Network service registration based on role-goal-process-service meta-model in a P2P network

Service composition-based network software customisation is currently a research hotspot in the field of software engineering. A key problem of the hotspot is how to efficiently discover services distributed over the Internet. In the service oriented architecture, service discovery suffers from the performance bottleneck of centralised universal description discovery and integration (UDDI), and inaccurate matching of service semantics. In this study, the authors describe a novel method for service labelling, registration and discovery, which is based on the role-goal-process-service meta-model. This approach enables ones to achieve accurate matching of service semantics by extending web service description language with RGP demand-information. The authors also suggest a peer-to-peer (P2P)-based architecture of service discovery to address the issues in the UDDI bottleneck and the complexity of semantic computation. By adopting the proposed approach, an experiment prototype system has been designed and implemented in Beijing municipal transportation system. The experimental results show the proposed approach is effective in addressing the aforementioned problems

Web Service Broker

Práce se zabývá studiem technologií webových služeb, možností jejich vyhledávání a implementací systémů určených k registraci a vyhledávání webových služeb, tzv. adresářů. Blíže se věnuje adresáři UDDI (The Universal Description, Discovery and Integration), jeho datovým strukturám, programovému rozhranní a problematice registrace služby a jejího vyhledání s využitím UDDI. Hlavní část práce je zaměřena na implementaci části standardu UDDI v.3.0.2 pro účely demonstrace registrace a vyhledání služby v adresáři typu UDDI. Výsledná aplikace má sloužit při výuce problematiky webových služeb. Aplikace je napsána v programovacím jazyce C++ s využitím SŘBD Firebird, knihoven pro komunikaci s databází IBPP a C++ toolkitu pro vývoj webových služeb v C++ - gSOAP.The thesis deals with the study of the technology of web services and how to search for them, and with the implementation of systems used for registration of and searching for web services - directories. Greater attention is paid to the UDDI (The Universal Description, Discovery and Integration) directory, its data structures, program interface and problems related to registration of the service and searches using UDDI. The main part of the study deals with the implementation of a part of UDDI standard version 3.0.2 for the demonstration of the registration and search of the service in a UDDI type directory. The resultant application should be used for teaching problems concerning web services. It is written in C++ programming language using Firebird, libraries for communication with Firebird database IBPP and C++ toolkit for the development of web services in C++ - gSOAP.

Integration via Meaning: Using the Semantic Web to deliver Web Services

Presented at the CRIS2002 Conference in Kassel.-- 9 pages.-- Contains: Conference paper (PDF) + PPT presentation.The major developments of the World Wide Web (WWW) in the last two years have been Web Services and the Semantic Web. The former allows the construction of distributed systems across the WWW by providing a lightweight middleware architecture. The latter provides an infrastructure for accessing resources on the WWW via their relationships with respect to conceptual descriptions. In this paper, I shall review the progress undertaken in each of these two areas. Further, I shall argue that in order for the aims of both the Semantic Web and the Web Services activities to be successful, then the Web Service architecture needs to be augmented by concepts and tools of the Semantic Web. This infrastructure will allow resource discovery, brokering and access to be enabled in a standardised, integrated and interoperable manner. Finally, I survey the CLRC Information Technology R&D programme to show how it is contributing to the development of this future infrastructure

The pragmatic proof: hypermedia API composition and execution

Machine clients are increasingly making use of the Web to perform tasks. While Web services traditionally mimic remote procedure calling interfaces, a new generation of so-called hypermedia APIs works through hyperlinks and forms, in a way similar to how people browse the Web. This means that existing composition techniques, which determine a procedural plan upfront, are not sufficient to consume hypermedia APIs, which need to be navigated at runtime. Clients instead need a more dynamic plan that allows them to follow hyperlinks and use forms with a preset goal. Therefore, in this paper, we show how compositions of hypermedia APIs can be created by generic Semantic Web reasoners. This is achieved through the generation of a proof based on semantic descriptions of the APIs' functionality. To pragmatically verify the applicability of compositions, we introduce the notion of pre-execution and post-execution proofs. The runtime interaction between a client and a server is guided by proofs but driven by hypermedia, allowing the client to react to the application's actual state indicated by the server's response. We describe how to generate compositions from descriptions, discuss a computer-assisted process to generate descriptions, and verify reasoner performance on various composition tasks using a benchmark suite. The experimental results lead to the conclusion that proof-based consumption of hypermedia APIs is a feasible strategy at Web scale.Peer ReviewedPostprint (author's final draft

Museums as disseminators of niche knowledge: Universality in accessibility for all

Accessibility has faced several challenges within audiovisual translation Studies and gained great opportunities for its establishment as a methodologically and theoretically well-founded discipline. Initially conceived as a set of services and practices that provides access to audiovisual media content for persons with sensory impairment, today accessibility can be viewed as a concept involving more and more universality thanks to its contribution to the dissemination of audiovisual products on the topic of marginalisation. Against this theoretical backdrop, accessibility is scrutinised from the perspective of aesthetics of migration and minorities within the field of the visual arts in museum settings. These aesthetic narrative forms act as modalities that encourage the diffusion of ‘niche’ knowledge, where processes of translation and interpretation provide access to all knowledge as counter discourse. Within this framework, the ways in which language is used can be considered the beginning of a type of local grammar in English as lingua franca for interlingual translation and subtitling, both of which ensure access to knowledge for all citizens as a human rights principle and regardless of cultural and social differences. Accessibility is thus gaining momentum as an agent for the democratisation and transparency of information against media discourse distortions and oversimplifications