585 research outputs found

    A New Approach to Manage QoS in Distributed Multimedia Systems

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    Dealing with network congestion is a criterion used to enhance quality of service (QoS) in distributed multimedia systems. The existing solutions for the problem of network congestion ignore scalability considerations because they maintain a separate classification for each video stream. In this paper, we propose a new method allowing to control QoS provided to clients according to the network congestion, by discarding some frames when needed. The technique proposed, called (m,k)-frame, is scalable with little degradation in application performances. (m,k)-frame method is issued from the notion of (m,k)-firm realtime constraints which means that among k invocations of a task, m invocations must meet their deadline. Our simulation studies show the usefulness of (m,k)-frame method to adapt the QoS to the real conditions in a multimedia application, according to the current system load. Notably, the system must adjust the QoS provided to active clients1 when their number varies, i.e. dynamic arrival of clients.Comment: 10 pages, International Journal of Computer Science and Information Security (IJCSIS

    BOF4WSS : a business-oriented framework for enhancing web services security for e-business

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    When considering Web services' (WS) use for online business-to-business (B2B) collaboration between companies, security is a complicated and very topical issue. This is especially true with regard to reaching a level of security beyond the technological layer, that is supported and trusted by all businesses involved. With appreciation of this fact, our research draws from established development methodologies to develop a new, business-oriented framework (BOF4WSS) to guide e-businesses in defining, and achieving agreed security levels across these collaborating enterprises. The approach envisioned is such that it can be used by businesses-in a joint manner-to manage the comprehensive concern that security in the WS environment has become

    Interval Neutrosophic Sets and Logic: Theory and Applications in Computing

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    A neutrosophic set is a part of neutrosophy that studies the origin, nature, and scope of neutralities, as well as their interactions with different ideational spectra. The neutrosophic set is a powerful general formal framework that has been recently proposed. However, the neutrosophic set needs to be specified from a technical point of view. Here, we define the set-theoretic operators on an instance of a neutrosophic set, and call it an Interval Neutrosophic Set (INS). We prove various properties of INS, which are connected to operations and relations over INS. We also introduce a new logic system based on interval neutrosophic sets. We study the interval neutrosophic propositional calculus and interval neutrosophic predicate calculus. We also create a neutrosophic logic inference system based on interval neutrosophic logic. Under the framework of the interval neutrosophic set, we propose a data model based on the special case of the interval neutrosophic sets called Neutrosophic Data Model. This data model is the extension of fuzzy data model and paraconsistent data model. We generalize the set-theoretic operators and relation-theoretic operators of fuzzy relations and paraconsistent relations to neutrosophic relations. We propose the generalized SQL query constructs and tuple-relational calculus for Neutrosophic Data Model. We also design an architecture of Semantic Web Services agent based on the interval neutrosophic logic and do the simulation study

    Метод оценивания качества информационных сервисов в корпоративной сети

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    Рассматриваются вопросы оценивания качества сервисов в корпоративной сети. Показана связь методов оценивания качества с показателями состояния сервисов, предложено обобщение метода оценивания для случаев однородных и неоднородных сервисов. Правильность полученных решений подтверждается на примерах.It is considered evaluation qualities of services questions in a corporate network. It is sown the relation of qualities evaluating methods with state parameters of services, the generalization of the evaluation method for cases of homogeneous and heterogeneous services. Correctness of the received solutions is proved by examples

    Survey on wireless technology trade-offs for the industrial internet of things

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    Aside from vast deployment cost reduction, Industrial Wireless Sensor and Actuator Networks (IWSAN) introduce a new level of industrial connectivity. Wireless connection of sensors and actuators in industrial environments not only enables wireless monitoring and actuation, it also enables coordination of production stages, connecting mobile robots and autonomous transport vehicles, as well as localization and tracking of assets. All these opportunities already inspired the development of many wireless technologies in an effort to fully enable Industry 4.0. However, different technologies significantly differ in performance and capabilities, none being capable of supporting all industrial use cases. When designing a network solution, one must be aware of the capabilities and the trade-offs that prospective technologies have. This paper evaluates the technologies potentially suitable for IWSAN solutions covering an entire industrial site with limited infrastructure cost and discusses their trade-offs in an effort to provide information for choosing the most suitable technology for the use case of interest. The comparative discussion presented in this paper aims to enable engineers to choose the most suitable wireless technology for their specific IWSAN deployment

    QoS-aware predictive workflow scheduling

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    This research places the basis of QoS-aware predictive workflow scheduling. This research novel contributions will open up prospects for future research in handling complex big workflow applications with high uncertainty and dynamism. The results from the proposed workflow scheduling algorithm shows significant improvement in terms of the performance and reliability of the workflow applications

    Fault Tolerance Framework for Composite Web Services

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    A composite Web service combines multiple, logically interrelated services for creating more common services meeting complex requirements from users. The services participating in a composition coordinate the actions of distributed activity using Web services protocols to reach consistent agreement on the outcome of joint operation. However, as services run over unreliable protocols, there is a great chance that services fail due to the failure of protocols. However, current protocol standards provide fault-tolerance but are limited to backward recovery using expensive compensation and roll-back strategies. This paper gives an extension of the existing Web services business activity (WS-BA) protocol to deal with failures using forward recovery approach. A set of common failure types affecting the execution of component services is identified, and recovery solutions for each identified failure are also presented. The fault-handling extension of the WS-BA protocol implements recovery solutions for each of the identified failures to handle failures at runtime. Another important aspect about which the WS-BA protocol specification is unclear is reaching and notifying consistent outcome on the completion of joint work. This study extends the WS-BA protocol to notify consistent outcome reached by all participating services. The implementation and testing of the framework are performed using the model-checking and verification tool UPPAAL. A well-known application example supports the study. The key properties of the framework, like the execution of corresponding recovery actions in cases of failures and reaching a consistent agreement on the outcome of joint operation, are verified
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