Behavior Relativity of Petri Nets

This paper presents a novel methodology for modelling and analyzing of behavior relations of concurrent systems. The set of all firing sequences of a Petri net is an important tool for describing the dynamic behavior of concurrent systems. In this paper, the behavior relativity of two concurrent subsystems in their synchronous composition is presented. Such behavior relativities, including Controlled Relativity, United Relativity, Interactive Relativity and Exclusive Relativity, are defined respectively. The properties of the relativities are discussed in detail. The analysis method for these properties is based on minimum T-invariants, when two subsystems are live bounded Petri nets. A well-known example has also been analyaed using the new methodology to demonstrate the advantages of the proposed methodology.     

First Order Stålmarck

We present a proof method with a novel way of introducing universal lemmas. The method is a first order extension of Stålmarck’s method, containing a branch-and-merge rule known as the dilemma rule. The dilemma rule creates two branches in a tableau-like way, but later recombines the two branches, keeping the common consequences. While the propositional version uses normal set intersection in the merges, the first order version searches for pairwise unifiable formulae in the two branches. Within branches, the system uses a special kind of variables that may not be substituted. At branch merges, these variables are replaced by universal variables, and in this way universal lemmas can be introduced. Relevant splitting formulae are found through failed unifications of variables in branches. This article presents the calculus and proof procedure, and shows soundness and completeness. Benchmarks of an implementation are also presented.     

基于Petri Nets的BDI Agent模型

Petri nets是一种图形和数学的建模工具,广泛应用于各种系统。它们主要描述和研究信息处理系统一些特点,如并发、异步、分布、并行、非确定和随机过程。为了更容易、方便、自然地描述agent系统,该文提出了面向agent的Petri nets分析方法。该方法主要对面向对象的Petri nets分析方法作了一些改进。最后给出了基于Petri nets的BDI agent实现模型。     

基于Time Petri Nets的实时系统资源冲突检测

Time Petri Nets在实时系统的建模和性能分析中得到广泛应用,而冲突是Petri网及其扩展模型的重要行为,解决冲突是正确分析模型动态行为的关键.目前随机Petri网、混合Petri网和区间速率连续Petri网的冲突检测方法由于没有考虑到时间约束因此无法在TPN网中使用.时间约束的引入使得Time Petri Nets模型的使能和触发语义比Petri网模型的语义复杂,冲突检测变得更加困难.为了计算冲突发生的时间和概率,首先根据时间约束,给出了变迁持续使能时延迟区间的计算方法,并证明了该方法的合理性和完备性;然后在此基础上定义并证明了Time Petri Nets模型中不冲突的检测方法;并提出了Time Petri Nets模型的冲突检测方法,给出了冲突时间区间和变迁实施概率的计算方法;最后通过实例验证说明了该方法的正确性和有效性.     

基于Petri Nets的协调机制研究*

利用形式化和图形化的建模工具Petri Nets对协调问题中的依赖关系及协调机制进行研究;提出任务之间基于资源的三种基本依赖关系;并用Petri Nets对这三种依赖关系相应的协调机制进行了表述,为协调问题的可计算描述提供了一种新的思考角度。     

软件编程构造和实现Petri Nets可达树

采用数据结构的思想和一些算法,将C 中的一些优良特性应用到Matlab编程语言中,用Matlab编程语言编程实现了PetriNets的可达树的构造。该程序对Petri Nets系统的动态性能分析具有一定的参考价值。     

The Expressibility of First Order Dynamic Logic

This paper resolved an open problem proposed by A .P. Stolboushkin and M .A. Taitslin.We studied the expressibility of first order dynamic logic, and constructed infinite recursive programclasses K_1 , K_2, …, RG K_1 K_2 … RF, such that L (RG)相似文献   

基于Time Petri Nets的UML时序图分析

引入一种称为Clock的变迁,用来改进TPNs,讨论了如何将时序图转换为基于Clock变迁的TPNs,使这种TPNs能正确反映时序图的流程和时间约束。最后,利用普通Petri网的可达性分析技术对时序图模型进行了分析和验证。     

Soft set theory—First results

The soft set theory offers a general mathematical tool for dealing with uncertain, fuzzy, not clearly defined objects. The main purpose of this paper is to introduce the basic notions of the theory of soft sets, to present the first results of the theory, and to discuss some problems of the future.     

