Abstract: Spontaneous networks such as VANET are in general deployed in an open and thus easily accessible environment. Therefore, they are vulnerable to attacks. Trust management is one of a set of security solutions dedicated to this type of networks. Moreover, the strong mobility of the nodes (in the case of VANET) makes the establishment of a trust management system complex. In this paper, we present a concept of ‘Active Vehicle’ which means an autonomous vehicle that is able to make decision about trustworthiness of alert messages transmitted about road accidents. The behavior of an “Active Vehicle” is modeled using Petri Nets.
Abstract: The Petri nets are the first standard for business
process modeling. Most probably, it is one of the core reasons why
all new standards created afterwards have to be so reformed as to
reach the stage of mapping the new standard onto Petri nets. The paper presents a business process repository based on a
universal database. The repository provides the possibility the data
about a given process to be stored in three different ways. Business
process repository is developed with regard to the reformation of a
given model to a Petri net in order to be easily simulated. Two different techniques for business process simulation based on
Petri nets - Yasper and Woflan are discussed. Their advantages and
drawbacks are outlined. The way of simulating business process
models, stored in the Business process repository is shown.
Abstract: The final biological effect of ionizing particles may be influenced strongly by some chemical substances present in cells mainly in the case of low-LET radiation. The influence of oxygen may by particularly important because oxygen is always present in living cells. The corresponding processes are then running mainly in the chemical stage of radiobiological mechanism.
The radical clusters formed by densely ionizing ends of primary or secondary charged particles are mainly responsible for final biological effect. The damage effect depends then on radical concentration at a time when the cluster meets a DNA molecule. It may be strongly influenced by oxygen present in a cell as oxygen may act in different directions: at small concentration of it the interaction with hydrogen radicals prevails while at higher concentrations additional efficient oxygen radicals may be formed.
The basic radical concentration in individual clusters diminishes, which is influenced by two parallel processes: chemical reactions and diffusion of corresponding clusters. The given simultaneous evolution may be modeled and analyzed well with the help of Continuous Petri nets. The influence of other substances present in cells during irradiation may be studied, too. Some results concerning the impact of oxygen content will be presented.
Abstract: One major difficulty that faces developers of
concurrent and distributed software is analysis for concurrency based
faults like deadlocks. Petri nets are used extensively in the
verification of correctness of concurrent programs. ECATNets [2] are
a category of algebraic Petri nets based on a sound combination of
algebraic abstract types and high-level Petri nets. ECATNets have
'sound' and 'complete' semantics because of their integration in
rewriting logic [12] and its programming language Maude [13].
Rewriting logic is considered as one of very powerful logics in terms
of description, verification and programming of concurrent systems.
We proposed in [4] a method for translating Ada-95 tasking
programs to ECATNets formalism (Ada-ECATNet). In this paper,
we show that ECATNets formalism provides a more compact
translation for Ada programs compared to the other approaches based
on simple Petri nets or Colored Petri nets (CPNs). Such translation
doesn-t reduce only the size of program, but reduces also the number
of program states. We show also, how this compact Ada-ECATNet
may be reduced again by applying reduction rules on it. This double
reduction of Ada-ECATNet permits a considerable minimization of
the memory space and run time of corresponding Maude program.
Abstract: This paper addresses the problem of forbidden states in
non safe Petri Nets. In the system, for preventing it from entering the
forbidden states, some linear constraints can be assigned to them.
Then these constraints can be enforced on the system using control
places. But when the number of constraints in the system is large, a
large number of control places must be added to the model of system.
This concept complicates the model of system. There are some
methods for reducing the number of constraints in safe Petri Nets.
But there is no a systematic method for non safe Petri Nets. In this
paper we propose a method for reducing the number of constraints in
non safe Petri Nets which is based on solving an integer linear
programming problem.
Abstract: To analyze the behavior of Petri nets, the accessibility
graph and Model Checking are widely used. However, if the
analyzed Petri net is unbounded then the accessibility graph becomes
infinite and Model Checking can not be used even for small Petri
nets. ECATNets [2] are a category of algebraic Petri nets. The main
feature of ECATNets is their sound and complete semantics based on
rewriting logic [8] and its language Maude [9]. ECATNets analysis
may be done by using techniques of accessibility analysis and Model
Checking defined in Maude. But, these two techniques supported by
Maude do not work also with infinite-states systems. As a category
of Petri nets, ECATNets can be unbounded and so infinite systems.
