Made available in DSpace on 2015-03-05T13:56:58Z (GMT). No. of bitstreams: 0 Previous issue date: 14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Para promover a reutilização de conteúdos de aprendizagem é necessário promover a normalização desses conteúdos para que possam funcionar corretamente em qualquer sistema de e-learning. A normalização permite: uma fácil reutilização; a portabilidade dos conteúdos criados; a padronização dos processos de criação; e a gestão dos conteúdos de aprendizagem. Porém, normalizar um ambiente de Educação a Distância já existente não é uma tarefa trivial e necessita de uma adequação tanto dos conteúdos de aprendizagem quanto do sistema de e-learning, pois toda a arquitetura é alterada, sendo necessário separar o conteúdo da estrutura. Esta pesquisa propõe e implementa uma arquite-tura denominada Fábrica de Adequação capaz de promover a interoperabilidade dos conteúdos educacionais e promover a adequação de recursos educacionais para Objetos de Aprendizagem Reutilizáveis, respeitando a norma SCORM, utilizando de tecnologias de Agentes de Software,Meta-dado (SCORM) e Web Services, os quais dispõem de mecanismo de auton / To promote learning object reusability it is necessary to provide the normalization of its contents so that they can work appropriately in any e-learning system. The normalization alows easy reusability, portability of created contents, standardization of processes of creation, and management of learning objects. However, to normalize an existing E-learning environment it is not a trivial task and it requires adequacy either of the learning contents and the e-learning system, once the whole architecture is modified, being necessary though to separate the content from the structure. This research proposes and implements an architecture caled Adequacy Factory which is capable of promoting the interoperability of educational contents and the adequacy of educational resources for Learning Object Reusability, respecting the SCORM norm by using technologies such as Soft-ware Agents, Meta-Data (SCORM), and Web Services which make use of autonomy mechanism, interaction, invocation, access, and reuse of services

Esta tese tem como objetivo o projeto e implementação de uma arquitetura orientada a serviços, denominada WSARCH - Web Services Architecture, que possibilita acesso a Web Services com Qualidade de Serviço (QoS). Os atributos de QoS que devem ser considerados, visando à avaliação de desempenho deWeb services e a obtenção de QoS em uma arquitetura orientada a serviços, são identificados e discutidos. Esses atributos de QoS são mapeados para os componentes participantes de uma arquitetura orientada a serviços que incorpora qualidade de serviço. A arquitetura proposta prevê a monitoração dos provedores de serviços e um módulo que utiliza os dados obtidos para a localização do serviço apropriado. Visando a validação da arquitetura proposta e dos atributos definidos desenvolveu-se um protótipo da WSARCH. O protótipo desenvolvido permite que estudos de avaliação de desempenho sejam realizados considerando os diferentes componentes da arquitetura, algoritmos, protocolos e padrões. A proposta da WSARCH se insere em um contexto em que é importante definir como deve ser projetada uma arquitetura SOA com foco em desempenho, uma vez que a correta caracterização do que avaliar, e como avaliar, se faz necessário. Nesta tese, a avaliação de desempenho está focada nas diferentes entidades que participam de uma arquitetura orientada a serviço: cliente, provedor e os demais participantes / This thesis aims at the design and implementation of a service-oriented architecture, named WSARCH - Web Services Architecture, which allows accessing Web Services with Quality of Service (QoS). The attributes of QoS that shall be considered, aiming at evaluating the performance of Web Services in order to achieve QoS in a service-oriented architecture are identified and discussed. These QoS attributes were mapped to the components participating in a service-oriented architecture that incorporates quality of service. The proposed architecture provides the monitoring of service providers and a module that uses the data to locate the appropriate service. Aiming at the validation of the proposed architecture and the set of attributes proposed, a prototype of WSARCH was developed. The prototype allows performance evaluation studies being conducted considering the different components of the architecture, algorithms, protocols and standards. The proposal of WSARCH is inserted in a context where is important to define how a SOA architecture focusing on performance shall be designed, since the correct characterization of what to evaluate, and how to evaluate is necessary. In this thesis, the evaluation of performance is focused on the different entities participating in a service-oriented architecture: client, provider and other participants

