Thesis (M. Sc. (Computer Science))--Rhodes University, 2006.

Η παρούσα διπλωματική εργασία αναφέρεται στην δημιουργία μιας εφαρμογής για κινητά τηλέφωνα, σε πλατφόρμα J2ME. Η εφαρμογή αυτή δίνει τη δυνατότητα στους χρήστες της, με τη βοήθεια υπηρεσιών βασισμένων στη θέση, να συγκρίνουν τις τιμές στις οποίες πωλούνται διάφορα βιβλία στα καταστήματα της περιοχής τους. Για την ανάπτυξη αυτής της εφαρμογής χρησιμοποιήθηκαν υπηρεσίες διαδικτύου που επιτρέπουν την επικοινωνία μεταξύ κινητών συσκευών και ενός κεντρικού εξυπηρετητή. Επίσης, αναπτύχθηκε μια βάση δεδομένων από την πλευρά του εξυπηρετητή, η οποία ενημερώνεται από τους ίδιους τους χρήστες. Για τον καθορισμό της γεωγραφικής θέσης του χρήστη χρησιμοποιείται το σύστημα GPS, ενώ για την παρουσίαση των αποτελεσμάτων χρησιμοποιήθηκε το Static Maps API. / The purpose of this diploma thesis is the development of an application designed for mobile phones, based on a J2ME platform. This application enables the users to use their phones in order to compare the prices of books among stores of a specific area. The development of this application includes a distributed system, which consists of two components: the client application, namely the users and the server application that contains a data base. This data base gets updated by the end users. The communication between the server and the client is based on Web Services. The users’ location is determined by the phone’s embedded GPS receiver. Finally, the Static Maps API is used for mapping the results.

Στην παρούσα διπλωματική εργασία ασχοληθήκαμε με την ανάπτυξη Υπηρεσιών Ιστού (της περισσότερο δημοφιλούς και ευρέως διαδεδομένης υλοποίησης της υπηρεσιοστρεφούς αρχιτεκτονικής) για την υλοποίηση του παρακάτω σεναρίου ( use case scenario) : • Μηχανογράφηση του τμήματος Ηλεκτρολόγων Μηχανικών του Πανεπιστημίου Πατρών Στο σενάριο αυτό υλοποιήσαμε υπηρεσίες που εξυπηρετούν τους φοιτητές, τους καθηγητές και την γραμματεία αυτού. Πιο συγκεκριμένα απαιτείται μέσω του Internet: • Ο φοιτητής να έχει την δυνατότητα : α) να δηλώσει τα μαθήματα και τα συγγράμματα που επιθυμεί για το τρέχων εξάμηνο β) να δει το ιστορικό δηλώσεων των δηλώσεων και αλλαγών για όλα τα μαθήματα και γ) την αναλυτική βαθμολογία του. • Ο καθηγητής να έχει την δυνατότητα α) να ανεβάζει τη βαθμολόγια των μαθημάτων .β) να έχει πρόσβαση στη λίστα των φοιτητών που έχουν δηλώσει τα μάθηματά του. Eπιπλέον ο πρόεδρος του τμήματος έχει τη δυνατότητα πρόσβασης σε στατιστικά στοιχεία για τις εξεταστικές. • Η γραμματεία του τμήματος α) να έχει τη δυνατότητα να εγκρίνει τις δηλώσεις των φοιτητών και β) να έχει την δυνατότητα πρόσβασης στα στοιχεία των φοιτητών( δηλώσεις , βαθμολογίες κ.λ.π.) / The purpose of this diploma thesis was the development of Web Services ( one of the most popular and well known implementation solution of Service Oriented Architecture) in purpose of providing a solution using methods in the following use case scenario • Computerization of the Electrical and Computer Engineering Department of the University of Patras In this use case we developed web services that allow both the students and the department staff (faculty members and secretaries alike) to interact with each other. More specifically via the use of Internet: • The students have the ability to a) apply for their semester courses and their respective books b) view their course application history and c) view their exam grades for each course • The faculty staff and professors, have the ability a) to upload the exam grades to the department's database and b) have access to the list which contains the names of the students that have applied for their courses. In addition the dean must have access to statistical data concerning the exam grades. • The secretary staff has the ability to review the course applications of the students and take the appropriate action (such as reject or accept the application). In addition the secretary staff has access to all data concerning the students (grades ,course application history etc.)

M. Tech. Electrical Engineering. / Proposes a public-key encryption scheme based on Qi hyperchaos, which is considered much better than chaos and other hyperchaos in terms of pseudo-randomness. In an environment where digital information is being extensively used, a cat map based hyperchaotic system is proposed. This map is used to design the public key encryption scheme that uses private keys, public keys and shared private keys. This encryption is tested successfully on text messages and images. The application of the hyperchaos-based scheme on a web server client platform concludes this work. MATLAB is used for simulation. PHP, HTML, and C are used in the development of the web form and the chat application.

