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A Location Algorithm with Improved Accuracy Based on Correction of Noise High-Order Cumulant

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Chinese Journal of Electronics 2017年第1期26卷 179-184页

作者： wang jianhui LU Zhiyu wang Jialiang PLA Information Engineering University China National Software & Service Co. Ltd.

The Non-line-of-sight(NLOS) error is the key issue for mobile user location in cellular wireless communication system. In this paper, we propose a robust and accurate approach using biased Kalman filter based on third-order cumulant to mitigate the NLOS error. The simulation results indicate that with less prior information about communication environments, the approach we present has a better location performance even in severe NLOS situations.

关键词： Location Non-line-of-sight(NLOS) Third-order cumulant Skewness

Feasibility study of a large-scale tuned mass damper with eddy current damping mechanism

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Earthquake Engineering and Engineering Vibration 2012年第3期11卷 391-401页

作者： wang Zhihao Chen Zhengqing wang jianhui Wind Engineering Research Center Hunan UniversityChangsha 410082China School of Civil Engineering and Communication North China University of Water Resources and Electric PowerZhengzhou 450011China

Tuned mass dampers （TMDs） have been widely used in recent years to mitigate structural vibration. However, the damping mechanisms employed in the TMDs are mostly based on viscous dampers, which have several well-known disadvantages, such as oil leakage and difficult adjustment of damping ratio for an operating TMD. Alternatively, eddy current damping （ECD） that does not require any contact with the main structure is a potential solution. This paper discusses the design, analysis, manufacture and testing of a large-scale horizontal TMD based on ECD. First, the theoretical model of ECD is formulated, then one large-scale horizontal TMD using ECD is constructed, and finally performance tests of the TMD are conducted. The test results show that the proposed TMD has a very low intrinsic damping ratio, while the damping ratio due to ECD is the dominant damping source, which can be as large as 15% in a proper configuration. In addition, the damping ratios estimated with the theoretical model are roughly consistent with those identified from the test results, and the source of this error is investigated. Moreover, it is demonstrated that the damping ratio in the proposed TMD can be easily adjusted by varying the air gap between permanent magnets and conductive plates. In view of practical applications, possible improvements and feasibility considerations for the proposed TMD are then discussed. It is confirmed that the proposed TMD with ECD is reliable and feasible for use in structural vibration control.

关键词： tuned mass damper eddy current damping permanent magnets conductive plate modal damping ratio

Research on semi-active control method of a building structure based on non-smooth control

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Earthquake Engineering and Engineering Vibration 2019年第2期18卷 425-432页

作者： wang Qing wang jianhui Ma Kemao School of Mechanical and Electric Engineering Guangzhou University School of Astronautics Harbin Institute of Technology

This study investigates the effectiveness of the non-smooth semi-active control algorithm on suppressing the vibration performance of a building structure subjected to seismic waves. According to the Lyapunov stability theory, it has bene proven that the non-smooth semi-active control algorithm can achieve a finite-time stability of the vibration relative to the isolation layer of a building structure. Through numerical simulation of two buildings with different parameters subjected to the input of a seismic wave, the vibration conditions of passive control, LQR semi-active control and non-smooth semiactive control are compared and analyzed. The simulation results show that the non-smooth semi-active control algorithm has a better robustness and effectiveness in restraining the impact of earthquakes on the structure.

关键词： building structure isolation layer semi-active control non-smooth control vibration

In-situ construction of high-mechanical-strength and fast-ion-conductivity interphase for anode-free Li battery

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Journal of Energy Chemistry 2023年第5期80卷 207-214,I0006页

作者： Yangfan Lin Juner Chen Han Zhang jianhui wang Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province School of EngineeringWestlake UniversityHangzhou 310024ZhejiangChina Institute of Advanced Technology Westlake Institute for Advanced StudyHangzhou 310024ZhejiangChina Department of Chemistry Zhejiang UniversityHangzhou 310027ZhejiangChina

The solid electrolyte interphase(SEI)with strong mechanical strength and high ion conductivity is highly desired for Li metal batteries,especially for harsh anode-free ***,we report a pragmatic approach to the in-situ construction of high-quality SEI by applying synergistic additives of Li NO_(3)and ethylene sulfite(ES)in the *** obtained SEI exhibits a high average Young’s modulus(9.02GPa)and exchanging current density(4.59 mA cm^(-2)),which are 3.0 and 1.2 times as large as those using the sole additive of LiNO_(3),*** this improved SEI,Li-dendrite growth and side reactions are effectively suppressed,leading to an ultra-high Coulombic efficiency(CE)of 99.7%for Li plating and *** applying this improved electrolyte in full cells,it achieves a high capacity retention of 89.7%for over 150 cycles in a LiFePO_(4)||Li battery(~12 mg cm^(-2)cathode,50μm Li)and of 44.5%over 100 cycles in a LiFePO_(4)||Cu anode-free battery.

关键词： Anode-free Li battery Solid electrolyte interphase Additive Lithiu mnitrate Ethylene sulfite

VLSI Implementation of Area and Power Efficient Digital Control Circuit for HF RFID Tag Chip

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Chinese Journal of Electronics 2020年第1期29卷 82-88页

作者： wang Deming HU Jianguo wang jianhui DING Yanyu WU Jing School of Physics and Telecommunication Engineering South China Normal University Hong Kong Applied Science and Technology Research Institute Company Limited

A fully integrated area efficient digital control circuit based on the ISO/IEC 15693 protocol is proposed for high frequency RFID tag chip. The proposed circuit is mainly composed of pulse position modulation decoder, Manchester encoder, anticonllision, low power circuit and other control logic. It supports six different data rates, namely, low or high data rate with one subcarrier(6.62 or 26.48 Kbit/s), low or high data rate with two subcarriers(6.67 or 26.69 Kbit/s), fast data rate with one subcarrier(13.24 or 52.97 Kbit/s). The proposed digital control circuit was integrated in an RFID tag IC and was fabricated using a 0.18-μm 2 P6 M CMOS process with an area of 306μm by 326μm which is smaller than the existing designs. Besides of small area, the circuit has an advantage of low power with a power consumption of less than 50μW.

