Generalized Stochastic Petri Nets Research Articles

Research on Dynamic Reliability of a Jet Pipe Servo Valve Based on Generalized Stochastic Petri Nets

The jet pipe servo valve is widely used in the military fields of aviation and ship, whose reliability has obvious randomness and dynamic. However, existing methods are either having complicated theory or analyzing static reliability. Based on the generalized stochastic petri nets (GSPN) theory and the collected basic failure modes and failure rate data of jet pipe servo valve, this paper proposes a novel modeling and simulating method for system’s dynamic behavior analysis. In this method, the dynamic reliability model considering failure’s random and repair is established and is simulated using GSPN software. Then, the steady state probability of servo valve is calculated, which is compared with the value calculated by Markov method. Finally, the dynamic reliability parameters of jet pipe servo valve are calculated using collected failure rate data and different repair rate data. Results show the probability that the maximum error between methods of GSPN and Markov is 2.07%, the optimal repair rate set is less than 1.71µi, and also the dynamic reliability parameters become better with increasing simulation time because of failure’s recovery. Therefore, research methods and results based on GSPN are concise and realistic, which can be used for failure’s qualitative forecast and dynamic reliability’s quantitative calculation of similar complicated system.

Using generalised stochastic Petri nets to model and analyse search behaviour patterns

In recent years, discovering and understanding users' search behaviour attract attention in the research community. Different approaches have been proposed for: 1) learning and modelling how users search; 2) predicting future users' search behaviour patterns, most of them based on statistical analysis and application of data mining techniques on a query log data. In this paper, we focus on the application of the class of generalised stochastic Petri nets (GSPN) on already discovered users' search behaviour patterns, where consecutive actions for query reformulation during the course of a single user session are considered as transitions. An understanding of the motives underlying user actions can help designers to better accommodate to what appears to be chaos: make available those capabilities that best support the range of known behaviour patterns.

Petri Net Reliability Models for CORBA Wireless Networks

Since the dynamic behavior of wireless networks inherits different communication patterns for the execution processes of the desired parallel tasks and the occurrence processes of handoff operations, the available reliability metrics are not applicable to study and analyze such networks. Therefore, in this paper, we propose a novel Petri net modeling methodology for accurately calculating the reliability of wireless networks that incorporate theses aspects, such as wireless CORBA network. The proposed reliability methodology is developed based on using the End-to-End Expected Instantaneous Reliability (EIR) measure. The EIR has the capability to measure the reliability of wireless networks that incorporate the handoff processes as well as the service processes. In the proposed technique, we firstly build Generalized Stochastic Petri Net (GSPN) performance model for describing the different communication pattern that can occur among the various network resources under the execution of parallel tasks. Secondly, we build GSPN performance model for describing the handoff communication processes among the various network resources. Finally, we build generic reliability model consists of the following parts: the first part describes the execution of the desired parallel tasks, the second part illustrates the mobility characteristic introduced by handoff processes, and the third part describes the dynamic behavior of failure processes of network resources. The developed model has the capability to accurately describe the occurrence of many handoff processes in CORBA network. We study and analyze the various reliability results as well as the performance results obtained from the developed GSPN models under the effect of communication distance among the CORBA network resources.

Model and Analysis of Cloud Storage Service Reliability Based on Stochastic Petri Nets

HDFS is a distributed file system of Hadoop cluster, providing storage service for cloud computing. Files in HDFS are broken into block-sized chunks, each block is replicated to physically separated machines. Some studies have been conducted to HDFS, but no work focuses on the performance analysis of HDFS. In this paper, a concise mathematic tool is adopted, Stochastic Petri Nets (SPNs), to establish a system model of HDFS. By the general SPNs model, the reliability, availability and maintainability of HDFS can be measured, and a hierarchical decomposition method is proposed to avoid the state space explosion problem as well, which give a theoretical basis for further studying on the optimal reliability of cloud services.

The impact of breakdowns disciplines and repeated attempts on performances of Small Cell Networks

This paper aims at presenting an approach to study performance and reliability of Small Cell Networks, taking into account the retrial phenomenon, the finite number of customers (mobiles) served in a cell and the random breakdowns of the base station channels. We consider the classical disciplines namely, active and dependent breakdowns and moreover we propose new breakdowns disciplines, in which we give to the interrupted customers due to a channel failure, a higher priority compared to other customers. To this end, we use the Generalized Stochastic Petri Nets (GSPNs) model as a support. However, one of the major drawbacks of this high-level formalism in performance evaluation of large networks is the state space explosion problem which increases when considering repeated calls and multiple unreliable channels. Hence, the novelty of this investigation is the presentation, for the different breakdowns disciplines with and without priority, of an approach which allows a direct computing of the infinitesimal generator describing the customers behavior and the channels allocation in as small cell, neither generating nor storing the reachability set. In addition, we develop the formulas of the main stationary performance and reliability indices, as a function of the network parameters, the stationary probabilities and independently of the reachability set markings. Through numerical examples, we discuss the effect of retrials, breakdowns disciplines and the priority on performances.

