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Coordinating EV Charging via Blockchain

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Journal of Modern Power Systems and Clean Energy 2020年第3期8卷 573-581页

作者： jian Ping zheng Yan Sijie chen Liangzhong yao Minhui Qian Department of Electrical Engineering School of Electronics Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghaiChina School of Electrical Engineering and Automation Wuhan UniversityWuhanChina China Electric Power Research Institute BeijingChina

The increasing electric vehicle(EV) penetration in a distribution network triggers the need for EV charging coordination. This paper firstly proposes a hierarchical EV charging coordination model and an algorithm based on Lagrangian relaxation. A barrier to the implementation of the coordination algorithm is that there usually does not exist a reliable coordinator of charging stations. This paper shows that an unreliable coordinator may collude with some charging stations and behave dishonestly by disobeying the coordination algorithm. Thus, the collusion coalition can gain more profits while lowering the profits of others and the total social welfare. To provide reliable coordination of charging stations, a novel blockchain-based coordination platform via Ethereum is established, including a coordination structure and a smart contract. A mathematical analysis is given to show that the proposed platform can mitigate the collusion behaviors in the coordination. Simulation results show the consequence of collusion and how blockchain can prevent the collusion.

关键词： Electric vehicle(EV)charging coordination collusion blockchain smart contract

Preparation of Surfactant-Free Pt and PtRu Nanoparticles with High Activity for Methanol Oxidation

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Chinese Journal of Chemical Physics 2014年第3期27卷 332-336页

作者： yao yao jun Cai Yong-li zheng Yan-xia chen Hefei National Laboratory for Physical Sciences at the Microscale Department of Chemical PhysicsUniversity of Science and Technology of China Hefei 230025 China

A simple and green approach to synthesize highly active electro-catalysts for methanol oxi- dation reaction （MOR） without using any organic agents is described. Pt nanoparticles are directly deposited on the pre-cleaned and pre-oxidized multiwall carbon nanotubes （MWC- NTs） from Pt salt by using CO as the reductant. MOR activity has been characterized by both cyclic voltammetry and chronoamperometry, the current density and mass specific current at the peak potential （ca. 0.9 V vs. RHE） reaches 11.6 mA/cm^2 and 860 mA/mgpt, respectively. After electro-deposition of Ru onto the Pt/MWCNTs surface, the catalysts show steady state mass specific current of 20 and 80 mA/mgpt at 0.5 and 0.6 V, respectively.

关键词： Pt nano-electrocatalyst PtRu nano-electrocatalyst Green synthesis Methanol oxidation reaction Carbon monoxide

Automated detection and identification of white-backed planthoppers in paddy fields using image processing

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维普期刊数据库

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Journal of Integrative Agriculture 2017年第7期16卷 1547-1557页

作者： yao Qing chen Guo-te WANG zheng ZHANG Chao YANG Bao-jun TANG jian School of Information Science and Technology Zhejiang Sci-Tech University State Key Laboratory of Rice Biology China National Rice Research Institute

A survey of the population densities of rice planthoppers is important for forecasting decisions and efficient control. Tra- ditional manual surveying of rice planthoppers is time-consuming, fatiguing, and subjective. A new three-layer detection method was proposed to detect and identify white-backed planthoppers （WBPHs, Sogatella furcifera （Horvath）） and their developmental stages using image processing. In the first two detection layers, we used an AdaBoost classifier that was trained on a histogram of oriented gradient （HOG） features and a support vector machine （SVM） classifier that was trained on Gabor and Local Binary Pattern （LBP） features to detect WBPHs and remove impurities. We achieved a detection rate of 85.6% and a false detection rate of 10.2%. In the third detection layer, a SVM classifier that was trained on the HOG features was used to identify the different developmental stages of the WBPHs, and we achieved an identification rate of 73.1%, a false identification rate of 23.3%, and a 5.6% false detection rate for the images without WBPHs. The proposed three-layer detection method is feasible and effective for the identification of different developmental stages of planthoppers on rice plants in paddy fields.