MÉTODOS de geração de casos de teste visam a gerar um conjunto de casos de teste com uma boa relação custo/benefício. Critérios de cobertura de teste definem requisitos de teste, os quais um conjunto de teste adequado deve cobrir. Métodos e critérios visam a selecionar casos de teste baseados em especificações, que podem ser descritas por meio de modelos, tais como Máquinas de Estados Finitos (MEF). Existem diversos métodos de geração e critérios de cobertura, diferindo entre si em função das propriedades exigidas da MEF, do custo dos testes gerados e da eficácia na revelação de defeitos. Apesar de pesquisas intensas na definição desses métodos e critérios, são poucas as ferramentas de apoio disponíveis assim como são poucos os relatos de aplicação em termos de custo e eficácia para a definição de estratégias de teste efetivas. Dessa forma, é necessário obter dados reais das vantagens e desvantagens dos métodos e critérios para subsidiar a tomada de decisão no processo de desenvolvimento de software no que tange às atividades de teste e validação. Este trabalho apresenta resultados de experimentos para avaliar o custo e a eficácia de aplicação dos métodos e critérios mais relevantes para subsidiar a definição de estratégias de teste em diversos contextos, como por exemplo, no desenvolvimento de protocolos e de sistemas reativos. Utiliza-se um protótipo desenvolvido a partir de uma reengenharia da ferramenta Plavis/FSM para apoiar os experimentos / TEST case generation methods aim to generate a test suite that offers an acceptable trade-off between cost and avail. Test coverage criteria define testing requirements, which an adequate test suite must fulfill. Methods and criteria help to select test case from specifications, which can be describe as models, for example Finite State Machines (FSM). There are several generation methods and coverage criteria that differ depending on the required properties of the FSM, the cost of generated tests and the effectiveness in revealing faults. In spite of intense researches in the definition of those methods and criteria, there are few available tools to apply them as well as application reports about cost and effectiveness issues to define effective test strategies. Thus, it is necessary to obtain real data of the advantages and disadvantages of the methods and criteria to provide decision-making in the software development process as far in the validation and test activities. This work aimed to lead experiments to evaluate the cost and the effetiveness in applying the most relevant methods and criteria to subsidize test strategies definition in several contexts as the communication protocol development and the reactive systems development. A prototype was developed based on reengineering of the Plavis/FSM tool to support the experiments

Business process analysis and integration are key endeavours for today's enterprises. Recently, Web services have been widely adopted for the implementation and integration of business processes within and across enterprises. In this dissertation, we investigate the problem of enabling the analysis of service interactions, in today's enterprises, in the context of business process executions, and that of service integration. Our study shows that only fraction of interactions in the enterprise are supported by process-aware systems. However, enabling above-mentioned analyses requires: (i) a model of the underlying business process to be used as a reference for the analysis, and (ii) the ability to correlate events generated during service interactions into process instances. We refer to a process model and the corresponding process instances as a "process view". We propose the concept of process space to refer to all process related information sources in the enterprise, over which various process views are defined. We propose the design and development of a system called "process space discovery system" (PSDS) for discovering process views in a process space. We introduce novel approaches for the correlation of events into process instances, focusing on the public processes of Web services (business protocols), and also for the discovery of the business protocol models from the process instances of a process view. Analysis of service integration approaches shows that while standardisation in Web services simplifies the integration in the communication level, at the higher levels of abstractions (e.g., services interfaces and protocol models) services are still open to heterogeneities. We characterise the mismatches between service interfaces and protocol specifications and introduce "mismatch patterns" to represent them. A mismatch pattern also includes an adapter template that aims at the resolution of the captured mismatch. We also propose semi-automated approaches for identifying the mismatches between interface and protocol specifications of two services. The proposed approaches have been implemented in prototype tools, and experimentally validated on synthetic and real-world datasets. The discovered process views, using PSDS, can be used to perform various analyses in an enterprise, and the proposed adaptation approach facilitates the adoption of Web services in business process integration.

The World Wide Web has become the standard mechanism for information distribution and scientific collaboration on the Internet. This dissertation research explores a suite of techniques for discovering relevant dynamic sources in a specific domain of interest and for managing Web data effectively. We first explore techniques for discovery and automatic classification of dynamic Web sources. Our approach utilizes a service class model of the dynamic Web that allows the characteristics of interesting services to be specified using a service class description. To promote effective Web data management, the Page Digest Web document encoding eliminates tag redundancy and places structure, content, tags, and attributes into separate containers, each of which can be referenced in isolation or in conjunction with the other elements of the document. The Page Digest Sentinel system leverages our unique encoding to provide efficient and scalable change monitoring for arbitrary Web documents through document compartmentalization and semantic change request grouping. Finally, we present XPack, an XML document compression system that uses a containerized view of an XML document to provide both good compression and efficient querying over compressed documents. XPack's queryable XML compression format is general-purpose, does not rely on domain knowledge or particular document structural characteristics for compression, and achieves better query performance than standard query processors using text-based XML. Our research expands the capabilities of existing dynamic Web techniques, providing superior service discovery and classification services, efficient change monitoring of Web information, and compartmentalized document handling. DynaBot is the first system to combine a service class view of the Web with a modular crawling architecture to provide automated service discovery and classification. The Page Digest Web document encoding represents Web documents efficiently by separating the individual characteristics of the document. The Page Digest Sentinel change monitoring system utilizes the Page Digest document encoding for scalable change monitoring through efficient change algorithms and intelligent request grouping. Finally, XPack is the first XML compression system that delivers compression rates similar to existing techniques while supporting better query performance than standard query processors using text-based XML.

