3,328 research outputs found

    Research on Construction and Operation of Microgrid

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    In order to cope with the objective contradiction of the worsening environmental problems and the rigid demand for energy due to the rapid economic development, it is of great significance to explore the technology and management mode of microgrid which is self-used and locally consumed with renewable energy. In this study, on the basis of clarifying the construction goal of microgrid, the energy management system of microgrid is designed, the control mode consistent with the characteristics of renewable energy is selected, the business scope of microgrid is expanded according to the interactive needs of different users, and the intelligent interactive operation of microgrid is realized, which can make better use of renewable energy to meet the rising demand for energy while protecting the environment

    A game theory control scheme in medium access for wireless body area network

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    Wireless Body Area Network (WBAN) has been considered for applications in medical, healthcare and sports fields. Although there are several protocols for wireless personal area networks, specific features and reliability requirements in WBAN bring new challenges in protocol design. An appropriate control scheme in the MAC layer can make a significant improvement in network performance. Based on traffic priority and prior knowledge this paper proposes a game theoretical framework to smartly control access in contention period and contention free period as defined in IEEE 802.15.6 standard. The coordinator controls access probability of contention period based on users' priority in CSMA/CA and allocates suitable slots with strategies for best payoff based on link states in guaranteed time slots (GTS). The simulation results show the improved performance especially in heavily loaded channel condition when the optimal control mode is applied

    The Critical Role of Public Charging Infrastructure

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    Editors: Peter Fox-Penner, PhD, Z. Justin Ren, PhD, David O. JermainA decade after the launch of the contemporary global electric vehicle (EV) market, most cities face a major challenge preparing for rising EV demand. Some cities, and the leaders who shape them, are meeting and even leading demand for EV infrastructure. This book aggregates deep, groundbreaking research in the areas of urban EV deployment for city managers, private developers, urban planners, and utilities who want to understand and lead change

    Long-lived space observatories for astronomy and astrophysics

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    NASA's plan to build and launch a fleet of long-lived space observatories that include the Hubble Space Telescope (HST), the Gamma Ray Observatory (GRO), the Advanced X Ray Astrophysics Observatory (AXAF), and the Space Infrared Telescope Facility (SIRTF) are discussed. These facilities are expected to have a profound impact on the sciences of astronomy and astrophysics. The long-lived observatories will provide new insights about astronomical and astrophysical problems that range from the presence of planets orbiting nearby stars to the large-scale distribution and evolution of matter in the universe. An important concern to NASA and the scientific community is the operation and maintenance cost of the four observatories described above. The HST cost about 1.3billion(1984dollars)tobuildandisestimatedtorequire1.3 billion (1984 dollars) to build and is estimated to require 160 million (1986 dollars) a year to operate and maintain. If HST is operated for 20 years, the accumulated costs will be considerably more than those required for its construction. Therefore, it is essential to plan carefully for observatory operations and maintenance before a long-lived facility is constructed. The primary goal of this report is to help NASA develop guidelines for the operations and management of these future observatories so as to achieve the best possible scientific results for the resources available. Eight recommendations are given

    Service-aware multi-resource allocation in software-defined next generation cellular networks

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    Şefik Şuayb Arslan (MEF Author)Network slicing is one of the major solutions needed to meet the requirements of next generation cellular networks, under one common network infrastructure, in supporting multiple vertical services provided by mobile network operators. Network slicing makes one shared physical network infrastructure appear as multiple logically isolated virtual networks dedicated to different service types where each Network Slice (NS) benefits from on-demand allocated resources. Typically, the available resources distributed among NSs are correlated and one needs to allocate them judiciously in order to guarantee the service, MNO, and overall system qualities. In this paper, we consider a joint resource allocation strategy that weights the significance of the resources per a given NS by leveraging the correlation structure of different quality-of-service (QoS) requirements of the services. After defining the joint resource allocation problem including the correlation structure, we propose three novel scheduling mechanisms that allocate available network resources to the generated NSs based on different type of services with different QoS requirements. Performance of the proposed schedulers are then investigated through Monte-Carlo simulations and compared with each other as well as against a traditional max-min fairness algorithm benchmark. The results reveal that our schedulers, which have different complexities, outperform the benchmark traditional method in terms of service-based and overall satisfaction ratios, while achieving different fairness index levels.WOS:000430793600019Scopus - Affiliation ID: 60105072Science Citation Index ExpandedQ1 - Q2ArticleUluslararası işbirliği ile yapılmayan - HAYIRMart2018YÖK - 2017-1

