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Vehicle (bike or car) sharing represents an emerging transportation scheme which may comprise an important link in the green mobility chain of smart city environments. This chapter offers a comprehensive review of algorithmic approaches for the design and management of vehicle sharing systems. Our focus is on one-way vehicle sharing systems (wherein customers are allowed to pick-up a vehicle at any location and return it to any other station) which best suits typical urban journey requirements. Along this line, we present methods dealing with the so-called asymmetric demand-offer problem (i.e. the unbalanced offer and demand of vehicles) typically experienced in one-way sharing systems which severely affects their economic viability as it implies that considerable human (and financial) resources should be engaged in relocating vehicles to satisfy customer demand. The chapter covers all planning aspects that affect the effectiveness and viability of vehicle sharing systems: the actual system design (e.g. number and location of vehicle station facilities, vehicle fleet size, vehicles distribution among stations); customer incentivisation schemes to motivate customer-based distribution of bicycles/cars (such schemes offer meaningful incentives to users so as to leave their vehicle to a station different to that originally intended and satisfy future user demand); cost-effective solutions to schedule operator-based repositioning of bicycles/cars (by employees explicitly enrolled in vehicle relocation) based on the current and future (predicted) demand patterns (operator-based and customer-based relocation may be thought as complementary methods to achieve the intended distribution of vehicles among stations)., Comment: 38 pages, 3 figures, 4 tables, In: "Smart Cities and Homes: Key Enabling Technologies", M.S. Obaidat and P. Nicopolitidis (Eds.), Elsevier Science, in press

This paper discusses the implementation of the pervasive game PacMap. Openness and portability have been the main design objectives for PacMap. We elaborate on programming techniques which may be applicable to a broad range of location-based games that involve the movement of virtual characters over map interfaces. In particular, we present techniques to execute shortest path algorithms on spatial environments bypassing the restrictions imposed by commercial mapping services. Last, we present ways to improve the movement and enhance the intelligence of virtual characters taking into consideration the actions and position of players in location-based games., Comment: 6 pages, 3 figures, Proceedings of the International Conference on Pervasive Games (PERGAMES'2014), Rome, Italy, 27 October 2014

In this paper we present the evaluation process for Barbarossa, a pervasive role playing game. Barbarossa involves an invitational (preparatory) and a main execution phase. The former is freely available though Google Play store and may be played anytime/ anywhere. The latter defines three inter-dependent player roles acted by players who need to collaborate in a treasure hunting game. The eligibility of players for participating in the main game phase is restricted among those ranked relatively high in the invitational phase. Herein, we investigate the impact of the invitational game mode on the players overall game experience. The main hypothesis tested is that game awareness (gained from participating in a preliminary game phase) may serve as a means for recruiting the most suitable subjects for user trials on pervasive game research prototypes., Comment: 7 pages, 4 Tables, Proceedings of the International Conference on Pervasive Games (PERGAMES'2014), Rome, Italy, 27 October 2014

Organization, scalability and routing have been identified as key problems hindering viability and commercial success of mobile ad hoc networks. Clustering of mobile nodes among separate domains has been proposed as an efficient approach to address those issues. In this work, we introduce an efficient distributed clustering algorithm that uses both location and energy metrics for cluster formation. Our proposed solution mainly addresses cluster stability, manageability and energy efficiency issues. Also, unlike existing active clustering methods, our algorithm relieves the network from the unnecessary burden of control messages broadcasting, especially for relatively static network topologies. This is achieved through adapting broadcast period according to mobile nodes mobility pattern. The efficiency, scalability and competence of our algorithm against alternative approaches have been demonstrated through simulation results., Comment: 7 pages, 9 figures; IEEE International Conference on Communications, 2006. ICC '06

Mobile Agents (MAs) represent a distributed computing technology that promises to address the scalability problems of centralized network management. A critical issue that will affect the wider adoption of MA paradigm in management applications is the development of MA Platforms (MAPs) expressly oriented to distributed management. However, most of available platforms impose considerable burden on network and system resources and also lack of essential functionality. In this paper, we discuss the design considerations and implementation details of a complete MAP research prototype that sufficiently addresses all the aforementioned issues. Our MAP has been implemented in Java and tailored for network and systems management applications., Comment: 7 pages, 5 figures; Proceedings of the 2006 Conference on Mobile Computing and Wireless Communications (MCWC'2006)

