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Proactive eviction of flow entry for SDN based on hidden Mark.v model

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Frontiers of Computer Science 2020年第4期14卷 107-116页

作者： gan HUANG Hee Yong YOUN College of Software Sungkyunkwan UniversitySuwon440746Korea

With the fast development of software defined network.SDN),numerous researches have been conducted for maximizing the performance of ***,flow tables are utilized in OpenFlows witch for *** to the space limitation of flow table and switch capacity,various issues exist in dealing with the *** existing schemes typically employ reactive approach such that the selection of evicted entries occurs when timeout or table miss *** this paper a proactive approach is proposed based on the prediction of the probability of matching of the *** eviction occurs proactively when the utilization of flow table exceeds a threshold,and the flow entry of the lowest matching probability is *** matching probability is estimated using hidden Mark.v model(HMM).Computersimulation reveals that it significantly enhances the prediction accuracy and decreases the number of table misses compared to the standard Hard timeout scheme and Flow master scheme.

关键词： SDN OpenFlow flow entry eviction HMM matching probability

Novel DDS Based OFDM Transmitter Structure without IFFT and Interpolation Filter

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China Communications 2021年第12期18卷 219-229页

作者： Sanjun Liu Guangming gan School of Information Engineering Hubei Minzu UniversityEnshi 445000China School of physics and electronic information engineering Hubei Engineering UniversityWuhan 432003China

The traditional orthogonal frequency divi-sion multiplexing(OFDM)transmitter is implemented by inverse fast Fourier transform(IFFT),up-sampling and low pass shaping filter(LPSF),which occupy a large number of hardware resources and have long *** further meet the 5G and future 6G commu-nication requirements,this paper proposes a novel di-rect digital synthesis(DDS)based OFDM transmitter structure that can replace these *** to the strong parallelism of the system structure,it is very suitable for implementation on field programable gate array(FPGA)*** mak.ng two special sim-plifications to the primary structure,the refined struc-ture becomes very simple compared with the tradi-tional *** attractively,the proposed struc-ture has the following three advantages that i)the data transformation from frequency domain to time domain has zero latency,ii)the transformation length does not need to be an integer power of 2 and iii)the struc-ture does not even need to use any multiplier,thus leading to low implementation complexity and high *** experiments are carried out on Intel FPGA platform which show that our DDS based structure can save more than half of the resources com-pared with the traditional structures and can provide the same bit error rate(BER)performance under the condition without using any LPSF.

关键词： OFDM transmitter direct digital synthe-sis(DDS) fast Fourier transform(FFT)

Status of the Advanced Space-based Solar Observatory

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空间科学学报 2020年第5期40卷 704-706页

作者： gan Weiqun k.y Laboratory of Dark.Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210033

The Advanced Space-based Solar Observatory(ASO-S)was formally approved at the end of *** the past two years,ASO-S underwent its official Phase-B and Phase-C *** Phase-B study was successfully accomplished by the end of April 2019,and the Phase-C study is being now undertak.n until August *** the flight model is planned to finish within 16 *** the end of 2021,ASO-S will be ready in the launch *** briefly summarize the history of ASO-S,the phase-B studies,and the phase-C studies.

关键词： Space astronomy Solar physics Spacecraft

Progress Report on ASO-S

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空间科学学报 2022年第4期42卷 565-567页

作者： gan Weiqun k.y Laboratory of Dark.Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023

The Advanced Space-based Solar Observatory(ASO-S)started officially its engineering phases at the beginning of *** the past two years from 2020 to 2022 ASO-S completed smoothly the Phase-C study and is now undertak.ng the Phase-D *** launch date is finally set in October of *** here briefly summarize the progress of ASO-S from the late Phase-C to the current Phase-D studies,and plan the scientific affairs around the launch.

关键词： Space astronomy Solar physics Spacecraft

The Structure of Vector Bundles on Non-primary Hopf Manifolds

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Chinese Annals of Mathematics,Series B 2020年第6期41卷 929-938页

作者： Ning gan Xiangyu ZHOU School of Sciences Jimei Uni vers计yXiamen 361021FujianChina Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

Let X be a Hopf manifold with non-Abelian fundamental group and E be a holomorphic vector bundle over X,with trivial pull-back.to C^n-k..The authors show that there exists a line bundle L over X such that E■L has a nowhere vanishing *** is proved that in case dim(X)≥3,π*(E)is trivial if and only if E is filtrable by vector *** the structure theorem,the authors get the cohomology dimension of holomorphic bundle E over X with trivial pull-back.and the vanishing of Chern class of E.

