599 research outputs found

    Towards business model and technical platform for the service oriented context-aware mobile virtual communities

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    The focus of existing virtual communities is centered on a particular product or social interaction and the role of mobile devices is restricted to exchange a limited amount of contents. Herewith we envisage that the upcoming virtual communities will exploit the potential of social interaction and context information to offer personalized services to its members and mobile devices will play a significant role in this process. As a step towards this direction, in this paper we propose a business model for the mobile virtual communities in which the mobile device takes on the role of a content producer and content consumer. Though there are a number of research issues which need to be addressed to realize such virtual communities, in this paper we focus on the service requirements, architecture and open source software implementation of a technical platform for the content producer and consumer mobile devices

    Quality assessment technique for ubiquitous software and middleware

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    The new paradigm of computing or information systems is ubiquitous computing systems. The technology-oriented issues of ubiquitous computing systems have made researchers pay much attention to the feasibility study of the technologies rather than building quality assurance indices or guidelines. In this context, measuring quality is the key to developing high-quality ubiquitous computing products. For this reason, various quality models have been defined, adopted and enhanced over the years, for example, the need for one recognised standard quality model (ISO/IEC 9126) is the result of a consensus for a software quality model on three levels: characteristics, sub-characteristics, and metrics. However, it is very much unlikely that this scheme will be directly applicable to ubiquitous computing environments which are considerably different to conventional software, trailing a big concern which is being given to reformulate existing methods, and especially to elaborate new assessment techniques for ubiquitous computing environments. This paper selects appropriate quality characteristics for the ubiquitous computing environment, which can be used as the quality target for both ubiquitous computing product evaluation processes ad development processes. Further, each of the quality characteristics has been expanded with evaluation questions and metrics, in some cases with measures. In addition, this quality model has been applied to the industrial setting of the ubiquitous computing environment. These have revealed that while the approach was sound, there are some parts to be more developed in the future

    CSP channels for CAN-bus connected embedded control systems

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    Closed loop control system typically contains multitude of sensors and actuators operated simultaneously. So they are parallel and distributed in its essence. But when mapping this parallelism to software, lot of obstacles concerning multithreading communication and synchronization issues arise. To overcome this problem, the CT kernel/library based on CSP algebra has been developed. This project (TES.5410) is about developing communication extension to the CT library to make it applicable in distributed systems. Since the library is tailored for control systems, properties and requirements of control systems are taken into special consideration. Applicability of existing middleware solutions is examined. A comparison of applicable fieldbus protocols is done in order to determine most suitable ones and CAN fieldbus is chosen to be first fieldbus used. Brief overview of CSP and existing CSP based libraries is given. Middleware architecture is proposed along with few novel ideas

    Resource Allocation for Device-to-Device Communications in Multi-Cell Multi-Band Heterogeneous Cellular Networks

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    Heterogeneous cellular networks (HCNs) with millimeter wave (mm-wave) communications are considered as a promising technology for the fifth generation mobile networks. Mm-wave has the potential to provide multiple gigabit data rate due to the broad spectrum. Unfortunately, additional free space path loss is also caused by the high carrier frequency. On the other hand, mm-wave signals are sensitive to obstacles and more vulnerable to blocking effects. To address this issue, highly directional narrow beams are utilized in mm-wave networks. Additionally, device-to-device (D2D) users make full use of their proximity and share uplink spectrum resources in HCNs to increase the spectrum efficiency and network capacity. Towards the caused complex interferences, the combination of D2D-enabled HCNs with small cells densely deployed and mm-wave communications poses a big challenge to the resource allocation problems. In this paper, we formulate the optimization problem of D2D communication spectrum resource allocation among multiple micro-wave bands and multiple mm-wave bands in HCNs. Then, considering the totally different propagation conditions on the two bands, a heuristic algorithm is proposed to maximize the system transmission rate and approximate the solutions with sufficient accuracies. Compared with other practical schemes, we carry out extensive simulations with different system parameters, and demonstrate the superior performance of the proposed scheme. In addition, the optimality and complexity are simulated to further verify effectiveness and efficiency.Comment: 13 pages, 11 figures, IEEE Transactions on Vehicular Technolog

    The Extended Family: Reviewing an Invaluable Resource

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    During the last two decades, the extended family has been rediscovered as a viable and meaningful resource for nurturing and protecting children. The purpose of this article is to provide an historical context for involving the extended family in child welfare cases and to identify key factors influencing that involvement

