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Finite-time asynchronous dissipative filtering of conic-type nonlinear Markov jump systems

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Science China(Information Sciences) 2021年第5期64卷 151-162页

作者： Xiang ZHANG Shuping HE Vladimir STOJANOVIC Xiaoli LUAN Fei LIU Key Laboratory of Intelligent Computing and Signal Processing (Ministry of Education) School of Electrical Engineering and Automation Anhui University Department of Automatic Control Robotics and Fluid Technique Faculty of Mechanical and Civil EngineeringUniversity of Kragujevac Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education) Institute of AutomationJiangnan University

In the present study, the finite-time asynchronous dissipative filter design problem for the Markov jump systems with conic-type nonlinearity is studied. The hidden Markov model can describe the asynchronism embodied in the system modes and the filter modes reasonably. Moreover, a suitable LyapunovKrasovskii function is utilized and linear matrix inequalities are applied to obtain adequate conditions. These techniques guarantee the finite-time boundedness and strict dissipativity of the filtering error dynamic system. Furthermore, the design problems of the passive filter and the H∞ filter are studied by adjusting the three parameters U, G and V. Finally, the filter gains and the optimal index α*are obtained and the correctness and feasibility of the designed approach are verified by a simulation example.

关键词： dissipative filtering hidden Markov model finite-time boundedness Markov jump systems conic-type nonlinearity

Explore Contextual Information for 3D Scene Graph Generation

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arXiv

arXiv 2022年

作者： Liu, Yuanyuan Long, Chengjiang Zhang, Zhaoxuan Liu, Bokai Zhang, Qiang Yin, Baocai Yang, Xin The Department of Electronic Information and Electrical Engineering Dalian University of Technology Dalian116024 China Meta Reality Labs BurlingameCA94010 United States The Key Lab of Advanced Design and Intelligent Computing Dalian University Ministry of Education Dalian116622 China The Beijing Key Laboratory of Multimedia and Intelligent Software Technology Beijing Institute of Artificial Intelligence Faculty of Information Technology Beijing University of Technology Beijing100124 China

3D scene graph generation (SGG) has been of high interest in computer vision. Although the accuracy of 3D SGG on coarse classification and single relation label has been gradually improved, the performance of existing works is still far from being perfect for fine-grained and multi-label situations. In this paper, we propose a framework fully exploring contextual information for the 3D SGG task, which attempts to satisfy the requirements of fine-grained entity class, multiple relation labels, and high accuracy simultaneously. Our proposed approach is composed of a Graph Feature Extraction module and a Graph Contextual Reasoning module, achieving appropriate information-redundancy feature extraction, structured organization, and hierarchical inferring. Our approach achieves superior or competitive performance over previous methods on the 3DSSG dataset, especially on the relationship prediction sub-task. Copyright © 2022, The Authors. All rights reserved.

关键词： Feature extraction

Effect of the Graphene Oxide Incorporation on the Morphology, Corrosion Resistance and Fatigue Performance of Micro-Arc Oxidation Coating on Magnesium Alloy

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SSRN 2024年

作者： Tan, Yansong Liu, Xin Sun, Xiaohao Gao, Lilan Liu, Debao Zhang, Chunqiu Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Cont rol School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineerin g Education Tianjin University of Technology Tianjin300384 China School of Materials Science and Engineering Tianjin University of Technology Tianjin300384 China

Magnesium (Mg) alloy has great potential in biomedical applications, but the rapid corrosion rate which mismatches with bone reconstruction rate limits its clinical use. In this study, the graphene oxides (GO) were added into alkaline electrolyte solution during micro-arc oxidation (MAO) process, aiming to form a corrosion resistant surface coating on Mg alloy. By changing the concentration of GO, the coatings' morphology, composition, corrosion resistance, and fatigue property were compared to reveal the strengthening mechanism and find out the optimal graphene concentration. The results show that the MAO coating is composed of MgO, Mg2SiO4, Mg3(PO4)2 and GO. The added GO exhibits excellent adsorption property in the MAO process, reducing the intermolecular gap, thereby improving densification and obturation of the MAO coating. The surface morphology of MAO coating initially improves with increasing GO content, but then deteriorates, reaching its best quality at 0.4 g/L. Compared to MAO samples without GO, the samples with 0.4g/L GO not only have lower corrosion current density of 5.226 μA/cm2, but also show higher fatigue lives both before and after pre-corrosion. This study offers a promising approach to enhance the corrosion resistance and fatigue performance of Mg alloy by applying a GO-strengthened MAO coating onto its surface. © 2024, The Authors. All rights reserved.

关键词： Magnesium alloys

Accurate MTPA Control Based on Ferrari Method for IPMSM with Partial Derivative Term Calculation

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Accurate MTPA Control Based on Ferrari Method for IPMSM with...

