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Research and implementation on multi-dimension trust evaluation method with web service

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High Technology Letters 2011年第3期17卷 252-258页

作者： mao Hongyan qi Zhengwei Shanghai Key Laboratory of Trustworthy Computing East China Normal University Shanghai 200062 P.R. China School of Software Shanghai Jiao Tong University Shanghai 200030 P.R. China

Integrating with practical e-commerce application, this paper introduces a novel multi-dimension evaluation method to depict and calculate the trust values. The multi-dimension evaluation metrics include functional and nonfunctional properties and corresponding weights. The continuous measurement values and the Markov chain mechanism are adopted to compute the trust value and detect the malicious behaviors. The current evaluation has larger influence factor on the next transaction behavior. A trust model is implemented with web service which consists of publication, filtrating, calculating and storage center. It is easily extended and the user only defines each property and its weights according to specific requirements, then the trust values are got. In order to conveniently manage and avoid the dead-lock, some constraint rules are proposed. The results show that the method based on multi-dimension can reflect objectively the dynamic change of trust values.

关键词： multi-dimension measurement trusting model Markov chain mechanism web service

Evaluating the usage of fault localization in automated program repair:an empirical study

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Frontiers of Computer Science 2021年第1期15卷 53-67页

作者： Deheng YANG Yuhua qi Xiaoguang mao Yan LEI College of Computer National University of Defense TechnologyChangsha 410073China Laboratory of Software Engineering for Complex Systems Changsha 410073China Beijing Institute of Tracking and Communication Technology Beijing 100094China School of Big Data&Software Engineering Chongqing UniversityChongqing 400044China

Fault localization techniques are originally proposed to assist in manual debugging by generally producing a rank list of suspicious *** the increasing popularity of automated program repair,the fault localization techniques have been introduced to effectively reduce the search space of automated program *** developers who mainly focus on the rank information,current automated program repair has two strategies to use the fault localization information:suspiciousness-first algorithm(SFA)based on the suspiciousness accuracy and rank-first algorithm(RFA)relying on the rank ***,despite the fact that the two different usages are widely adopted by current automated program repair and may result in different repair results,little is known about the impacts of the two strategies on automated program *** this paper we empirically compare the performance of SFA and RFA in the context of automated program ***,we implement the two strategies and six well-studied fault localization techniques into four state-of-the-art automated program repair tools,and then use these tools to perform repair experiments on 60 real-world bugs from *** study presents a number of interesting findings:RFA outperforms SFA in 70.02%of cases when measured by the number of candidate patches generated before a valid patch is found(NCP),while SFA performs better in parallel repair and patch diversity;the performance of SFA can be improved by increasing the suspiciousness accuracy of fault localization techniques;finally,we use SimFix that deploys SFA to successfully repair four extra Defects4J bugs which cannot be repaired by SimFix originally using *** observations provide a new perspective for future research on the usage and improvement of fault localization in automated program repair.

关键词： automated program repair fault localization empirical study

A framework for cloned vehicle detection

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Frontiers of Computer Science 2020年第5期14卷 181-198页

作者： Minxi Li Jiali mao Xiaodong qi Cheqing Jin School of Data Science and Engineering East China Normal UniversityShanghai200062China

Rampant cloned vehicle offenses have caused great damage to transportation management as well as public safety and even the world *** necessitates an efficient detection mechanism to identify the vehicles with fake license plates accurately,and further explore the motives through discerning the behaviors of cloned *** ubiquitous inspection spots that deployed in the city have been collecting moving information of passing vehicles,which opens up a new opportunity for cloned vehicle *** detection methods cannot detect the cloned vehicle effectively due to that they use the fixed speed *** this paper,we propose a two-phase framework,called CVDF,to detect cloned vehicles and discriminate behavior patterns of vehicles that use the same plate *** the detection phase,cloned vehicles are identified based on speed thresholds extracted from historical trajectory and behavior abnormality analysis within the local *** the behavior analysis phase,consider the traces of vehicles that uses the same license plate will be mixed together,we aim to differentiate the trajectories through matching degree-based clustering and then extract frequent temporal behavior *** experimental results on the real-world data show that CVDF framework has high detection precision and could reveal cloned vehicles’behavior *** proposal provides a scientific basis for traffic management authority to solve the crime of cloned vehicle.