    Service Oriented Computing Imperatives in Ad Hoc Wireless Settings

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    Service oriented computing is a new paradigm that is gaining popularity in dis-tributed computing environments due to its emphasis on highly specialized, modular and platform-agnostic code facilitating interoperability of systems. It borrows concepts from more mature paradigms such as object-oriented and component computing. This results in a progression from object-oriented computing to component computing and ïŹnally to service oriented computing, a new paradigm for designing and delivering software. Just as an object encapsulates state and behavior at a ïŹne level of granularity, a service oïŹ€ers similar encapsulation at a larger scale. This evolution raises the level of abstraction at which systems are engineered, while preserving beneïŹcial properties such as modularity, substitution and encapsulation. Every participant in a service oriented computing system is a provider or user of a service, or both. The service oriented computing paradigm is characterized by a minimalist philosophy, in that a user needs to carry only a small amount of code in its local storage, and exploits other services by discovering and using their capabilities to complete its assigned task. This chapter is the result of our experiences with designing and building service oriented computing frameworks for ad hoc wireless networks (Handorean & Roman, 2002). It examines the salient imperatives required to deliver a service oriented computing frame-work for ad hoc wireless networks. Ad hoc wireless networks are collections of hosts capable of wireless communication. Hosts within proximity of each other opportunistically form a network which changes due to host mobility. An ad hoc wireless network is a dynamic environment by necessity, which exhibits transient interactions, decoupled computing, physical mobility of hosts, and logical mobility of code. The network infrastructure is supported by the participating hosts themselves and there is no dependence on external, ïŹxed resources. Ad hoc wireless environments are especially challenging to program when compared against other classes of ïŹxed wireless environments because of the implications of mobility, i.e., frequent disconnections and inherent dynamism of the network on program execution. An important class of ad hoc mobile systems is based on small, portable devices, and this class of systems is the focus of this chapter. Such devices have limited storage capacity and battery power, which restricts the number of programs they can store and run locally. Service oriented computing oïŹ€ers a solution to this problem. By its very nature, service oriented computing is designed to facilitate sharing of capabilities while minimizing the amount of functionality a single host needs to maintain. Such a design is especially eïŹ€ective in ad hoc networks where storage space on individual hosts is at a premium, yet where the open environment allows a large number of hosts to contribute small functions resulting in a rich set of capabilities being available in the network as a whole. Service oriented computing has received much attention from researchers worldwide. However, most of this work has been focused on architectures and implementations for wired networks. Migrating service oriented computing to ad hoc networks is non-trivial and requires a systematic rethinking of core concepts. Many lessons have been learned from the work done in the wired setting, especially regarding description and matching of services. However, the more demanding environment of an ad hoc wireless network requires novel approaches to advertising, discovering and invoking services. We envision such ad hoc networks being used in a range of application domains, such as response coordination by ïŹremen and police at disaster sites, or command and control of military units in a battleïŹeld. Such scenarios demand reliability despite the dynamic nature of the underlying network. The motivation for this chapter is to understand the unique imperatives for a viable service oriented computing framework in ad hoc wireless settings, and to illustrate selected solution strategies. We begin by examining current technologies, algorithms and capabilities that have been implemented for use in wired networks as a baseline. We then extend these concepts to cater to the special challenges of service oriented computing in ad hoc networks and direct the reader’s attention to research issues in this area, presenting some of our own contributions in the process. The rest of the chapter is organized as follows. We describe existing service oriented computing architectures and the Semantic Web eïŹ€ort in the Background section. The section on Ad Hoc Wireless Network Perspective on Service Oriented Computing represents the main thrust of this chapter and discusses the elements of a service oriented computing framework, examining current technologies alongside our ideas on how these concepts may be applied to ad hoc networks. We cover potential areas of research in the Future Trends section. Finally, we summarize our ïŹndings in the Conclusion section

    Context gathering in Ubiquitous Environments: Enhanced Service Discovery

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    Delivering individualized services that conform to the user’s current situation will form the focus of ubiquitous environments. A description of the networked environment at a semantic level will necessitate contextually oriented knowledge acquisition methods. This then engenders unique challenges for the crucial step of resource discovery. A number of service discovery protocols exist to perform this role. In this paper, we identify the requirements inherent for such an environment and investigate the suitability of the available protocols against these. A suitable candidate solution is proposed with an implementation with semantic extensions and reference points for further enhancements
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