Business process analysis and integration are key endeavours for today's enterprises. Recently, Web services have been widely adopted for the implementation and integration of business processes within and across enterprises. In this dissertation, we investigate the problem of enabling the analysis of service interactions, in today's enterprises, in the context of business process executions, and that of service integration. Our study shows that only fraction of interactions in the enterprise are supported by process-aware systems. However, enabling above-mentioned analyses requires: (i) a model of the underlying business process to be used as a reference for the analysis, and (ii) the ability to correlate events generated during service interactions into process instances. We refer to a process model and the corresponding process instances as a "process view". We propose the concept of process space to refer to all process related information sources in the enterprise, over which various process views are defined. We propose the design and development of a system called "process space discovery system" (PSDS) for discovering process views in a process space. We introduce novel approaches for the correlation of events into process instances, focusing on the public processes of Web services (business protocols), and also for the discovery of the business protocol models from the process instances of a process view. Analysis of service integration approaches shows that while standardisation in Web services simplifies the integration in the communication level, at the higher levels of abstractions (e.g., services interfaces and protocol models) services are still open to heterogeneities. We characterise the mismatches between service interfaces and protocol specifications and introduce "mismatch patterns" to represent them. A mismatch pattern also includes an adapter template that aims at the resolution of the captured mismatch. We also propose semi-automated approaches for identifying the mismatches between interface and protocol specifications of two services. The proposed approaches have been implemented in prototype tools, and experimentally validated on synthetic and real-world datasets. The discovered process views, using PSDS, can be used to perform various analyses in an enterprise, and the proposed adaptation approach facilitates the adoption of Web services in business process integration.

The success of Web services comes from the benefits that it brings in reducing the cost and the time needed to develop data and applications by reusing them, and simplifying their integrations through standardization. However, standardization in Web services does not remove the need for adapters due to possible heterogeneity among service interface and protocol definitions. Moreover, the current service APIs are targeted toward professional programmers, but not accessible to a wider class of users without programming expertise, but would never the less like to build their own integrated applications. In this dissertation, we propose methods and tools to support both service developers and non-expert users in their data and application integration tasks. To support service developers, we propose a framework that enables rapid development of Web service adapters. We investigate particularly the problem of service adaptation focusing on business interface and protocol layers. Our study shows that many differences between business interfaces and protocols are recurring. We introduce mismatch patterns to capture these recurring differences and provide solutions to resolve them. We present the notion of adaptation aspects, which is based on the aspect-oriented programming paradigm, to enable rapid development and deployment of service adapters. We also present a comparative study between standalone and aspect-oriented adapters development. The study shows that the aspect-oriented approach is preferable in many cases, especially when adapters need to access internal states of services. The proposed approach is implemented in a prototype tool, which is used to illustrate how it simplifies adapters development through a case study. To support users without programming expertise, we propose a spreadsheet-based Web mashups development framework, which enables users to develop mashups in the popular spreadsheet environment. First, we provide a mechanism that makes structured data first class values of spreadsheet cells. Second, we propose a new component model that can be used to develop fairly sophisticated mashups, involving joining data sources and keeping spreadsheet data up to date. Third, to simplify mashup development, we provide a collection of spreadsheet-based mashup patterns that captures common Web data access and spreadsheet presentation functionalities. Users can reuse and customize these patterns to build spreadsheet-based Web mashups instead of developing them from scratch. Fourth, we enable users to manipulate structured data presented on spreadsheet in a drag-and-drop fashion. Finally, we have developed and tested a prototype tool to demonstrate the utility of the proposed framework.