关键词： cloned vehicle detection object identification behavior pattern mining

Decentralized transceiver optimization for multi-relay aided multiuser MIMO networks

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Science China(Information Sciences) 2014年第8期57卷 18-30页

作者： SUN qi LI LiHua mao junLing State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications China Unicom Research Institute

In this paper,the decentralized transceivers and corresponding channel state information(CSI)signaling concepts are proposed for weighted sum rate(WSR)maximization,via linear downlink transceiver optimization in multi-relay aided multiuser multiple-input multiple-output(MIMO)*** decentralized algorithms are proposed with the local CSI requirements at the base station(BS)and the relay *** the first proposed algorithm,the generalized channel inversion precoding is used at the BS to avoid the second hop channel sharing requirements among the relay nodes,and decentralized transceiver optimization of the relay nodes and users are developed to maximize the WSR.A minimum mean square error(MMSE)-based enhanced method is proposed as *** further improve the performance,we provide a novel structure of the precoding matrix of the *** decentralized joint BS,relay and user transceiver optimization problem is formulated and ***,the CSI signaling and decentralized processing in the time division duplex(TDD)system are *** results show the effectiveness of the decentralized transceiver design compared to the existing algorithms.

关键词： decentralized relay multiuser transceiver optimization sum rate maximization

Effect of heavy metals on soil nematode communities in the vicinity of a metallurgical factory

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Journal of Environmental Sciences 2006年第2期18卷 323-328页

作者： LI qi JIANG Yong LIANG Wen-ju Key Laboratory of Terrestrial Ecological Process Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

The influence of Cu and Zn on soil nematode communities was examined along a pollution gradient with increasing distance from a metallurgical factory. Total and available heavy metal contents were used to study the effects of heavy metals on nematode abundance, trophic groups and ecological indices. The results demonstrated significant correlations between the number of total nematodes, bacterivores, plant-parasites and the total and available heavy metals. Bacterivores and plant-parasites were the dominant trophic groups. Significant differences in different sampling sites were found only in the number of bacterivores（P〈0.01）. The Shannon-Weaver diversity index（W）, trophic diversity index（TD）, evenness index（J＇） and dominance index（λ） were found to be sensitive to soil pH and C/N ratios. Significant correlations were found between the total nematodes （TNEM）, some genera （A crobeloides, Aphelenchoides, Cephalobus, Ditylenchus, Mesorhabditis, Tetylenchus and Tylenchus） and distance from the factory.

关键词： soil nematodes trophic groups ecological indices heavy metals metallurgical factory

Kinetic effects of nanosecond discharge on ignition delay time

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Chinese Journal of Chemical Engineering 2016年第12期24卷 1719-1727页

作者： Xingqian mao Guoxiu Li qi Chen Yujun Zhao School of Mechanical Electronic and Control Engineering Beijing Jiaotong University

The effects of nanosecond discharge on ignition characteristics of a stoichiometric methane–air mixture without inert diluent gas were studied by numerical simulation at 0.1 MPa and an initial temperature of 1300 K. A modified non-equilibrium plasma kinetic model was developed to simulate the temporal evolution of particles produced during nanosecond discharge and its afterglow. As important roles in ignition, path fluxes of O and H radicals were analyzed in detail. Different strength of E/N and different discharge duration were applied to the discharge process in this study. And the results presented that a deposited energy of 1–30 m J·cm^(-3) could dramatically reduce the ignition delay time. Furthermore, temperature and radicals analysis was conducted to investigate the effect of non-equilibrium plasma on production of intermediate radicals. Finally, sensitivity analysis was employed to have further understanding on ignition chemistries of the mixture under nanosecond discharge.

