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1.
A semantics-based approach for achieving self fault-tolerance of protocols 总被引:1,自引:0,他引:1 下载免费PDF全文
The cooperation of different processes may be lost by mistake when a protocol is executed.The protocol cannot be normally operated under this condition.In this paper,the self fault-tolerance of protocols is discussed,and a semanticslbased approach for achieving self fault-tolerance of protocols is presented.Some main characteristics of self fault-tolerance of protocols concerning liveness,nontermination and infinity are also presented.Meanwhile,the sufficient and necessary conditions for achieving self fault-tolerance of protocols are given.Finally,a typical protocol that does not satisfy the self fault-tolerance is investigated,and a new redesign version of this existing protocol using the proposed approach is given. 相似文献
2.
Stability analysis of buffer priority scheduling policies using Petri nets 总被引:1,自引:0,他引:1 下载免费PDF全文
A Petri net approach to determining the conditions for stability of a re-entrant system with buffer priority scheduling policy is described in this paper.The concept of buffer boundedness based on the dynamic behavior of the markings in the system model is emphasized.The method is used to demonstrate the stability of the first buffer first served(FBFS)and the last buffer first served(LBFS)scheduling policies.Finally a sufficient condition for instability of systems with a positive feedback Joop(PFL) is established,and an example is given. 相似文献
3.
XUE Lei HAO Yue Lucent Tochnologies China Bell Labs Innovations Beijing China Institute of Microelectronics Xidian University Xi''''an China 《中国科学F辑(英文版)》2004,47(3):273-286
In this paper, an autonomous subnet based structural methodology forbottom-up synthesis of Petri Nets for Flexible Manufacturing Systems is proposed.Furthermore, the theoretical analysis of the model constructed by the method is carried byintensively using model's structural information, such as invariants, siphons, etc.. As aresult, the analysis leads us to draw the general conclusion that the model obtained isconservativeness and thus bound, and characterize its liveness in terms of zero-markingminimal siphons. It is based on model's structural information that distinguishes ourmethod from others. in line of this thought, a liveness guarantying policy for the obtainedmodel is proposed. Some control subnets are merged into the original model according tothe proposed synthesis rules in this paper to ensure that no minimal siphons are emptiedin any state, therefore the liveness is guaranteed. As a result, a live, conservative andrevertible Petri Nets is obtained. A practical example is also presented to 相似文献
4.
Jiang Chanaiun 《计算机科学技术学报》1995,10(6):509-517
This paper presents the iterated addition operation of Petri nets and discusses its application in analysis and synthesis of cycle type systems and star type systems.A group of necessary and sufficient conditions for analysis of structural properties is obtained.In addition sufficient conditions for general systems are obtained. 相似文献
5.
This paper shows an environment which supports the development of multi-thread dialogue interactive systems.The environment includes several tools and run-time support programs for the design and implementation of the user interface of an interactive system.First,methods of user interface specification with Elementary Nets are discussed.Then,the syntax of a user interface specification language based on Elementary Nets and the pre-compiler for the language as well as a graphic editor for Elementary Nets construction are described.Finally,an example is given to illustrate the design process of a user interface. 相似文献
6.
By means of F[x]-lattice basis reduction algorithm, a new algorithm is presented for synthesizing minimum length linear feedback shift registers (or minimal polynomials) for the given mul-tiple sequences over a field F. Its computational complexity is O(N2) operations in F where N is the length of each sequence. A necessary and sufficient condition for the uniqueness of minimal polynomi-als is given. The set and exact number of all minimal polynomials are also described when F is a finite field. 相似文献
7.
ZHOU Wu-Neng~ 《自动化学报》2005,(3)
A necessary and sufficient condition of the quadratic D-stability for a class of uncertain linear systems is presented in terms of linear matrix inequality (LMI) technology.Finally,the validity and less conservatism of the obtained results in this paper are illustrated by a benchmark example. 相似文献
8.
A necessary and sufficient condition of the quadratic D-stability for a class of uncertain linear systems is presented in terms of linear matrix inequality (LMI) technology. Finally, the validity and less conservatism of the obtained results in this paper are illustrated by a benchmark example. 相似文献
9.
A new approach to consensus problems in discrete-time multiagent systems with time-delays 总被引:1,自引:0,他引:1
In this paper, consensus problems in discrete-time multiagent systems with time-invariant delays are considered. In order to characterize the structures of communication topologies, the concept of "pre-leader-follower" decomposition is introduced. Then, a necessary and sufficient condition for state consensus is established. By this method, consensus problems in networks with a single time-delay, as well as with multiple time-delays, are studied, and some necessary and sufficient conditions for solvability of consensus problems are obtained. 相似文献
10.
Based on an innovation analysis method in the Krein space, a sufficient and necessary condition is given for the existence of the solution of H1 control problem for a linear continuous-time system with multiple delays. By introducing a re-organized innovation sequence, the H1 control problem with delayed measurements is converted into a linear quadratic (LQ) problem and a delay-free H2 estimation problem in the Krein space. The controller is given in terms of two forward Riccati equations and a backward Riccati equation. 相似文献
11.
扩展强化非对称选择网的活性和有界性 总被引:5,自引:1,他引:4
给出了一类非对称选择网(asymmetricchoicenet,简称AC网),扩展了强化非对称选择网结构活的充分必要条件,证明了扩展强化非对称选择网如果是结构活的,其标识的活性是可判定的.同时也证明了扩展强化非对称选择网活性的单调性,并给出其结构活和结构有界的充分必要条件. 相似文献
12.