GSPN-Based Modeling of Virtual Teams Building in Collaborative Process Planning

Virtual teams have been adopted by organizations to gain competitive advantages in this global economy. It was extremely important of modeling for virtual teams building in collaborative process planning. Based on the flow analysis of virtual teams building in collaborative process planning, the relationship of actual virtual teams building and the elements of GSPN were studied. Finally, the modeling method generalized stochastic Petri nets (GSPN) - based was proposed and the model can excellently describe the flow of virtual teams building in collaborative process planning.

On the study of simultaneous service by random number of servers with retrial and preemptive priority

In this paper, we propose to study the performance of a multi-server queuing system in which a customer requires simultaneous service from a random number of servers with the queuing disciplines retrial and preemptive priority. The infinitesimal generator matrix is presented for the proposed model and steady state measures are discussed. In particular, analytical expressions are obtained for the case where a customer (single type) requires simultaneous service from a random number of servers. Also, the generalised stochastic Petri net (GSPN) is developed for the proposed model and the particular cases. The performance of the models is analysed and compared, in terms of average system size and throughput. It is found that queuing systems in which a customer requires simultaneous service from a random number of servers performs better when the queuing discipline of retrial is appended into the system.

잠수함 전투체계를 위한 이중채널 CAN 버스의 신뢰도 분석

최근 항공기, 잠수함, 로봇 등 고도의 신뢰성이 요구되는 군사무기체계 분야에 상용 필드버스의 적용이 활발히 이루어지고 있다. 잠수함 전투체계 역시 대표적인 군사용 전자 장비로서 다양한 컴퓨터와 센서 및 액추에이터들이 실시간 네트워크로 연결되어 있다. 잠수함의 작전수행능력 및 생존성과 직결되는 전투체계용 네트워크는 매우 높은 수준의 신뢰성을 만족해야 된다. 그 결과 잠수함 전투체계의 구성장비들을 제어하기 위한 필드버스로써 표준 CAN(Controller Area Network)을 기반으로 채널과 제어기를 이중화한 이중채널 CAN 버스가 주로 이용되고 있다. 본 논문에서는 Petri Net을 이용하여 이중채널 CAN 버스의 신뢰도 분석 모델을 제시한다. 기존연구에서는 네트워크를 통한 정보전송 성능 분석에 주안점이 주어졌으나, 본 논문에서는 CAN의 다양한 물리적 고장 유형을 반영하여 GSPN(Generalized Stochastic Petri Nets) 모델을 제안한다. 제안된 모델을 기반으로 고장율과 고장복구율을 변경하면서 각 고장 유형이 이중채널 CAN 버스의 신뢰도에 미치는 영향을 분석한다. Thanks to various benefits, low-cost real-time communication networks so called fieldbus have been widely used in many industrial applications including military systems, such as aircrafts, submarines, and robots. This paper presents a reliability analysis of dual-channel CAN(Controller Area Network) fieldbus which is used for controlling various equipment of submarine combat system. A submarine combat system playing a critical role to the success of missions and survivability consists of various devices including sensors/actuators and computers. Since a communication network for submarine combat system must satisfy an extremely high level of reliability, a dual channel technique is commonly adopted. In this paper, a Petri Net based reliability model for dual-channel CAN is discussed. A reliability model called generalized stochastic Petri Nets (GSPN) is built by utilizing the information on physical faults with CAN. The effectiveness of the proposed model is analyzed in terms of unreliability with respect to failure rate and repair rate.

Stochastic modeling for delay analysis of a VoIP network

VoIP (“Voice Over Internet Protocol”) is the transmission of voice communication through the Internet via IP-based telephony networks. VoIP has become very popular over recent years due to the cost advantages for consumers and businesses compared to the traditional telephony networks. Since it is deployed on packet-based networks, one of the major Quality of Service (QoS) concerns of VoIP technology is the average end-to-end connection delay. The objective of this paper is to present a queuing model for obtaining the end-to-end delay of a VoIP connection. The paper first describes all the partial delay components, and their mathematical formulations. Subsequently, based on all the partial delay components, a queuing model for the end-to-end delay of a VoIP connection is presented. The proposed queueing model is analyzed using a generalized stochastic Petri net (GSPN) model. From the GSPN model, we obtain numerical results for the end-to-end delay, which are presented graphically. The results are in accordance with the expected behavior of delay in a VoIP network.

