46,213 research outputs found

    Trust-based Service Composition and Binding for Tactical Networks with Multiple Objectives

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    Abstract —Tactical networks must select service providers to meet service requirements of an operation while facing resource constraints and high security vulnerability. In such an environment nodes provide services to support various operations and / may request services to support the operations as well. We formulate the problem of service composition and service binding as a multi-objective optimization (MOO) problem, minimizing the service cost, while maximizing the quality of service (QoS) and quality of information (QoI). The MOO problem is essentially a node-to-service assignment problem such that by dynamically formulating service composition, and selecting the right nodes to provide requested services, the network can support concurrent operations while achieving multiple system objectives. We develop a trust-based service composition and binding protocol. We demonstrate that the trust-based scheme outperforms the counterpart non-trustbased scheme. Furthermore, our trust-based scheme can effectively penalize malicious nodes performing self-promotion attacks, thus filtering out malicious nodes and can ultimately lead to high user satisfaction. Keywords—service composition, tactical networks, trust, multiobjective optimization. I

    Attack-Surface Metrics, OSSTMM and Common Criteria Based Approach to “Composable Security” in Complex Systems

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    In recent studies on Complex Systems and Systems-of-Systems theory, a huge effort has been put to cope with behavioral problems, i.e. the possibility of controlling a desired overall or end-to-end behavior by acting on the individual elements that constitute the system itself. This problem is particularly important in the “SMART” environments, where the huge number of devices, their significant computational capabilities as well as their tight interconnection produce a complex architecture for which it is difficult to predict (and control) a desired behavior; furthermore, if the scenario is allowed to dynamically evolve through the modification of both topology and subsystems composition, then the control problem becomes a real challenge. In this perspective, the purpose of this paper is to cope with a specific class of control problems in complex systems, the “composability of security functionalities”, recently introduced by the European Funded research through the pSHIELD and nSHIELD projects (ARTEMIS-JU programme). In a nutshell, the objective of this research is to define a control framework that, given a target security level for a specific application scenario, is able to i) discover the system elements, ii) quantify the security level of each element as well as its contribution to the security of the overall system, and iii) compute the control action to be applied on such elements to reach the security target. The main innovations proposed by the authors are: i) the definition of a comprehensive methodology to quantify the security of a generic system independently from the technology and the environment and ii) the integration of the derived metrics into a closed-loop scheme that allows real-time control of the system. The solution described in this work moves from the proof-of-concepts performed in the early phase of the pSHIELD research and enrich es it through an innovative metric with a sound foundation, able to potentially cope with any kind of pplication scenarios (railways, automotive, manufacturing, ...)

    A Taxonomy of Workflow Management Systems for Grid Computing

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    With the advent of Grid and application technologies, scientists and engineers are building more and more complex applications to manage and process large data sets, and execute scientific experiments on distributed resources. Such application scenarios require means for composing and executing complex workflows. Therefore, many efforts have been made towards the development of workflow management systems for Grid computing. In this paper, we propose a taxonomy that characterizes and classifies various approaches for building and executing workflows on Grids. We also survey several representative Grid workflow systems developed by various projects world-wide to demonstrate the comprehensiveness of the taxonomy. The taxonomy not only highlights the design and engineering similarities and differences of state-of-the-art in Grid workflow systems, but also identifies the areas that need further research.Comment: 29 pages, 15 figure

    A survey of QoS-aware web service composition techniques

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    Web service composition can be briefly described as the process of aggregating services with disparate functionalities into a new composite service in order to meet increasingly complex needs of users. Service composition process has been accurate on dealing with services having disparate functionalities, however, over the years the number of web services in particular that exhibit similar functionalities and varying Quality of Service (QoS) has significantly increased. As such, the problem becomes how to select appropriate web services such that the QoS of the resulting composite service is maximized or, in some cases, minimized. This constitutes an NP-hard problem as it is complicated and difficult to solve. In this paper, a discussion of concepts of web service composition and a holistic review of current service composition techniques proposed in literature is presented. Our review spans several publications in the field that can serve as a road map for future research

    The impact of central government steering and local network dynamics on the performance of mandated service delivery networks: the case of the Primary Health Care networks in Flanders

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    This paper focuses on the impact of central – local relations on the performance of local service delivery networks set up by central government. Analyzing network literature leaves us with some questions about the impact of coordination strategies of central government as a possible determinant of network-level effectiveness for this type of network and the possible interaction between central government coordination (as part of the network context) and internal network dynamics and the combined effects hereof on the effectiveness of mandated service delivery networks in particular. Our analysis shows that both levels are important to explain the outcomes of the Primary Health Care networks in Flanders. Our study also leads to some important observations about the meaning of ‘central government coordination’ in this context

    Twelve Theses on Reactive Rules for the Web

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    Reactivity, the ability to detect and react to events, is an essential functionality in many information systems. In particular, Web systems such as online marketplaces, adaptive (e.g., recommender) systems, and Web services, react to events such as Web page updates or data posted to a server. This article investigates issues of relevance in designing high-level programming languages dedicated to reactivity on the Web. It presents twelve theses on features desirable for a language of reactive rules tuned to programming Web and Semantic Web applications
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