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A Multi-criteria Service Ranking Approach Based on Non-Functional Properties Rules Evaluation

Service oriented architectures (SOAs) are quickly becoming the de-facto solutions for providing end-to-end enterprise connectivity. However realizing the vision of SOA requires, among others, solutions for one fundamental challenge, namely service ranking. Once a set of services that fulfill the requested functionality is discovered, an ordered list of services needs to be created according to users preferences. These preferences are often expressed in terms of multiple non-functional properties (NFPs). This paper proposes a multi-criteria ranking approach for semantic web services. We start by briefly introducing ontological models for NFPs. These models are used to specify rules which describe NFP aspects of services and goals/requests. The ranking mechanism evaluates these NFPs rules using a reasoning engine and produces a ranked list of services according to users preferences.

Semantic Web Service Choreography: Contracting and Enactment

The emerging paradigm of service-oriented computing requires novel techniques for various service-related tasks. Along with automated support for service discovery, selection, negotiation, and composition, support for automated service contracting and enactment is crucial for any large scale service environment, where large numbers of clients and service providers interact. Many problems in this area involve reasoning, and a number of logic-based methods to handle these problems have emerged in the field of Semantic Web Services. In this paper, we build upon our previous work where we used Concurrent Transaction Logic (CTR) to model and reason about service contracts. We significantly extend the modeling power of the previous work by allowing iterative processes in the specification of service contracts, and we extend the proof theory of CTR to enable reasoning about such contracts. With this extension, our logic-based approach is capable of modeling general services represented using languages such as WS-BPEL.

Semantic Web Fred - Automated Goal Resolution on the Semantic Web

Semantic Web Fred, SWF for short, is a context-independent, goal-driven system for automated execution of tasks that are delegated to electronic representatives along with dynamic service usage. A task is assigned to an agent for automated resolution, represented as a Goal. This is used to determine potential partners for collaborative task resolution, and for discovery of suitable goal-resolving services that can be internal implementations as well as external Semantic Web Services. The SWF technology integrates agent technology, ontologies, and Semantic Web Service technologies - the technological building blocks identified for the Semantic Web - into a coherent system. This paper describes the architecture of SWF, explains the mechanisms for establishing automated and cooperative goal resolution, and the alignment of SWF with the Web Service Modeling Ontology WSMO, a well-structured overall framework for Semantic Web Services. We also outline the contribution of SWF to the development of Semantic Web technologies.

On Describing and Ranking Services based on Non-Functional Properties

Service-oriented architectures are rapidly becoming the dominant computing paradigm. However, current SOA solutions are still restricted in their application context to being in-house solutions of companies. While service orientation is widely acknowledged for its potential to revolutionize the world of computing, its success depends on resolving a number of fundamental challenges, such as discovery, ranking and selection of services. Robust and automatic solutions for these challenges requires various services and user requests aspects, including functional and non-functional, to be semantically described. Non-functional properties especially are highly relevant especially during ranking and selection tasks. This paper introduces a semantically- enables approach for describing non-functional properties of services and further discusses how such descriptions can be used during in one service related task, namely ranking.

Towards best practices in designing for the cloud

The explosion of Cloud computing propaganda has forced many companies to quickly move towards this new technology. Particularly given the current economic climate it seems like a prudent way to dynamically increase and decrease infrastructure at low cost. However, past experience with SOA has taught us that lack of commercial adaption and a proliferation of unusable standards may hinder this technology. Support from IBM and Microsoft for cloud is promising and leads to the need for strong design of cloud based systems to ensure quality and productivity. Issues already identified in Grid Computing and SOA will certainly prove important in the design of cloud based systems Due to the speed of network development due to cloud architectures, an increasing level of importance must be placed on the design to regulate issues such as: instance access control, regulatory issues, development practices, security and practical operational issues. Capturing and discussing best practices on these subjects will contribute to a healthy movement in the right direction for those who will develop the Service Cloud.

Stream Reasoning: A Survey and Further Research Directions

Data streams occur widely in various real world applications. The research on streaming data mainly focuses on the data management, query evaluation and optimization on these data, however the work on reasoning procedures for streaming knowledge bases on both the assertional and terminological levels is very limited. Typically reasoning services on large knowledge bases are very expensive, and need to be applied continuously when the data is received as a stream. Hence new techniques for optimizing this continuous process is needed for developing efficient reasoners on streaming data. In this paper, we survey the related research on reasoning that can be applied to this setting, summarize existing approaches according to a set of parameters, and point to further research directions in this area.

The Place of Policy in Semantically Enabled Service-oriented Architectures

Service-oriented architectures (SOAs) suggest that IT systems should be developed from coarse-grained, loosely coupled, business-aligned components, so called services. One way towards loose coupling is to refrain from hard-coding policies in the system and to represent them explicitly. This approach is increasingly implemented in Web service deployments (the main realization of SOAs). Semantic Web services (SWS) add semantics to Web services, to automate the various tasks common in service-oriented systems. While some work has been done on semantic approaches to policy expression and evaluation, SWS research so far has mostly ignored policies, therefore in this paper we analyze where Web service policies fit within the context of SWS.

A Logic-based Approach for Service Discovery with Composition Support

Web service discovery given a user request becomes a fundamental challenge in a service-oriented world. The overall success of Service Oriented Architectures (SOA) however will very much depend on automatic and accurate solutions for the discovery problem. Furthermore such solutions need to be efficiently integrated with other service related tasks (e.g. service composition). In this paper we propose a logic based approach for service discovery with composition support. First, we provide a formal model for service discovery based on semantic description of services and then we show how such an approach can be integrated with service composition. Furthermore we provide a prototype implementation that validates our theoretical solution.

Service Selection via Extreme Geotagging

Location of services plays an important role in the process of service selection. Geotagging emerged as a technique for attaching location information to Web elements, including Web services. In this context, this paper proposes a Web service selection framework based on geotagging. First, we introduce tagging and geotagging as an operation that emphasizes processes and the dynamic aspects of the environment. Then, we propose a conceptual model that defines a set of relations between tags. Furthermore, we develop a service selection technique based on this model and give an example of service selection. An overview of a system that implements geotagging-based service selection is presented at the end.

Ontologies and Matchmaking

The word ontology is used with different meanings in different communities. We distinguish between Ontology (uncountable reading and capital initial) and an ontology (countable reading and lower-case initial). In the first case, we refer to a philosophical discipline, namely the branch of philosophy which deals with the nature and the organisation of reality. Unlike the special sciences, each of which investigates a class of beings and their determinations, Ontology regards all the species and tries to answer the question: What is being?, or What are the features common to all beings? In the second case, we refer to an information object and engineering artefact as the most prevalent use in the computer science communities.