Synthesis of Σ-Automata Specified in the First Order Logical Languages LP and LF

This paper presents methods for synthesizing Σ-automata from specifications in the language LP with deterministic semantics and in the language LF with nondeterministic semantics. These methods are based on the equivalent transformation of a formula of the form ?tF (t) into the so-called normal form whose structure corresponds to the state transition graph of a specified Σ-automaton.     

Net Operations (Ⅱ)-The Iterated Addition Operation of Petri Nets

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.     

Preference–Based Matchmaking of Grid Resources with CP–Nets

We deal with the problem of preference-based matchmaking of computational resources belonging to a Grid. We introduce CP–Nets, a recent development in the field of Artificial Intelligence, as a means to deal with user’s preferences in the context of Grid scheduling. We discuss CP–Nets from a theoretical perspective and then analyze, qualitatively and quantitatively, their impact on the matchmaking process, with the help of a Grid simulator we developed for this purpose. Many different experiments have been setup and carried out, and we report here our main findings and the lessons learnt.     

Problems of Synthesis of Σ-Automata Specified in Languages LP and LF of First Order Logic

For two fragments LP and LF of monadic first-order logic with bounded quantifiers, the corresponding versions of the proposed specification theorem are formulated and proved that allow one to reduce the procedure for synthesizing Σ-automata specified by formulas of these logics to an equivalent transformation of formulas.     

Hybrid static–dynamic selection of implementation alternatives in heterogeneous environments

The Journal of Supercomputing - With the emergence of heterogeneous architectures, developing parallel software has become an increasingly complex task. The ability of using multiple devices in a...     

State Estimation of λ-free Labeled Petri Nets with Contact-Free Nondeterministic Transitions*

In this paper we deal with the problem of estimating the marking of a labeled Petri net with nondeterministic transitions. In particular, we consider the case in which nondeterminism is due to the presence of transitions that share the same label and that can be simultaneously enabled. Under the assumption that: the structure of the net is known, the initial marking is known, the transition labels can be observed, the nondeterministic transitions are contact-free, we present a technique for characterizing the set of markings that are consistent with the actual observation. More precisely, we show that the set of markings consistent with an observed word can be represented by a linear system with a fixed structure that does not depend on the length of the observed word.*Contact author is Alessandro Giua.     

Hybrid CPU–GPU execution support in the skeleton programming framework SkePU

In this paper, we present a hybrid execution backend for the skeleton programming framework SkePU. The backend is capable of automatically dividing the workload and simultaneously executing the computation on a multi-core CPU and any number of accelerators, such as GPUs. We show how to efficiently partition the workload of skeletons such as Map, MapReduce, and Scan to allow hybrid execution on heterogeneous computer systems. We also show a unified way of predicting how the workload should be partitioned based on performance modeling. With experiments on typical skeleton instances, we show the speedup for all skeletons when using the new hybrid backend. We also evaluate the performance on some real-world applications. Finally, we show that the new implementation gives higher and more reliable performance compared to an old hybrid execution implementation based on dynamic scheduling.

     

Hybrid lean–agile manufacturing system technical facet,in automotive sector

In the automotive sector, planners have a difficult balancing act. They benefit from commonality of vehicle parts, yet they must meet more niche demands. The challenge is to strike a balance between these extremes in a cost-effective way without compromising quality. Lean strategies could increase competitiveness and profitability by reducing manufacturing costs. Concurrently, agile strategies could enable enterprises to cope with fluctuations. A hybrid lean–agile approach can be an optimal strategic blend for a manufacturing enterprise to meet this challenge. Flexible focused factory, globalized fractal E-manufacturing, innovative value chain strategies, and designing dynamic manufacturing strategies are the four technical pillars of the proposed hybrid lean–agile manufacturing system technical facet. The study shows that hybridizing the lean and agile systems together is technically valid and can be implemented in an industrial setting. It shows how strategically a hybrid lean–agile system can be implemented. It also shows that about one third of the variation in successfully dealing with the sources of competitive advantage in automotive industry can be explained by adopting the technical facet of the hybrid lean–agile manufacturing system.