Les systèmes de services contextualisés ont connu un grand essor ces dernières années dans des domaines variés tels que la santé, la logistique ou bien le tourisme. Cette thèse s'intègre dans un projet plus global, nommé E-Tourism, qui vise à réaliser une plateforme de fourniture de services sensibles au contexte à des utilisateurs en situation de mobilité. Le travail de cette thèse se focalise sur la problématique de composition de services web et de leur exécution. La composition de services web permet la réutilisation de services existants afin d'en faire une synthèse répondant au besoin de l'utilisateur. Cette composition se fait en général au niveau de la phase conceptuelle ce qui limite le choix de services potentiels. Cette thèse présente une nouvelle approche de la composition de services Web automatisé et une plateforme d'exécution. Notre approche vise à composer les opérations de services qui répondent aux besoins des utilisateurs mobiles exprimées dans une logique propositionnelle et exécuter le service composé en agrégeant plusieurs services composants. Nous avons proposé une plateforme d'exécution de services et nous avons introduit un nouvel algorithme de planification intégré à cette plateforme. Nous avons défini un contexte basé sur le modèle BPMN. Afin de valider notre modèle sémantique nous avons utilisé une approche de type « model-checking » . Enfin, nous avons réalisé un prototype sous forme d'une plateforme de composition de services et d'exécution automatique en Java. Nous avons implémenté les règles d'inférence et les modèles BPMN en prolog. Enfin, nous avons intégré ces algorithmes dans l'ensemble du système. En perspectives, nous prévoyons d'étendre notre travail actuel et prendre en compte des scénarios plus complexes nécessitant des services web dynamiques. / Recently, distributed computing systems based on context awareness have been proposing in several domains such as healthcare, logistics and tourism. The study described in this thesis is a part of a broader project of E-Tourism system that provides nomad user, context-aware personalized services. The work of this thesis focuses on the issues raised by web service composition and execution. Web service composition brings benefits of reusing existing services to synthesize the new resulting service that meets users needs. The way to create web service composition normally happens at design time, but this limits choices of services. This thesis presents a novel approach of automated web service composition and execution framework. Our approach aims to compose service operations that fulfill mobile users' requirements expressed in propositional logic and execute the resulting service based on aggregating multi service components. In the proposed framework, we have introduced our planning algorithm based on abstract goal states to search and connect to service operations, by mean of service operation annotations, for an abstract plan. The abstract plan is expected for workflow model of sequencing, paralleling and conditioning among service operations. However, the generated workflow is not in an executable form, this is why we perform the transformation of the workflow into an executable business process. To achieve the business process execution, we defined context based BPMN model for mapping the abstract plan to BPMN semantics. We also propose a new validation algorithm and exploited planning-as-model-checking approach to validate the semantic BPMN model whether it is Well-formed and Well-defined BPMN process. Finally, we implemented the automated service composition and execution framework system in Java platform as a proof of concept. We developed the logical composition and, transformation and validation BPMN algorithms written in Prolog. We have integrated these algorithms into the whole system. From the perspective, we plan to extend our current work and take into account more complex user's scenarios that explicitly and implicitly express other pattern controls and we will also consider the scenarios required for stateful web services

Context awareness means sending the right information to the right user at the righttime. Context is our environment, which can be anything around us such as location,lights, noises etc. To make the context interact with our mobile devices or sensors,there must be protocols for communication and data formats for the “sent” or “received”contextual information so we can give very specific context information tothe user. Since this communication and adaptive part is not well understood, in thispaper we are interested in investigating the technology used for adaptation. We willalso explain how this technology works to adapt itself to changes in the environment.

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.