International Conference on Electrical Machines and Systems (ICEMS)

作者： Yiyang Li Xin Gu Zhiqiang Wang Liyan Guo Wei Chen Xinmin Li Chen Li School of Electronics and Information Engineering Tiangong University Tianjin China Tianjin Key Laboratory of Intelligent Control of Electrical Equipment Tianjin China School of Electrical Engineering Tiangong University Tianjin China National Local Joint Engineering Research Center of Electrical Machine System Design and Manufacturing China Zhejiang University Advanced Electrical Equipment Innovation Center Hangzhou China

ISBN: (数字)9784886864406

ISBN: (纸本)9798350379105

Even if the exact motor parameters are known, the MTPA strategy cannot obtain precise maximum torque per ampere (MTPA) points under large current amplitude because the partial derivative of inductance to current is ignored in the modeling process. In view of this, the MTPA mathematical model considering the partial derivative of inductance to current is established in this paper, and the MTPA point tracking error caused by ignoring the partial derivative in the modeling process based on Ferrari method is analyzed. Then, an offline-online combined method for calculating the partial derivative term is proposed to compensate the MTPA tracking error. On this basis, an MTPA control strategy based on Ferrari method considering the partial derivative of inductance to current is proposed. Experiment to verify the feasibility and effectiveness of the proposed method.

关键词： Inductance Analytical models Torque Accuracy Permanent magnet motors Mathematical models Trajectory

Effect of the Graphene Oxide Incorporation on the Morphology, Corrosion Resistance And Fatigue Performance Of Micro-Arc Oxidation Coating on Mg Alloy

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SSRN 2024年

Mg alloy has great potential in biomedical applications, but the rapid corrosion rate which mismatches with bone reconstruction rate limits its clinical use. A protective oxide coating layer can be generated on the surface of Mg alloy by micro-arc oxidation (MAO) technique, aiming to improve the corrosion performance and long-term structural integrity of Mg alloy. In this study, the MAO coating layer of Mg alloy was improved by adding appropriate content of graphene oxide (GO) into electrolyte solution. GO has excellent adsorption property and plays a role in the MAO process, reducing the intermolecular gap, thereby improving the densification and obturation of the coating surface. With the increase of GO content, the surface morphology of the MAO coating initially has improved, then later deteriorated, and the best surface morphology has achieved at a GO content of 0.4 g/L. When the GO content increases from 0 g/L to 0.4 g/L, the corrosion current density reduces to 5.226 μA/cm2, with a reduction two orders in magnitude;in addition, at a stress amplitude of 140 MPa and a frequency of 4 Hz, the fatigue life increases from 9261 cycles to 13887 cycles without corrosion, and from 2042 cycles to 2759 cycles after pre-corrosion. This study provided a promising approach to ameliorate the morphology, corrosion resistance and fatigue performance of MAO coating on Mg alloy by elaborately configuring the electrolyte solution and customizing the process parameters. © 2024, The Authors. All rights reserved.

关键词： Corrosion resistance

Low-Light Enhancement Effect on Classification and Detection: An Empirical Study

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arXiv

arXiv 2024年

作者： Wu, Xu Lai, Zhihui Jie, Zhou Gao, Can Hou, Xianxu Zhang, Ya-Nan Shen, Linlin The Computer Vision Institute College of Computer Science and Software Engineering Shenzhen University Shenzhen518060 China Shenzhen Institute of Artificial Intelligence and Robotics for Society Shenzhen518060 China Guangdong Key Laboratory of Intelligent Information Processing Shenzhen University Shenzhen518060 China School of AI and Advanced Computing Xi’an Jiaotong-Liverpool University China The National Engineering Laboratory for Big Data System Computing Technology Shenzhen University SZU Branch Shenzhen Institute of Artificial Intelligence and Robotics for Society Guangdong Shenzhen518060 China

Low-light images are commonly encountered in real-world scenarios, and numerous low-light image enhancement (LLIE) methods have been proposed to improve the visibility of these images. The primary goal of LLIE is to generate clearer images that are more visually pleasing to humans. However, the impact of LLIE methods in high-level vision tasks, such as image classification and object detection, which rely on high-quality image datasets, is not well explored. To explore the impact, we comprehensively evaluate LLIE methods on these high-level vision tasks by utilizing an empirical investigation comprising image classification and object detection experiments. The evaluation reveals a dichotomy: While Low-Light Image Enhancement (LLIE) methods enhance human visual interpretation, their effect on computer vision tasks is inconsistent and can sometimes be harmful. Our findings suggest a disconnect between image enhancement for human visual perception and for machine analysis, indicating a need for LLIE methods tailored to support high-level vision tasks effectively. This insight is crucial for the development of LLIE techniques that align with the needs of both human and machine vision. Copyright © 2024, The Authors. All rights reserved.

