【作者】 刘晓光；

【导师】 金烨；

【作者基本信息】 上海交通大学 ， 机械制造及其自动化， 2008， 博士

【摘要】 为挖掘并提升网络化制造的内涵和优势,发挥其商业价值,本文突破传统网络化制造在已结盟企业间进行数据共享与传递的实质,致力于通过计算机系统、商务应用和软件组件之间的交互,自动地实现商务实体间的无缝、动态集成。Web服务是网络化制造的软件资源构件,网络化制造中应用的组合即为Web服务的组合。然而,随着Web服务数目的增多,人工查找和组合Web服务将变得越来越困难和不现实,同时,网络化制造的网络化协作与敏捷特性使其有别于其它传统制造模式,它更加强调软件与软件之间的交互,要求协作中尽可能减少人为干涉,最大程度实现Web服务组合的自动化。因此,实现Web服务自动组合是构建和运行网络化制造的必然要求和重要内容。本文基于网络化制造中Web服务自动组合这一背景,就实现服务自动组合中的服务描述、服务功能匹配、服务组合方法、服务(组合)选择以及服务组合平台等问题进行了较为深入的讨论和研究,论文工作主要包括:1.提出了一个基于本体的Web服务描述元模型M4WEB(Metal- model for Web service)。该模型以语义本体为依托,在Web服务的WSDL(Web Services Description Language)描述基础上,增加了服务基本信息、性能信息和功能信息,回答了“服务做什么?”、“服务如何做?”、“如何获取服务?”、“使用服务需要哪些支撑?”等Web服务描述必须回答的问题。模型在结构上分为5个部分,这5个部分在本体映射下一起构成了一个基于语义本体的完整的Web服务描述元模型。模型与WSDL保持一致,可以利用其成熟技术并使用业已存在的WSDL描述的Web服务;基于本体为模型增加了语义信息,使其具有了良好的辨识度;模型可以表示服务提供者提供的服务,也可以描述服务请求者所需的服务,而且描述的繁简还可根据实际情况进行适当取舍。为使计算机能够处理该模型,研究了模型的形式化问题。提出了对模型形式化语言的要求,在分析和综合比较了相关形式化语言后,给出了利用OWL DL(Web Ontology Language Description Logic)语言形式化描述模型的详细方法与过程。该方法为了应对Web服务的差异性以及服务描述繁简、侧重不同等实际问题,区分了通用定义和参考定义,使得模型形式化在保持程式化的同时具有较大程度的灵活性。2.根据服务组合形成过程,区分和定义了服务过程中的两类功能匹配:服务与服务间的功能匹配以及需求与服务间的功能匹配,并根据Web服务描述特点,分别为这两类匹配设计了基于接口的功能匹配方法。方法根据接口参数三元组的描述形式<类型,名称,值(值域)>,采用纵向分解、横向分组的方式,先对匹配双方的接口参数进行分类分组,然后对参数类型进行匹配,在类型匹配满足匹配度要求的情况下,对类组内的参数名称和值(值域)进行匹配。根据匹配时参数间的语义及逻辑关系,定义了4种匹配度并给出了判据。方法中加入匹配度增强了方法的适应性与灵活性,为用户提供了较大的选择空间。3.提出了一个基于定向泛洪算法的Web服务组合方法。方法利用传统泛洪算法在消息传递和资源查找时所具有的便捷、快速特点进行Web服务的搜索和组合,同时又利用同一路径是否有重复节点、P/E(Precondition/Effect)是否相容作为约束,对组合路径进行定向,消除了组合过程中可能出现的“内爆”和“重叠”,避免了组合陷入死循环。方法还借鉴了深度优先搜索思想,迭代查找组合树中状态为UNKNOWN的首叶子节点,确保了组合路径的全覆盖。最终,方法将形成一棵以OR为根节点,在逻辑上自上而下、从左到右成瀑布状扩散的服务组合树,作为后续服务选择的输入。4.针对Web服务的动态性与领域性,在不失一般性的前提下,从宏观角度给出了选取与制定Web服务非功能性条件的原则,用于指导Web服务非功能性条件的选取与制定。作为非功能性条件之一的服务质量对服务选择至关重要,为发挥服务质量在服务选择中的作用并使其具有可操作性,对Web服务质量的量化进行了专门探讨和研究,提出了一个能体现服务质量走势、评价力求客观的服务质量评价体系,然后在加权平均法与三点法等统计学相关理论支持下给出了一个实用、高效却又易于实现的Web服务质量评价机制与方法,从而使服务质量的评价有了相对科学而又具体的标准和规范,使其不再仅仅只是一个抽象空洞的概念。在理清和分析了影响选择的非功能性条件之后,根据Web服务选择具有非功能性条件期望值确定、指标因素分层少的特点,在扩展和补充模糊层次分析法的基础上,提出了一个适合Web服务自动组合的基于非功能性条件约束的服务选择方法。该方法在采用模糊层次分析法确定条件指标权重的同时,提出基于供求双方对非功能性条件的期望值距离确定权数,并且据此建立了目标函数,最后通过求解该函数便可从满足用户功能需求的服务中选取最佳服务。方法消除了条件量纲不同带来的影响并统一了期望值距离刻度,使不同意义的条件指标具有了可比性。5.基于上述关键技术的探索,设计和实现了一个Web服务组合原型系统ComWS-DEB(Composition Web Service - Dynamic Electronic Business),该系统面向网络化制造中的Web服务自动组合。系统从结构上划分为4层,从上到下依次为:Gallery Layer、Resource Gate Layer、Portal Layer和Composition Layer。这样的设计与安排既与本文的研究内容相吻合,同时也与目前较为流行的模块化设计理念相一致,从而使得系统在保持结构清晰、易于扩展的同时便于开发实现。从功能上看,该系统包括两大子系统:服务注册与描述以及服务组合与选择,这两大子系统运用了前述几章的研究成果。论文实验案例的运行验证了本文研究内容的有效性和正确性。本文针对网络化制造中实现Web服务自动组合所需要解决的几个关键技术问题展开了探索与研究,提出了初步的解决方案,对推动Web服务自动组合这一问题域的解决具有一定的理论价值和实用价值。更多还原

