Ontologies in Cloud Computing—Review and Future Directions

Cloud computing as a technology has the capacity to enhance cooperation, scalability, accessibility, and offers discount prospects using improved and effective computing, and this capability helps organizations to stay focused. Ontologies are used to model knowledge. Once knowledge is modeled, knowledge management systems can be used to search, match, visualize knowledge, and also infer new knowledge. Ontologies use semantic analysis to define information within an environment with interconnecting relationships between heterogeneous sets. This paper aims to provide a comprehensive review of the existing literature on ontology in cloud computing and defines the state of the art. We applied the systematic literature review (SLR) approach and identified 400 articles; 58 of the articles were selected after further selection based on set selection criteria, and 35 articles were considered relevant to the study. The study shows that four predominant areas of cloud computing—cloud security, cloud interoperability, cloud resources and service description, and cloud services discovery and selection—have attracted the attention of researchers as dominant areas where cloud ontologies have made great impact. The proposed methods in the literature applied 30 ontologies in the cloud domain, and five of the methods are still practiced in the legacy computing environment. From the analysis, it was found that several challenges exist, including those related to the application of ontologies to enhance business operations in the cloud and multi-cloud. Based on this review, the study summarizes some unresolved challenges and possible future directions for cloud ontology researchers.

Verifiable Model Construction for Business Processes

Business process specified in Business Process Execution Language (BPEL), which integrates existing services to develop composite service for offering more complicated function, is error-prone. Verification and testing are necessary to ensure the correctness of business processes. SPIN, for which the input language is PROcess MEta-LAnguage (Promela), is one of the most popular tools for detecting software defects and can be used both in verification and testing. In this paper, an automatic approach is proposed to construct the verifiable model for BPEL-based business process with Promela language. Business process is translated to an intermediate two-level representation, in which eXtended Control Flow Graph (XCFG) describes the behavior of BPEL process in the first level and Web Service Description Models (WSDM) depict the interface information of composite service and partner services in the second level. With XCFG of BPEL process, XCFGs for partner services are generated to describe their behavior. Promela model is constructed by defining data types based on WSDM and defining channels, variables and processes based on XCFGs. The constructed Promela model is closed, containing not only the BPEL process but also its execution environment. Case study shows that the proposed approach is effective.

Creating a Сatalog of IT Services of Universities Based on ITIL Standards

In today’s information world, the competitiveness of universities is closely related to the effectiveness of the IT services provided. However, the development of IT infrastructure requires maintaining a balance between cost and efficiency of services. An IT service includes information technologies, processes and people. In accordance with ITIL standards, the university’s IT department should move from supporting software, applications, servers and networks to timely providing IT services to end users. The first step to this is to create a catalog of IT services. The purpose of the catalog implementation is to provide a single source of consistent information about all operational services and ensure quick access to them. Unlike foreign universities, domestic higher education institutions do not practice a systematic description of IT services and their presentation through the IT catalog. Direct transfer of management models of foreign universities to the Ukrainian educational environment appears impractical. The publication proposes a three-level catalog model, describes the categories of services that can be provided by Ukrainian universities, and defines the attributes of the IT service description template. The attributes of the description include: name, type of services, brief description, business owner, priority, service owner, consumers, request order, SLA, support system, status/phase. From the moment the IT service catalog is fully formed, its periodic monitoring begins according to the following criteria: SLA validity, correctness of provision of IT services, etc. The publication considers the formation of a catalog by stakeholders of the University on the example of the National University of Water Management and Environmental Management. In general, the use of the suggested recommendations will provide a description of the IT infrastructure of universities in the form of a set of services, the value of which is understandable to stakeholders and university management, as well as will allow to achieve competitive advantages in the educational services market.

Context WEB-services matching as a means of search query. Ontological approaches

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.