一种基于领域本体的最优Web服务组合方法

基于领域本体技术,提出了一种最优Web服务组合(OWSC)方法。将众多的服务及它们间的匹配度用树的形式表示出来,结点代表Web服务,边值表示服务匹配度。服务组合的分支汇合结构用服务组表示,将服务组简化为由两个服务组成的服务链,以便于在树中表示。树中从根结点到不同叶结点的路径表达了服务组合的选择结构,树中的关键路径(即适配度最大的路径)对应的服务组合为最优Web服务组合。该方法考虑了服务组合的顺序、选择和并发结构,而不涉及循环结构,能较好地实现Web服务的自动组合,同时选择出最优的服务组合。

一种面向QoS的Web服务组测试方法TF

Web服务及SOA技术的出现为Web应用架构提供了一个新的范式.未来会有大量功能相同或相近的Web服务,如何从中优选出符合用户需要的Web服务已成为一个正在研究的问题.在研究了现有的Web服务组中Web服务优选方法基础上,针对其仅局限于功能优选的不足,提出了一种面向QoS的Web服务组中Web服务优选方法.在定义Web服务QoS向量特征分量、QoS向量、最大相似度、QoS测试预言、QoS向量特征分量测试预言等参数基础上,基于层次聚类思想实现QoS向量聚类,依据最大相似度控制聚类层次,之后利用QoS测试预言、QoS向量特征分量测试预言及决策树实现优选.实验结果表明该方法是有效的,克服了以前的方法仅限于功能优选的局限性.

一种基于语义的Web服务组合算法研究

语义Web服务组合算法研究对于Web服务组合有着重要的意义。说明一种基于语义的Web服务组合算法的思想,给出服务组合框架和算法的工作流程。它的核心是通过语义I/O和P/E的匹配来实现自动化Web服务组合,本质是通过交互不断地寻找合适的前继服务,以满足用户的服务请求。

Web服务组合QoS最优化问题研究

随着云计算的蓬勃发展,Web服务的研究和应用也迎来了新的挑战。传统的服务组合一般只考虑到服务的功能性需求,对服务的非功能性需求和总体服务质量(QoS)考虑较少。本文首先对近年来基于QoS的服务组合问题进行了归纳总结,目前大多数研究都是基于粒子群算法、模拟退火算法,skyline方法等。本文做出新的尝试,提出将布谷鸟算法应用于服务组合问题,通过使用从QWS数据集中挑选出的相似服务构建服务集进行实验,与传统的应用粒子群算法的服务组合方法进行对比,对提出的方法的可行性进行了验证。

Web services composition with QoS bound based on simulated annealing algorithm

In order to enable quality-aware web services selection in the process of service composition,this paper first describes the non-functional requirements of service consumers and the quality of elementary service or composite service as a quality vector,and then models the QoS（quality of service）-aware composition as a multiple criteria optimization problem in extending directed graph.A novel simulated annealing algorithm for QoS-aware web services composition is presented.A normalizing for composite service QoS values is made,and a secondary iterative optimization is used in the algorithm.Experimental results show that the simulated annealing algorithm can satisfy the multiple criteria and global QoS requirements of service consumers.The algorithm produces near optimum solution with much less computation cost.

Task-oriented web service discovery algorithm using semantic similarity for adaptive service composition

In order to achieve adaptive and efficient service composition, a task-oriented algorithm for discovering services is proposed. The traditional process of service composition is divided into semantic discovery and functional matching and makes tasks be operation objects. Semantic similarity is used to discover services matching a specific task and then generate a corresponding task-oriented web service composition （TWC） graph. Moreover, an algorithm for the new service is designed to update the TWC. The approach is applied to the composition model, in which the TWC is searched to obtain an optimal path and the final service composition is output. Also, the model can implement realtime updating with changing environments. Experimental results demonstrate the feasibility and effectiveness of the algorithm and indicate that the maximum searching radius can be set to 2 to achieve an equilibrium point of quality and quantity.

