A framework for deriving semantic web services

Web service-based development represents an emerging approach for the development of distributed information systems. Web services have been mainly applied by software practitioners as a means to modularize system functionality that can be offered across a network (e.g., intranet and/or the Internet). Although web services have been predominantly developed as a technical solution for integrating software systems, there is a more business-oriented aspect that developers and enterprises need to deal with in order to benefit from the full potential of web services in an electronic market. This ‘ignored’ aspect is the representation of the semantics underlying the services themselves as well as the ‘things’ that the services manage. Currently languages like the Web Services Description Language (WSDL) provide the syntactic means to describe web services, but lack in providing a semantic underpinning. In order to harvest all the benefits of web services technology, a framework has been developed for deriving business semantics from syntactic descriptions of web services. The benefits of such a framework are two-fold. Firstly, the framework provides a way to gradually construct domain ontologies from previously defined technical services. Secondly, the framework enables the migration of syntactically defined web services toward semantic web services. The study follows a design research approach which (1) identifies the problem area and its relevance from an industrial case study and previous research, (2) develops the framework as a design artifact and (3) evaluates the application of the framework through a relevant scenario

Flexible virtual learning environments: a schema-driven approach using sematic web concepts

Flexible e-Iearning refers to an intelligent educational mechanism that focuses on simulating and improving traditional education as far as possible on the Web by integrating various electronic approaches, technologies, and equipment. This mechanism aims to promote the personalized development and management of e-learning Web services and applications. The main value of this method is that it provides high-powered individualization in pedagogy for students and staff.Here, the thesis mainly studied three problems in meeting the practical requirements of users in education. The first question is how a range of teaching styles (e.g. command and guided discovery) can be supported. The second one is how varieties of instructional processes can be authored. The third question is how these processes can be controlled by learners and educators in terms of their personalized needs during the execution of instruction.In this research, through investigating the existing e-Iearning approaches and technologies, the main technical problems of current virtual learning environments (VLEs) were analyzed. Next, by using the Semantic Web concepts as well as relevant standards, a schema-driven approach was created. This method can support users' individualized operations in the Web-based education. Then, a flexible e-learning system based on the approach was designed and implemented to map a range of extensive didactic paradigms. Finally, a case study was completed to evaluate the research results. The main findings of the assessment were that the flexible VLE implemented a range of teaching styles and the personalized creation and control of educational processes

iDRM - Interoperability Mechanisms for Open Rights Management Platforms

Today’s technology is raising important challenges in the Intellectual Property (IP) field in general and to Copyright in particular [Arkenbout et al., 2004]. The same technology that has made possible the access to content in a ubiquitous manner, available to everyone in a simple and fast way, is also the main responsible for the challenges affecting the digital content IP of our days [Chiariglione, 2000]. Technological solutions and legal frameworks were created to meet these new challenges. From the technological point of view, Rights Management Systems (RMS) and Copy Protection Systems (CPS) have been developed and deployed to try to cope with them. At first, they seemed to work however, their closed and non-interoperable nature and a growing number of wrong strategic business decisions, soon lead to a strong opposition. One of the strongest negative points is the lack of rights management interoperability [Geer, 2004]. The work presented on this thesis primarily addresses the RMS interoperability problems. The objective of the thesis is to present some possible mechanisms to improve the interoperability between the different existing and emerging rights management platforms [Guth, 2003a]. Several different possible directions to rights management interoperability are pointed in this thesis. One of the most important is openness. Interoperability between different rights management mechanisms can only be achieved if they are open up to a certain level. Based on this concept, an open rights management platform is designed and presented in this thesis. Also, some of the interoperability mechanisms are presented and explained. This platform makes usage of the emerging service-oriented architectures to provide a set of distributed rights management services. Rights management solutions rely heavily on the establishment of authenticated and trust environments between its different elements. While considering different RMS, the establishment of such trust environments can be somehow complex. This thesis provides a contribution to the establishment of interoperable RMS trust environments through the usage of Public-Key Infrastructure (PKI) mechanisms. Modern rights management systems have to handle with both keying material and licenses which are used mostly to define how content is governed by the system. Managing this is a complex and hard task when different rights management solutions are considered. This thesis presents and describes a generic model to handle the key and license management life cycle, that can be used to establish a global interoperable management solution between different RMS

Implementação de serviços baseados em localização utilizando arquiteturas e padrões abertos

