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Could social media reflect acquisitive crime patterns in London?

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Journal of Safety Science and Resilience 2022年第2期3卷 115-127页

作者： zenghui wang Yijing Li CIM Warwick UniversityCoventryCV47ALUK CUSP London King’s College LondonLondonWC2R 2LSUK

Embraced within the framework of crime opportunities integrated with Social Disorganization theory and Broken Windows theory,this paper intends to explore the patterns of four types of acquisitive crimes,using social media data,i.e.,Twitter,Foursquare and cross-sectional data acquired through text analysis *** Greater London as the study area,models like negative binominal regression(NBR)and geographically weighted regression(GWR)are performed to illustrate the aggregated relationships between acquisitive crimes and crime opportunities at London-wide and sub-regional MSOAs levels *** results work towards to hypotheses that:the tweets sentiment could reflect property-related crime rates positively in light of Broken Windows Theory;more tweets with negative sentiment may incur increases in acquisitive *** contributed to existing studies in(1)providing empirical evidence for integrating these three theories;(2)complementing current research on local discrepancies of acquisitive crimes by utilising both GWR and NBR models;(3)challenging the traditional stereotypes about racial disparities with the finding that ethnic heterogeneity and instrumental crimes have counterintuitive association,especially taking education factor into consideration;(4)implicating some localised acquisitive crime prevention strategies to policy makers in light of the reality that the relationship between local variations and different crime types may vary by place.

关键词： Crime opportunity Acquisitive crime Social disorganization Broken windows Twitter Foursquare Big data

A non-equilibrium molecular dynamics study of the thermal conductivity of uranium dioxide

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Nuclear Science and Techniques 2010年第1期21卷 39-43页

作者： wang zenghui HUANG Xiaofeng College of Physical Sciences Graduate University of Chinese Academy of Sciences Beijing 100049 China

The thermal conductivity of uranium dioxide in the temperature range of 300–2400 K was estimated by non-equilibrium molecular dynamics calculation using Fourier *** Kawamura function was adopted as the interatomic potential *** calculated thermal conductivities are found to be strongly dependent on the temperature of the simulation *** thermal conductivity simulation results are compared with the experiment results and agreed well with the experimental results when the temperature is above 600 *** thermal conductivities scale effects are found to be existed in uranium dioxide nanometer thin *** approximate mean free paths of phonons in different temperatures can be examined.

关键词：非平衡分子动力学二氧化铀热导率模拟计算温度范围温度依赖性傅里叶法仿真结果

Analyzing electrostatic modulation of signal transduction efficiency in MoS2 nanoelectromechanical resonators with interferometric readout

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Science China(Information Sciences) 2022年第2期65卷 218-224页

作者： Jiankai ZHU Pengcheng ZHANG Rui YANG zenghui wang Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong University

Optical interferometry is a highly sensitive method for detecting the miniscule resonant motion in two-dimensional（2D） nanoelectromechanical systems（NEMS）. However, the technique to control the interferometry signal strength has not been fully understood. In this work, we present analytical modeling of an effective method for tuning motion-to-signal responsivity in interferometric detection of 2D molybdenum disulfide（MoS2） NEMS resonators. We show that the responsivity can be tuned very efficiently, all the way from maximum to 0, by varying the vacuum gap underneath the 2D membrane electrostatically. We further show that the gate voltage corresponding to 0 responsivity, which means no motion signal can be detected,varies with the MoS2thickness, diameter, pre-strain, and initial vacuum gap. Our findings provide an important guideline for optimizing measurement conditions when detecting motion in 2D NEMS structures using laser interferometry.

关键词： MoS$_{2}$ 2D NEMS resonators laser interferometry responsivity

Application of grey model on analyzing the passive natural circulation residual heat removal system of HTR-10

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Nuclear Science and Techniques 2008年第5期19卷 308-313页

作者： ZHOU Tao PENG Changhong wang zenghui wang Ruosu School of Nuclear Science and Engineering North China Electricity Power University Beijing 102206 China Probabilistic Safety Assessment and Reliability Analysis Branch China Nuclear Power Technology Research Institute Shenzhen 518026 China College of Physical Sciences Graduate University of Chinese Academy of Sciences Beijing 100049 China

Using the grey correlation analysis,it can be concluded that the reactor pressure vessel wall temperature has the strongest effect on the passive residual heat removal system in HTR (High Temperature gas-cooled Reactor), the chimney height takes the second place,and the influence of inlet air temperature of the chimney is the *** conclusion is the same as that analyzed by the traditional *** to the grey model theory,the GM(1,1) and GM(1,3) model are built based on the inlet air temperature of chimney,pressure vessel temperature and the chimney *** the effect of three factors on the heat removal power is studied in this *** model plays an important role on data prediction,and is a new method for studying the heat removal *** method can provide a new theoretical analysis to the passive residual heat removal system of HTR.

关键词：核反应堆 HTR-10 剩余热去除系统灰色模型

Nanomechanics: emerging opportunities for future computing

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Science China(Information Sciences) 2021年第10期64卷 245-247页

作者： zenghui wang Jiawei FANG Pengcheng ZHANG Rui YANG Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong University

The exploration for greater computing power has existed for a long time. Since the 1960 s, transistors in modern electronic computers have kept advancing following Moore’s ***, as silicon transistors continue to scale down, they face challenges such as increases in OFF-state leakage power due to the limited subthreshold swing, incompatibility with high-temperature operation, and lack of ***, new types of computing devices are being explored to address these problems.