The Semantic Web is an extension of the current Web, where the availability of information is expected to enable the cooperation between man and, above all, machines. The creation of standards which express shared meaning enable the construction of applications to solve integration, collaboration and automation problems which were already been identified by scientific community and technology consumers. The use of Web Services has brought several advances in this sense, and their annotation in semantic terms, transforming them into Semantic Web Services, enables the Semantic Web intent. Several technologies also enable the creation of such elements and their inherent use as basic blocks of application development whose scope is embedded on Web. This way, due to the fast growing of the number of services, some approaches to effectively solve the problem of services integration and use become necessary. This work proposes a modeling of a software solution to the discovery and composition of Semantic Web Services problem through the use of a genetic algorithm based on abstract data types. It is also proposed a tool implementation using OWL, OWL-S and OWL-S API languages and frameworks as well as the formal problem definition along with the scientific community expectations to the given solution. / AWeb Semântica é uma ampliação da web atual onde a disposição da informação viabiliza a cooperação entre homens e, sobretudo, entre máquinas. O surgimento de padrões web que expressam significado compartilhado possibilitam a construção de aplicações que resolvem problemas de integração, colaboração e automação já identificados pela comunidade científica e mercado consumidor de tecnologias. A utilização de Serviços Web trouxe grandes ganhos neste sentido, e sua anotação em termos semânticos, tornando-os Serviços Web Semânticos, viabiliza a proposta da Web Semântica. Diversas tecnologias viabilizam a construção de tais elementos e sua conseqüente utilização como blocos básicos do desenvolvimento de aplicações cujo escopo é embarcado na web. Assim, dado o rápido crescimento da quantidade de serviços, tornam-se necessárias abordagens que resolvam de forma efetiva, com garantias de qualidade e tempo de resposta aceitável, a integração e posterior utilização destes. Este trabalho propõe a modelagem de uma solução de software para o problema da Descoberta e Composição de Serviços Web Semânticos através do uso do Algoritmo Genético Baseado em Tipos Abstratos de Dados. Também é proposta uma implementação utilizando OWL, OWL-S e a OWL-S API. São apresentadas a definição formal do problema, as expectativas da comunidade científica quanto às soluções elaboradas e os resultados obtidos com respeito à viabilidade da proposta.

Made available in DSpace on 2016-06-02T19:06:11Z (GMT). No. of bitstreams: 1 5689.pdf: 7157103 bytes, checksum: 6394b210d78146b40e721a0693b0654b (MD5) Previous issue date: 2009-06-19 / Financiadora de Estudos e Projetos / System reuse is a Software Engineering technique that proposes the construction of software systems from existing artifacts. One way to develop systems reusing code and project in a specific domain is using application generators. These generators automate part of the development process, reduce costs, allow the increase of the development team productivity, enhance systems quality and minimize error insertion arising from the implementation phase. The GawCRe (Web based Application Generator to the Rehabilitation Clinic domain) was developed using the software product lines technique based in the SiGCli (Rehabilitation Clinics Management System) pattern language. This generator went through some maintenance in order to allow the MySQL RDBMS usage, as well as to carry out version control of the generated applications and increase its domain to others related to it. Currently, there is interest in the usage of Service Oriented Architectures (SOA) to support the construction of software applications that use services available in a network, as the Web. These services are an implementation of well-defined business functionality that can be used by clients of different applications. The reutilization of available services in the construction of new Web systems is increasing, reducing the rework and facilitating the maintenance of these systems. This master's thesis presents an approach to modify application generators in a way that its domain is increased by the use of Web Services provided by Service Oriented Architecture. This architecture eases systems' adaptation, making them dynamic, as their services can be swapped in runtime. This allows future maintenances to be eased, because modifications in the services are reflected in the applications without user intervention. The GAwCRe undergone for maintenance to support the use of Web Services provided by a SOA, thereby, broadening its domain. A case study was conducted using the GAwCRe and some Web Services attempt to evaluate the combined use of SOA and Application Generators. / O reúso de sistemas é uma técnica da Engenharia de Software que propõe a construção de sistemas de software a partir de artefatos já existentes. Uma das formas de desenvolver sistemas reutilizando código, projeto, em um domínio específico, é por meio de geradores de aplicação. Eles automatizam parte do processo de desenvolvimento, reduzem custos, possibilitam o aumento de produtividade da equipe de desenvolvimento, melhoram a qualidade dos sistemas e minimizam a inserção de erros provenientes da fase de implementação. O GAwCRe - Gerador de Aplicações baseadas na Web para o Domínio de Gestão de Clínicas de Reabilitação - foi desenvolvido com a técnica de linhas de produtos de software e com base na linguagem de padrões SiGCli (Sistema de Gestão de Clínicas de Reabilitação). Esse gerador passou por algumas manutenções para possibilitar a utilização do SGBD MySQL, bem como realizar controle de versões das aplicações geradas e ter seu domínio ampliado para domínios conexos ao seu. Atualmente, há o interesse em utilizar arquiteturas orientadas a serviços (SOA) para apoiar a construção de aplicações de software que utilizam serviços disponíveis em uma rede como a Web. Esses serviços são implementações de uma funcionalidade de negócios bem definida, que pode ser utilizada por clientes de diferentes aplicações. É cada vez mais constante a reutilização de serviços já disponíveis para a construção de novos sistemas Web, reduzindo retrabalho e facilitando a manutenção desses sistemas. Esta dissertação de mestrado apresenta uma abordagem para modificar geradores de aplicação, de modo que seu domínio seja ampliado com a utilização de serviços Web providos por uma arquitetura orientada a serviços. Essa arquitetura facilita a adaptação de sistemas, fazendo com que esses se tornem dinâmicos, uma vez que os seus serviços podem ser substituídos em tempo de execução. Também permite que futuras manutenções sejam facilitadas, pois as modificações, feitas nos serviços, são refletidas nas aplicações sem a intervenção do usuário. O GAwCRe passou por manutenções para que pudesse apoiar o uso dos serviços Web providos por uma SOA e, assim, ampliar o seu domínio. Um estudo de caso foi realizado utilizando o GAwCRe e alguns serviços Web buscando avaliar o uso conjunto de SOA e Geradores de Aplicação.

