Logic Petri Nets Research Articles

Property analysis of logic Petri nets by marking reachability graphs

Logic Petri nets (LPNs) are suitable to describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. To investigate the dynamic properties of LPNs directly, a new method for analyzing LPNs is proposed based on marking reachability graphs in this paper. Enabled conditions of transitions are obtained and a marking reachability graph is constructed. All reachable markings can be obtained based on the graph; the fairness and reversibility of LPNs are analyzed. Moreover, the computing complexity of the enabled conditions and reachable markings can be reduced by this method. The advantages of the proposed method are illustrated by examples and analysis.

Toward Fuzzy Traffic Adaptation Solution in Wireless Mesh Networks

Wireless technologies are becoming an essential part of our daily life. These technologies are expected to provide a wide variety of real-time applications; hence, there is a vital need to provide quality-of-Service (QoS) support. One of the key mechanisms to support QoS is traffic regulation. The basic idea behind traffic regulation is to measure the network state (e.g., load) in order to adapt the rate of carefully selected application flows. In this paper, we propose a novel model, called FuzzyWMN, which can be used to implement traffic adaptation in Wireless Mesh Networks (WMNs).The objective of FuzzyWMN is to compute the rate adaptation to apply to application flows according to the current network state; it relies on two parameters to meet this objective: (1) packet delays between sources and destinations; and (2) buffer occupancy of network nodes. The proposed model combines the essential notions of both fuzzy logic theory and Petri nets; this enables FuzzyWMN to realize traffic adaptation in networks characterized by information uncertainty and imprecision due to the dynamic traffic behavior, channel interferences, etc. Extensive simulations show that FuzzyWMN achieves stable end-to-end delay and good throughput under different network conditions.

Fault severity analysis of the time-dependent mechanical systems by the revised Time Petri net

This article presents a fault severity analysis model to assess the fault severity at different time intervals by the revised Time Petri net, which reveals the principle of the time-dependent failure and explores the weak links in the mechanical system. A revised Time Petri net is introduced in this article by extending the tuples of the ordinary Time Petri net. The basic functional units are defined by the revised Time Petri net logic symbols, and the time firing schedule as well as the state diagram which reflects the characteristics of the mechanical system is used to assist in modeling the fault propagation of the mechanical system in the early phase of design. A numerical example of the spacecraft solar array illustrates the revised Time Petri net–based modeling method, investigates the fault mechanism and realizes the weak links of the system. The proposed method is demonstrated by analyzing the failure history data of 100 spacecraft solar arrays to get proportion of the failures at the most dangerous time intervals. The results also reveal some special phenomena related to the time-dependent failure in the mechanical system of the solar array.

Service net algebra based on logic Petri nets

Web service process reuse can help us efficiently to construct a new service or service process by using the existing service processes generated by service composition. Since service requests are characteristic of multiformity, the existing service processes can hardly be reused unless they are modified and transformed to some specific scenarios. In this paper, a service process is modeled as a service net (SN) using logic Petri nets. Inspired by the relational algebra, service net algebra (SNA) is proposed to provide a formal foundation for structural transformations of SNs including composition and decomposition. It is constructed on the basis of logic Petri nets and consists of structure algebra, evolution algebra and synthesis algebra. Some algebra operators of SNA are defined, and their corresponding operational rules are presented. The properties and soundness preservation of SNA are analyzed. A framework for service process reuse is also given based on SNA.

Reachability analysis of logic Petri nets using incidence matrix

Logic Petri nets (LPNs) can simplify the net-structure and mitigate the problem of state space explosion. To directly investigate the properties of LPNs, a new analysis method of LPNs is introduced in this paper based on incidence matrix. The enabled conditions of transitions are given, and reachable markings are calculated based on the constructed incidence matrix of LPNs. The state equation of LPNs is defined, and the reachability of LPNs is analysed. Compared with the previous work, the incidence matrix in this paper can contain more information and describes the logic expressions and arcs of LPNs. The computational complexity of LPNs is lower. Finally, the validity, reliability and effectiveness of the proposed method are illustrated by analysing an actual case. The theoretical and practical values of LPNs are enhanced.