【Abstract】 In order to exploit and upgrade the connotation and advantage of networked manufacturing, differing from the traditional method in which data are shared and transfered among allied enterprises, the dissertation aims at achieving the dynamic and seamless integration among business entities through interaction and collaboration among computer systems, business applications and software components. Web service, as the software component of networked manufacturing, makes the composition of applications of networked manufacturing equals the compostion of web services. Yet, with the increase of web services, it will be more and more dificult and unpractical to search and compose web services manually, meanwhile, the characteristic of networked manufacturing makes it different from other traditional manufacturing mode, more interaction among softwares and less interference by people are required, so naturally, automoted web service composition becomes the necessary requirements and unlackable contents for constructing and running networked manufacturing.Based on the above background, in order to realize automoted web service composing in networked manufacturing, several key technologies such as web service description, web service function matching, web service composing method, web service composition selection and web service composing platform are researched in the dissertation. The main work and achievements are listed as follows:1. One Metal Model for Web service description M4WEB is proposed under the support of ontology. The model is grounded on WSDL description of web services, on the basis, some extra information such as web service primary information, performance information, functional information and semantic information are supplemented. The model answers the problems that must be resolved to accomplish web service automoted composing, they are:‘what the web service does?’,‘how the web service does?’,‘how to get the web service?’and‘how to use the web service?’. The model is structally composed of 5 parts: ServiceOutline, ServiceProcess, WSDLDescription, WSDLMapping and ServiceOntologyLink. The model is on the basis of WSDL which makes it convenient to use large numbers of WSDL-described web services, and also the use of ontology enables the web services identifical each other. The model could be used to describe both web services and web service requirements, and the detailing degree can be adjusted according to the accutal requirements.In order to be processed by computer, the model formalization is suceessionly studied. In the section, the requirements for formalization language is firstly proposed, with that, several formalization languages are studied and analyzed, after this, OWL DL is selected as the proper language to formalize the model. Consequently, the detailed formalization method are designed and presented. In the method, general formalization and reference formalization are distinguished in order to deal with the actual problems such as web service individuality, different detailing degrees and detailing emphases, which makes the formalization method more flexible as well as pattern-fixed.2. Two types of function matching are distinguished according to the composing process: the matching between R and S called MR-S and the matching between S and S called MS1-S2, in accordance with this, two methods that based on service interface are proposed respectively. According to the characteristics of web service interfaces, web service interface parameters are decomposed and firstly grouped and matched by types, if the matching degree is satisfied, parameters name and value or value domain matching will be continued in turn.Based on the semantic and logical relationships among the matched parameters, four matching degrees are regulated as well as the corresponding matching rules, which bring much adaptability and flexibility to the methods.3. One directed flood-based composing method is proposed. In the method, the advantages that rapid and convenient message transfering and resource searching of traditional flood algorithm are taken into account, the P/E conflict-checking and the composition nodes repeatition-checking are used as the constraints to direct the composing path, thus, the disadvantages that uncontrolled transfering and repetition of traditional flood algorithm are eliminated, and the closed circulation trap is therefore avoided. In the method, DFS (Deepth First Searching) idea is used to iterate searching the first node that is marked UNKNOWN on the composing tree, which ensures the full cover of composing tree branches.4. Some principles that used for web services to select and regulate nonfunctional conditions are proposed. Especially, due to the importance of QoS (Quality of web Service), one web service quality rating system that with QoS trend is constructed, and whit this, a QoS rating mechanism and method is proposed under the support of weighted average method and three-point method. The method is relatively practicable easily to use, which makes QoS rating no longer inefficient and unscientific.After analyzing and making clear the nonfunctional conditions, one nonfunctional condition-based web service composition selection method is developed on the basis of extension and supplementarity to the Fuzzy Analytic Hierarchy Process (FAHP). The method employs FAHP to computer the weight factors of nonfunctional conditions, and determines the conditions’weight number based on the expectation distance and hereby constructs the goal function. In the method, dimensionless functions and correction formulae are constructed to eliminate and correct the errors that arise from the differences of dimensions and the inconsistency of expectation distance scale, which makes distinct nonfunctional conditions comparable.5. One web service composing prototype system ComWS-DEB is designed and developed. The system is aimed at the automated composing of web services in the networked manufacturing environment. ComWS-DEB is structlly divided into four layers: Gallery Layer, Resource Gate Layer, Portal Layer and Composition Layer, which is not only clearly consistent with above key technologies, but also is easily realized with currently popular module design idea. The system is functionally composed of two parts: registration&description and composing&selection. The two parts use and cover the above research outcomes.Finally, one RP (Rapid Protoype) example runs through and illustrates the protype system. The running result shows that the prototype system and the research outcomes are primarily correct. To sum up, several key technologies of accompolishing networked manufacturing such as web service description, web service function matching, web service composing, web service composition selection and web service composing prototype system are discussed and researched in the dissertation, and correspondingly, some primarily-evaluated solutions are proposed. This research is of theoretical and practicable values and is helpful to accomplish the goal of networked manufacturing.更多还原