Generalized stochastic Petri nets based models for performance analysis of communication networks of IEC61850 system

In this paper, data streams are classified into four types conforming to a standardized infrastructure of communication networks for a substation automation system （SAS） based on IEC61850 system. The data exchanged on the net are demonstrated to be stochastic according to investigation on the Ethemet communication principles. Four generalized stochastic Petri nets （GSPN） based models for performance analysis of communication networks of IEC61850 system are developed based on the three-level structure of SAS, different time requirements of the four data streams and different networks topology for different voltage level. The GSPN-based model associated with immediate and exponential transitions is proven to be theoretically isomorphic with Markov chain; hence we apply the mathematic methods of performance evaluation contained in Markov chain to the GSPN models proposed. The computer simulation of the model including only sample value data streams shows that it can meet performance evaluation needs of communication networks of IEC61850 system. Further researches should be focused on the pe^ormance of the other three models to explain clear how those different data streams are interrelated to and interact on each other.

End-of-Life Decision making in circular economy using generalized colored stochastic Petri nets

Circular economy enables to restore product value at the end of life i.e.when no longer used or damaged.Thus,the product life cycle is extended and this economy permits to reduce waste increase and resources rarefaction.There are several revaluation options(reuse,remanufacturing,recycling,...).So,decisionmakers need to assess these options to determine which is the best decision.Thus,we will present a study about an End-Of-Life(EoL)decision making which aims to facilitate the industrialization of circular economy.For this,it is essential to consider all variables and parameters impacting the decision of the product trajectory.A first part of the work proposes to identify the variables and parameters impacting the decision making.A second part proposes an assessment approach based on a modeling by Generalized Colored Stochastic Petri Net(GCSPN)and on a Monte-Carlo simulation.The approach developed is tested on an industrial example from the literature to analyze the efficiency and effectiveness of the model.This first application showed the feasibility of the approach,and also the limits of the GCSPN modelling.

Anti-Attacking Modeling and Analysis of Cyberspace Mimic DNS

With the rapid development of information technology,the cyberspace security problem is increasingly serious.Kinds of dynamic defense technology have emerged such as moving target defense and mimic defense.This paper aims to describe the architecture and analyze the performance of Cyberspace Mimic DNS based on generalized stochastic Petri net.We propose a general method of anti-attacking analysis.For general attack and special attack model,the available probability,escaped probability and nonspecial awareness probability are adopted to quantitatively analyze the system performance.And we expand the GSPN model to adjust to engineering practice by specifying randomness of different output vectors.The result shows that the proposed method is effective,and Mimic system has high anti-attacking performance.To deal with the special attack,we can integrate the traditional defense mechanism in engineering practice.Besides,we analyze the performance of mimic DNSframework based on multi-ruling proxy and input-output desperation,the results represent we can use multi ruling or high-speed cache servers to achieve the consistent cost of delay,throughput compared with single authorized DNS,it can effectively solve 10%to 20%performance loss caused by general ruling proxy.

An Approach to Modelling and Analysing Reliability of Breeze/ADL-based Software Architecture

Breeze/architecture description language（ADL）, is an eX tensible markup language（XML） based architecture description language which is used to model software systems at the architecture level. Though Breeze/ADL provides an appropriate basis for architecture modelling, it can neither analyse nor evaluate the architecture reliability. In this paper, we propose a Breeze/ADL based strategy which, by combining generalized stochastic Petri net（GSPN） and tools for reliability analysis, supports architecture reliability modelling and evaluation. This work expands the idea in three directions： Firstly, we give a Breeze/ADL reliability model in which we add error attributes to Breeze/ADL error model for capturing architecture error information, and at the same time perform the system error state transition through the Breeze/ADL production. Secondly, we present how to map a Breeze/ADL reliability model to a GSPN model, which in turn can be used for reliability analysis. The other task is to develop a Breeze/ADL reliability analysis modelling tool–EXGSPN（Breeze/ADL reliability analysis modelling tool）, and combine it with platform independent petri net editor 2（PIPE2） to carry out a reliability assessment.Abstract： Breeze/architecture description language （ADL）, is an eXtensible markup language （XML） based architecture description language which is used to model software systems at the architecture level. Though Breeze/ADL provides an appropriate basis for architecture modelling, it can neither analyse nor evaluate the architecture reliability. In this paper, we propose a Breeze/ADL based strategy which, by combining generalized stochastic Petri net （GSPN） and tools for reliability analysis, supports architecture reliability modelling and evaluation. This work expands the idea in three directions： Firstly, we give a Breeze/ADL reliability model in which we add error attributes to Breeze/ADL error model for capturing architecture error information, and at the same time perform the system error state transition through the Breeze/ADL production. Secondly, we present how to map a Breeze/ADL reliability model to a GSPN model, which in turn can be used for reliability analysis. The other task is to develop a Breeze/ADL reliability analysis modelling tool-EXGSPN （Breeze/ADL reliability analysis modelling tool）, and combine it with platform independent petri net editor 2 （PIPE2） to carry out a reliability assessment.