Orientador: Geovane Cayres MagalhãesDissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Serviços Baseados em Localização (Location-Based Service (LBS)) são serviços que usam informações geográficas para obter e gerar informações úteis para os usuários, como por exemplo, a localização do posto de gasolina mais próximo ou a melhor rota da posição corrente do usuário até o hospital mais próximo. Existem várias iniciativas na definição de padrões com o objetivo de aumentar a interoperabilidade entre aplicações baseadas em serviços de localização. Dentre as principais iniciativas podemos citar as especificações Open Location Services (OpenLS) do Open Geospatial Consortium (OGC) e Mobile Location Protocol (MLP) do Open Mobile Alliance (OMA). O uso da tecnologia Web Services também é uma forma de garantir a interoperabilidade entre as aplicações de LBS, uma vez que ela permite que aplicações em diferentes plataformas e linguagens de programação se comuniquem via XML ou outros padrões Web. Esta dissertação tem como objetivo apresentar um estudo sobre as tecnologias envolvidas no desenvolvimento de Serviços Baseados em Localização e propor uma arquitetura baseada em padrões abertos para oferecimento destes serviços. Esta arquitetura é validada através do desenvolvimento de um protótipo do Serviço de Apresentação de Mapas definido na especificação OpenLS. Este trabalho também contempla uma análise de alguns produtos disponíveis no mercado que oferecem aplicações LBS que utilizam padrões abertosAbstract: Location-Based Services (LBS) are services which use geographic information to obtain and generate useful information for users such as the location of the nearest gas station, for instance, or the best route for the nearest hospital by taking the user's current position as a starting point. There are several initiatives for the definition of standards aiming at increasing the interoperability of applications, which are based upon location services. Among the main initiatives, the Open Location Services (OpenLS) of the Open Geospatial Consortium (OGC), and Mobile Location Protocol (MLP) of the Open Mobile Alliance (OMA) should be mentioned. The use of the Web Services technology is also a way to assure the interoperability involving LBS applications, once it allows applications in different platforms and programming languages to communicate via XML or other Web standards. This dissertation is aimed at presenting a study regarding the technologies involved in the development of Location-Based Services and proposing an architecture which is based on open standards to make these services available. This architecture is validated through the development of a prototype of the Presentation Service defined in the OpenLS specification. This study also comprises an analysis of some market-available products that offer LBS applications that use open standardsMestradoEngenharia de ComputaçãoMestre em Ciência da Computaçã

Generative aspect-oriented component adaptation

Due to the availability of components and the diversity of target applications, mismatches between pre-qualified existing components and the particular reuse context in applications are often inevitable and have been a major hurdle of component reusability and successful composition. Although component adaptation has acted as a key solution for eliminating these mismatches, existing practices are either only capable for adaptation at the interface level, or require too much intervention from software engineers. Another weakness of existing approaches is the lack of reuse of component adaptation knowledge. Aspect Oriented Programming (AOP) is a new methodology that provides separation of crosscutting concerns by introducing a new unit of modularization - an Aspect that crosscuts other modules. In this way, all the associated complexity of the crosscutting concerns is isolated into the Aspects, hence the final system becomes easier to design, implement and maintain. The nature of AOP makes it particularly suitable for addressing non-functional mismatches with component-based systems. However, current AOP techniques are not powerful enough for efficient component adaptation due to the weaknesses they have, including the limited reusability of Aspects, platform specific Aspects, and naive weaving processes. Therefore, existing AOP technology needs to be expanded before it can be used for efficient component adaptation. This thesis presents a highly automated approach to component adaptation through product line based Generative Aspect Oriented Component adaptation. In the approach, the adaptation knowledge is captured in Aspects and aims to be reusable in various adaptation circumstances. Automatic generation of adaptation Aspects is developed as a key technology to improve the level of automation of the approach and the reusability of adaptation knowledge. This generation is realised by developing a two dimensional Aspect model, which incorporates the technologies of software product line and generative programming. The adaptability and automation of the approach is achieved in an Aspect oriented component adaptation framework by generating and then applying the adaptation Aspects under a designed weaving process according to specific adaptation requirements. To expand the adaptation power of AOP, advanced Aspect weaving processes have been developed with the support of an enhanced aspect weaver. To promote the reusability of adaptation Aspects, an expandable repository of reusable adaptation Aspects has been developed based on the proposed two-dimensional Aspect model. A prototype tool is built as a leverage of the approach and automates the adaptation process. Case studies have been done to illustrate and evaluate the approach, in terms of its capability of building highly reusable Aspects across various AOP platforms and providing advanced weaving process. In summary, the proposed approach applies Generative Aspect Oriented Adaptation to targeted components to correct the mismatch problem so that the components can be integrated into a target application easily. The automation of the adaptation process, the deep level of the adaptation, and the reusability of adaptation knowledge are the advantages of the approach.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

An exploration of the diffusion of a new technology from communities of practice perspective: Web services technologies in digital libraries