    Design of an integrated airframe/propulsion control system architecture

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    The design of an integrated airframe/propulsion control system architecture is described. The design is based on a prevalidation methodology that uses both reliability and performance. A detailed account is given for the testing associated with a subset of the architecture and concludes with general observations of applying the methodology to the architecture

    UniFuzz: Optimizing Distributed Fuzzing via Dynamic Centralized Task Scheduling

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    Fuzzing is one of the most efficient technology for vulnerability detection. Since the fuzzing process is computing-intensive and the performance improved by algorithm optimization is limited, recent research seeks to improve fuzzing performance by utilizing parallel computing. However, parallel fuzzing has to overcome challenges such as task conflicts, scalability in a distributed environment, synchronization overhead, and workload imbalance. In this paper, we design and implement UniFuzz, a distributed fuzzing optimization based on a dynamic centralized task scheduling. UniFuzz evaluates and distributes seeds in a centralized manner to avoid task conflicts. It uses a "request-response" scheme to dynamically distribute fuzzing tasks, which avoids workload imbalance. Besides, UniFuzz can adaptively switch the role of computing cores between evaluating, and fuzzing, which avoids the potential bottleneck of seed evaluation. To improve synchronization efficiency, UniFuzz shares different fuzzing information in a different way according to their characteristics, and the average overhead of synchronization is only about 0.4\%. We evaluated UniFuzz with real-world programs, and the results show that UniFuzz outperforms state-of-the-art tools, such as AFL, PAFL and EnFuzz. Most importantly, the experiment reveals a counter-intuitive result that parallel fuzzing can achieve a super-linear acceleration to the single-core fuzzing. We made a detailed explanation and proved it with additional experiments. UniFuzz also discovered 16 real-world vulnerabilities.Comment: 14 pages, 4 figure

    Smart and Secure CAV Networks Empowered by AI-Enabled Blockchain: Next Frontier for Intelligent Safe-Driving Assessment

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    Securing safe-driving for connected and autonomous vehicles (CAVs) continues to be a widespread concern despite various sophisticated functions delivered by artificial intelligence for in-vehicle devices. Besides, diverse malicious network attacks become ubiquitous along with the worldwide implementation of the Internet of Vehicles, which exposes a range of reliability and privacy threats for managing data in CAV networks. Combined with the fact that the capability of existing CAVs in handling intensive computation tasks is limited, this implies a need for designing an efficient assessment system to guarantee autonomous driving safety without compromising data security. Motivated by this, in this article, we propose a novel framework, namely Blockchain-enabled intElligent Safe-driving assessmenT (BEST), that offers a smart and reliable approach for conducting safe driving supervision while protecting vehicular information. Specifically, a promising solution that exploits a long short-term memory model is introduced to assess the safety level of the moving CAVs. Then, we investigate how a distributed blockchain obtains adequate trustworthiness and robustness for CAV data by adopting a byzantine fault tolerance-based delegated proof-of-stake consensus mechanism. Simulation results demonstrate that our presented BEST gains better data credibility with a higher prediction accuracy for vehicular safety assessment when compared with existing schemes. Finally, we discuss several open challenges that need to be addressed in future CAV networks.Comment: 8 pages, 6 figures. This paper has been accepted for publication by IEEE Networ

    Workshop proceedings: Information Systems for Space Astrophysics in the 21st Century, volume 1

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    The Astrophysical Information Systems Workshop was one of the three Integrated Technology Planning workshops. Its objectives were to develop an understanding of future mission requirements for information systems, the potential role of technology in meeting these requirements, and the areas in which NASA investment might have the greatest impact. Workshop participants were briefed on the astrophysical mission set with an emphasis on those missions that drive information systems technology, the existing NASA space-science operations infrastructure, and the ongoing and planned NASA information systems technology programs. Program plans and recommendations were prepared in five technical areas: Mission Planning and Operations; Space-Borne Data Processing; Space-to-Earth Communications; Science Data Systems; and Data Analysis, Integration, and Visualization
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