关键词： MEMS NEMS mechanical computing logic devices switches resonators

Proportion integral-type active disturbance rejection generalized predictive control for distillation process based on grey wolf optimization parameter tuning

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Chinese Journal of Chemical Engineering 2022年第9期35卷 234-244页

作者： Jia Ren Zengqiang Chen Mingwei Sun Qinglin Sun zenghui wang College of Artificial Intelligence Nankai UniversityTianjin 300350China Key Lab of Intelligent Robotics of Tianjin Tianjin 300350China Department of Electrical and Mining Engineering University of South AfricaFlorida 1710South Africa

The high-purity distillation column system is strongly nonlinear and coupled,which makes it difficult to *** disturbance rejection control(ADRC)has been widely used in distillation systems,but it has limitations in controlling distillation systems with large time delays since ADRC employs ESO and feedback control law to estimate the total disturbance of the system without considering the large time *** paper designs a proportion integral-type active disturbance rejection generalized predictive control(PI-ADRGPC)algorithm to control the distillation column system with large time *** replaces the PD controller in ADRC with a proportion integral-type generalized predictive control(PI-GPC),thereby improving the performance of control systems with large time *** the proposed controller has many parameters and is difficult to tune,this paper proposes to use the grey wolf optimization(GWO)to tune these parameters,whose structure can also be used by other intelligent optimization *** performance of GWO tuned PI-ADRGPC is compared with the control performance of GWO tuned ADRC method,multi-verse optimizer(MVO)tuned PI-ADRGPC and MVO tuned *** simulation results show that the proposed strategy can track reference well and has a good disturbance rejection performance.

关键词： Proportion integral-type active disturbance rejection generalized predictive control Grey wolf optimization Parameter tuning Distillation Process control Prediction

Multi-scale detector optimized for small target

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Optoelectronics Letters 2024年第4期20卷 243-248页

作者： ZHU Yongchang YANG Sen TONG Jigang wang zenghui School of Electrical Engineering and Automation Tianjin University of TechnologyTianjin 300384China Center of Artificial Intelligence and Data Science University of South AfricaFlorida 1709South Africa Department of Electrical Engineering University of South AfricaFlorida 1709South Africa

The effectiveness of deep learning networks in detecting small objects is limited,thereby posing challenges in addressing practical object detection *** this research,we propose a small object detection model that operates at multiple *** model incorporates a multi-level bidirectional pyramid structure,which integrates deep and shallow networks to simultaneously preserve intricate local details and augment global ***,a dedicated multi-scale detection head is integrated into the model,specifically designed to capture crucial information pertaining to small *** comprehensive experimentation,we have achieved promising results,wherein our proposed model exhibits a mean average precision(mAP)that surpasses that of the well-established you only look once version 7(YOLOv7)model by 1.1%.These findings validate the improved performance of our model in both conventional and small object detection scenarios.

关键词： networks details thereby

On-chip mechanical computing:status,challenges,and opportunities

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Chip 2023年第1期2卷 58-72页

作者： Luming wang Pengcheng Zhang Zuheng Liu zenghui wang Rui Yang Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China School of Electronic Information and Electrical En-gineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Electronic Thin Films and Integrated Devices University of Elec-tronic Science and Technology of ChinaChengdu 610054China

With increasing challenges towards continued scaling and improve-ment in performance faced by electronic computing,mechanical com-puting has started to attract growing *** advantage of the mechanical degree of freedom in solid state devices,micro/nano-electromechanical systems(MEMS/NEMS)could provide alternative solutions for future computing and memory systems with ultralow power consumption,compatibility with harsh environments,and high *** this review,MEMS/NEMS-enabled memories and logic processors were surveyed,and the prospects and challenges for future on-chip mechanical computing were also analyzed.

关键词： MEMS/NEMS switch MEMS/NEMS resonator Mechanical computing Mechanical memory Low-power computing

Nonlinear dynamics analysis of cluster-shaped conservative flows generated from a generalized thermostatted system

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Chinese Physics B 2022年第1期31卷 170-178页

作者： Yue Li Zengqiang Chen zenghui wang Shijian Cang College of Artificial Intelligence Nankai UniversityTianjin 300350China Department of Electrical and Mining Engineering University of South AfricaFlorida 1710South Africa Department of Product Design Tianjin University of Science and TechnologyTianjin 300222China

The thermostatted system is a conservative system different from Hamiltonian systems,and has attracted much attention because of its rich and different nonlinear *** report and analyze the multiple equilibria and curve axes of the cluster-shaped conservative flows generated from a generalized thermostatted *** is found that the cluster-shaped structure is reflected in the geometry of the Hamiltonian,such as isosurfaces and local centers,and the shapes of cluster-shaped chaotic flows and invariant tori rely on the isosurfaces determined by initial conditions,while the numbers of clusters are subject to the local centers solved by the Hessian matrix of the ***,the study shows that the cluster-shaped chaotic flows and invariant tori are chained together by curve axes,which are the segments of equilibrium curves of the generalized thermostatted ***,the interesting results are vividly demonstrated by the numerical simulations.

关键词： multiple equilibria curve axes invariant tori cluster-shaped conservative chaos