A Formal Semantic Model of the Semantic Web Service Ontology (WSMO)

Semantic Web Services, one of the most significant research areas within the Semantic Web vision, has attracted increasing attention from both the research community and industry. The Web Service Modelling Ontology (WSMO) has recently been proposed as an enabling framework for the total/partial automation of the tasks (e.g., discovery, selection, composition, mediation, execution, monitoring, etc.) involved in both intra- and inter-enterprise integration of Web Services. To support the standardization and tool support of WSMO, a formal semantics of the language is highly desirable. As there are a few variants of WSMO and it is still under development, the semantics of WSMO needs to be formally defined to facilitate easy reuse and future development. In this paper, we present a formal Object-Z semantics of WSMO. Different aspects of the language have been precisely defined within one unified framework. This model not only provides a formal unambiguous model which can be used to develop tools and facilitate future development, but as demonstrated in this paper, can be used to identify and eliminate errors presented in existing documentation

Métodos relacionales para la especificación, verificación, y composición de servicios semánticos en la web

El objetivo de nuestra investigación consiste en la aplicación de métodos formales de la ingeniería del software, específicamente aquellos basados en sistemas formales relacionales, a los problemas de desarrollo de servicios semánticos en la web. Los sistemas formales relacionales que se tienen en mente son descendientes de las álgebras relacionales de Tarski, y su uso será asistido por herramientas de software existentes o a crear durante la investigación propuesta. Los servicios en web son una clase particular de programas, y como tales su desarrollo se beneficiaría de la aplicación de métodos formales de la ingeniería del software. Los problemas usuales de asegurar su corrección y otras propiedades deseables se suman a las propiedades específicas que deben brindar como servicios (en particular la composición de los mismos para obtener comportamientos más complejos y/o acordes a las necesidades específicas de la aplicación), más aún cuando se añade a ellos un nivel semántico de anotaciones que deben ser procesables por computadoras.Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI

Métodos relacionales para la especificación, verificación, y composición de servicios semánticos en la web

El objetivo de nuestra investigación consiste en la aplicación de métodos formales de la ingeniería del software, específicamente aquellos basados en sistemas formales relacionales, a los problemas de desarrollo de servicios semánticos en la web. Los sistemas formales relacionales que se tienen en mente son descendientes de las álgebras relacionales de Tarski, y su uso será asistido por herramientas de software existentes o a crear durante la investigación propuesta. Los servicios en web son una clase particular de programas, y como tales su desarrollo se beneficiaría de la aplicación de métodos formales de la ingeniería del software. Los problemas usuales de asegurar su corrección y otras propiedades deseables se suman a las propiedades específicas que deben brindar como servicios (en particular la composición de los mismos para obtener comportamientos más complejos y/o acordes a las necesidades específicas de la aplicación), más aún cuando se añade a ellos un nivel semántico de anotaciones que deben ser procesables por computadoras.Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI

On Utilizing Web Service Equivalence for Supporting the Composition Life Cycle

Deciding on web service equivalence in process-aware service compositions is a crucial challenge throughout the composition life cycle. Restricting such decisions to (activity) label equivalence, however, is not sufficient for many practical applications: if two activities and web services respectively have equivalent labels, does this necessarily mean they are equivalent as well? In many scenarios (e.g., evolution of a composition schema or mining of completed composition instances) other factors may play an important role as well. Examples include context information (e.g., input and output messages) and information on the position of web services within compositions. In this paper, we introduce the whole composition life cycle and discuss specific requirements for web service equivalence along its different phases. We define adequate equivalence notions for the design, execution, analysis, and evolution of service compositions. Main focus is put on attribute and position equivalence. Altogether this paper shall contribute a new understanding and treatment of equivalence notions in service compositions

A Semantic-Oriented Description Framework and Broker Architecture for Publication and Discovery in Cloud Based Conferencing