关键词： RFID Digital control circuit Low power VLSI

Large-scale branch contingency analysis through master/slave parallel computing

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Journal of Modern Power Systems and Clean Energy 2013年第2期1卷 159-166页

作者： Xi YANG Cong LIU jianhui wang Decision and Information Sciences Division of Argonne National Laboratory ArgonneIL 60439USA

Contingency analysis(CA)requires fast execution time for real-time power system *** CA problems can naturally be divided into separate subtasks,parallel computing helps to speed up the computation *** paper proposes a master/slave parallel computing architecture and studies the computation of CA in a large-scale power system through high performance computing,adopting a message passing interface for *** particular,although the execution time of CA varies,there is a tradeoff between having an imbalanced workload and"paying"a synchronization penalty for parallel computing:either factor blocks the progress of *** proposed layered dynamic scheduling method is effective to tackle the challenge of high synchronization cost and workload imbalance and have the potential to further scale for the N-2 contingency analysis.

关键词： Massive parallel computing Power system Contingency analysis

Performance of a quantum heat engine cycle working with harmonic oscillator systems

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Science China(Physics,Mechanics & Astronomy) 2007年第2期50卷 163-176页

作者： wang jianhui HE JiZhou MAO ZhiYuan Department of Physics Nanchang UniversityNanchang 330047China

A cycle model of an irreversible heat engine working with harmonic systems is established in this paper. Based on the equation of motion of an operator in the Heisenberg picture and semi-group approach, the first law of thermodynamics for a harmonic system and the time evolution of the system are obtained. The general expressions for several important parameters, such as the work, efficiency, power output, and rate of entropy production are derived. By means of numerical analysis, the optimally operating regions and the optimal values of performance parameters of the cycle are determined under the condition of maximum power output. At last, some special cases, such as high temperature limit and frictionless case, are dis-cussed in brief.

关键词： harmonic systems heat engine cycle irreversible thermodynamics performance optimization

A direct position determination method with combined TDOA and FDOA based on particle filter

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Chinese Journal of Aeronautics 2018年第1期31卷 161-168页

作者： Zhiyu LU Bin BA jianhui wang Wenchao LI Daming wang China National Digital Switching System Engineering & Technological R&D Cente Zhengzhou 450000 China Jiuquan Satellite Launch Center Jiuquan 735000 China

The localization of a stationary transmitter using moving receivers is considered. The original Direct Position Determination （DPD） methods, with combined Time Difference of Arrival （TDOA） and Frequency Difference of Arrival （FDOA）, do not perform well under low Signal-to-Noise Ratio （SNR）, and worse still, the computation cost is difficult to accept when the computational capabilities are limited. To get better positioning performance, we present a new DPD algorithm that proves to be more computationally efficient and more precise for weak signals than the conventional approach. The algorithm partitions the signal received with the same receiver into multiple non-overlapping short-time signal segments, and then uses the TDOA, the FDOA and the coherency among the short-time signals to locate the target. The fast maximum likelihood estimation, one iterative method based on particle filter, is designed to solve the problem of high computation load. A secondary but important result is a derivation of closed-form expressions of the Cramer-Rao Lower Bound （CRLB）. The simulation results show that the algorithm proposed in this paper outperforms the traditional DPD algorithms with more accurate results and higher computational efficiency, and especially at low SNR, it is more close to the CRLB.

关键词： Direct position determination Cramer-Rao lower bound Frequency difference of arrival Time difference of arrival Particle filter

Activating copper oxide for stable electrocatalytic ammonia oxidation reaction via in-situ introducing oxygen vacancies

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Nano Research 2022年第7期15卷 5987-5994页

作者： Jingjing Huang Zhe Chen Jinmeng Cai Yongzhen Jin Tao wang jianhui wang Department of Chemistry Zhejiang UniversityHangzhou 310027China Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province School of EngineeringWestlake UniversityHangzhou 310024China Institute of Advanced Technology Westlake Institute for Advanced StudyHangzhou 310024China Center of Artificial Photosynthesis for Solar Fuels School of ScienceWestlake UniversityHangzhou 310024China Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450001China School of Science Westlake Institute for Advanced StudyHangzhou 310024China

Electrocatalytic ammonia oxidation reaction(EAOR)provides an ideal solution for on-board hydrogen supply for fuel cells,while the lack of efficient and durable EAOR catalysts has been a long-standing obstacle for its practical ***,we reported that the defect engineering via in-situ electrochemically introducing oxygen vacancies(Vo)not only turns the inactive CuO into efficient EAOR catalyst but also achieves a high stability of over 400 h at a high current density of~200 mA·cm^(−2).Theoretical simulation reveals that the presence of Vo on the CuO surface induces a remarkable upshift of the d-band center of active Cu site closer to the Fermi level,which significantly stabilizes the reaction intermediates(*NHx)and efficiently oxidizes NH3 into *** Vo-modulated CuO shows a different catalytic mechanism from that on the conventional Pt-based catalysts,paving a new avenue to develop inexpensive,efficient,and robust catalysts,not limited to EAOR.

关键词： electrocatalysis ammonia oxidation reaction oxygen vacancy CuO stability