Specification and Verification of Context-dependent Services

Current approaches for the discovery, specification, and provision of services ignore the relationship between the service contract and the conditions in which the service can guarantee its contract. Moreover, they do not use formal methods for specifying services, contracts, and compositions. Without a formal basis it is not possible to justify through formal verification the correctness conditions for service compositions and the satisfaction of contractual obligations in service provisions. We remedy this situation in this paper. We present a formal definition of services with context-dependent contracts. We define a composition theory of services with context-dependent contracts taking into consideration functional, nonfunctional, legal and contextual information. Finally, we present a formal verification approach that transforms the formal specification of service composition into extended timed automata that can be verified using the model checking tool UPPAAL.Comment: In Proceedings WWV 2011, arXiv:1108.208

Characterization and Efficient Management of Big Data in IoT-Driven Smart City Development

Smart city is an emerging initiative for integrating Information and Communication Technologies (ICT) in effective ways to support development of smart cities with enhanced quality of life for its citizens through safe and secure context-aware services. Major technical challenges to realize smart cities include resource use optimization, service delivery without interruption at all times in all aspects, minimization of costs, and reduction of resource consumption. To address these challenges, new techniques and technologies are required for modeling and processing the big data generated and used through the underlying Internet of Things (IoT). To this end, we propose a data-centric approach to IoT in conceptualizing the “things” from a service-oriented perspective and investigate efficient ways to identify, integrate, and manage big data. The data-centric approach is expected to better support efficient management of data with complexities inherent in IoT-generated big data. Furthermore, it supports efficient and scalable query processing and reasoning techniques required in development of smart city applications. This article redresses the literature and contributes to the foundations of smart cities applications

A Framework for Developing Context-aware Systems

Context-aware computing refers to a general class of mobile real-time reactive systems that continuously sense their physical environment, and adapt their behavior accordingly. Context-awareness is an essential inherent property of ubiquitous computing or pervasive computing systems. Such systems are much richer and more complex than many software systems. The richness mainly comes from context-awareness, the heterogeneity of mobile devices and their service types, while complexity arises in the multitude of adaptations enforced by system policies. In order to provide the true intended effect on the application of services without compromising on the richness, the complexity must be tamed. Towards this goal, this paper proposes a component-based architecture for a Context-aware Framework in which context, awareness capabilities, reactions, and adaptations are formally dealt with. Two formal languages are designed to express context situations and express workflow policies, which respectively lead to a context reasoner and to enforce adaptations.With these formalisms and a component design that can be formalized, this work fulfills a formal approach to construct context-aware applications. Two case studies are explained, of which one is a proof-of-concept case study from service-oriented domain. It is fully implemented to illustrate the expressiveness of the framework design and robustness of its implementation

Context-Aware Systems and ApplicationsSecond International Conference, ICCASA 2013, Phu Quoc Island, Vietnam, November 25-26, 2013, Revised Selected Papers /

XIII, 380 p. 145 illus.online resource