Контекстне співставлення ВЕБ-сервісів у вирішенні задачі виявлення. Онтологічні підходи

Abstract

Matching is integral part of all web services tasks. The effective implementation of the process of matching services with a search query, or with each other, ensures successful resolving of the problems of service discovery, building the best coverage of the search query and a complex composite service that implements the business task. All web services have own characteristics, solve different problems, use different methods, but they all also have a certain set of characteristics: functional and process models, formal description language, communication protocol, a common set of element types, such as identifiers, service messages, parameters and etc. This allows to classify services in a certain way, the analysis of these characteristics permits to define the elements and aspects of the comparison process. Today there is a huge number of services, and their number is constantly growing, and the process of services discovery is very complex and multifaceted. It should take into account the structural, syntactic, but, first of all, the semantic suitability of services, to ensure their comparative analysis according to the maximum possible number of characteristics that are significant for matching. It should be step-by-step process and it has be designed in such a way that each step reduces the set of candidates, leaving services with a greater degree of compliance. This requires algorithms that return quantitative estimates for each step, each type of matching, and algorithms that effectively generalize these estimates to define the final values of the proximity of services and the request. These researches are devoted to problems of using the descriptive logics formalisms for web services matching by their contexts, which, as a rule, contain information about the services purposes, the area of use, business functions, etc. That is, it is information representing the semantics of the service, but in text form, that is not convenient for automated processing. There are many studies that try to solve this problem by applying standard text analysis methods to contextual service descriptions. This study proposes an ontological approach to matching web services by context. It is determined the extension of the previously proposed the top-level service DL ontology. It also involves the use of a special ontology of the general textual service description, a fragment of the taxonomy of which is presented in the paper. This ontology should cover all important semantic aspects of contextual descriptions. It have not only promote to determining the matching a service and a request, but it also have to allow semantically categorizing the available services: by subject area, implemented functions, etc.