Foreword:

This special issue, with papers contributed by prominent researchers from academia and industry, will serve as a reference material for researchers, scientists, professionals and students in computer science and computer engineering as well as developers and practitioners in computing and networking systems design by providing them with state-of-the-art research findings and future opportunities and trends. These contributions include some recent advances in context-awareness of mobile systems reflected in the six papers that we chose to invite for this special issue. In particular, the special issue covers various problems on models, algorithms and applications for context-awareness of mobile systems.

Paper 1 by Phan Cong Vinh and Nguyen Thanh Tung is both to give an in-depth analysis as well as to present the new material on the notion of context-aware computing, an idea that computing can both sense and react accordantly based on its environment. The paper formalizes context-awareness process using coalgebraic language, including the coalgebraic definition of context-awareness, bisimulation between context-awarenesses, homomorphism between context-awarenesses and context-awarenesses as coalgebras.

Paper 2 by Sara Montagna, Mirko Viroli, Jose Luis Fernandez Marquez, Giovanna Di Marzo Serugendo and Franco Zambonelli aims at deepening how self-organization can be injected in pervasive service ecosystems in terms of spatial structures and algorithms for supporting the design of context-aware applications. To this end, authors start from an existing classification of self-organization patterns, and systematically show how they can be supported in pervasive service ecosystems, and be composed to generate a self-organizing emergent behavior. A paradigmatic crowd steering case study is used to demonstrate the effectiveness of the approach.

Paper 3 by Julien Freudiger, Murtuza Jadliwala, Jean-Pierre Hubaux, Valtteri Niemi and Philip Ginzboorg discusses the ability to discover geographic proximity of specific communities of people (e.g., friends or neighbors). To do so, mobile devices must exchange some community identifiers or messages. Authors investigate privacy threats introduced by such communications, in particular, adversarial community detection. Authors use the general concept of community pseudonyms to abstract anonymous community identification mechanisms and define two distinct notions of community privacy using challenge-response methodology. An extensive cost analysis and simulation results throw further light on the feasibility of these mechanisms in the upcoming generation of wireless peer-to-peer networks.

Paper 4 by Andrei Olaru, Adina Magda Florea and Amal El Fallah Seghrouchni provides a model for a such middleware, based on software agents, in which context-awareness is implemented both in the agent’s representation of context information, and in the logical topology of the agent system. The model is oriented towards decentralization of the system and relies mostly on local behavior. The paper also reports on several proof-of-concept applications that have been developed and tested using the proposed model, proving thus the validity of the approach.

Paper 5 by Antonio Coronato and Giuseppe De Pietro provides a new formal approach for the situation-awareness and the detection of abnormal behaviors of cognitive impaired people in situation-aware smart spaces. Instead of relying on the identification of deviations from normal behaviors, the approach is based on the specification and runtime verification of correctness properties. Situation Calculus is the formal method adopted to model the world; whereas, intelligent agents detect abnormal and dangerous situations. Dangerous situation recovery is also performed by ad-hoc intelligent agents.

Paper 6 by Nguyen Thanh Tung and Phan Cong Vinh provides the importance of considering neighboring nodes in the energy efficiency routing problem. After showing that the routing problem that considers the remaining energy of all sensor nodes is NP-complete, heuristics are proposed for the problem. Simulation results show that the routing algorithm that considers the remaining energy of all sensor nodes improves the system lifetime significantly compared to that of minimum transmission energy algorithms. Also, the energy dissipation of neighboring nodes accounts for a considerable amount of the total energy dissipation. Therefore, a method that reduces the energy dissipation by notifying the neighboring nodes to turn off their radio when not necessary is proposed. By reducing the unnecessary energy dissipation of the neighbors, the lifetime is increased significantly.

We owe our deepest gratitude to Dr. Nguyen Manh Hung – Chairman and Rector of NTT University in Vietnam for his useful support, especially to all the authors for their valuable contribution to this special issue and their great efforts, and also to the referees for ensuring the high quality of the material presented here. All of them are extremely professional and cooperative. We wish to express our thanks to the Editor-in-Chief, Prof. Imrich Chlamtac, for his important assistance with the process of assembling the special issue.

Phan Cong Vinh

Jun Suzuki