关键词： Nanosecond discharge Ignition delay time Methane Kinetic modeling Numerical simulation

Investigation on plume interference effect of solid propellant micro-thruster

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航空动力学报 2011年第9期26卷 2027-2031页

作者： ZHANG Bin mao Gen-wang HU Song-qi CHEN mao-lin （National Key Laboratory of Combustion Flow and Thermo-Structure College of Astronautics Northwestern Polytechnical University Xi＇an 710072 China

The three-dimensional numerical simulation of two-phase plume flow of solid propellant micro-thrusters was *** it was used to investigate the plume interference effect by combining the direct simulation Monte Carlo(DSMC) method for multi-component gas flow with the two-way coupling model for two-phase rarefied *** different space between the two micro-thrusters and different wall temperature,the plume interference effect was analyzed *** results show that under the plume interference effect the gas is compressed and the flow direction is changed,which resulted in the increasing of gas pressure and temperature;solid phase made no significant effect on the flow parameters of gas phase;with the rising of the space between the two micro-thrusters,the maximum pressure decreased and the maximum temperature increased in the domain under the plume interference effect;the wall temperature could influence the temperature of the gas which is extremely close to the wall,but not the gas pressure.

关键词： solid propellant micro-thruster plume interference effect two-phase plume flow catalytic decomposition specific impulse

Optimizing Non-Decomposable Evaluation Metrics for NeuralMachine Translation

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Journal of Computer Science & Technology 2017年第4期32卷 796-804页

作者： Shi-qi Shen Yang Liu mao-Song Sun Department of Computer Science and Technology Tsinghua University Beijing 100084 China State Key Laboratory of Intelligent Technology and Systems Tsinghua University Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China Jiangsu Collaborative Innovation Center for Language Ability Jiangsu Normal University Xuzhou 221009 China

While optimizing model parameters with respect to evaluation metrics has recently proven to benefit end to-end neural machine translation (NMT), the evaluation metrics used in the training are restricted to be defined at the sentence level to facilitate online learning algorithms. This is undesirable because the final evaluation metrics used in the testing phase are usually non-decomposable (i.e., they are defined at the corpus level and cannot be expressed as the sum of sentence-level metrics). To minimize the discrepancy between the training and the testing, we propose to extend the minimum risk training (MRT) algorithm to take non-decomposable corpus-level evaluation metrics into consideration while still keeping the advantages of online training. This can be done by calculating corpus-level evaluation metrics on a subset of training data at each step in online training. Experiments on Chinese-English and English-French translation show that our approach improves the correlation between training and testing and significantly outperforms the MRT algorithm using decomposable evaluation metrics.

关键词： neural machine translation training criterion non-decomposable evaluation metric

Graphene-wrapped multiloculated nickel ferrite:A highly efficient electromagnetic attenuation material for microwave absorbing and green shielding

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Nano Research 2022年第7期15卷 6751-6760页

作者： Yuchang Wang Lihua Yao qi Zheng mao-Sheng Cao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China School of Mechatronical Engineering Shanxi Datong UniversityDatong 037003China

Dedicating to the exploration of efficient electromagnetic(EM)absorption and electromagnetic interference(EMI)shielding materials is the main strategy to solve the EM radiation *** development of multifunction EM attenuation materials that are compatible together EM absorption and EMI shielding properties is deserved our exploration and ***,the graphenewrapped multiloculated NiFe_(2)O_(4) composites are reported as multifunction EM absorbing and EMI shielding *** conductive networks configurated by the overlapping flexible graphene promote the riched polarization genes,as well as electron transmission paths,and thus optimize the dielectric constant of the ***,the introduction of magnetic NiFe_(2)O_(4) further establishes the magnetic-dielectric synergy *** abundant non-homogeneous interfaces not only generate effective interfacial polarization,also the deliberate multiloculated structure of NiFe_(2)O_(4) strengthens multi-scattering and multi-reflection sites to expand the transmission path of EM *** it turns out,the best impedance matching is matched at a lower filled concentration to achieve the strongest reflection loss value of−48.1 ***,green EMI shielding based on a predominantly EM absorption and dissipation is achieved by an enlargement of the filled concentration,which is helpful to reduce the secondary EM wave reflection pollution to the *** addition,the electrocatalytic properties are further *** graphene-wrapped multiloculated NiFe_(2)O_(4) shows the well electrocatalytic activity as electrocatalysts for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),which is mainly attributed to the interconnected structures formed by graphene and NiFe_(2)O_(4) *** structural advantages of multiloculated NiFe_(2)O_(4) expose more active sites,which plays an important role in optimizing catalytic *** work provides an excellent jumping-off point

关键词： electromagnetic absorbing green electromagnetic shielding multifunction electromagnetic attenuation material graphenewrapped multiloculated Fe_(2)O_(4) oxygen evolution reaction hydrogen evolution reaction