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Author

Joaquín Ezpeleta

Other affiliations: Instituto Politécnico Nacional
Bio: Joaquín Ezpeleta is an academic researcher from University of Zaragoza. The author has contributed to research in topics: Petri net & Deadlock. The author has an hindex of 17, co-authored 72 publications receiving 2253 citations. Previous affiliations of Joaquín Ezpeleta include Instituto Politécnico Nacional.


Papers
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Journal ArticleDOI
01 Apr 1995
TL;DR: This paper illustrates a compositional method for modeling the concurrent execution of working processes in flexible manufacturing systems (FMS) through a special class of Petri nets that is built from state machines sharing a set of places modeling the availability of system resources.
Abstract: In this paper we illustrate a compositional method for modeling the concurrent execution of working processes in flexible manufacturing systems (FMS) through a special class of Petri nets that we call S/sup 3/PR. In essence, this class is built from state machines sharing a set of places modeling the availability of system resources. The analysis of S/sup 3/PR leads us to characterize deadlock situations in terms of a zero marking for some structural objects called siphons. In order to prevent the system from deadlocks, we propose a policy for resource allocation based on the addition of new places to the net imposing restrictions that prevent the presence of unmarked siphons (direct cause of deadlocks). Finally we present the application of this technique to a realistic FMS case. >

1,108 citations

Journal ArticleDOI
10 Dec 2002
TL;DR: The paper presents an extension of the classical Banker's algorithm to a class of flexible manufacturing systems modeled by means of Petri nets, which have two interesting characteristics from the application point of view.
Abstract: Banker's-like approaches to deadlock avoidance are based on a decision procedure to grant active processes resources using information about the maximum needs of resources that a process can request in order to ensure termination. The paper presents an extension of the classical Banker's algorithm to a class of flexible manufacturing systems modeled by means of Petri nets. These systems have two interesting characteristics from the application point of view. First, flexible routing of parts is allowed, and second, a multiset of resources is allowed to be used at each processing step. The decision procedure introduced is polynomial in the Petri net model size.

135 citations

Proceedings ArticleDOI
18 Apr 2005
TL;DR: A liveness characterization is introduced, establishing how deadlocks can be studied in terms of circular waits and an iterative method that successively forbids deadlock related states is obtained, synthesizing the control necessary to ensure a final live behavior.
Abstract: A new method for the deadlock prevention problem in concurrent systems where a set of processes share a set of common resources in a conservative way is proposed. It can be applied to flexible manufacturing systems, modeled with Petri nets. In this paper, we present a set of important results related to the deadlock prevention problem in S4PR nets. First, a liveness characterization is introduced, establishing how deadlocks can be studied in terms of circular waits. Second, we show how a circular wait situation corresponds to a particular marking related to a siphon of the Petri net model. Finally, this last characterization is used to obtain an iterative method that successively forbids deadlock related states, synthesizing the control necessary to ensure a final live behavior. The method can be implemented by means of the solutions of a set of integer linear programming problems.

124 citations

Book ChapterDOI
01 Jan 2000
TL;DR: The algorithm which establishes the control is improved and some experimental results are presented which try to compare a few control methods from the perspective of their “permissivity”.
Abstract: In [Tricas et al., 1999] we presented a new method for deadlock prevention in flexible manufacturing systems using Petri nets as the modelling tool. It was based on an iterative method, using the structure of the Petri net model. Here we present two things; first, we improve the algorithm which establishes the control; second, we present some experimental results which try to compare a few control methods from the perspective of their “permissivity”.

95 citations

Journal ArticleDOI
06 Oct 2002
TL;DR: A deadlock avoidance algorithm for a class of resource allocation systems modeling manufacturing systems that has a nonsequential nature and the usefulness of the proposed solution is shown by means of its application to a real system.
Abstract: The paper concentrates on the deadlock-avoidance problem for a class of resource allocation systems modeling manufacturing systems. In these systems, a set of production orders have to be executed in a concurrent way. To be executed, each step of each production order needs a set of reusable system resources. The competition for the use of these resources can lead to deadlock problems. Many solutions, from different perspectives, can be found in the literature for deadlock-related problems when the production orders have a sequential nature [sequential resource allocation systems (S-RAS)]. However, in the case in which the involved processes have a nonsequential nature [nonsequential resource allocation systems (NS-RAS)], the problem becomes more complex. In this paper, we propose a deadlock avoidance algorithm for this last class of systems. We also show the usefulness of the proposed solution by means of its application to a real system.

88 citations


Cited by
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01 Jan 2003

3,093 citations

Proceedings Article
01 Jan 2003

1,212 citations

Journal ArticleDOI
01 Apr 1995
TL;DR: This paper illustrates a compositional method for modeling the concurrent execution of working processes in flexible manufacturing systems (FMS) through a special class of Petri nets that is built from state machines sharing a set of places modeling the availability of system resources.
Abstract: In this paper we illustrate a compositional method for modeling the concurrent execution of working processes in flexible manufacturing systems (FMS) through a special class of Petri nets that we call S/sup 3/PR. In essence, this class is built from state machines sharing a set of places modeling the availability of system resources. The analysis of S/sup 3/PR leads us to characterize deadlock situations in terms of a zero marking for some structural objects called siphons. In order to prevent the system from deadlocks, we propose a policy for resource allocation based on the addition of new places to the net imposing restrictions that prevent the presence of unmarked siphons (direct cause of deadlocks). Finally we present the application of this technique to a realistic FMS case. >

1,108 citations

Journal ArticleDOI
01 Jan 2004
TL;DR: It is proved that by adding a control place for each elementary siphon to make sure that it is marked, deadlock can be successfully prevented and is suitable for large-scale Petri nets.
Abstract: A variety of important Petri net-based methods to prevent deadlocks arising in flexible manufacturing systems (FMS) are to add some control places and related arcs to strict minimal siphons (SMS) such that no siphon can be emptied. Since the number of minimal siphons grows in general exponentially with respect to a Petri net size, their disadvantages lie in that they often add too many additional places to the net, thereby making the resulting net model much more complex than the original one. This paper explores ways to minimize the new additions of places while achieving the same control purpose. It proposes for the first time the concept of elementary siphons that are a special class of siphons. The set of elementary siphons in a Petri net is generally a proper subset of the set of all SMS. Its smaller cardinality becomes evident in large Petri net models. This paper proves that by adding a control place for each elementary siphon to make sure that it is marked, deadlock can be successfully prevented. Compared with the existing methods, the new method requires a much smaller number of control places and, therefore, is suitable for large-scale Petri nets. An FMS example is used to illustrate the proposed concepts and policy, and show the significant advantage over the previous methods.

631 citations

01 Jan 2007
TL;DR: Publish or Perish is designed to help individual academics to present their case for research impact to its best advantage.
Abstract: Are you applying for tenure, promotion or a new job? Is your work cited in journals which are not ISI listed? Publish or Perish is designed to help individual academics to present their case for research impact to its best advantage.

515 citations