关键词： white-backed planthopper developmental stage automated detection and identification image processing histogram of oriented gradient features gabor features local binary pattern features

A Numerical Investigation of the Reduction of Solitary Wave Runup by A Row of Vertical Slotted Piles

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China Ocean Engineering 2020年第1期34卷 10-20页

作者： yao Yu JIA Mei-jun MAO Da-wei DENG zheng-zhi LIU Xiao-jian School of Hydraulic Engineering Changsha University of Science and TechnologyChangsha410114China Hunan Provincial Key Laboratory of Key Technology on Hydropower Development Changsha 410014China Ocean College Zhejiang UniversityZhoushan 316021China Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province Changsha 410114China

To improve the current understanding of the reduction of tsunami-like solitary wave runup by the pile breakwater on a sloping beach, we developed a 3D numerical wave tank based on the CFD tool OpenFOAM in this study. The Navier Stokes equations were applied to solve the two-phase incompressible flow, combined with an LES model to solve the turbulence and a VOF method to capture the free surface. The adopted model was firstly validated with existing empirical formulas for solitary wave runup on the slope without the pile structure. It is then validated using our new laboratory observations of the free surface elevation, the velocity and the pressure around a row of vertical slotted piles subjected to solitary waves, as well as the wave runup on the slope behind the piles. Subsequently, a set of numerical simulations were implemented to analyze the wave reflection, the wave transmission, and the shoreline runup with various offshore wave heights, offshore water depths, adjacent pile spaces and beach slopes. Finally, an improved empirical equation accounting for the maximum wave runup on the slope was proposed by taking the presence of the pile breakwater into consideration.

关键词： Wave runup solitary wave slotted piles Navier Stokes equations

Developing a Subjective Evaluation Scale for Assessing the Built Environments of China’s Hygienic City Initiative

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Biomedical and Environmental Sciences 2021年第5期34卷 372-378页

作者： zheng Wen Jing yao Hong Yan LIU jian jun YU Shi cheng Office of Epidemiology Chinese Center for Disease Control and PreventionBeijing 102206China Chinese Center for Disease Control and Prevention Beijing 102206China

Objective To develop a preliminary subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative and to evaluate its reliability and *** The initial items of the scale were determined based on a review of policy documents and consultations with experts. The final items of the scale were confirmed through individual interviews with residents combined with the discretetrend method, critical ratio method, correlation coefficient method, and factor analysis method. Then, the dimensions of the scale were determined using exploratory factor analysis(EFA). The Cronbach’s α coefficient, split-half reliability coefficient, and confirmatory factor analysis(CFA) were used to assess the reliability and validity of the *** A scale containing five dimensions with 22 items was established, including urban lifestyle,governance, basic functions, environmental sanitation, and amenities. The Cronbach’s α coefficient of the scale was 0.876, and the split-half reliability coefficient was 0.796. The CFA results indicate that each inspection level was within the standard *** The preliminarily subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative demonstrates a high level of reliability and validity. Additional empirical studies should be carried out to further verify the value of the scale in terms of practical application.

关键词： Subjective built environment China’s Hygienic City Reliability and validity Scale

A new data normalization method for unsupervised anomaly intrusion detection

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第10期11卷 778-784页

作者： Long-zheng CAI jian chen Yun KE yao chen Zhi-gang LI Engineering and Commerce College South-Central University for Nationalities Wuhan 430065 China Guangdong Institute of Science and Technology Zhuhai 519090 China

Unsupervised anomaly detection can detect attacks without the need for clean or labeled training *** paper studies the application of clustering to unsupervised anomaly detection(ACUAD).Data records are mapped to a feature *** are detected by determining which points lie in the sparse regions of the feature space.A critical element for this method to be effective is the definition of the distance function between data *** propose a unified normalization distance framework for records with numeric and nominal features mixed data.A heuristic method that computes the distance for nominal features is proposed,taking advantage of an important characteristic of nominal features-their probability ***,robust methods are proposed for mapping numeric features and computing their distance,these being able to tolerate the impact of the value difference in scale and diversification among features,and outliers introduced by *** experiments with the KDD 1999 dataset showed that ACUAD can detect intrusions with relatively low false alarm rates compared with other approaches.