Clustering is a promising approach for building hierarchies and simplifying the routing process in mobile ad-hoc network environments. The main objective of clustering is to identify suitable node representatives, i.e. cluster heads (CHs), to store routing and topology information and maximize clusters stability. Traditional clustering algorithms suggest CH election exclusively based on node IDs or location information and involve frequent broadcasting of control packets, even when network topology remains unchanged. More recent works take into account additional metrics (such as energy and mobility) and optimize initial clustering. However, in many situations (e.g. in relatively static topologies) re-clustering procedure is hardly ever invoked; hence initially elected CHs soon reach battery exhaustion. Herein, we introduce an efficient distributed clustering algorithm that uses both mobility and energy metrics to provide stable cluster formations. CHs are initially elected based on the time and cost-efficient lowest-ID method. During clustering maintenance phase though, node IDs are re-assigned according to nodes mobility and energy status, ensuring that nodes with low-mobility and sufficient energy supply are assigned low IDs and, hence, are elected as CHs. Our algorithm also reduces control traffic volume since broadcast period is adjusted according to nodes mobility pattern: we employ infrequent broadcasting for relative static network topologies, and increase broadcast frequency for highly mobile network configurations. Simulation results verify that energy consumption is uniformly distributed among network nodes and that signaling overhead is significantly decreased., Comment: 5 pages, 4 figures; Proceedings of the 1st IEEE International Symposium on Wireless Pervasive Computing (ISWPC'2006)

Museum stores represent integral parts of the museums that have also a lot to benefit from a successful presence on the web arena. In addition to traditional web sites, carefully designed electronic commerce (e-commerce) sites may increase the potential of museum stores offering possibilities for on-line shopping and other commercial functions. In parallel, the recent convergence of the traditionally separate technologies of the Internet and mobile telephony has brought the concept of 'wireless Internet' into the spotlight. Within this context, 'mobile commerce' (m-commerce) is a relatively new trend that represents a natural extension of e-commerce into the wireless world. M-commerce refers to electronic business transactions and differentiates from e-commerce since it involves the use of mobile devices and wireless medium rather than wired. The unique characteristics of mobile computing bring forward new challenges and opportunities for museum stores. This article presents the design and implementation of an e-commerce and an m-commerce museum shop application. The aim is to evaluate and compare the two applications in terms of several parameters, such as available technologies, strengths and limitations, design requirements, usability, interaction speed, usage cost, etc and also to identify ways for enhancing the potential of such applications and designing successful and profitable business models., Comment: 9 pages, 8 figures

The field of mobile agent (MA) technology has been intensively researched during the past few years, resulting in the phenomenal proliferation of available MA platforms, all sharing several common design characteristics. Research projects have mainly focused on identifying applications where the employment of MAs is preferable compared to centralised or alternative distributed computing models. Very little work has been made on examining how MA platforms design can be optimised so as the network traffic and latency associated with MA transfers are minimised. The work presented in this paper addresses these issues by investigating the effect of several optimisation ideas applied on our MA platform prototype. Furthermore, we discuss the results of a set of timing experiments that offers a better understanding of the agent migration process and recommend new techniques for reducing MA transfers delay., Comment: 8 pages, 7 figures

This paper proposes a framework based completely on Java technology. The advantages brought about by the use of Java in network management answer some critical problems existing in current systems. With this work we address several factors concerning interoperability and security in heterogeneous network environments. Specifically, we present a manager application and a multithreaded agent engine that make use of a lightweight communication mechanism for message exchange. A MIB parser is introduced to accelerate handling of incoming management requests, and the RSA public-key cryptosystem is implemented to provide both encryption and authentication features. Results, measured in terms of response time, compare favourably with other published work and standard management frameworks., Comment: 12 pages, 7 figures, 1st International Conference and Exhibition on the Practical Applications of Java (PA-Java'99), ISBN: 1-902426-03-07, pp. 61-72, London, UK, 21-23 April 1999