IEEE CONTROL SYSTEMS SOCIETY TECHNICAL COMMITTEE
ON DISCRETE EVENT SYSTEMS

    Ryan J. Leduc
    Chair, IEEE CSS Technical Committee on DES
    Dept. of Computing and Software
    McMaster University
    1280 Main Street West
    Hamilton, Ontario
    Canada L8S 4K1

    Phone: (905) 525-9140 Ext. 27962
    Fax: (905) 524-0340
    e-mail: leduc@mcmaster.ca
    WWW: http://www.cas.mcmaster.ca/~leduc/

DESTC Web Page: http://www.cas.mcmaster.ca/destc/

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Contents:

1. Editorial

2. Announcements
 2.1 DCDS09 special session: Petri net based RAMS  modeling

3. Journals
 3.1 Selections from Automatica, Volume 44, Issue 12, December 2008
 3.2 Selections from   IEEE Transactions on Software Engineering, Volume
     34, Issue 6, December 2008

Welcome to the newsletter of the IEEE Control Systems Technical Committee on Discrete Event Systems!

See http://www.cas.mcmaster.ca/destc/ for information on the DESTC.

Personal note from the editor:

Welcome to the December 2008 edition of the DESTC newsletter.

I'd like to take this opportunity to wish all of you a prosperous and happy new year!

Ryan

Contributed by: Ryan Leduc <leduc aT mcmaster dOt ca>

DCDS09 SPECIAL SESSION: PETRI NET BASED RAMS MODELING

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			DCDS'09
2nd IFAC WORKSHOP ON DEPENDABLE CONTROL OF DISCRETE SYSTEMS
		alace Hotel, Bari, Italy 
		  June 10-12, 2009 
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		      WEB SITE
	      http://dcds09.poliba.it/ 

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	  CALL FOR PAPERS OF Special Session on 

	  "Petri net based RAMS modeling"

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Session Chairs:

Prof. Dr.-Ing. Dr.h.c. Eckehard Schnieder

Institute for Traffic Safety and Automation Engineering

University of Braunschweig

Langer Kamp 8

38104 Braunschweig

Germany

Email: e.schnieder@tu-bs.de

 

Dr. rer. nat. Joerg R. Mueller

Institute for Traffic Safety and Automation Engineering

University of Braunschweig

Langer Kamp 8

38104 Braunschweig

Germany

Email: mueller@iva.ing.tu-bs.de

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	     DESCRIPTION OF THE Special session

 

Questions concerning dependability, i.e. Reliability, Availability,
Maintainability and Safety (RAMS) play an essential role not only
during development but through the whole life cycle of systems. In
addition, dependability is often influenced not only by physical
issues, but also by administrative controls and human actions.
Therefore, several international standards have been introduced related
to the design and evaluation of dependability, e.g. IEC 61508. As the
complexity of dependability related functions is rapidly increasing and
formal methods are explicitly recommended in the IEC 61508, more
sophisticated methods and tools are required. 

 

Petri nets as a description means for distributed systems have gained
widespread acceptance in all industrial fields of application (e. g.
information, communication, transportation, processing and
manufacturing industry and power engineering). The essential modeling
power of Petri nets is based on the description of the global causal
behavior of a system through modeling the relationship between local
states and local events.  Compared to other automata based
dependability techniques (e.g. Markov techniques) the explicit modeling
of local states as well as independent local events allows a more
appropriate and intuitive modeling of systems and their dynamics.
Moreover, the modeling of stochastic behavior is not restricted to
exponential distributed properties, but can be chosen freely.

 

The goal of this session is to present new theoretical approaches as
well as industrial applications of Petri nets in the field of
dependability.

 

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	  SUBMISSIONS TO THE SPECIAL SESSION


Please send an acknowledgement to the session chairs before December
15, 2008 indicating you wish to propose a paper (indicate the title,
the authors, your contact information and an extended abstract about 2
usual size pages). We will then contact you for more details about the
organization of the session. 

 

Please send it to mueller@iva.ing.tu-b.s.de and CC to
e.schnieder@tu-bs.de in PDF format.

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Contributed by: Ryan Leduc <leduc aT mcmaster dOt ca>

SELECTIONS FROM AUTOMATICA
VOLUME 44, ISSUE 12
DECEMBER, 2008

1) State estimation and detectability of probabilistic discrete event
systems

Shaolong Shu, Feng Lin, Hao Ying, Xinguang Chen

Abstract:

A probabilistic discrete event system (PDES) is a nondeterministic
discrete event system where the probabilities of nondeterministic
transitions are specified. State estimation problems of PDES are more
difficult than those of non-probabilistic discrete event systems. In
our previous papers, we investigated state estimation problems for
non-probabilistic discrete event systems. We defined four types of
detectabilities and derived necessary and sufficient conditions for
checking these detectabilities. In this paper, we extend our study to
state estimation problems for PDES by considering the probabilities.
The first step in our approach is to convert a given PDES into a
nondeterministic discrete event system and find sufficient conditions
for checking probabilistic detectabilities. Next, to find necessary and
sufficient conditions for checking probabilistic detectabilities, we
investigate the "convergence" of event sequences in PDES. An
event sequence is convergent if along this sequence, it is more and more
certain that the system is in a particular state. We derive conditions
for convergence and hence for detectabilities. We focus on systems with
complete event observation and no state observation. For better
presentation, the theoretical development is illustrated by a
simplified example of nephritis diagnosis.

web site: click here

Contributed by: Ryan Leduc <leduc aT mcmaster dOt ca>

SELECTIONS FROM IEEE TRANSACTIONS ON SOFTWARE ENGINEERING
VOLUME 34, ISSUE 6
DECEMBER, 2008

1) Timed Automata Patterns

Jin Song Dong, Ping Hao, Shengchao Qin, Jun Sun, Wang Yi

Abstract:

Timed Automata have proven to be useful for specification and
verification of real-time systems. System design using Timed Automata
relies on explicit manipulation of clock variables. A number of
automated analyzers for Timed Automata have been developed. However,
Timed Automata lack of composable patterns for high-level system
design. Logic-based specification languages like Timed CSP and TCOZ are
well suited for presenting compositional models of complex real-time
systems. In this work, we define a set of composable Timed Automata
patterns based on hierarchical constructs in timed enriched process
algebras. The patterns facilitate hierarchical design of complex
systems using Timed Automata. They also allow a systematic translation
from Timed CSP/TCOZ models to Timed Automata so that analyzers for
Timed Automata can be used to reason about TCOZ models. A prototype has
been developed to support system design using Timed Automata patterns
or, if given a TCOZ specification, to automate the translation from
TCOZ to Timed Automata.

web site: click here