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Transfer film effects induced by 3D-printed polyether-ether-ketone with excellent tribological properties for joint prosthesis

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Bio-Design and manufacturing 2024年第1期7卷 43-56页

作者： Yang Li Jibao Zheng Changning Sun Dichen Li State Key Laboratory for manufacturing system Engineering School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710054China National Medical Products Administration(NMPA)Key Laboratory for Research and Evaluation of Additive manufacturing Medical Devices Xi’an Jiaotong UniversityXi’an 710054China

Based on the building principle of additive manufacturing,printing orientation mainly determines the tribological properties of joint *** this study,we created a polyether-ether-ketone(PEEK)joint prosthesis using fused filament fabrication and investigated the effects of printing orientation on its tribological properties using a pin-on-plate tribometer in 25% newborn calf *** ultrahigh molecular weight polyethylene transfer film is formed on the surface of PEEK due to the mechanical capture of wear debris by the 3D-printed groove morphology,which is significantly impacted by the printing orientation of *** the printing orientation was parallel to the sliding direction of friction,the number and size of the transfer film increased due to higher steady *** transfer film protected the matrix and reduced the friction coefficient and wear rate of friction pairs by 39.13%and 74.33%,***,our findings provide a novel perspective regarding the role of printing orientation in designing knee prostheses,facilitating its practical applications.

关键词： 3D printing orientation Transfer film Tribological properties Polyether-ether-ketone Knee prosthesis

A Tutorial on Quantized Feedback Control

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 5-17页

作者： Minyue Fu IEEE the School of system Design and Intelligent manufacturing Shenzhen Key Laboratory of Control Theory and Intelligent Systems and Centre for Control Science and TechnologySouthern University of Science and TechnologyShenzhen 518055China

In this tutorial paper, we explore the field of quantized feedback control, which has gained significant attention due to the growing prevalence of networked control systems. These systems require the transmission of feedback information, such as measurements and control signals, over digital networks, presenting novel challenges in estimation and control design. Our examination encompasses various topics, including the minimal information needed for effective feedback control, the design of quantizers, strategies for quantized control design and estimation,achieving consensus control with quantized data, and the pursuit of high-precision tracking using quantized measurements.

关键词： Consensus control high-precision control networked control quantized estimation quantized feedback control robust control

The Rising Burden of Hepatocellular Carcinoma: Is the Gender Gap Narrowing?

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Journal of Clinical and Translational Hepatology 2024年第9期12卷 763-764页

作者： James K.H.Ho Prem H.Thurairajah Daniel Q.Huang Kristie H.Fan division of Gastroenterology and Hepatology National University HospitalNational University Health SystemSingaporeSingapore

Dear Editors,The landscape of hepatocellular carcinoma(HCC)is continuously *** global trends indicate a significant shift in the epidemiology of HCC from viral-related to non-viral-related ***-associated fatty liver disease has emerged as the fastest-growing contributor to HCC in recent years,due to the increased prevalence of obesity and metabolic risk factors.

关键词： Carcinoma epidemiology obesity

MEMS Huygens Clock Based on Synchronized Micromechanical Resonators

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Engineering 2024年第5期36卷 124-131页

作者： Xueyong Wei Mingke Xu Qiqi Yang Liu Xu a Yonghong Qi Ziming Ren Juan Ren Ronghua Huan Zhuangde Jiang State Key Laboratory for manufacturing system Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Construction Machinery Chang’an UniversityXi’an 710064China Department of Mechanics Zhejiang UniversityHangzhou 310027China

With the continuous miniaturization of electronic devices,microelectromechanical system(MEMS)oscillators that can be combined with integrated circuits have attracted increasing *** study reports a MEMS Huygens clock based on the synchronization principle,comprising two synchronized MEMS oscillators and a frequency compensation *** MEMS Huygens clock improved shorttime stability,improving the Allan deviation by a factor of 3.73 from 19.3 to 5.17 ppb at 1 s.A frequency compensation system based on the MEMS oscillator’s temperature-frequency characteristics was developed to compensate for the frequency shift of the MEMS Huygens clock by controlling the resonator *** effectively improved the long-term stability of the oscillator,with the Allan deviation improving by 1.6343105 times to 30.9 ppt at 6000 *** power consumption for compensating both oscillators simultaneously is only 2.85 mW·℃^(-1).Our comprehensive solution scheme provides a novel and precise engineering solution for achieving high-precision MEMS oscillators and extends synchronization applications in MEMS.