基于Web的变电站监控系统设计

出于电力企业变电站综合管理信息化的需求,建立一套基于Web服务器的变电站监控系统。该系统将变电站管理、改扩建管理、变电站信息表梳理等功能组件封装于Web服务器中,并利用SQL Server 2019数据库技术对系统数据进行存储与管理,形成一套基于MVC框架的变电设备在线管理方案,以变电站管控统计功能模块为例展示界面设计结果。

Business domain oriented AI planning for web service composition

In order to improve the effectiveness of the artificial intelligence （AI） planning based web service composition problem, a business domain oriented AI planning algorithm for web service composition is introduced. The algorithm uses the proposed business relation model to minimize the searching space and uses the proposed goal distance as a heuristic rule. Compared with other algorithms tackling web service composition such as AI planning, the proposed algorithm focuses not only on how to convert the web service composition problem to the AI planning problem, but also exerts its effort on how to apply the business feature of web service composition into planning in order to improve the effectiveness. The experiment shows the better performance of the proposed algorithm.

Typed formal model for WS-CDL specification of web services composition

In order to formally reason and verify web services composition described by web services choreography specification WS-CDL,a typed formal model named typed Abstract WS-CDL（web services choreography description language）for WS-CDL specifications is proposed.In typed Abstract WS-CDL,the syntax of type and session,typing rules and operational semantics are formalized;the collaborations of web services are formally described by sessions;the operational semantics of a session can help to formally reason the execution of the choreography;the typing rules can help to formally check the data type consistency of exchanged information between web services and capture run-time errors due to type mismatches.Particularly,the concepts of type assumption set extension and type assumption set compatibility are proposed,and the merging algorithm of type assumption sets is defined so as to eliminate type assumption conflict.Based on the formal model,typed mapping rules for mapping web services choreography to orchestration is also defined.With the typed mapping rules,orchestration stubs and their type assumption sets can be generated from a given choreography; thus, web services composition can be verified at choreography and orchestration levels,respectively.The model is proved to have properties of type safety,and how the model can help to reason and verify web services composition is illustrated through a case study.

Supporting web services reuse by semantic service component and composition pattern

Due to the fact that the existing web service description methods cannot address the issue of service reuse of various levels of granularity, the concept of service component is introduced, which packages together web services and choreography, and their operations and properties are presented in a consistent and uniform manner. Service components are published externally as normal web services and can thus be employed by webbased applications. In order to improve reusability and testability of service components, the concept of composition pattern is also proposed, which presents the relationships among service components. The relationships and relationship compositions have a rigorous semantic, so that composite components can be validated at the configuration stage. The composition patterns support to integrate service components of various levels of granularity. Experience indicates that the application assembly can effectively be conducted by understanding, selecting, and reusing components easily.

MAS-based dynamic web service composition formal model

Applying dynamic web services composition is one of the important schemas for solving service-oriented architecture （SOA）and service-oriented computing（SOC）.For implementing dynamic web services composition,the multi agent system （MAS）is applied to web services composition.First, the essentials of the MAS and web services composition are analyzed and their relationship is discussed.Secondly, an MAS-based architecture is designed for dynamic web services composition,and it is named as CSMWC.A Jade tool is used to implement the major components.The architecture can primarily implement syntactic level dynamic web services composition,and it gives a basis for semantic level dynamic web services composition.For specifying the correctness of the architecture,by using pi-calculus,the architecture of the MAS is formally described,and its dynamic properties and adaptability are reasoned.Finally,it demonstrates the idea proposed by the Pi4SOA tool.

Reachability analysis of web service compositions via NWA

In order to improve the design and implementation quality of web service compositions,formal methods are used to model them and certain properties are verified.WCFA （web service interface control flow automata）is used to model web services,especially the control flow and possible interactions with other web services.A web service composition consists of a set of interacting WCFA.The global behavior of web service compositions is captured by NWA（nested word automata）.A variation of the depth-first search algorithm is used to transform a set of WCFA into an NWA.State formulae and call stacks at each node of NWA are computed by a path-sensitive reachability analysis.Safety properties,call stack inspection properties and pre/post-conditions of service invocations are described by assertions.Then verification of these assertions is carried out by an automated SAT tool.

Heuristic web service composition method based on domain ontology

In order to realize automatic web service composition, a heuristic web service composition method based on domain ontology is proposed. First, this method integrates the domain ontology and the artificial intelligence （AI） planning algorithm. Then, it uses the domain ontology and its reasoning capability to infer the semantic relationship among parameters. Finally, it transforms the web service composition problem into the planning problem based on the AI planning heuristic algorithm. The preliminary experimental results show that the above method compensates for the lack of semantics in the previous AI planning method and it can satisfy the requirements of quality and efficiency of composition, thus generating composite web services according to customer requirements automatically and efficiently.