The success of Web services comes from the benefits that it brings in reducing the cost and the time needed to develop data and applications by reusing them, and simplifying their integrations through standardization. However, standardization in Web services does not remove the need for adapters due to possible heterogeneity among service interface and protocol definitions. Moreover, the current service APIs are targeted toward professional programmers, but not accessible to a wider class of users without programming expertise, but would never the less like to build their own integrated applications. In this dissertation, we propose methods and tools to support both service developers and non-expert users in their data and application integration tasks. To support service developers, we propose a framework that enables rapid development of Web service adapters. We investigate particularly the problem of service adaptation focusing on business interface and protocol layers. Our study shows that many differences between business interfaces and protocols are recurring. We introduce mismatch patterns to capture these recurring differences and provide solutions to resolve them. We present the notion of adaptation aspects, which is based on the aspect-oriented programming paradigm, to enable rapid development and deployment of service adapters. We also present a comparative study between standalone and aspect-oriented adapters development. The study shows that the aspect-oriented approach is preferable in many cases, especially when adapters need to access internal states of services. The proposed approach is implemented in a prototype tool, which is used to illustrate how it simplifies adapters development through a case study. To support users without programming expertise, we propose a spreadsheet-based Web mashups development framework, which enables users to develop mashups in the popular spreadsheet environment. First, we provide a mechanism that makes structured data first class values of spreadsheet cells. Second, we propose a new component model that can be used to develop fairly sophisticated mashups, involving joining data sources and keeping spreadsheet data up to date. Third, to simplify mashup development, we provide a collection of spreadsheet-based mashup patterns that captures common Web data access and spreadsheet presentation functionalities. Users can reuse and customize these patterns to build spreadsheet-based Web mashups instead of developing them from scratch. Fourth, we enable users to manipulate structured data presented on spreadsheet in a drag-and-drop fashion. Finally, we have developed and tested a prototype tool to demonstrate the utility of the proposed framework.

Το παράδειγμα του Service Oriented computing αναφέρεται σε ένα σύνολο από έννοιες, αρχές και μεθόδους οι οποίες αξιοποιούν την Service Oriented αρχιτεκτονική, σύμφωνα με την οποία οι εφαρμογές λογισμικού κατασκευάζονται από ανεξάρτητες συνιστώσες υπηρεσιών με πρότυπες διεπαφές. Η υπηρεσιοστρεφής (Service Oriented) αρχιτεκτονική είναι ένα σύνολο από κανόνες και μεθοδολογίες για το σχεδιασμό και την ανάπτυξη λογισμικού με τη μορφή διαλειτουργικών υπηρεσιών. Μία από τις σημαντικότερες τεχνολογίες για την αξιοποίηση αυτής της αρχιτεκτονικής είναι τα Web Services. Τα Web Services είναι μία τεχνολογία σχεδιασμένη για την υποστήριξη διαλειτουργικών αλληλεπίδρασης σταθμών πάνω από το διαδίκτυο. Τα συστήματα βιομηχανικών αυτοματισμών είναι συστήματα τα οποία χρησιμοποιούνται για την αύξηση της απόδοσης των βιομηχανικών καθώς και των διαδικασιών παραγωγής. Οι παραδοσιακές τεχνικές ανάπτυξης των συστημάτων αυτών δεν ικανοποιούν πλέον τις απαιτήσεις των σύνθετων βιομηχανικών συστημάτων και υπάρχει μια τάση για αξιοποίηση τεχνολογιών αιχμής από την περιοχή του Software Engineering. Στην κατεύθυνση αυτή η παρούσα εργασία μελετά τα πλεονεκτήματα αλλά και τα μειονεκτήματα που προσφέρει η αξιοποίηση του SOC παραδείγματος στην ανάπτυξη βιομηχανικών συστημάτων. Μελετήθηκε η DPWS τεχνολογία η οποία αποτελεί μια επέκταση της τεχνολογίας των Web Services με σκοπό την ικανοποίηση των αναγκών που παρουσιάζουν οι εφαρμογές βιομηχανικού αυτοματισμού. Ως μελέτη περίπτωσης χρησιμοποιήθηκε το εργαστηριακό σύστημα Festo MPS. Σχεδιάστηκε και υλοποιήθηκε ένας εξομοιωτής του συστήματος αυτού, ο οποίος στη συνέχεια επεκτάθηκε για να είναι συμβατός με την DPWS Τεχνολογία. Με βάση αυτόν σχεδιάστηκε και υλοποιήθηκε ένας ελεγκτής του συστήματος ο οποίος αξιοποιώντας τις υπηρεσίες που προσφέρει η DPWS τεχνολογία υλοποίει την διαδικασία ελέγχου του συστήματος Festo MPS. Στη συνέχεια με βάση τα αποτελέσματα των δοκιμών προχωρήσαμε σε μια συνολική αξιολόγηση της τεχνολογίας. / The Service-Oriented Computing (SOC) paradigm refers to the set of concepts, principles, and methods that represent computing in Service-Oriented Architecture (SOA), in which software applications are constructed based on independent component services with standard interfaces. In software engineering, a Service-Oriented Architecture (SOA) is a set of principles and methodologies for designing and developing software in the form of interoperable services. One of the most important technologies used utilize this architecture is Web Services technology. Web service technology, is designed to support interoperable machine-to-machine interaction over a network. Industrial automation systems are the systems used for the enhancement of industrial and manufacturing processes. Traditional techniques to develop these systems, no longer satisfy the requirements of the complex industrial systems and there is a tendency to utilize state of the art technologies of software engineering area. The current thesis discusses the advantages and disadvantages as a result of utilizing the Service-Oriented Computing (SOC) paradigm in the development of industrial Systems. The technology that was utilized was the Devices Profile for Web Services technology(DPWS). DPWS is the extension of the Web Services technology that was designed in order to satisfy the requirements of the industrial systems applications. As a case study we used Festo Modular Production System. We designed and implemented a simulator of this system. This simulator was then redesigned and implemented in order to be compatible with DPWS technology. Based on the redesigned Simulator we designed and implemented a system Controller which utilizes the DPWS technology and implements the control process of Festo MPS. Then we proceeded with the evaluation of the technology based on the results of the tests.

