查询词典 composition algebra

From the view of the number of composition series and table subset of order or elementary abelian table algebra is depicted by making use of fundamental theorem on homomorphism of table algebra.

分别从合成列及表基的p阶、阶表子集的数目角度刻画了初等abelian表代数。

Arad and Blau proved that an abelian table algebra can be viewed as a group algebra of some abelian group G. Chapter 3 of this paper gives the structural theorem of abelian table algebras by defining a group structure in table basis. Furthermore, the structure of elementary abelian table algebras is discussed using the number of composition series of table algebras.

Arad和Blau证明了abel表代数等价于某个有限生成abel群G的群代数，受此启发本文第3节通过定义表基的一个群结构给出了abel表代数的结构定理，并从合成列数目的角度对初等abel表代数进行了细致刻画。

In addition, access control policies of aggregated resources can be formulated as expressions of the algebra. Several algebraic properties of policy expressions are discussed. It shows that the algebraic properties of policy expressions can be used to verify whether policy composition results meet the protection needs of each party.

用代数表达式形式化地描述聚合资源的访问控制策略，讨论了策略表达式的若干代数性质，说明可借助策略表达式的代数性质去验证策略合成结果是否符合各方对聚合资源的保护性需求。

However, despite such categorical pronouncements as "…the above shows that the ring is not the fundamental system for associative algebra of double composition "found in [Vandiver,1939], semirings never became popular and the interest in them among algebraists gradually petered out, although it never died completely.

这些年来，半环被各类研究者所探究或者是在他们的本身及尝试从半群理论和环论中拓展研究方法，或者联系于各种应用。然而，尽管这种范畴的看法"…上面表明环不是最基本的系统对于双复合结合代数"（这句话出自[Vandiver ，1939]）。半环没有受到他们的欢迎和引起他们的兴趣进而逐渐淡化，尽管没有彻底的消亡。

Formalization verification of service composition based on Process Algebra and Discrete Time Ambient-Calculus, as well as combinatorial optimization and the partition method based on QoS mathematic model are deeply studied. The service composition architecture supporting formalization verification and QoS-aware composition has been also implemented. Furthermore, the architecture is applied to digital cartoon cooperation manufacturing in the Internet.

为实现动态的跨企业业务协作与集成，本文围绕服务组合行为的正确性检验以及服务质量保证这二个正交的性质，深入研究了基于进程代数Pi演算及离散时间Ambient演算的服务组合形式化检验，以及基于QoS数学模型进行精确计算的服务组合优化与划分方法。

To regulate policy composition and guarantee its correctness, an algebraic model called APoCA (attribute-based access control policy composition algebra) is proposed for composing access control policy. In APoCA, an authorization relation between entities is described at the attribute level. APoCA fertilizes the existing formal frameworks by taking into account the computation of attribute values.

为了规范策略合成和保障策略合成正确性，基于属性刻画了实体间的授权关系，通过属性值的计算结构扩展了现有的策略合成形式化框架，建立了新的基于属性的策略合成代数模型APoCA(attribute-base access control policy composition algebra)。

The thesis studies the difference between GWSs composition and traditional workflow applications, proposes the implement mechanism and technical architecture of GWSs composition and defines the reference model of GWSs composition platform, which provide holistic framework and top-level guidance for studying dynamic GWSs composition technology, designing GWSs composition platform, and implementing representative composite service applications.2、Theories and methods of composite process modeling and process analysis. This thesis proposes a meta-model of Geo-spatial Web services composition process defining from two aspects, i.e. process and resource. According to the process definition meta-model, we propose a new Geo-spatial Web services composition Process/Resource model based on extended WF-net, which effectively resolves the problems on uncertain activity option and dynamic variation of service in composite process model. A notion with regard to soundness of process model is proposed from three aspects, i.e. the structural correctness of process model, validity of data link and validity of resource. The notion of soundness definitely gives a dividing line on correctness of composite GWS process. This thesis analyzes sufficient and essential terms of soundness, and studies compositional property of WSCP/R-net models which provides an effective method to construct a soundness WSCP/R-net model. According to WSCP/R-net, the thesis proposes composition algebra and studies the properties of it. Based on the composition algebra, 6 kinds of composite process reduction rules are induced to optimize the process.3、Geo-spatial Web service QoS model and its application architecture. This thesis proposes an extendable GWS QoS model from three aspects, i.e. Geo-spatial Web Service itself, networking conditions and service consumer which can be used to distinguish GWSs with overlapping or identical functionality. We work over the QoS evaluation methods of composite GWS process which can be used to guide the execution, monitor and service selection of composition process. Aming at some disadvantages in traditional Web service discovery model for its lacking of QoS supporting, this thesis proposes a new service discovery model SDMQ supporting QoS constraints.4、Technologies of composite service executing. SSPL, a new composite service process language, is defined to overcome the disadvantages of existing composite services process languages which can not adapt to the dynamic variation of Geo-spatial Web Services. An algorithm is described to translate WSCP/R-net model into SSPL. The thesis studies the model of dynamic services selection with QoS global optimization, presenting an algorithm GODSS to resolve dynamic services selection with QoS global optimization in GWSs Composition.5、Design and implement experimental system and representative applications. According to the research findings presented above, we design and implement an experimental system and construct two representative applications to show that our achievements are effective and practical.