Reliability Modeling and Availability Simulating Based on GSPN Considering Hardware, Software and Human Factors

Aiming at the functional and structural characteristics of helicopter power transmission systems, this paper researches on the dynamic reliability modeling and simulating methods of complex mechanical systems. The hardware reliability, the human reliability and the software reliability related to helicopter power transmission systems are analyzed in this paper from the view point of systems engineering; the General Stochastic Petri Nets (GSPN) reliability models are established and the availability is simulated. According to the logistic connection among the attributions of the systems availability, two conceptions are presented: degree of facilitation and a new availability calculation model. Results show that the calculational value is very close to the simulating value. The new model based on facilitation is proved to be correct. The paper contributes to provide an effective reliability analyzing method and theoretical basis for complex mechanical system.

GSPN-Based Reliability Model of Wireless Control System

It is difficult to model and solve the reliability of complicated dynamic system in the traditional reliability modeling method. A new reliability modeling method based on generalized stochastic petri net (GSPN) is proposed to analyze the wireless control system (WCS). After studying the common faults of the WCS, a dynamic fault tree is constructed to analyze the system, and it is transformed into formalization definition of GSPN. Finally, a certain type of WCS is selected to validate the proposed method. This method has important value to other WCS design and analysis.

Analytical modeling of Transmission Control Protocol NewReno using Generalized Stochastic Petri Nets

SUMMARYThis paper presents a novel analytical model of Transmission Control Protocol (TCP) using a generalized stochastic Petri net (GSPN). Extensive simulation work has been done for the performance evaluation of TCP NewReno protocol. In view of the limitations of the simulation technique, we present an analytical approach using GSPN. A GSPN is a useful mathematical tool that solves continuous time Markov chains for complex systems and evaluates the stationary behavior. In this paper, we analyze the slow‐but‐steady variant of TCP NewReno. The model captures the behavioral aspects of the slow start and the congestion avoidance phase together with the fast retransmit and recovery capabilities of TCP NewReno. Performance metrics such as throughput, goodput, and task completion time of the system are obtained. The effect of variation in the model parameters on the performance is studied. The results are validated using the network simulator, and their accuracy is verified by evaluating the confidence interval. The performance of the proposed model is compared with that of TCP Reno. The performance of the proposed model is also compared with one of the previous models. The numerical illustrations and comparison of the proposed technique with simulation validates the accuracy, efficiency, and competence of the GSPN technique. While GSPN modeling for TCP is investigated in depth for the TCP NewReno and TCP Reno variant in this paper, other protocols could be also analyzed similarly. Copyright © 2013 John Wiley & Sons, Ltd.

An Exposition of Performance-Security Trade-offs in RANETs Based on Quantitative Network Models

Security mechanisms, such as encryption and authentication protocols, require extra computing resources and therefore, have an adverse effect upon the performance of robotic mobile wireless ad hoc networks (RANETs). Thus, an optimal performance and security trade-off should be one of the main aspects that should be taken into consideration during the design, development, tuning and upgrading of such networks. In this context, an exposition is initially undertaken on the applicability of Petri nets (PNs) and queueing networks (QNs) in conjunction with their generalisations and hybrid integrations as robust quantitative modelling tools for the performance analysis of discrete flow systems, such as computer systems, communication networks and manufacturing systems. To overcome some of the inherent limitations of these models, a novel hybrid modelling framework is explored for the quantitative evaluation of RANETs, where each robotic node is represented by an abstract open hybrid G-GSPN_QN model with head-of-line priorities, subject to combined performance and security metrics (CPSMs). The proposed model focuses on security processing and state-based control and it is based on an open generalised stochastic PN (GSPN) with a gated multi-class `On---Off' traffic and mobility model. Moreover, it employs a power consumption model and is linked in tandem with an arbitrary QN consisting of finite capacity channel queues with blocking for `intra' robot component-to-component communication and `inter' robot-to-robot transmission. Conclusions and future research directions are included.

Evaluation of the logistic model of the reconfigurable manufacturing system based on generalised stochastic Petri nets

To reveal the influence on system performance by the logistic model of reconfigurable manufacturing system (RMS), the generalised stochastic Petri nets (GSPN) modular modelling approach is presented in this paper. It is based upon the characteristics of a bottleneck service. According to this approach, the bottleneck service in the production process is found first. By corresponding different resources in the service to different modules of the GSPN, the module is reconfigured. The analysis of the model using the Markov chain is hereby presented, as is the average utilisation factor of RMS. Following this, the production capacity of different products and the average productivity of reconfigurable manufacturing cells (RMCs) are discussed.