A área de gerência de redes encontra uma série de desafios desde seu príncipio. O protocolo que surgiu como padrão para gerência de redes, o SNMP, possui uma série de limitações, por exemplo, no tocante à segurança, configuração de equipamentos e composição de serviços. Por essa razão, tecnologias alternativas para o gerenciamento de redes têm sido pesquisadas. A tecnologia de Web Services surgiu como forte alternativa, por características como o uso de padrões amplamente suportados (HTTP e XML) e modelo de desenvolvimento orientado a serviços. Pesquisas iniciais demonstraram que os Web Services são uma alternativa viável em termos de desempenho. Assim, o uso de Web Services em áreas específicas de gerência de redes, como notificações e gerência por delegação, tem sido pesquisado. Porém, há carência de estudos sobre o uso de segurança no gerenciamento de redes via Web Services. Os Web Services trazem facilidade para uso de segurança, que é vital para a gerência de redes, e este é o foco deste trabalho. É proposta uma arquitetura de integração de segurança à comunicação de mensagens de gerenciamento de redes via Web Services. Para isso, foram utilizados o padrão WS-Security, para segurança em Web Services, e o padrão WS-Management, para gerenciamento de redes via Web Services. Também foi integrado controle de acesso à arquitetura, com uso do padrão XACML. Uma avaliação de desempenho foi realizada para verificar o impacto do uso de segurança, e comparações com SNMPv3 foram realizadas na solução de controle de acesso via XACML. Os testes mostram que, como é tradicional, a segurança tem impacto considerável no tempo de processamento e tráfego na rede. Porém, a arquitetura e implementação realizadas comprovam que, também na área de segurança, a tecnologia de Web Services tem aplicação eficaz para o gerenciamento de redes. / The network management field has several challenges since its beginning. The standard protocol for network management, SNMP, has many drawbacks, related to security, device configuration, and service composition. For these reason, alternative technologies for network management have been investigated. Web Services technology emerged as a strong solution, due to advantages such as employing widely supported standards (HTTP and XML) and service-oriented development model. The first performed investigations in the area showed that Web Services are a valid alternative to SNMP in terms of performance. Thus, Web Services usage in specific areas of network management, such as notifications and management by delegation, have been researched. However, there are currently no studies on security aspects of Web Services-based network management. Web Services enable easy integration of security, which is mandatory for network management, and this is the main goal of this work. An architecture is proposed for security integration in a network management message communication using Web Services. The standards used in this architecture were WSSecurity, which enables security in Web Services, and WS-Management, which targets Web Services-based network management. Access control integration was also developed, using XACML standard. A performance evaluation was carried out in order to verify security usage impact, and comparisons with SNMPv3 were performed in XACML access control solution. Tests showed that, as expected, security has a considerable impact in processing time and network traffic. However, the architecture and implementation show that, also in the security area, the Web Services technology has effective aplication in network management.