199 research outputs found
Proceedings of the 2012 Workshop on Ambient Intelligence Infrastructures (WAmIi)
This is a technical report including the papers presented at the Workshop on Ambient Intelligence Infrastructures (WAmIi) that took place in conjunction with the International Joint Conference on Ambient Intelligence (AmI) in Pisa, Italy on November 13, 2012. The motivation for organizing the workshop was the wish to learn from past experience on Ambient Intelligence systems, and in particular, on the lessons learned on the system architecture of such systems. A significant number of European projects and other research have been performed, often with the goal of developing AmI technology to showcase AmI scenarios. We believe that for AmI to become further successfully accepted the system architecture is essential
Proceedings of the 2012 Workshop on Ambient Intelligence Infrastructures (WAmIi)
This is a technical report including the papers presented at the Workshop on Ambient Intelligence Infrastructures (WAmIi) that took place in conjunction with the International Joint Conference on Ambient Intelligence (AmI) in Pisa, Italy on November 13, 2012. The motivation for organizing the workshop was the wish to learn from past experience on Ambient Intelligence systems, and in particular, on the lessons learned on the system architecture of such systems. A significant number of European projects and other research have been performed, often with the goal of developing AmI technology to showcase AmI scenarios. We believe that for AmI to become further successfully accepted the system architecture is essential
Service-oriented design of environmental information systems
Service-orientation has an increasing impact upon the design process and the architecture of environmental information systems. This thesis specifies the SERVUS design methodology for geospatial applications based upon standards of the Open Geospatial Consortium. SERVUS guides the system architect to rephrase use case requirements as a network of semantically-annotated requested resources and to iteratively match them with offered resources that mirror the capabilities of existing services
Service-Oriented Middleware for the Future Internet: State of the Art and Research Directions
International audienceService-oriented computing is now acknowledged as a central paradigm for Internet computing, supported by tremendous research and technology development over the last ten years. However, the evolution of the Internet, and in particular, the latest Future Internet vision, challenges the paradigm. Indeed, service-oriented computing has to face the ultra large scale and heterogeneity of the Future Internet, which are orders of magnitude higher than those of today's service-oriented systems. This article aims at contributing to this objective by identifying the key research directions to be followed in light of the latest state of the art. This article more specifically focuses on research challenges for service-oriented middleware design, therefore investigating service description, discovery, access and composition in the Future Internet of services
OpenUP/MDRE: A Model-Driven Requirements Engineering Approach for Health-Care Systems
The domains and problems for which it would be desirable to introduce information systems are currently very complex and the software development process is thus of the same complexity. One of these domains is health-care. Model-Driven Development (MDD) and Service-Oriented Architecture (SOA) are software development approaches that raise to deal with complexity, to reduce time and cost of development, augmenting flexibility and interoperability. However, many techniques and approaches that have been introduced are of little use when not provided under a formalized and well-documented methodological umbrella. A methodology gives the process a well-defined structure that helps in fast and efficient analysis and design, trouble-free implementation, and finally results in the software product improved quality.
While MDD and SOA are gaining their momentum toward the adoption in the software industry, there is one critical issue yet to be addressed before its power is fully realized. It is beyond dispute that requirements engineering (RE) has become a critical task within the software development process. Errors made during this process may have negative effects on subsequent development steps, and on the quality of the resulting software. For this reason, the MDD and SOA development approaches should not only be taken into consideration during design and implementation as usually occurs, but also during the RE process.
The contribution of this dissertation aims at improving the development process of health-care applications by proposing OpenUP/MDRE methodology. The main goal of this methodology is to enrich the development process of SOA-based health-care systems by focusing on the requirements engineering processes in the model-driven context. I believe that the integration of those two highly important areas of software engineering, gathered in one consistent process, will provide practitioners with many benets. It is noteworthy that the approach presented here was designed for SOA-based health-care applications, however, it also provides means to adapt it to other architectural paradigms or domains. The OpenUP/MDRE approach is an extension of the lightweight OpenUP methodology for iterative, architecture-oriented and model-driven software development. The motivation for this research comes from the experience I gained as a computer science professional working on the health-care systems. This thesis also presents a comprehensive study about: i) the requirements engineering methods and techniques that are being used in the context of the model-driven development, ii) known generic but flexible and extensible methodologies, as well as approaches for service-oriented systems development, iii) requirements engineering techniques used in the health-care industry. Finally, OpenUP/MDRE was applied to a concrete industrial health-care project in order to show the feasibility and accuracy of this methodological approach.Loniewski, G. (2010). OpenUP/MDRE: A Model-Driven Requirements Engineering Approach for Health-Care Systems. http://hdl.handle.net/10251/11652Archivo delegad
Web Service Reputation Evaluation Based on QoS Measurement
In the early service transactions, quality of service (QoS) information was published by service provider which was not always true and credible. For better verification the trust of the QoS information was provided by the Web service. In this paper, the factual QoS running data are collected by our WS-QoS measurement tool; based on these objectivity data, an algorithm compares the difference of the offered and measured quality data of the service and gives the similarity, and then a reputation evaluation method computes the reputation level of the Web service based on the similarity. The initial implementation and experiment with three Web services' example show that this approach is feasible and these values can act as the references for subsequent consumers to select the service
Verifying predictive services'quality with Mercury
Due to the success of service technology, there are lots of services nowadays that make predictions about the future in domains such as weather forecast, stock market and bookmakers. The value delivered by these predictive services relies on the quality of their predictions. This paper presents Mercury, a tool that measures predictive service quality in the domain of weather forecast, and automates the context-dependent selection of the most accurate predictive service to satisfy a customer query. To do so, candidate predictive services are monitored so that their predictions can be eventually compared with real observations obtained from some trusted source. Mercury is a proof-of-concept to show that the selection of predictive services can be driven by the quality of their predictions. Its service-oriented architecture (SOA) aims to support the easy adaptation to other prediction domains and makes feasible its integration in self-adaptive SOA systems, as well as its direct use by end-users as a classical web application. Thoughout the paper, we show how Mercury was built.Preprin
Monitoring the quality of service to support the service based system lifecycle
Service Oriented Computing (SOC) has been established in the last recent years as a successful paradigm in Software Engineering. The systems built under this paradigm, known as Service Based System (SBS), are composed of several services, which are usually third-party software run by external service providers. SBS rely on these service providers to ensure that their services comply with the agreed Quality of Service (QoS). In contrast to
other systems, the dynamic behaviour of SBS requires up-to-date QoS information for its proper management in the different stages of its lifecycle, from their initial construction until their decommission.