Cloud computing is an emerging paradigm for provisioning network, storage, and computing resources on demand using a pay-per-use model. Conferencing is the conversational exchange of media between several parties. Cloud-based conferencing services can provide benefits such as easy introduction of different types of conferences, resource usage efficiency and scalability. A business model has been recently proposed in a position paper for cloud-based conferencing with the following roles: conference substrate provider, conference infrastructure provider, conference platform provider, conference service provider, and broker. Conference substrates are generally atomic and served as elementary building blocks (e.g. signaling, mixing) of conferencing applications. They can be virtualized and shared for resource efficiency purposes. Multiple conferencing substrates can be combined to build a conferencing service (e.g. a dial-out audio signaling conference service composed from dial-out signaling and audio mixer substrates). The focus of this thesis is to design a semantic-oriented description framework for conferencing substrates and an architecture for their publication and discovery. The description framework is made up of a description language and a cloud-based conference ontology. The conference ontology is modeled on the basis of the interacting roles in the proposed cloud-based conferencing business model. The overall publication and discovery architecture for cloud-based conference substrates is made up of three brokers and the related publication and discovery interfaces. The publication and discovery interfaces are modelled using REpresentation State Transfer (REST) interfaces. A prototype is built to demonstrate the feasibility of this architecture. The effectiveness of the architecture is also proved using the performance measurements

A platform-independent domain-specific modeling language for multiagent systems

Associated with the increasing acceptance of agent-based computing as a novel software engineering paradigm, recently a lot of research addresses the development of suitable techniques to support the agent-oriented software development. The state-of-the-art in agent-based software development is to (i) design the agent systems basing on an agent-based methodology and (ii) take the resulting design artifact as a base to manually implement the agent system using existing agent-oriented programming languages or general purpose languages like Java. Apart from failures made when manually transform an abstract specification into a concrete implementation, the gap between design and implementation may also result in the divergence of design and implementation. The framework discussed in this dissertation presents a platform-independent domain-specific modeling language for MASs called Dsml4MAS that allows modeling agent systems in a platform-independent and graphical manner. Apart from the abstract design, Dsml4MAS also allows to automatically (i) check the generated design artifacts against a formal semantic specification to guarantee the well-formedness of the design and (ii) translate the abstract specification into a concrete implementation. Taking both together, Dsml4MAS ensures that for any well-formed design, an associated implementation will be generated closing the gap between design and code.Aufgrund wachsender Akzeptanz von Agentensystemen zur Behandlung komplexer Problemstellungen wird der Schwerpunkt auf dem Gebiet der agentenorientierten Softwareentwicklung vor allem auf die Erforschung von geeignetem Entwicklungswerkzeugen gesetzt. Stand der Forschung ist es dabei das Agentendesign mittels einer Agentenmethodologie zu spezifizieren und die resultierenden Artefakte als Grundlage zur manuellen Programmierung zu verwenden. Fehler, die bei dieser manuellen Überführung entstehen, machen insbesondere das abstrakte Design weniger nützlich in Hinsicht auf die Nachhaltigkeit der entwickelten Softwareapplikation. Das in dieser Dissertation diskutierte Rahmenwerk erörtert eine plattformunabhängige domänenspezifische Modellierungssprache für Multiagentensysteme namens Dsml4MAS. Dsml4MAS erlaubt es Agentensysteme auf eine plattformunabhängige und graphische Art und Weise darzustellen. Die Modellierungssprache umfasst (i) eine abstrakte Syntax, die das Vokabular der Sprache definiert, (ii) eine konkrete Syntax, die die graphische Darstellung spezifiziert sowie (iii) eine formale Semantik, die dem Vokabular eine präzise Bedeutung gibt. Dsml4MAS ist Bestandteil einer (semi-automatischen) Methodologie, die es (i) erlaubt die abstrakte Spezifikation schrittweise bis hin zur konkreten Implementierung zu konkretisieren und (ii) die Interoperabilität zu alternativen Softwareparadigmen wie z.B. Dienstorientierte Architekturen zu gewährleisten