关键词： Machine vision

Biomechanical Finite Element Methods Study of a Novel Internal Fixation System for Lumbar Spondylolysis

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SSRN 2025年

作者： Li, Jingyuan Du, Chengfei Wang, Yulei Du, Di Liang, Jinlong Shao, Nengqi Feng, Fanzhe Xu, Wenhao Xu, Yongqing Cui, Yi Center for Joint Surgery Intelligent Manufacturing and Rehabilitation Engineering Center The First Affiliated Hospital of Army Medical University Chongqing400038 China Chongqing Municipal Science and Technology Bureau Key Laboratory of Precision Medicine in Joint Surgery Chongqing400038 China Chongqing Municipal Education Commission Key Laboratory of Joint Biology Chongqing400038 China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of mechanical engineering Tianjin University of Technology Tianjin300384 China Department of Orthopaedic Surgery 920th Hospital of Joint Logistics Support Force Kunming650032 China Department of Orthopaedic Surgery 920th Hospital of Joint Logistics Support Force No. 212 of Da-Guan Road Xishan District Kunming650032 China

ObjectiveThis study aimed to verify the biomechanical efficacy of a novel internal fixation system for repairing lumbar spondylolysis (LS). Additionally, the changes in the mechanical performance of the novel internal fixation device during compression were *** healthy 25-year-old male volunteer was recruited for lumbar spine CT data acquisition to construct and validate a nonlinear finite element model of the L4-S1 spinal segment (A). Based on this, models were established for L5 spondylolysis (B), traditional internal fixation (C), and the pressurization process of the novel LS repair device fixation (D→E→F). For these six models, we constrained the lower surface of the S1 vertebral body while applying an axial compression force of 500 N and a moment load of 7.5 N·m on the upper surface of the L4 vertebral body to simulate six motions of the lumbar spine. The performance of each finite element model was evaluated by comparing the range of motion (ROM), maximum displacement, and maximum pressure experienced by the lumbar spine under different motion *** with Model C, Models D, E, and F exhibited a reduced ROM and maximum displacement (1%-38.5%, 12.8%-63.6%, and 32.8%-80.2%) compared with Model C during six different motions. Notably, compared with Model C, the novel internal fixation models consistently demonstrated a decreasing trend in the maximum stress on the intervertebral discs (IVD) and an increasing trend in the maximum stress on the articular cartilage and maximum stress and displacement of the bone graft. Moreover, the novel internal fixation model displayed larger ranges of evenly distributed stresses on the isthmus and reduced maximum stress on the internal fixation device across all six motions, with improved stiffness effects during the pressurization process of the novel internal fixation system (D→E→F).ConclusionsAccording to several mechanical comparisons, the novel internal fixation system had better biomechan

关键词： Axial compression

design of MEMS Step Impedance Microstrip Filter in Ku Band

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Design of MEMS Step Impedance Microstrip Filter in Ku Band

IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP)

作者： Tianyu Bai Guohui Yang Kuang Zhang Yingsong Li Tao Jiang School of Electronics and Information Engineering Harbin Institute of Technology Harbin China Anhui Province Key Laboratory of Target Recognition and Feature Extraction LuAn China Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Anhui University China Key Laboratory of Advanced Marine Communication and Information Technology Ministry of Industry and Information Technology Harbin Engineering University Harbin China

According to the miniaturization characteristics of step impedance resonators, a step impedance bandpass filter with a center frequency of 16.55 GHz and a bandwidth of 500MHz is designed. The effects of parameter changes such as substrate resistivity and the shape of metal via etching on the performance of the filter are studied. Finally, the filter is fabricated and its performance is tested under MEMS technology.

关键词： Band-pass filters Micromechanical devices Microstrip filters Shape Resonator filters Metals Conductivity

Joint Optimization of Integrated Mixed Maintenance and Distributed Two-Stage Hybrid Flow-Shop Production for Multi-Site Maintenance Requirements

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SSRN 2022年

作者： Wang, Zhen Deng, Qianwang Zhang, Like Li, Haiqiu Li, Fengyuan State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Changsha410082 China Henan Provincial Key Laboratory of Intelligent Manufacturing of Mechanical Equipment Zhengzhou University of Light Industry Zhengzhou450002 China China Railway Tunnel Group Co. Ltd Guangzhou511400 China

Similar to the synergy of machines and workers in the production process, a perfect operation and maintenance (O&M) service can be implemented only when spare parts and service workers are available at the same time. Considering the production of spare parts and the limited number of workers, an integrated optimization problem of dual scheduling of comprehensive production and maintenance is proposed in this paper. Specifically, in view of the characteristics that distributed hybrid flow-shops are often encountered in the industrial environment and one maintenance activity can be completed by one worker or two workers jointly, we integrate a mixed maintenance service with single and two workers into distributed two-stage hybrid flow-shop production based on multi-site maintenance requirements. By reasonably arranging production and maintenance, a comprehensive production and maintenance scheduling scheme for minimizing the total weighted earliness/tardiness penalty and the number of orders lost is provided. To the end, this paper establishes a mixed integer programming model with dual objectives and proposes an improved NSGA-II (INSGA-II) to solve the above problem. In INSGA-II, an initialization rule, an initialization optimization strategy and three local search operators are designed according to the relevant characteristics of the problem. To give full play to the best performance of the algorithm, the key parameters are set by a full factor experiment. Extensive experiments are carried out, whose results verify that INSGA-II has good advantages in solving the problem studied. © 2022, The Authors. All rights reserved.

关键词： Scheduling