In this thesis, a web service composition and execution framework is presented for semantically annotated web services. A monolithic approach to automated web service composition and execution problem is chosen, which provides some benefits by separating the composition and execution phases. An AI planning method using a logical formalism called Event Calculus is chosen for the composition phase. This formalism allows one to generate a narrative of actions and temporal orderings using abductive planning techniques given a goal. Functional properties of services, namely input/output/precondition/effects(IOPE) are taken into consideration in the composition phase and non-functional properties, namely quality of service (QoS) parameters are used in selecting the most appropriate solution to be executed. The repository of OWL-S semanticWeb services are translated to Event Calculus axioms and the resulting plans found by the Abductive Event Calculus Planner are converted to graphs. These graphs can be sorted according to a score calculated using the defined quality of service parameters of the atomic services in the composition to determine the optimal solution. The selected graph is converted to an OWL-S file which is executed consequently.

Among the plethora of solutions to the Business-to-Business interoperability problem, no other solution has obtained as much attention asWeb Services Technology (WST), which allows entities to exchange data regardless of their underlying platforms. WST also allows services to be composed in order to provide high quality customer service over the web. In order to perform transactions across different service providers, standard protocols need to be supported by participating providers. Many useful protocols are coming into the market, but are often ambiguously specified by protocol designers and not fully verified. Furthermore, even if the specifications are reasonably clear, programmers often make subtle assumptions, possibly leading to errors that are hard to detect and locate, especially when the number of participating entities is dynamic. Consequently, these can lead to interoperability problems among implementations of the same protocol and high software maintenance costs. To address these issues, a hierarchical automata-based framework is proposed to model the functional aspects of Web Services (WS) protocols that also assists in verifying their correctness. The modelling formalism has a sound mathematical foundation and aims to reconcile desirable features while still maintaining syntactic and semantic simplicity. The properties to be verified are specified using a pattern system and/or 'observer' states, which have been adapted for WS protocols. In particular, always in a positive observer state implies proper termination and partial functional correctness while reachability of a negative observer state signifies deadlock and/or violation of a safety property. Verification itself is handled by automatic translation of the model and its properties into a model-checker's input code and interpretation of the output produced by the model-checker. A test-bed is proposed to check the conformance of a protocol implementation to its specification It helps in locating errors in the implementations of WS protocols especially where the number of participating entities is dynamic. Conformance checking is achieved by capturing sequences of exchanged messages of the actual implementations and checking them against the formal specification. Experience using the framework is also described and illustrated using two non-trivial WS protocols, namely WS-BusinessActivity and WS-AtomicTransaction.

University (TH), Diss.--Karlsruhe, 2007. / Print on demand.

Cette thèse présente MELQART, un système d'exécution de mashups avec disponibilité de données. Un mashup est une application web qui combine des données provenant de fournisseurs hétérogènes (web services). Ces données sont agrégées pour former un résultat homogène affiché dans des composants appelés mashlets. Les travaux dans le domaine des mashups, se sont principalement intéressés au fonctionnement des mashups, aux différents outils de construction et à leur utilisation et interaction avec les utilisateurs. Dans cette thèse, nous nous intéressons à la gestion de données dans les mashups et plus particulièrement à la disponibilité et la fraîcheur de ces données. L'amélioration de la disponibilité tient compte du caractère dynamique des données des mashups. Elle garantit (1) l'accès aux données même si le fournisseur est indisponible, (2) la fraicheur de ces données et (3) un partage de données entre les mashups afin d'augmenter la disponibilité de données. Pour cela nous avons défini un modèle de description de mashups permettant de spécifier les caractéristiques de disponibilité des données. Le principe d'exécution de mashups est défini selon ce modèle en proposant d'améliorer la disponibilité et la fraicheur des données du mashup par des fonctionnalités orthogonales à son processus d'exécution. Le système MELQART implante ce principe et permet de valider notre approche à travers l'exécution de plusieurs instances de mashups dans des conditions aléatoires de rupture de communication avec les fournisseurs de données. / This thesis presents MELQART: a mashup execution system that ensures data availability. A mashup is a Web application that application that combines data from heterogeneous provides (Web services). Data are aggregated for building a homogenous result visualized by components named mashlets. Previous works have mainly focused, on the definition of mashups and associated tools and on their use and interaction with users. In this thesis, we focus on mashups data management, and more specifically on fresh mashups data availability. Improving the data availability take into account the dynamic aspect of mashups data. It ensures (1) the access to the required data even if the provider is unavailable, (2) the freshness of these data and (3) the data sharing between mashups in order to avoid the multiple retrieval of the same data. For this purpose, we have defined a mashup description formal model, which allows the specification of data availability features. The mashups execution schema is defined according to this model with functionalities that improve availability and freshness of mashed-up data. These functionalities are orthogonal to the mashup execution process. The MELQART system implements our contribution and validates it by executing mashups instances with unpredictable situations of broken communications with data providers.