This study explored and described decision factors related to technology adoption. The research used diffusion of innovations and communities of practice (CoP) theoretical frameworks and a case study of Web services technology in the digital library (DL) environment to develop an understanding of the decision-making process. A qualitative case study approach was used to investigate the research problems and data were collected through semi-structured interviews, documentary evidence (e.g., meeting minutes), and a comprehensive member check. The research conducted face-to-face and phone interviews with seven respondents with different job titles (administraive vs. technical) from five different DL programs selected based on distinctive characteristics such as size of the DL program. Findings of the research suggested that the decision-making process is a complex process in which a number of factors are considered when making technology adoption decisions. These factors are categorized as organizational, individual, and technology specific factors. Further, data showed that DL CoPs played an important role in enabling staff members of a DL program to access up-to-date and experienced-based knowledge, provided a distributed problem solving and learning environment, facilitating informal communication and collaborative activities, and informing the decision-making process.Committee Co-Chair: William E. Moen; Committee Co-Chair: Brian C. O'Connor; Committee Member: Samantha K. Hastings; Committee Member: Rada Mihalcea; Committee Member: Guillermo A. Oyarce: Dean of Program: Herman L. Totten; Dean of Graduate Studies: Sandra L. TerrellPh

Generative aspect-oriented component adaptation

Due to the availability of components and the diversity of target applications, mismatches between pre-qualified existing components and the particular reuse context in applications are often inevitable and have been a major hurdle of component reusability and successful composition. Although component adaptation has acted as a key solution for eliminating these mismatches, existing practices are either only capable for adaptation at the interface level, or require too much intervention from software engineers. Another weakness of existing approaches is the lack of reuse of component adaptation knowledge.Aspect Oriented Programming (AOP) is a new methodology that provides separation of crosscutting concerns by introducing a new unit of modularization - an Aspect that crosscuts other modules. In this way, all the associated complexity of the crosscutting concerns is isolated into the Aspects, hence the final system becomes easier to design, implement and maintain. The nature of AOP makes it particularly suitable for addressing non-functional mismatches with component-based systems. However, current AOP techniques are not powerful enough for efficient component adaptation due to the weaknesses they have, including the limited reusability of Aspects, platform specific Aspects, and naive weaving processes. Therefore, existing AOP technology needs to be expanded before it can be used for efficient component adaptation.This thesis presents a highly automated approach to component adaptation through product line based Generative Aspect Oriented Component adaptation. In the approach, the adaptation knowledge is captured in Aspects and aims to be reusable in various adaptation circumstances.Automatic generation of adaptation Aspects is developed as a key technology to improve the level of automation of the approach and the reusability of adaptation knowledge. This generation is realised by developing a two dimensional Aspect model, which incorporates the technologies of software product line and generative programming. The adaptability and automation of the approach is achieved in an Aspect oriented component adaptation framework by generating and then applying the adaptation Aspects under a designed weaving process according to specific adaptation requirements. To expand the adaptation power of AOP, advanced Aspect weaving processes have been developed with the support of an enhanced aspect weaver. To promote the reusability of adaptation Aspects, an expandable repository of reusable adaptation Aspects has been developed based on the proposed two-dimensional Aspect model.A prototype tool is built as a leverage of the approach and automates the adaptation process. Case studies have been done to illustrate and evaluate the approach, in terms of its capability of building highly reusable Aspects across various AOP platforms and providing advanced weaving process.In summary, the proposed approach applies Generative Aspect Oriented Adaptation to targeted components to correct the mismatch problem so that the components can be integrated into a target application easily. The automation of the adaptation process, the deep level of the adaptation, and the reusability of adaptation knowledge are the advantages of the approach

A detailed investigation of interoperability for web services

The thesis presents a qualitative survey of web services' interoperability, offering a snapshot of development and trends at the end of 2005. It starts by examining the beginnings of web services in earlier distributed computing and middleware technologies, determining the distance from these approaches evident in current web-services architectures. It establishes a working definition of web services, examining the protocols that now seek to define it and the extent to which they contribute to its most crucial feature, interoperability. The thesis then considers the REST approach to web services as being in a class of its own, concluding that this approach to interoperable distributed computing is not only the simplest but also the most interoperable. It looks briefly at interoperability issues raised by technologies in the wider arena of Service Oriented Architecture. The chapter on protocols is complemented by a chapter that validates the qualitative findings by examining web services in practice. These have been implemented by a variety of toolkits and on different platforms. Included in the study is a preliminary examination of JAX-WS, the replacement for JAX-RPC, which is still under development. Although the main language of implementation is Java, the study includes services in C# and PHP and one implementation of a client using a Firefox extension. The study concludes that different forms of web service may co-exist with earlier middleware technologies. While remaining aware that there are still pitfalls that might yet derail the movement towards greater interoperability, the conclusion sounds an optimistic note that recent cooperation between different vendors may yet result in a solution that achieves interoperability through core web-service standards