De nos jours, les projets de conception complexes de produits exigent que les équipes de concepteurs se réunissent pour faciliter le partage de leurs compétences et expertises respectives afin de produire un ensemble de solutions de conception efficace. Dû au besoin croissant d’échanger les connaissances, les projets de conception modernes sont encore plus structurés pour travailler avec des équipes distribuées qui collaborent sur un réseau informatique pour accomplir une conception optimale de produit. Néanmoins, dans ce processus de conception collaborative, l'intégration d'équipes multidisciplinaires – qui implique l'échange et le partage des connaissances et compétences – génère fréquemment des situations conflictuelles. Les différents points de vue et perspectives des experts, les différentes façons de communiquer et collaborer au niveau de connaissances, rendent le processus difficilement maitrisable. Pour accomplir un scénario optimal, certains problèmes doivent d’abords être résolus comme la spécification et formalisation des besoins, l’intégration d'ontologies, la détection et la résolution des conflits. Spécifier et formaliser les connaissances demandent un grand effort afin d’obtenir un modèle de représentation pour agréger plusieurs domaines différents des connaissances. Chaque expert pourrait s'exprimer afin que les autres comprennent leurs informations correctement. Il est donc nécessaire d’utiliser un modèle de représentation de données suffisamment clair et flexible pour accomplir cette tâche. Certains modèles actuels ne parviennent pas à fournir une solution efficace pour le partage des connaissances et pour la collaboration des projets de conception, car ces modèles n’intègrent pas les aspects géographiques, temporels, fonctionnels de la conception avec un modèle de représentation des connaissances flexible et générique. Ce travail propose une architecture, pour la conception collaborative, qui ambitionne d'être synchrone, générique, orientée aux services, basée sur les agents, et basée sur les ontologies. Des modèles particuliers de représentation sont transformés en instances d'ontologie et sont fusionnés pour accomplir le model final de conception d’un produit. C'est une approche synchrone parce que le processus de fusion est entrepris en même temps que l'interaction entre concepteurs. C'est générique parce qu'elle permet aux utilisateurs de travailler avec deux approches pour l’intégration d'ontologies : celle qui utilise une ontologie générique et celle qui utilise un processus d'harmonisation. Notre proposition se concentre sur les conflits de la conception collaborative et fait usage de Web Ontology Language (OWL) et des Services Web, le premier comme langage pour représenter les connaissances et le dernier comme un support technologique pour la communication. / Today’s complex design projects require teams of designers to work collaboratively by sharing their respective expertise in order to produce effective design solutions. Due to the increasing need for exchanging knowledge, modern design projects are more structured to work with distributed virtual teams that collaborate over computer networks to achieve overall optimization in design. Nevertheless, in a collaborative design process, the integration of multidisciplinary virtual teams – involving exchange and sharing of knowledge and expertise – frequently and inevitably generates conflicting situations. Different experts’ viewpoints and perspectives, in addition to several ways of communicating and collaborating at the knowledge level, make all this process very hard to manage. In order to achieve an optimal scenario, some problems must first be solved, such as requirement specification and formalization, ontology integration, and conflict detection and resolution. Specifying and formalizing the knowledge demands a great effort towards obtaining representation patterns that aggregate several disjoint knowledge areas. Each expert should express himself so that the others can understand his information correctly. It is necessary, therefore, to use a flexible and sufficiently extensive data representation model to accomplish such a task. Some current models fall short of providing an effective solution to effective knowledge sharing and collaboration on design projects, because they fail to combine the geographical, temporal, and functional design aspects with a flexible and generic knowledge representation model. This work proposes an information model-driven collaborative design architecture that supports synchronous, generic, service-oriented, agent-based, and ontology-based teamwork. Particular representation models are transformed into ontology instances and merged together in order to accomplish the final product design. It is a synchronous approach because the concurrent processes are undertaken at the same time that the interactions among designers take place. It is generic because it provides the users with two approaches for ontology integration: the use of a predefined generic ontology and the harmonization process. Our proposal focuses on collaborative design conflict resolution by using Web Ontology Language (OWL) and Web Services, the former as a tool for knowledge representation and the latter as a technological support for communication.