Automatic Web services composition algorithm based on optimal matching

A novel layered method was proposed to solve the problem of Web services composition.In this method,services composition problem was formally transformed into the optimal matching problem of every layer,then optimal matching problem was modeled based on the hypergraph theory,and solved by computing the minimal transversals of the hypergraph.Meanwhile,two optimization algorithms were designed to discard some useless states at the intermediary steps of the composition algorithm.The effectiveness of the composition method was tested by a set of experiments,in addition,an example regarding the travel services composition was also given.The experimental results show that this method not only can automatically generate composition tree whose leaf nodes correspond to services composition solutions,but also has better performance on execution time and solution quality by adopting two proposed optimization algorithms.

A Distributed Optimal Scheme Based on Local QoS for Web Service Composition

The goal of web service composition is to choose an optimal scheme according to Quantity of Service （QoS） which selects instances in a distributed network. The networks are clustered with some web services such as ontologies, algorithms and rule engines with similar function and interfaces. In this scheme, web services acted as candidate service construct a distributed model which can＇t obtain the global services＇ information. The model is utilized to choose instances according to local QoS information in the progress of service composition. Some QoS matrixes are used to record and compare the instance paths and then choose a better one. Simulation result has proven that our ~pproach has a tradeoff between efficiency and ~quality.

Pre-filtering based automatic composition of multi-QoS semantic web services

To support the rapid automatic services composition and fulfill multi-quality of service （multi- QoS） demand, we propose a novel approach to realize services composition automatically by a prefihering process. Aimed at a set of web services with similar functionality and different quality of service （QoS） , a semantic services chain is given and a corresponding constructing algorithm is proposed to construct the data structure. A pre-filtering process is put forward to find whether a composition service before planning exists. It can avoid aborted planning. An optimal planning algorithm is proposed which can choose the most suitable service from a lot of similar candidate services based on semantic service chains and multi-QoS values. The algorithms can improve the correctness and automation performances of automated semantic web services composition. As an example, a concrete composite process is analyzed. Experimental results show the validity of the composite process.

Research on Intrusion Detection Method of Web Service Composition

The paper takes Web service composition document as the research object, through the analysis of the documents, the port and address on the Web server, to create a Web intrusion detection model. The core of the model will monitor the Web server host resources, and finally discusses in detail the design and implementation of resource monitoring system. Intrusion detection model proposed can effectively regulate the behavior of users in this paper, allowing users follow a pre-standard service to call service providers, largely to protect the security of Web services.

基于SOA的油气资源评价系统设计与实现

传统的开发模式很难将多源、异构的地学数据集成起来。本文建立了以SOA为基本架构、分层的油气资源评价服务体系结构,使用Web服务对已有的数据访问组件和地学计算组件进行封装和发布,与新开发的地学Web服务组件一起由WSM统一注册和管理,使用BPEL进行灵活地流程设计满足不同评价的业务需要,通过门户等多种客户端工具调用评价服务并将结果展示给用户。应用结果表明,采用SOA实现了地学数据和应用一体化集成与共享,达到了油气资源评价系统要求,为地学系统开发提供了一个新的参考模型。

高校信息化平台遗留系统的重用设计与实现

目前,随着国家推进国民教育资源的优化组合,许多高校进行扩建和合并,增设了院系,新建或接收了新校区,信息系统规模不断扩大。新增院系和校区的信息系统与主校区的信息系统无法有效融合,大量需要共享的关键信息被封闭在相对独立的系统里。如何对现有遗留系统进行统一规划,封装成可重用的Web服务组件,从而集成各个孤立的信息系统,消除"信息孤岛"现象,实现遗留系统的重用设计,是高校信息一体化平台建设中的亟待解决的问题。

Service composition algorithm using semantic constraint to implement user personality

In order to improve the efficiency and quality of service composition,a service composition algorithm based on semantic constraint is proposed.First, a user’s requirements and services from a service repository are compared with the help of a matching algorithm.The algorithm has two levels and filters out the services which do not match the user’s constraint personality requirements.The mechanism can reduce the searching scope at the beginning of the service composition algorithm.Secondly,satisfactions of those selected services for the user’s personality requirements are computed and those services,which have the greatest satisfaction value to make up the service composition,are used.The algorithm is evaluated analytically and experimentally based on the efficiency of service composition and satisfaction for the user’s personality requirements.