针对当前空间信息服务聚合研究中存在的若干不足，本文重点在基于工作流的空间信息服务聚合框架、空间信息服务聚合流程建模和分析技术、空间信息服务QoS模型及应用体系以及空间信息服务聚合流程执行等几个方面进行深入研究，主要工作和创新点包括：1、基于工作流的空间信息服务动态聚合框架：研究了空间信息服务动态聚合和传统工作流应用的不同，在此基础上提出了基于工作流技术的空间信息服务动态聚合实现机制、技术体系和参考模型，为研究空间信息服务聚合的关键技术、开发服务聚合支撑平台以及在此基础上构造特定的空间信息服务聚合应用提供了总体框架和顶层指导。2、空间信息服务聚合流程建模和分析技术：首先基于动态服务聚合流程建模的需求和空间信息服务动态变化的应用实际，从服务聚合的过程维和资源维出发定义了服务聚合流程定义元模型；与之相对应，对基本的WF-net进行扩展，提出服务聚合流程/资源网作为空间信息服务聚合流程的形式化描述模型，有效解决了现有的基于基本Petri网和工作流网的服务聚合建模方法所不能解决的不确定路径选择和服务的动态变化性问题；从流程结构正确性、数据依赖有效性和资源实现有效性三个方面提出了WSCP/R-net健壮性的概念，明确界定了聚合流程正确性的标准，并对WSCP/R-net模型的健壮性分析方法和WSCP/R-net模型的组合特性进行了研究；提出了空间信息服务聚合代数算子并对其性质进行了研究，在此基础上提出了6种聚合流程约简规则，从而可达到优化聚合流程、提高聚合流程执行效率的目的。3、空间信息服务QoS模型和应用体系：从服务本身、网络环境和服务消费者三个层次出发，提出了一个可扩展的空间信息服务QoS模型GSQM，实现了对空间信息服务的度量和评价，并对GSQM不同质量要素信息的客观、公正采集方法进行了研究；研究了空间信息服务聚合流程QoS评价方法，有效支持了空间信息服务聚合流程的执行、监控以及服务选择等操作；针对目前的服务发现模型仅支持服务功能性描述、不能有效满足空间信息服务应用需求的现状，提出了一种新的支持QoS约束的服务发现模型SDMQ，并对模型的实现框架进行了研究。4、空间信息服务聚合流程执行技术：针对现有的服务聚合流程描述语言不能有效满足空间信息服务动态聚合流程描述的特点，基于BPEL4WS提出了一种新的空间信息服务聚合流程描述语言SSPL；研究了满足健壮性要求的WSCP/R-net模型向SSPL的转换算法，在此基础上可以满足用户无显式编码来实现空间信息服务聚合应用的目的；研究了服务动态选择QoS全局优化模型，并在此基础上提出了一种解决服务动态选择QoS全局优化问题的实现算法GODSS.5、基于论文研究成果，设计实现了"空间信息服务聚合实验系统"，并构建了"矿产资源评价"和"城市消防应急响应"两个典型应用案例，对论文所述模型、方法的可行性和有效性进行了验证。

Security protocols are used to provide secure communications over open network,which are essentially concurrent programs in distributed systems,and can be described as a parallel composition system of multiple role-processes by process algebra.

安全协议用于实现开放互连网络的安全通讯，它本质上是分布式并发程序，使用进程代数可以将其描述为角色进程的并发合成系统。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失