An Approach of Web Service Discovery and Composition Based on Logic Petri Nets

A new model is proposed based on logic Petri nets for web service clusters. The service parameters of a cluster are unified and logical expressions are introduced to represent the indeterminacy of service clusters. A service cluster can be used as an integrated unit and parameter matching can be decided based on semantic similarity and logical inference in a service cluster. Some algorithms of web service discovery and composition are given based on logic Petri nets, and the redundant services are removed from service compositions by a backward method. The availability and efficiency of the proposed approach are illustrated by the experiments with large repositories of different sizes.

A vector matching method for analysing logic Petri nets

Batch processing function and passing value indeterminacy in cooperative systems can be described and analysed by logic Petri nets (LPNs). To directly analyse the properties of LPNs, the concept of transition enabling vector sets is presented and a vector matching method used to judge the enabling transitions is proposed in this article. The incidence matrix of LPNs is defined; an equation about marking change due to a transition's firing is given; and a reachable tree is constructed. The state space explosion is mitigated to a certain extent from directly analysing LPNs. Finally, the validity and reliability of the proposed method are illustrated by an example in electronic commerce.

Architecture of Dynamic Service Composition Using Logic Petri Nets

Services are preprocessed based on clustering techniques in the levels of function and similarily of services. Service clustering is modeled by means of the passing value indeterminacy of logic Petri nets. Thus service clustering can be described, and the services with indeterminacy parameters can be modeled formally. Thus service composition is investigated under the classified architecture of service clustering. The architecture of dynamic service composition is given, and logic Petri nets are used for service realization. Services can be combined rapidly and automatically, and the path of a composition service can be constructed by automatic inference.

Logic Petri Nets and Equivalency

(1) College of Information Science and Engineering, Shandong University of Science and Technology, Qingdao 266510, China; (2) State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of Sciences, Beijing 100080, China

Model checking multi-agent systems with logic based Petri nets

We introduce a class of Petri nets, simple logic Petri nets (SLPN), that are based on logical expressions. We show how this type of nets can be efficiently mapped into logic programs with negation: the corresponding answer sets describe interleaved executions of the underlying nets (Theorem 1). The absence of an answer set indicates a deadlock situation. We also show how to correctly model and specify AgentSpeak agents and multi-agent systems with SLPN's (Theorem 2). Both theorems allow us to solve the task of model checking AgentSpeak multi-agent systems by computing answer sets of the obtained logic program with any ASP system.

A study of fuzzy logical petri nets and its application

In this paper, a fuzzy Petri net approach to modelling fuzzy rule-based reasoning is proposed. Logical Petri net (LPN) and fuzzy logical Petri net (FLPN) are defined. The backward reasoning algorithm based on sub-fuzzy logical Petri net is given. It is simpler than the conventional algorithm of forward reasoning from initial propositions. An application to the partial fault model of a car engine in paper Portinale’s(1993) is used as an illustrative example of FLPN.

A Linear Logic View of Object Petri Nets

Linear Logic [4] has been shown to incorporate a fragment suitable for representing P/T-nets and giving a semantics to the computations of such nets (e.g. [1], [6], [2]). This result is generalised to coloured nets. Furthermore a new kind of high-level nets is defined: Linear Logic Petri Nets (LLPN). These nets are used as an intuitive semantics to well-known and new high-level net concepts like object systems ([8], [12], and [10]) and agent orientation.

Modeling data-intensive reactive systems with relational transition systems

In this paper, the formalism of Relational Transition Systems (RTSes) is used to model data-intensive reactive systems, and four RTS models of reactive systems based on temporal logic programming, production systems, recurrence equations, and Petri nets are presented. The paper also describes different methods of comparison of the expressive powers of various RTSes in terms of the trajectories they can generate and carries out this comparison for the four RTS formalisms. It is shown that these formalisms have the same expressive power in the deterministic case. The paper also compares expressive powers of non-deterministic production systems and non-deterministic temporal logic programming systems. It is shown that, although the two formalisms are incomparable in the general case, their restricted versions are isomorphic to each other.