关键词： Frequency stability Huygens clock MEMS Oscillator Synchronization

Research on Digital Twin system Platform Framework and Key Technologies of Unmanned Ground Equipment

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Complex system Modeling and Simulation 2024年第2期4卷 109-123页

作者： Kunyu Wang Lin Zhang Cheng Xu Han Lu Zhen Chen Hongbo Cheng Rui Guo the School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China the State Key Laboratory of Intelligent manufacturing system Technology Beijing 100854China the Beijing Institute of Electronic system Engineering Beijing 100854China

As an emerging technology,digital twin is expected to bring novel application modes to the whole life cycle process of unmanned ground equipment,including research and development,design,control optimization,operation and maintenance,*** highly dynamic,complex,and uncertain characteristics of unmanned ground equipment and the battlefield environment also pose new challenges for digital twin *** from the new challenges faced by the digital twin of unmanned ground equipment,this paper designs a service-oriented cloud-edge-end collaborative platform architecture of the digital twin system of unmanned ground equipment,and further analyzes several key technologies supporting the implementation of the platform architecture.

关键词： unmanned ground equipment digital twin native cloud platform Modeling and Simulation(M&S) artificial intelligence

Efficient Route Planning for Real-Time Demand-Responsive Transit

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Computers, Materials & Continua 2024年第4期79卷 473-492页

作者： Hongle Li SeongKi Kim Development Department Changseol Build SystemDaegu42601South Korea division of Software Convergence Sangmyung UniversitySeoul03016South Korea

Demand Responsive Transit (DRT) responds to the dynamic users’ requests without any fixed routes and timetablesand determines the stop and the start according to the demands. This study explores the optimization of dynamicvehicle scheduling and real-time route planning in urban public transportation systems, with a focus on busservices. It addresses the limitations of current shared mobility routing algorithms, which are primarily designedfor simpler, single origin/destination scenarios, and do not meet the complex demands of bus transit systems. Theresearch introduces an route planning algorithm designed to dynamically accommodate passenger travel needsand enable real-time route modifications. Unlike traditional methods, this algorithm leverages a queue-based,multi-objective heuristic A∗ approach, offering a solution to the inflexibility and limited coverage of suburbanbus routes. Also, this study conducts a comparative analysis of the proposed algorithm with solutions based onGenetic Algorithm (GA) and Ant Colony Optimization Algorithm (ACO), focusing on calculation time, routelength, passenger waiting time, boarding time, and detour rate. The findings demonstrate that the proposedalgorithmsignificantly enhances route planning speed, achieving an 80–100-fold increase in efficiency over existingmodels, thereby supporting the real-time demands of Demand-Responsive Transportation (DRT) systems. Thestudy concludes that this algorithm not only optimizes route planning in bus transit but also presents a scalablesolution for improving urban mobility.