Providing such QoS information has resulted in different technological solutions built around a monitor. Nonetheless, several research challenges in the field remain still open, ranging from theoretical aspects of quality assurance to architectonical challenges in decentralized monitoring.
Based on the current research challenges for service monitoring, the research gaps in which we aim to contribute are twofold:
- To investigate on the definition and structure of the different quality factors of services, and provide a framework of common understanding for the definition of what to monitor.
- To investigate on the different features required to support the activities of the whole SBS lifecycle (i.e. how to monitor), and develop a monitoring framework that accomplishes such features.
As a result of this thesis, we provide:
What to monitor
- A distribution of the quality models along the time dimension and the identification of their relationships.
- An analysis of the size and definition coverage of the proposed quality models.
- A quantified coverage of the different ISO/IEC 25010 quality factors given by the proposals.
- The identification of the most used quality factors, and provided the most consolidated definitions for them.
How to monitor
- The elicitation of the requirements of the different activities in the SBS lifecycle.
- The definition of the set of features that supports the elicited requirements.
- A modular service-oriented monitoring framework, named SALMon, implementing the defined features. SALMon has been validated by including it in several frameworks supporting the different activities of the SBS lifecycle. Finally, we have conducted a performance evaluation of SALMon over real web services.La Computació Orientada a Serveis (SOC) ha esdevingut en els darrers anys un paradigma exitós en el camp de l'Enginyeria del Software. Els sistemes construïts sota aquest paradigma, coneguts com Sistemes Basats en Serveis (SBS), estan composats de diversos serveis, que són, usualment, programari de tercers executats per proveïdors de serveis externs. Els SBS depenen dels proveïdors dels serveis per garantir que els serveis compleixen amb la Qualitat del Servei (QoS) acordada. En contrast amb altres sistemes, el comportament dinàmic dels SBS requereix d'informació actualitzada del QoS per a la correcta administració de les diferents etapes del cicle de vida dels SBS: des de la seva construcció inicial fins a la seva clausura. Proveir d'aquesta informació de QoS ha resultat en diferents solucions tecnològiques construïdes al voltant d'un monitor. Malgrat això, diversos reptes de recerca en el camp encara romanen obertes, des d'aspectes teòrics de l'assegurança de qualitat, a reptes arquitectònics en la monitorització descentralitzada. Basat en els reptes de recerca actuals per a la monitorització de serveis, els forats de recerca en els que pretenem contribuir són dobles: - Investigar en la definició i estructura dels diferents factors de qualitat dels serveis, i proveir un marc de treball d'entesa comuna per a la definició de què monitoritzar. - Investigar en les diferents característiques requerides per donar suport a les activitats de tot el cicle de vida dels SBS (i.e. com monitoritzar), i desenvolupar una plataforma de monitorització que acompleixi aquestes característiques. Com a resultats de la tesis, proveïm: Què monitoritzar - Una distribució dels models de qualitat al llarg de la dimensió temporal i la identificació de les seves interrelacions. - Un anàlisi de la mida i definició de la cobertura dels models de qualitat proposats. - Una cobertura quantificada dels diferents factors de qualitat ISO/IEC 25010 donat en les diferents propostes. - La identificació dels factors de qualitat més utilitzats, i la definició dels termes més consolidats. Com monitoritzar - L'elicitació dels requeriments per a les diferents activitats en el cicle de vida dels SBS. - La definició del conjunt de característiques que donen suport als requeriments elicitats. - Una platforma modular orientada a serveis, anomenat SALMon, que implementa les característiques definides. SALMon ha estatvalidat incloent la plataforma en diversos marcs de treball donant suport a les diferents activitat
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Context Aware Web-Service Monitoring
Monitoring the correct behaviour of a service-based system is a necessity and a key challenge in Service Oriented Computing. Several efforts have been directed towards the development of approaches dealing with the monitoring activity of service-based systems. However, these approaches are in general not suitable when dealing with modifications in service-based systems. Furthermore, existing monitoring approaches do not take into consideration the context of the users and how this context may affect the monitor activity. Consequently, a holistic monitor approach, capable of dealing with the dynamic nature of service-based systems and of taking into consideration the user context, would be highly desirable.
In this thesis we present a monitor adaptation framework capable of dealing with changes in a service-based system and different types of users interacting with it. More specifically, the framework obtains a set of monitor rules, necessary to verify the correct behaviour of a service-based system, for a particular user. Moreover, the monitor rules verifying the behaviour of a service-based system relate to properties of the context types defined for a user.
The main contributions of our work include the general characterisation of a user interacting with a service-based system and the generation of suitable monitor rules.The proposed framework can be applied to any service composition without the need of further modifications. Our work complements previous research carried on in the area of web service monitoring. More specifically, our work generates a set of suitable monitor rules - related to the user context - which are deployed in a run-time monitor component. Our framework has been tested and validated in several cases considering different scenarios
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