关键词： Hopf manifolds Holomorphic vector bundles Exact sequence Cohomology Filtration Chern class

Space Solar Physics in China

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空间科学学报 2018年第5期38卷 662-664页

作者： gan Weiqun FAN Quanlin k.y Laboratory of Dark.Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of Sciences National Space Science Center Chinese Academy of Sciences

The activities of Chinese space solar physics in 2016–2018 can be divided into two categories: prestudy projects and mission-level projects. Both projects were undertak.n smoothly. Especially the ASO-S,after several years' promotion, finally got formal approval at the end of 2017. This paper describes in brief the status of all related projects.

关键词：物理太阳空间中国工程

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Recent development of thermoelectric nanofibers and their composites

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Journal of Materiomics 2023年第1期9卷 99-130页

作者： Yong X.gan Department of Mechanical Engineering California State Polytechnic University Pomona3801 W Temple AvenuePomonaCA 91768USA

This review deals with the recent development of thermoelectric(TE)nanofibers and their composite *** processing and manufacturing technologies for preparing nanofibers are ***,electrospinning,electrochemical oxidation,and liquid phase chemical deposition approaches are *** k.nds of TE nanofibers are introduced *** important inorganic and organic nanofibers including carbon-based nanofibers,conducting polymer-based nanofibers,and transition metal oxide-based nanofibers with significant thermoelectric responses are *** properties of some important nanofibers are *** applications of TE nanofibers for energy conversion,thermal imaging and temperature sensing are *** and concluding remark. are presented.

关键词： Thermoelectricity Nanofibers and composites Processing and manufacturing Energy conversion Thermal imaging Temperature sensing

Pervosk.te-type ***0.1Fe0.9O3-δ as Intermediate-Temperature Solid Oxide Fuel Cell Cathode

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Chinese Journal of Chemical Physics 2012年第5期25卷 605-608,I0004页

作者： Yun gan k.i Xie Department of Energy Materials School of Materials Science and EngineerinEHefei University ofTechnologyHefei 230009China

A cobalt-free perovsk.te-type Ba0.5Sr0.5A10.1Fe0.9O3-δ （BSAF） chemically studied as solid oxide fuel cell （SOFC） cathode. The ductivity, and electrode polarizations in symmetrical cell based is developed and electro- structures, electrical con- on mixed ion conducting electrolyte were investigated, respectively. The temperature dependence of conductivity of BSAF in air shows a typical semiconductor behavior with positive temperature coefficient up to 450℃ where the conductivity reaches 14.0 S/cm while above this temperature the negative temperature coefficient dominates the total conductivity. Electrochemical charac- terizations show desirable polarization resistance of BSAF cathode in a symmetric cell based on mixed ion conducting electrolyte at 650-700℃, A single SOFC with BSAF cathode shows OCV of 1.0 V and maximum output of 420 mW/cm2 at 700 ℃ with humidified hydrogen fuel and static air oxidant.

关键词： Solid oxide fuel cell Perovsk.te Cathode Cobalt-free Mixed ionic conductor

Progress Report on ASO-S: 2022–2024

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空间科学学报 2024年第4期44卷 687-689页

作者： gan Weiqun k.y Laboratory of Dark.Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023

The Advanced Space-based Solar Observatory(ASO-S)mark.d China's first comprehensive solar mission in *** upon the previous reports covering 2018-2020 and 2020-2022,we present here an update on the ASO-S made from 2022 to *** August 2022,ASO-S completed its Phase D study and was successfully launched on October 9,*** commissioning phase was carried out and concluded within the first nine months following the *** data and associated analysis software have been opened to the community and the research on the early ASO-S data has been well *** anticipate also the achievements in data research pertaining to ASO-S in the near future.

关键词： Space astronomy Solar physics Spacecraft