关键词： Autonomous bus route planning real-time dynamic route planning path finding DRT bus route optimization sustainable public transport

Data-driven Wasserstein distributionally robust chance-constrained optimization for crude oil scheduling under uncertainty

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Chinese Journal of Chemical Engineering 2024年第5期69卷 152-166页

作者： Xin Dai Liang Zhao Renchu He Wenli Du Weimin Zhong Zhi Li Feng Qian Key Laboratory of Smart manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China Engineering Research Center of Process system Engineering Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

Crude oil scheduling optimization is an effective method to enhance the economic benefits of oil *** uncertainties,including uncertain demands of crude distillation units(CDUs),might make the production plans made by the traditional deterministic optimization models infeasible.A data-driven Wasserstein distributionally robust chance-constrained(WDRCC)optimization approach is proposed in this paper to deal with demand uncertainty in crude oil ***,a new deterministic crude oil scheduling optimization model is developed as the basis of this *** Wasserstein distance is then used to build ambiguity sets from historical data to describe the possible realizations of probability distributions of uncertain demands.A cross-validation method is advanced to choose suitable radii for these ambiguity *** deterministic model is reformulated as a WDRCC optimization model for crude oil scheduling to guarantee the demand constraints hold with a desired high probability even in the worst situation in ambiguity *** proposed WDRCC model is transferred into an equivalent conditional value-at-risk representation and further derived as a mixed-integer nonlinear programming *** case studies from a real-world refinery are conducted to show the effectiveness of the proposed ***-of-sample tests demonstrate that the solution of the WDRCC model is more robust than those of the deterministic model and the chance-constrained model.

关键词： Distributions Model Optimization Crude oil scheduling Wasserstein distance Distributionally robust chance constraints

A simple fabrication method of germanium-based metasurfaces

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Chinese Optics Letters 2024年第7期22卷 117-120页

作者： Dongzhi Shan Jinsong Gao Nianxi Xu Naitao Song Hongda Wei Qiang Li Yi Zhao Hai Liu Qiao Sun Xiaonan Jiang Chao Li Zhiyu Zhang Key Laboratory of Optical system Advanced manufacturing Technology Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Jilin Provincial Key Laboratory of Advanced Optoelectronic Equipment and Instrument manufacturing Technology Changchun 130033China

In this work,a simple fabrication method of germanium-based metasurfaces is proposed,where the deposited Al_(2)O_(3) layer with high selectivity is chosen as the hard mask and retained after the dry etching *** simulation and experimental characterization results verify the feasibility of the fabrication *** experimental study on the fabrication methods of germanium-based metasurfaces is very significant as the meta-atoms with a higher refractive index can achieve 0 to 2πtransmission phase variation with a smaller period under the same thickness-to-period ratio,which is consistent with the requirement of the period miniaturization in some cases.

关键词： metasurfaces period miniaturization refractive index.

Regularized automatic frequency response function acquisition of a milling robot operating in a high-dimensional workspace

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Science China(Technological Sciences) 2024年第6期67卷 1783-1797页

作者： LUO WenLong TANG XiaoWei MA Tao GUO QiuShuang XU YanYan YUAN Xing ZHANG Lei MAO XinYong School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Smart manufacturing for Special Vehicles and Transmission system Baotou014030China Wuhan Heavy Duty Machine Tool Group Corporation Wuhan430205China

Because robotic milling has become an important means for machining significant large parts,obtaining the structural frequency response function(FRF)of a milling robot is an important basis for machining process ***,because of its articulated serial structure,a milling robot has an enormous number of operating postures,and its dynamics are affected by the motion *** accurately obtain the FRF in the operating state of a milling robot,this paper proposes a method based on the structural modification *** the traditional excitation method,the proposed method uses robot joint motion excitation instead of hammering excitation to realize *** address the problem of the lack of information brought by motion excitation,which leads to inaccurate FRF amplitudes,this paper derives the milling robot regularization theory based on the sensitivity of structural modification,establishes the modal regularization factor,and calibrates the FRF *** to the commonly used manual hammering experiments,the proposed method has high accuracy and reliability when the milling robot is in different *** the measurement can be performed directly and automatically in the operation state,and the problem of inaccurate amplitudes is solved,the proposed method provides a basis for optimizing the machining posture of a milling robot and improving machining efficiency.

关键词： milling robot structural dynamics frequency response function automatic identification modal regularization factor high-dimensional workspace