Modeling and Analyzing Web Application with Aspect-Oriented Hierarchical Coloured Petri Nets

Aspect-oriented modeling can uncover potential design faults, yet most existing work fails to achieve both separation and composition in a natural and succinct way. This study presents an aspect-oriented modeling and analysis approach with hierarchical Coloured Petri Nets(HCPN). HCPN has sub-models and well-defined semantics combining a set of submodels. These two characteristics of HCPN are nicely integrated into aspect oriented modeling. Submodels are used to model aspects while the combination mechanism contributes to aspects weaving. Furthermore, the woven aspect oriented HCPN model can be simulated and analyzed by the CPN Tools. A systematic web application case study is conducted. The results show the system original properties are satisfied after weaving aspects and all design flaws are revealed. As such, the approach can support web application design and analysis in an aspect-oriented fashion concisely and effectively.

AN EQUIVALENCE METHOD FOR COLOURED PETRI NETS AND PLACE/TRANSITION NETS

Coloured Petri net(CPN)is a high-level net while place/transition net(PTN)is a low-level net.It is very important to establish the relationship betweenthe two nets both in theoretical analysis and practical application.In this paper,wegive a formal method of translating a CPN into a behaviourally equivalent PTN.APTN and its behaviour are formally constructed,a PTN equivalence definition is giv-en,and the same properties of the two nets are proved.

优先级Petri网的CPN Tools仿真模型研究

优先级概念的引入,增强了有色Petri网的描述能力,但同时也导致了重复开发相似的仿真工具,造成了极大的浪费。通用的有色Petri网仿真工具CPN Tools支持功能强大的元语言(ML),扩展性比较强。在CPN Tools中利用反库所(anti place)、列表(list)和元语言(ML)等方法建立了变迁、库所和托肯三种类型优先级Petri网的仿真模型,并通过示例表明了方法的有效性,这对于优先级Petri网的仿真具有重要意义。

基于着色Petri网(CPN)在案例推理(CBR)中的应用研究

案例推理(CBR)是人工智能的一种新求解方法,其中案例检索(case retrieval)是案例推理过程的一个重要环节。在CBR基础上引入了Petri网理论,建立了眼科疾病诊治基于案例推理的着色Petri网(CPN)模型,研究探讨了该模型在CBR系统的案例检索中的实际应用。

受控Petri Net在遥控机器人作业规划中的应用研究

在交互工作方式下的遥控机器人在太空开发和深海勘探等领域具有重要的实用价值，而如何增强其自主作业能力是一个重要的问题．本文采用受控ＰｅｔｒｉＮｅｔ理论建立了遥控机器人的作业规划模型。

MODELING RADIO RESOURCE MANAGEMENT IN COGNITIVE RADIO SYSTEM BASED ON OFDMA USING COLORED PETRI NET

Cognitive Radio(CR) system based on Orthogonal Frequency Division Multiple Access(OFDMA),such as Wireless Regional Area Networks(WRAN) and Worldwide Interoperability for Microwave Access(WiMAX),often attempt to improve performance via dynamic radio resource management,which is characterized as concurrent processing of different traffic and nondeterministic system capacity.It is essential to design and evaluate such complex system using proper modeling and analysis tools.In the previous work,most of the communication systems were modeled as Markov Chain(MC) and Stochastic Petri Nets(SPN),which have the explicit limitation in evaluating adaptive OFDMA CR system with wide area traffic.In this paper,we develop an executable top-down hier-archical Colored Petri Net(CPN) model for adaptive OFDMA CR system,and analyze its performance using CPN tools.The results demonstrate that the CPN can model different radio resource manage-ment algorithms in CR Systems,and the CPN tools require less computational effort than Markov model using Matlab,with its flexibility and adaptability to the traffics which arrival interval and processing time are not exponentially distributed.

A colored Petri net-based model for web service composition

In this paper, a model based colored Petri net （CPN） to provide semantic support for web service composition is proposed, and the reliability and maintainability of composite services are improved. The composite constructs in the model are sequence, concurrent, choice, loop and replace. The web service is formally defined by a CPN. A closed composing algebra is defined to obtain a framework which enables declarative composition of web services. Availability, confidentiality, and integrity of composite service are analyzed within the framework of the model based CPN.

