12 research outputs found

    Rate Adaptation Mechanism with Available Data Rate Trimming and Data Rate Information Provision for V2I Communications

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    We study a rate adaptation mechanism for improving communication performance between a connected vehicle and a roadside unit (RSU) using Wi-Fi during movement in a vehicle-to-infrastructure (V2I) environment. Wi-Fi communication provides various attractive services to connected vehicles during movement. However, as a connected vehicle is generally moving at high speed, the communication performance with an RSU that works as an access point is degraded because wireless link quality fluctuates abruptly and continuously. We then propose a rate adaptation mechanism employing the following two main features to mitigate such deterioration in communication performance: available data rate trimming and data rate information provision. To alleviate degradation of communication, the former avoids usage of excessively low data rates and the latter then provides data rate information suitable for channel quality from a dataset of adequate data rates based on the vehicle's location and speed. However, the data rate information provided from a dataset may not always be appropriate because of various indefinite factors such as multipath fading and shadowing. Thus, the proposed method also employs a measurement-based function to compensate for such a drawback of the dataset. Simulation experiments evaluate communication performance for 10, 60, and 100 km/h in single-vehicle and multiple-vehicles cases. Simulation results showed that the proposed method overall provides superior communication performance in situations involving more than one vehicle, in comparison with existing counter- and sample-based methods

    Vol. 4, No. 2 (Full Issue)

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    A comprehensive survey on Fog Computing: State-of-the-art and research challenges

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    Cloud computing with its three key facets (i.e., Infrastructure-as-a-Service, Platform-as-a-Service, and Softwareas- a-Service) and its inherent advantages (e.g., elasticity and scalability) still faces several challenges. The distance between the cloud and the end devices might be an issue for latencysensitive applications such as disaster management and content delivery applications. Service level agreements (SLAs) may also impose processing at locations where the cloud provider does not have data centers. Fog computing is a novel paradigm to address such issues. It enables provisioning resources and services outside the cloud, at the edge of the network, closer to end devices, or eventually, at locations stipulated by SLAs. Fog computing is not a substitute for cloud computing but a powerful complement. It enables processing at the edge while still offering the possibility to interact with the cloud. This paper presents a comprehensive survey on fog computing. It critically reviews the state of the art in the light of a concise set of evaluation criteria. We cover both the architectures and the algorithms that make fog systems. Challenges and research directions are also introduced. In addition, the lessons learned are reviewed and the prospects are discussed in terms of the key role fog is likely to play in emerging technologies such as tactile Internet

    Technology, Science and Culture

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    From the success of the first and second volume of this series, we are enthusiastic to continue our discussions on research topics related to the fields of Food Science, Intelligent Systems, Molecular Biomedicine, Water Science, and Creation and Theories of Culture. Our aims are to discuss the newest topics, theories, and research methods in each of the mentioned fields, to promote debates among top researchers and graduate students and to generate collaborative works among them

    Modeling the fundamental characteristics and processes of the spacecraft functioning

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    The fundamental aspects of modeling of spacecraft characteristics by using computing means are considered. Particular attention is devoted to the design studies, the description of physical appearance of the spacecraft, and simulated modeling of spacecraft systems. The fundamental questions of organizing the on-the-ground spacecraft testing and the methods of mathematical modeling were presented

    Computer Aided Verification

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    The open access two-volume set LNCS 11561 and 11562 constitutes the refereed proceedings of the 31st International Conference on Computer Aided Verification, CAV 2019, held in New York City, USA, in July 2019. The 52 full papers presented together with 13 tool papers and 2 case studies, were carefully reviewed and selected from 258 submissions. The papers were organized in the following topical sections: Part I: automata and timed systems; security and hyperproperties; synthesis; model checking; cyber-physical systems and machine learning; probabilistic systems, runtime techniques; dynamical, hybrid, and reactive systems; Part II: logics, decision procedures; and solvers; numerical programs; verification; distributed systems and networks; verification and invariants; and concurrency

    Computer Aided Verification

    Get PDF
    The open access two-volume set LNCS 11561 and 11562 constitutes the refereed proceedings of the 31st International Conference on Computer Aided Verification, CAV 2019, held in New York City, USA, in July 2019. The 52 full papers presented together with 13 tool papers and 2 case studies, were carefully reviewed and selected from 258 submissions. The papers were organized in the following topical sections: Part I: automata and timed systems; security and hyperproperties; synthesis; model checking; cyber-physical systems and machine learning; probabilistic systems, runtime techniques; dynamical, hybrid, and reactive systems; Part II: logics, decision procedures; and solvers; numerical programs; verification; distributed systems and networks; verification and invariants; and concurrency
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