关键词： Unsupervised anomaly detection Data mining Intrusion detection Network security

Adaptive robust control of mobile satellite communication system with disturbance and model uncertainties

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Journal of Systems Engineering and Electronics 2012年第5期23卷 761-767页

作者： jun jiang jian Guo Bin yao Qingwei chen School of Automation Nanjing University of Science and Technology Nanjing 210094 E R. China School of Mechanical Engineering Purdue University West Lafayette IN 47907 USA

The tracking and stable control of a typical shipmounted mobile satellite communication system（MSCS） is *** the former studies based on simplified single-axis models,a tri-axis nonlinear model including the kinematic and dynamic features of the MSCS is used as the control *** adaptive robust controller with trajectory planning is designed to deal with large parametric uncertainties and uncertain nonlinearities of the system.A theoretic performance result is given and *** designed adaptive robust controller and other two traditional controllers are tested in the comparative simulations under three different *** simulation results show the tracking and stable validity of the proposed controller.

关键词： ship-mounted mobile satellite communication system adaptive control robust control tracking control

Nonreciprocity of energy transfer in a nonlinear asymmetric oscillator system with various vibration states

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Applied Mathematics and Mechanics(English Edition) 2023年第5期44卷 727-744页

作者： jian’en chen jianling LI Minghui yao jun LIU jianhua ZHANG Min SUN Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China School of Aeronautics and Astronautics Tiangong UniversityTianjin 300387China Agricultural Information Institute of Chinese Academy of Agricultural Sciences Key Laboratory of Agricultural Big DataMinistry of Agriculture and Rural AffairsBeijing 100081China School of Science Tianjin Chengjian UniversityTianjin 300384China

The nonreciprocity of energy transfer is constructed in a nonlinear asymmetric oscillator system that comprises two nonlinear oscillators with different parameters placed between two identical linear *** slow-flow equation of the system is derived by the complexification-averaging *** semi-analytical solutions to this equation are obtained by the least squares method,which are compared with the numerical solutions obtained by the Runge-Kutta *** distribution of the average energy in the system is studied under periodic and chaotic vibration states,and the energy transfer along two opposite directions is *** effect of the excitation amplitude on the nonreciprocity of the system producing the periodic responses is analyzed,where a three-stage energy transfer phenomenon is *** the first stage,the energy transfer along the two opposite directions is approximately equal,whereas in the second stage,the asymmetric energy transfer is *** energy transfer is also asymmetric in the third stage,but the direction is reversed compared with the second ***,the excitation amplitude for exciting the bifurcation also shows an asymmetric *** vibrations are generated around the resonant frequency,irrespective of which linear oscillator is *** excitation threshold of these chaotic vibrations is dependent on the linear oscillator that is being *** addition,the difference between the energy transfer in the two opposite directions is used to further analyze the nonreciprocity in the *** results show that the nonreciprocity significantly depends on the excitation frequency and the excitation amplitude.

关键词： nonreciprocity strong nonlinearity energy transfer chaotic vibration higher branch of response

Unsteady simulation for a high-speed train entering a tunnel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第12期12卷 957-963页

作者： Xin-hua LI jian DENG Da-wei chen Fang-fang XIE yao zheng School of Aeronautics and Astronautics Zhejiang University Hangzhou 310027 China National Engineering Laboratory for System Integration of High-Speed Train （South） CSR Qingdao Sifang Co. Ltd Qingdao 266111 China

In order to study the unsteady aerodynamics effects in railway tunnels,the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved,and the two-equation k-ε model is used in the simulation of turbulence,while the dynamic grid technique is employed for moving *** focus on obtaining the changing tendencies of the aerodynamic force of the train and the aerodynamic pressures on the tunnel wall and train surface,and discovering the relationship between the velocity of the train and the intensity of the micro pressure wave at the tunnel *** is shown that the amplitudes of the pressure changes in the tunnel and on the train surface are both approximately proportional to the square of the train speed,so are the microwave and the drag of the train.

关键词： High-speed train Aerodynamics Railway tunnel Numerical analysis