Made available in DSpace on 2016-08-17T14:52:51Z (GMT). No. of bitstreams: 1 Samyr Beliche Vale.pdf: 1271783 bytes, checksum: 3556a7f5490acfc5fdf7431663fba9fc (MD5) Previous issue date: 2004-03-10 / This paper presents a methodology for integrating business applications with Web services through the creation of meta-models in MDA. This methodology covers steps for the integration process and presents an architecture based on semantic middlware to integrate legacy applications. / Este trabalho apresenta uma metodologia para integração de aplicações empresariais com web services através da criação de meta-modelos em MDA. Esta metodologia abrange fases para o processo de integração e apresenta uma arquitetura baseada em middlware semântico para integrar aplicações legadas.

WEb Services constituem uma tecnologia emergente utilizada para disponibilização de serviços na Web. Devido aos complexos processos de negócio existentes, esses serviços são combinados para que operem seguindo um fluxo de trabalho. Esse processo é chamado de composição de Web Services. Como no processo de desenvolvimento de um software tradicional, a atividade de teste é fundamental no processo de desenvolvimento da composição de Web Services. Neste trabalho é proposta uma estratégia de teste para a composição de Web Services, em que especificações de composições são transformadas para um modelo de teste de programas paralelos baseados em passagem de mensagens. É proposto o conceito de grupos de elementos requeridos para melhorar a cobertura dos critérios. Uma ferramenta de apoio à estratégia de teste foi desenvolvida. Alguns estudos experimentais para avaliar a aplicabilidade da estratégia proposta também são apresentados. Além disso, é proposto um método que utiliza redes de Petri para eliminar sincronizações não-executáveis no envio e recebimento de mensagens / WEb Services constitute an emerging technology for deploying services in the Web. Due to the complex business processes, these services are combined to operate, following a workflow. This process is named Web Services Composition. As in the development process of a traditional software, the testing activity is fundamental in the development process of Web Services Composition. This work proposes a test strategy for Web Services Composition, in that composition specifications are transformed into a test model of message-passing parallel programs. The concept of required elements groups is proposed to improve the criteria coverage. A tool that supports the test strategy was developed. Some experimental studies for evaluating the applicability of proposed strategy are also presented. Furthermore, it presents a method that uses Petri Nets to eliminate non-executable synchronizations in the sending and receiving of messages

