發(fā)布時間：2018-07-31 07:38

【摘要】： 由于Web服務(wù)的種種優(yōu)越性及廣闊的應用前景,自誕生之日起就受到許多機構(gòu)和公司的認可與推崇,許多組織機構(gòu)已將Web服務(wù)引入他們的商業(yè)流程中,并獲得了直接的經(jīng)濟效益。 然而隨著Web服務(wù)的發(fā)展,網(wǎng)絡(luò)上可用的Web服務(wù)會越來越多,如何從數(shù)量龐大的服務(wù)群中為用戶找到滿足其所需功能的Web服務(wù),即Web服務(wù)的匹配已經(jīng)成為一個亟待解決的問題。目前UDDI的Web服務(wù)發(fā)現(xiàn)機制還是基于關(guān)鍵字的匹配,從而導致Web服務(wù)發(fā)現(xiàn)的低精確性,同時,查詢關(guān)鍵字可能與注冊的Web服務(wù)的描述在語義上相同,而語法上不同,從而導致了低查全率;另一方面,隨著Web服務(wù)的大量涌現(xiàn),功能相似的服務(wù)會越來越多,而這些服務(wù)的非功能屬性,如服務(wù)收費,服務(wù)的可靠性、穩(wěn)定性等方面可能存在很大的差異;傳統(tǒng)的匹配機制缺乏Web服務(wù)質(zhì)量支持以實現(xiàn)最佳服務(wù)的發(fā)現(xiàn)。另外,用戶對這些非功能性能的關(guān)心程度可能也有差異,如何按照用戶的個性化要求為其找到認為性能最優(yōu)的服務(wù)也是服務(wù)匹配中應該考慮的重要問題。 針對傳統(tǒng)匹配機制的弊端,本文將本體技術(shù)引入到Web服務(wù)中,設(shè)計了一個基于語義的Web服務(wù)匹配模型,提出一套多層次、細粒度的匹配策略,改進了語義相似度的計算方法,具體工作包括: 第一,研究如何定義和表示W(wǎng)eb服務(wù)。構(gòu)建Web服務(wù)語義描述模型,使其支持對服務(wù)質(zhì)量描述,通過把服務(wù)語義描述和服務(wù)質(zhì)量描述以tModel的形式注冊到UDDI中心,實現(xiàn)服務(wù)語義描述在UDDI中心的使用。 第二,傳統(tǒng)的Web服務(wù)匹配模型已不能適應復雜的語義匹配的需要,本文提出基于語義和動態(tài)QOs的Web服務(wù)匹配模型,并進行了詳細的層次結(jié)構(gòu)設(shè)計,將模型分為四個層次和服務(wù)發(fā)布模塊、服務(wù)查詢模塊、OWL-S/UDDI映射等若干子模塊,對每個模塊都進行了功能設(shè)計。 第三,針對如何從眾多的功能相似的Web服務(wù)中根據(jù)服務(wù)質(zhì)量發(fā)現(xiàn)最佳服務(wù)的問題,提出了新的服務(wù)質(zhì)量描述模型,并且在綜合考慮web服務(wù)質(zhì)量的歷史統(tǒng)計信息的基礎(chǔ)上,提出了一個有效的Web服務(wù)質(zhì)量評價模型并對服務(wù)質(zhì)量綜合指標的評價算法進行了詳細的設(shè)計。為后續(xù)的服務(wù)描述研究和服務(wù)匹配研究提供基礎(chǔ)。 第四,根據(jù)智能化和高效性的要求,研究怎樣基于語義描述和本體論對廣告服務(wù)描述與請求服務(wù)描述進行匹配。提出了一種多層次、細粒度的服務(wù)匹配策略,通過服務(wù)類別、服務(wù)基本描述信息(服務(wù)名稱、服務(wù)描述)、服務(wù)I/O描述信息、服務(wù)質(zhì)量四級匹配,返回滿足用戶請求的服務(wù);并對詞語相似度和語義相似度的算法進行了改進。 最后,本文對提出的模型進行了模擬實現(xiàn),對改進的語義相似度等算法進行有效性驗證和性能測試,結(jié)果表明,本文提出的模型能夠很好地支持web服務(wù)的語義匹配,改進的算法一定程度上提高了服務(wù)匹配的準確性和查全率。
[Abstract]:Because of its advantages and broad application prospects, Web services have been recognized and respected by many organizations and companies since its birth. Many organizations have introduced Web services into their business processes and obtained direct economic benefits. However, with the development of Web services, there will be more and more Web services available on the network. How to find Web services to meet the needs of users from a large number of service groups, that is, the matching of Web services, has become an urgent problem to be solved. At present, UDDI's Web service discovery mechanism is still based on keyword matching, which leads to the low precision of Web service discovery. At the same time, query keywords may be semantically the same as registered Web services, but syntax is different. This leads to low recall rates; on the other hand, with the proliferation of Web services, there are more and more similar services, and the non-functional attributes of these services, such as service charges, service reliability, There may be great differences in terms of stability, and the traditional matching mechanism lacks Web QoS support to realize the discovery of the best service. In addition, the degree of concern of users to these non-functional performance may also be different. How to find the best performance services for users according to their personalized requirements is also an important issue that should be considered in service matching. Aiming at the disadvantages of traditional matching mechanism, this paper introduces ontology technology into Web services, designs a Web service matching model based on semantics, proposes a set of multi-level, fine-grained matching strategies, and improves the method of calculating semantic similarity. The specific work includes: first, how to define and represent Web services. The Web service semantic description model is constructed to support the service quality description. The service semantic description and the service quality description are registered to the UDDI center in the form of tModel to realize the use of the service semantic description in the UDDI center. Secondly, the traditional Web service matching model can no longer meet the needs of complex semantic matching. In this paper, a Web service matching model based on semantic and dynamic QOs is proposed, and the hierarchical structure is designed in detail. The model is divided into four levels and service release module, service query module, OWL-Sr / Uddi mapping and other sub-modules, each module is designed. Thirdly, aiming at the problem of how to find the best service according to the quality of service from many similar Web services, this paper proposes a new service quality description model, and on the basis of synthetically considering the historical statistical information of web service quality, In this paper, an effective Web service quality evaluation model is proposed and the algorithm for evaluating the comprehensive quality of service index is designed in detail. It provides the foundation for service description research and service matching research. Fourthly, according to the requirement of intelligence and efficiency, this paper studies how to match the description of advertising service with the description of request service based on semantic description and ontology. A multi-level, fine-grained service matching strategy is proposed, which returns the service satisfying the user's request through service category, service basic description information (service name, service description), service I / O description information, service quality four-level matching. The algorithm of word similarity and semantic similarity is improved. Finally, the proposed model is simulated and implemented, and the improved semantic similarity algorithms are validated and tested. The results show that the proposed model can support the semantic matching of web services well. The improved algorithm improves the accuracy and recall of service matching to some extent.
【學位授予單位】：山東師范大學
【學位級別】：碩士
【學位授予年份】：2008
【分類號】：TP393.09

【引證文獻】

相關(guān)碩士學位論文 前1條

1 衛(wèi)格格;一種支持QoS約束的Web服務(wù)組合的研究[D];西北大學;2010年

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本文編號：2154884