Dependability Analysis of Control Center Networks in Smart Grid Using Stochastic Petri Nets

As an indispensable infrastructure for the future life, smart grid is being implemented to save energy, reduce costs, and increase reliability. In smart grid, control center networks have attracted a great deal of attention, because their security and dependability issues are critical to the entire smart grid. Several studies have been conducted in the field of smart grid security, but few work focuses on the dependability analysis of control center networks. In this paper, we adopt a concise mathematic tool, stochastic Petri nets (SPNs), to analyze the dependability of control center networks in smart grid. We present the general model of control center networks by considering different backup strategies of critical components. With the general SPNs model, we can measure the dependability from two metrics, i.e., the reliability and availability, through analyzing the transient and steady-state probabilities simultaneously. To avoid the state-space explosion problem in computing, the state-space explosion avoidance method is proposed as well. Finally, we study a specific case to demonstrate the feasibility and efficiency of the proposed model in the dependability analysis of control center networks in smart grid.

Generalized Stochastic Petri Nets for Reliability Analysis of Lube Oil System with Common-Cause Failures

A very high level of availab ility is crucial to the economic operation of modern power plants, in view of the huge expenditure associated with their failures. Th is paper deals with the availab ility analysis of a Lube oil system used in a combined cycle power plant. The system is modeled as a Generalized Stochastic Petri Net (GSPN) taking into consideration of partial failures of their subsystems and common-cause failures; analyzed using Monte Carlo Simu lation approach. The major benefit of GSPN approach is hardware, software and human behavior can be modeled using the same language and hence more suitable to model co mplex system like power p lants. The superiority of this approach over others such as network, fault tree and Markov analysis are outlined. The numerical estimates of availability, failure criticality index o f various subsystems, co mponents causing unavailability of lube oil system are brought out. The proposed GSPN is a pro mising tool that can be conveniently used to model and analyze any co mplex systems.

Quantitative Analysis of Resource-Constrained Business Processes

To address the need for evaluation techniques for complex business processes, also known as workflows, this paper proposes an approach based on generalized stochastic Petri nets (GSPNs). We review ten related approaches published in the last fifteen years and compare them to our approach using a wide range of criteria. On the basis of this evaluation, we observe that the newly proposed approach provides results that are at least as good as those from the most accepted alternatives and holds a number of additional advantages, such as modeling simplicity, improved precision, and model reuse for qualitative analyses. The overall approach is formally defined in this paper, along with the definition of several performance metrics. Part of these metrics can be computed analytically, while the remainder can be obtained by simulating the GSPN. Furthermore, a tool has been developed to translate automatically business process execution language processes into GSPNs. Finally, we present a case study in which we applied the proposed approach, colored Petri net tools, and an industrial tool to obtain performance insights into a realistic workflow. The results were highly similar, demonstrating the feasibility and the accuracy of our approach.

Modeling of avionics blueprint architecture based on GSPN and LP

To solve incompact problem of modular avionics system, an improved blueprint architecture was proposed. Firstly, blueprint models were established with generalized stochastic Petri nets (GSPN), and then these modelsʼ optimal time parameters were ascertained with linear programming (LP), which provided a new method for blueprint research. The results of simulation confirm the blueprint modelsʼ validity, and show that using the blueprint can guarantee the whole avionics systemʼs reliability above 95 percent.

Modeling and Performance Evaluation of BPEL Processes: A Stochastic-Petri-Net-Based Approach

Business Process Execution Language (BPEL) is considered as the de facto standard for Web service composition. To analyze the performance of composite service processes specified in BPEL gives the way to tell whether the process meets the performance requirements. In this paper, we propose a translation-based approach for performance analysis of BPEL processes, which employs a general stochastic Petri net (GSPN) as the intermediate representation. A set of translation rules is defined for constructs and activities of BPEL so that the processes specified in BPEL can be translated into the GSPN representations. Based on the GSPN representation of BPEL processes, we introduce a state-space method to calculate the expected-process-normal-completion-time as the performance estimate. In the case study, we obtain experimental data and conduct a confidence interval analysis to validate the feasibility and accuracy of the translation-based approach.

Coordination of Multiple Control Schemes for Mobile Robot Navigation on the Basis of the Generalized Stochastic Petri-Nets

There have been two major streams of research for the motion control of mobile robots: model-based deliberate control and sensor-based reactive control. Since the two schemes have complementary advantages and disadvantages, each cannot completely replace the other. There are a variety of environmental conditions that affect the performance of navigation. The motivation of this study is that multiple motion control schemes are required to survive in dynamic real environments. In this paper, we exploit two discrete motion controllers for mobile robots. One is the deliberate trajectory tracking controller and the other is the reactive dynamic window approach. We propose the selective coordination of two controllers on the basis of the generalized stochastic Petri net (GSPN) framework. The major scope of this paper is to clarify the advantage of the proposed controller based on the coordination of multiple controllers from the results of quantitative performance comparison among motion controllers. For quantitative comparison, both simulations and experiments in dynamic environments were carried out. In addition, it is shown that navigation experiences are accumulated in the GSPN formalism. The performance of navigation service can be significantly improved owing to the automatically stored experiences.