论非对称选择网的活性与安全性 总被引:11,自引:3,他引:8
活性与安全性是网系统的重要行为特性.该文的贡献在于为非对称选择网导出其活性与安全性的一般性质.文章讨论了活性具有单调性的非对称选择网活性与安全性的条件,并给出一个多项式时间算法来判定一个给定的非对称选择网是否是活的、安全的与活性满足单调性.文章还讨论了非对称选择网的两个子类(强化I型与强化II型),并给出活性满足单调性时其(结构)活与(结构)安全的充分条件. 相似文献
13.
一类Petri网系统的活性 总被引:2,自引:0,他引:2
Petri网是一种用来研究具有异步、并发特征的离散事件系统的合适的工具,当用Petri网来模拟一个实际系统时,关心的问题之一就是要确定这个Petri网模型是否具有一些所期望的特生,如活性、有界性等,这些特性均是系统的重要动态行为,该文基于文献[1]给出了Petri网的一子类,即弱化非自控网(Weak Extended Non SelfControlling Nets,简称WENSeC网),该类网覆盖了扩展自由选择网和扩展非自控网,文中提出了并证明了WENSeC网系统活性的的充分必要条件满足死锁-陷阱性质,同时对WENSeC网的一子类,通过转化方法,证明了该类结构有界网的结构活判定算法可借用扩非自控网的有关结果也是多项式时间算法。 相似文献
14.
给出了Petri网系统的一个重要子类,即加权非对称选择网(weighted asymmetric choice net,简称WAC网)系统活性的一个充分条件和一个必要条件;同时,提出了活的有界的WAC网系统的判定条件,进而给出了WAC网活性满足单调性的充分必要条件. 相似文献
15.
论加权扩充自由选择网的活性与安全性 总被引:3,自引:2,他引:1
活性与安全性是网系统重要的行为性质.对于位置/变迁网系统的一些子类,人们已为之导出许多有意义的结果.该文贡献在于为一种称为加权扩充自由选择网的网系统子类找到活性与安全性的一般性质.文章先给出其活性等价条件的简要与直观的证明,随后,对于这一类安全的子系统又给出活性的充分必要条件. 相似文献
16.
活性和有界性是Petri网最重要的性质,对于传统Petri网的这些性质,国内外学者作过大量的研究工作,并且得到了不少成果,而对含时间因素的Petri网的这些相应性质国内外研究得很少。本文首先介绍了时间Petri网TPN的若干基本定义,然后说明了时间Petri网TPN的活性、有界性和对应传统Petri网的相应性质并无关系,接着给出了时间Petri网保持活性、有界性的时间区间上的两个充分强要条件。为利用传统Petri网的性质判定结果来判定时间Petri网的相应性质提供了可能性。 相似文献
17.
活性和有界性是网系统的重要行为特性.从分解以及尽可能简单分解的角度得到了非对称选择网的一个子类,可分解非对称选择网(简称DAC网),证明了DAC网系统活性的充分必要条件,同时给出了DAC网系统活性有界性的充分必要条件,也进一步讨论了判定一个Petri网系统是否是活的有界的DAC网系统的多项式算法. 相似文献
18.
Every arc from a place to a transition in a Free-Choice Petri net (FCPN) is either the unique output arc of the place, or, the unique input arc to the transition [M.H.T. Hack, Analysis of production schemata by Petri nets, Master’s thesis, Massachusetts Institute of Technology, February 1972; W. Reisig, Petri Nets, Springer-Verlag, Berlin, 1985; T. Murata, Petri nets: properties, analysis and applications, Proc. IEEE 77 (4) (1989) 541–580]. We consider FCPNs that are not live [J.L. Peterson, Petri Net Theory and the Modeling of Systems, Prentice-Hall, Englewood Cliffs, NJ, 1981; W. Reisig, Petri Nets, Springer-Verlag, Berlin, 1985; T. Murata, Petri nets: properties, analysis and applications, Proc. IEEE 77 (4) (1989) 541–580], and we investigate the existence of supervisory policies that can enforce liveness in partially controlled FCPNs. The external agent, or supervisor, can only prevent the firing of some (i.e. not all) transitions in a partially controlled FCPN.
We first present an observation on supervisory policies that enforce liveness in partially-controlled FCPNs. Using this observation, we solve the supervisory synthesis problem for the family of c hoice-controlled FCPNs, defined in this paper. We then identify a new, sub-class of partially-controlled FCPNs that posses an easily-characterized (and easily-enforced) supervisory policy that enforces liveness. 相似文献
19.
Petri网共享T型子网合成结构性质分析及其应用 总被引:1,自引:0,他引:1
为了解决系统设计中的子系统共享问题,提出了经由Petri网共享T-型子网构成共享T-型子网合成网的解决方案;研究了共享T-型子网合成网的结构性质,提出了共享T-型子网合成网保持结构有界性、守恒性、可重复性、相容性、P-不变量、T-不变量、公平性和结构活性的充分条件或充要条件;特别在证明结构活性保持性的过程中,体现了Petri网层次化的描述方法。本文的结果可为Petri网系统合成性质的考察提供有效途径,为复杂大系统的分析提供重要手段,并特别适合于一类系统的设计和分析,具有一定的实用价值。 相似文献
20.
论非对称选择网的活性 总被引:3,自引:5,他引:3
本文给出了非对称选择网AC网(asymmetric choice nets)活性单调性的充分必要条件,并在此基础上证明了一类AC网系统活性的单调性和此类网结构活的充要条件. 相似文献