Liveness

  • Boundedness

  • Safety

  • Refersibility


Firing sequence

Firing sequence

  • Firing sequence

  • Rechability analysis


  • Login