MODELING MULTI-TRAFFIC ADMISSION CONTROL IN OFDMA SYSTEM USING COLORED PETRI NET

Call Admission Control (CAC) is one of the key traffic management mechanisms that must be deployed in order to meet the strict requirements for dependability imposed on the services provided by modern wireless networks. In this paper, we develop an executable top-down hierarchical Colored Petri Net (CPN) model for multi-traffic CAC in Orthogonal Frequency Division Multiple Access (OFDMA) system. By theoretic analysis and CPN simulation, it is demonstrated that the CPN model is isomorphic to Markov Chain (MC) assuming that each data stream follows Poisson distribution and the corresponding arrival time interval is an exponential random variable, and it breaks through MC's explicit limitation, which includes MC's memoryless property and proneness to state space explosion in evaluating CAC process. Moreover, we present four CAC schemes based on CPN model taking into account call-level and packet-level Quality of Service (QoS). The simulation results show that CPN offers significant advantages over MC in modeling CAC strategies and evaluating their performance with less computational complexity in addition to its flexibility and adaptability to different scenarios.

Web Service Automatic Composition Model Based on Colored Petri Nets

As the capability of an individual Web service is limited, it’s necessary to create new functionalities with existing Web services. Web services composition is the ability to create a new value-added service by incorporating some existing web services together. A model based colored Petri net (CPN) to provide semantic support for web service composition is proposed. The basic composite constructs in the model are sequence, concurrent, choice and loop. A closed composing algebra is defined to obtain a framework which enables declarative composition of web services. Finally modeling composite processes of Web services based on CPN is applied to a case of naval vessel command and control system.

Verification of Session Initiation Protocol Using Timed Colored Petri Net

In this work, Session Initiation Protocol model is established by using Timed Colored Petri Nets (TCPN). SIP (Session Initiation Protocol) is a protocol developed to assist in providing advanced telephony services across the Internet. The Session Initiation Protocol (SIP) has become the quasi-standard for Voiceover-Internet Protocol (VoIP) communications. SIP is based on a client–server infrastructure in which user agents represent the end-terminals as clients, proxy servers handle SIP message routing between the user agents, and registrar servers store the client’s contact information into a location service. By use of timed color set and useful time attributes in tokens defined in CPN tools, timer and time-related problems of SIP are modeled and analyzed. Timer is an important part for SIP, especially the INVITE transaction.

An Attack Modeling Based on Colored Petri Net

A color petri net (CPN) based attack modeling approach is addressed. Compared with graph-based modeling, CPN based attack model is flexible enough to model Internet intrusions, because of their static and dynamic features. The processes and rules of building CPN based attack model from attack tree are also presented. In order to evaluate the risk of intrusion, some cost elements are added to CPN based attack modeling. This extended model is useful in intrusion detection and risk evaluation. Experiences show that it is easy to exploit CPN based attack modeling approach to provide the controlling functions, such as intrusion response and intrusion defense. A case study given in this paper shows that CPN based attack model has many unique characters which attack tree model hasn’t.

动车组列控车载子系统故障机理建模与分析

针对传统Petri网(P/T系统)无法根据后继标识确定系统失效部位的问题,采用着色Petri网(Colored Petri Net,CPN)建立动车组列控车载子系统的故障传播模型。首先,通过CPN与传统Petri网理论的对比说明采用CPN建模的可行性。其次,根据车载子系统的结构组成及工作模式建立故障树模型,并通过Petri网描述故障树逻辑门事件之间的逻辑关系,给出故障树的Petri网表示方法,建立车载子系统的P/T系统模型;进一步根据CPN理论确定托肯染色方法、权函数等模型参数,将P/T系统转化为着色网系统,并举例说明后继标识的计算规则。最后,通过与传统Petri网推理及故障识别过程的对比,证明了采用CPN分析系统故障机理的正确性及在故障识别过程中的高效性。所提方法可为车载子系统的故障识别提供一定依据。

基于层次着色Petri网的物资储配系统调度问题研究

采用层次着色Petri网研究了物资储配系统的调度问题。用首层Petri网给出了系统运行过程的总体宏观描述,在层次Petri网子页中对固定货架子系统、旋转货架子系统、分拣子系统和输送子系统的动态行为进行了详细刻画。在CPN-Tools仿真环境中分析了系统的整体动态特性,给出并验证了系统的总体调度策略。