In order to know if we can apply accessibility analysis and Model
Checking of Maude to an ECATNet, we propose in this paper an
algorithm allowing the detection if the ECATNet is bounded or not.
Moreover, we propose a rewriting logic based tool implementing this
algorithm. We show that the development of this tool using the
Maude system is facilitated thanks to the reflectivity of the rewriting
logic. Indeed, the self-interpretation of this logic allows us both the
modelling of an ECATNet and acting on it.
Abstract: Colored Petri Nets (CPN) are very known kind of
high level Petri nets. With sound and complete semantics, rewriting
logic is one of very powerful logics in description and verification of
non-deterministic concurrent systems. Recently, CPN semantics are
defined in terms of rewriting logic, allowing us to built models by
formal reasoning. In this paper, we propose an automatic translation
of CPN to the rewriting logic language Maude. This tool allows
graphical editing and simulating CPN. The tool allows the user
drawing a CPN graphically and automatic translating the graphical
representation of the drawn CPN to Maude specification. Then,
Maude language is used to perform the simulation of the resulted
Maude specification. It is the first rewriting logic based environment
for this category of Petri Nets.
Abstract: This paper proposes a modeling method of the laws controlling manufacturing systems with temporal and non temporal constraints. A methodology of robust control construction generating the margins of passive and active robustness is being elaborated. Indeed, two paramount models are presented in this paper. The first utilizes the P-time Petri Nets which is used to manage the flow type disturbances. The second, the quality model, exploits the Intervals Constrained Petri Nets (ICPN) tool which allows the system to preserve its quality specificities. The redundancy of the robustness of the elementary parameters between passive and active is also used. The final model built allows the correlation of temporal and non temporal criteria by putting two paramount models in interaction. To do so, a set of definitions and theorems are employed and affirmed by applicator examples.
Abstract: Petri Net (PN) has proven to be effective graphical, mathematical, simulation, and control tool for Discrete Event Systems (DES). But, with the growth in the complexity of modern industrial, and communication systems, PN found themselves inadequate to address the problems of uncertainty, and imprecision in data. This gave rise to amalgamation of Fuzzy logic with Petri nets and a new tool emerged with the name of Fuzzy Petri Nets (FPN). Although there had been a lot of research done on FPN and a number of their applications have been anticipated, but their basic types and structure are still ambiguous. Therefore, in this research, an effort is made to categorize FPN according to their structure and algorithms Further, literature review of the applications of FPN in the light of their classifications has been done.
Abstract: One major difficulty that faces developers of
concurrent and distributed software is analysis for concurrency based
faults like deadlocks. Petri nets are used extensively in the
verification of correctness of concurrent programs. ECATNets are a
category of algebraic Petri nets based on a sound combination of
algebraic abstract types and high-level Petri nets. ECATNets have
'sound' and 'complete' semantics because of their integration in
rewriting logic and its programming language Maude. Rewriting
logic is considered as one of very powerful logics in terms of
description, verification and programming of concurrent systems We
proposed previously a method for translating Ada-95 tasking
programs to ECATNets formalism (Ada-ECATNet) and we showed
that ECATNets formalism provides a more compact translation for
Ada programs compared to the other approaches based on simple
Petri nets or Colored Petri nets. We showed also previously how the
ECATNet formalism offers to Ada many validation and verification
tools like simulation, Model Checking, accessibility analysis and
static analysis. In this paper, we describe the implementation of our
translation of the Ada programs into ECATNets.
Abstract: This paper deals with the problem of constructing
constraints in non safe Petri Nets and then reducing the number of the
constructed constraints. In a system, assigning some linear constraints
to forbidden states is possible. Enforcing these constraints on the
system prevents it from entering these states. But there is no a
systematic method for assigning constraints to forbidden states in non
safe Petri Nets. In this paper a useful method is proposed for
constructing constraints in non safe Petri Nets. But when the number of these constraints is large enforcing them on the system may complicate the Petri Net model. So, another method is proposed for reducing the number of constructed constraints.