A crescente utilização de equipamentos inteligentes na área de automação industrial tem assegurado eficiência e qualidade na produção. Em conseqüência deste crescimento, existe uma grande quantidade de equipamentos interligados abrangendo áreas geográficas distantes. Este cenário criou a demanda de sistemas que permitissem o acesso às informações geradas no chão de fábrica a partir de qualquer computador localizado na área industrial ou em qualquer outro ponto do planeta. A Internet propiciou uma nova opção para gerenciamento e monitoramento de equipamentos inteligentes a longa distância. Assim, este trabalho propõe um algoritmo para monitorar, via Internet, os eventos gerados por equipamentos inteligentes instalados em plantas industriais. Com o monitoramento contínuo, é possível analisar o desempenho dos equipamentos, detectar problemas e tomar decisões de forma a garantir que toda uma malha de controle não venha a parar inesperadamente. / The increasing usage of smart field devices in the industrial automation area has assured efficiency and quality of production. Thanks to this expansion, a large number of devices can be interconnected through distant geographical areas. This scenario created the need of computational systems that would make the information from the plant floor accessible to any computer in the local industrial area or any other earth wide location. The Internet has created a new possibility of remote managing and monitoring of smart devices. This work proposes an algorithm to monitor, via Internet, the events generated by smart devices installed in industrial plants. The continuous monitoring makes it possible to analyze the performance of the devices, detect problems and make decisions to ensure that an entire control loop does not come to an unexpected halt.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-27T13:12:48Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) rmm_msc.pdf: 2280413 bytes, checksum: 90d0df51dde9092becb45756ff265100 (MD5) / Made available in DSpace on 2017-07-27T13:12:48Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) rmm_msc.pdf: 2280413 bytes, checksum: 90d0df51dde9092becb45756ff265100 (MD5) Previous issue date: 2016-03-03 / Contexto: A crescente adoção de computação em nuvem ofereceu diversos benefícios, como escalabilidade, eficiência e lucratividade, mas apresenta novos riscos de segurança que comprometem a confidencialidade, integridade e disponibilidade dos serviços prestados. Neste contexto, as organizações militares buscam modelos de nuvens privadas alinhadas com suas preocupações envolvendo segurança, conformidade e políticas. Atualmente, a segurança é o maior obstáculo para ampla adoção da computação em nuvem. Objetivo: Com base neste cenário, o trabalho propõe, a partir da análise das normas e implementações de segurança para Web Services, definir uma arquitetura segura para mitigar as principais ameaças de segurança em ambientes de nuvem, segundo o guia intitulado “The Notorious Nine: Cloud Computing Top Threats in 2013” da Cloud Security Alliance. Metodologia: Através de um estudo na literatura sobre computação em nuvem e segurança neste ambiente, foram utilizadas referências da área de pesquisa relacionadas ao problema identificado. Especificou-se uma arquitetura segura como hipótese de solução, e posteriormente avaliou-se tal hipótese por meio da implementação de um protótipo, evidenciando-se a importância desta solução. Resultados: Como resultado obteve-se uma arquitetura de referência para minimizar os riscos de segurança na implantação de nuvens privadas nas organizações militares. Experimentos de campo contemplaram aquisições a respeito dos mecanismos de segurança aplicados, em particular os padrões WS-Policy, WS-Security e SAML, os quais conseguiram oferecer mecanismos padrão de segurança necessários para realizar o intercâmbio seguro de mensagens certificadas em ambiente de nuvem. / Context: The ever increasing adoption of cloud computing has yielded several benefits, such as scalability, efficiency and profitability. However, it does present new security threats that compromise confidentiality, integrity and availability of the services offered. In this light, military organizations search for private cloud models that comply with their concerns about security, conformity and policies. Nowadays, security is the greatest obstacle for the widespread adoption of cloud computing. Objective: In this scenario, the work presented here aims, based on the analysis of the current security rules and implementations forWebServices, to define a secure architecture to mitigate the main security threats for cloud environment, as identified by the guide entitled“The NotoriousNine: CloudComputingTopThreatsin2013” issued by theCloudSecurityAlliance. Method: Through a bibliographical study about cloud computing and security in such environments, the main references on the problem were identified and used. In the sequel, a secure architecture was specified as a solution hypothesis. Such hypothesis was then evaluated through the implementation of a prototype, which has helped us to highlight the importance of such solution. Results: The main result of this work was a reference architecture that can be used to minimize the security threats in the deployment of private clouds in military organizations. Field experiments have taken into account inputs from the security mechanism patterns used, namely: WS-Policy,WS-Security e SAML. Such patterns offered the security levels needed for the secure exchange of certified messages in cloud environments.

Neste projeto é proposta uma avaliação e comparação de diretrizes e a adequação de técnicas que permitam não somente a criação de Web services seguros, mas também a validação dos serviços utilizados para determinar se a aplicação possui as características almejadas relacionadas ao desempenho e à segurança. Neste sentido, é primordial analisar as principais especificações de segurança empregadas em Web services no contexto atual, bem como avaliar os algoritmos criptográficos e o comprimento das chaves utilizadas. Os resultados obtidos permitem determinar, com base nos objetivos especificados, qual o impacto dos mecanismos de segurança utilizados no desempenho da aplicação / In this project we propose an evaluation and comparison of guidelines and appropriateness of techniques that allow not only the creation of secure Web services, but also the validation of the services used to determine whether the application has the desired characteristics related to performance and security. In this sense it is crucial to analyze the main security specifications used in Web services in the current context, as well as evaluating the cryptographic algorithms and key length used. The results obtained allow to determine, based on specified objectives, the impact of security mechanisms used in application performance

To achieve the dream of the semantic web, it must be possible for ordinary users to invoke services. It is clear that users need simple-to-invoke-and-use services. This dissertation offers an ontological approach to declaratively create services that users can invoke using free-form, natural-language-like specifications. Our approach uses task ontologies as foundational knowledge. A task ontology consists of a domain ontology and a process ontology. The domain ontology encodes domain information such as possible constraints and instances in terms of object sets, relationship sets among these object sets, and operations over values in object sets and relationship sets. The process ontology consists of generic processes that are domain independent-coded once and work for all. Our system recognizes the constraints in a service request, discovers any missing information and obtains it from users, and formalizes the constraints in the context of the domain ontology. The system satisfies the constraints by obtaining information from databases associated with the domain ontology and providing users with solutions or near solutions when there is no way to satisfy all the constraints. Our experiments with our prototype implementation show that our approach can create services that satisfy end-user needs.