基于multi-Agent和Petri网的分布式风光互补系统

近年来随着"大机组、高电压、大电网"发供电模式的弊端日益显露,分散式供电系统成为21世纪电力工业的发展方向.此外,随着风力、太阳能等可再生能源的飞速发展及其发电效率的不断提高,使研究风光互补系统的分布式供电有着重要意义.文中提出一种基于multi-Agent的分布式风光互补混合供电系统,将分散的风力、太阳能光伏发电装置组成分布式系统,并采用有色Petri网建立了multi-Agent的协作模型.通过模拟风力–太阳能的运行情况,证明了分散控制策略的有效性.

基于CPN的通信装备战场抢修系统效能优化

介绍了有色Petri网的基本理论及其仿真工具--CPN Tools,描述了通信装备战场抢修的一般流程和相关参量,建立了战场抢修系统的有色Petri网模型,并对实例进行了仿真实现。通过对原方案的结论分析提出了战场抢修系统的改进方案,并最终实现了系统的效能优化,从而证明了该通信装备战场抢修系统模型具有科学性和实用性。

基于着色Petri网的舰艇指挥控制信息流建模研究

针对海军舰艇指控模型复杂度高、易受人为因素干扰、复用率不高等问题,应用CPN Tools建立舰艇指挥信息流模型,通过命令信息流与反馈信息流的流动构建舰艇指挥控制模型。定义了标准的信息流结构与舰艇部位结构,较好地解决了模型重用问题,提高了模型的适用范围。信息流的真实性保证了模型的客观性,从模型层面提高了指控系统与舰艇实际的贴合程度。

基于分层时间有色Petri网的支付协议公平性分析

电子支付协议是一种重要的电子商务协议,公平性是其重要的安全属性之一。该文提出一种基于分层时间有色Petri网(HTCPN)的电子支付协议形式化分析方法。该方法在进行公平性分析时,充分考虑了两个环境因素:主体是否诚实和通信信道是否可靠,与其他形式化方法相比,可以更有效地分析协议公平性。使用该方法对典型支付协议IBS协议进行分析,分析结果验证了所提模型和方法的有效性。

有色Petri网在网络通信协议上的应用

自１９６２年Ｃ．Ａ．Ｐｅｔｒｉ在其博士论文中首先提出Ｐｅｔｒｉ网后，Ｐｅｔｒｉ网理论和应用都取得了长足的进步。有色Ｐｅｔｒｉ网是由Ｋ．Ｊｅｎｓｅｎ提出的一种高级网系统，可以为系统建模提供强有力的支持。文章介绍了有色Ｐｅｔｒｉ网，并利用仿真工具Ｄｅｓｉｇｎ／ＣＰＮ对一个通信协议停－等协议进行分析。

基于有色Petri网的FIFO栈建模与优化

先入先出FIFO栈在智能仪器及测试系统中起着重要作用。针对FIFO栈设计缺乏理论指导和严格数学验证的问题,提出采用有色Petri网(CP-net)来建模和优化FIFO栈。提出了一种FIFO栈设计模型,FIFO栈的入栈口和出栈口固定但容量可变。应用建模、仿真工具CPN Tools对FIFO栈的动态运行过程进行建模、仿真和分析,并在此基础上,对FIFO栈模型进行了优化。采用Verilog HDL在现场可编程逻辑门阵列FPGA上具体实现了FIFO栈的硬件电路。仿真结果和实际应用表明,该设计模型是活的、公平的、安全的和高效的。

电子支付协议可追究性的Petri网建模与分析

可追究性是电子支付协议必须满足的安全属性之一,针对电子支付协议,建立了支持支付协议可追究性分析的分层有色Petri网模型,并基于此提出一种对支付协议可追究性分析的一般性方法。Kungpisdan等人曾提出一种可追究性逻辑,证明一个典型的移动支付协议KSL协议满足可追究性。但使用上述所提方法对该协议建模并进行可追究性分析,发现了可追究性逻辑未发现的漏洞,分析例证结果表明了所提方法的有效性。