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Distributed disturbance-observer-based vibration control for a flexible-link manipulator with output constraints

science China(Technological sciences) 2018年第10期61卷 1528-1536页

作者： YANG HongJun LIU JinKun HE Wei State Key Laboratory of Management and Control for Complex System Institute of Automation Chinese Academy of Sciences School of Automation Science and Electrical Engineering Beihang University School of Automation and Electrical Engineering University of Science and Technology Beijing

The issue of output constraints is studied for a flexible-link manipulator in the presence of unknown spatially distributed disturbances. The manipulator can be taken as an Euler-Bernoulli beam and its dynamic is expressed by partial differential equations. On account of the uncertainty of disturbances, we present a disturbance observer to estimate infinite dimensional disturbances on the beam. The observer is proven exponentially stable. Considering the problem of output constraints in the practical engineering, we propose a novel distributed vibration controller based on the disturbance observer to fulfill the position regulation of the joint angle and suppress elastic deflections on the flexible link, while confining the regulating errors of output in a suitable scope that we can assign. The closed-loop system is demonstrated exponentially stable based on an integral-barrier Lyapunov function. Simulations validate the effectiveness of the design scheme.

关键词： flexible manipulator distributed vibration control disturbance observer partial differential equation output constraint distributed parameter system

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Machine learning-integrated computational analysis on a blood-based ternary nanofluid flow in a stenosed artery with the artificial neural networks and modified finite difference approach

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Chaos, Solitons and Fractals 2025年 199卷

作者： Hussain, Mohib Lin, Du Waqas, Hassan Ali, Bagh Shah, Nehad Ali School of Mathematics and Statistics Northwestern Polytechnical University Xian710072 China MIIT Key Laboratory of Dynamics and Control Complex System Northwestern Polytechnical University Xi'an710072 China School of Naval Architecture Ocean and Energy Power Engineering Wuhan University of Technology Hubei Wuhan430063 China Department of Software Engineering Faculty of Science & Technology ILMA University 75190 Karachi Pakistan Department of Mechanical Engineering Sejong University Seoul05006 Korea Republic of

Heart failure and stroke continue to be the most common cause of global death, with atherosclerosis artery stenosis becoming a significant contributor. Although prior research has progressed in comprehending blood circulation behaviour, however, the incorporation of artificial intelligence (AI) and machine learning (ML) in the examination of ternary nanofluids for stenosed arterial diseases signifies a notable breakthrough in this domain. We proposes an integration of ML technique with computational fluid dynamics (CFD) to analyse the non-linear dynamics of thermal characterization in blood-based tri-hybrid nano-fluid flow, influenced by thermal radiation, variable heat sources and sinks, and aligned magnetic field effects within a blood artery exhibiting cosine stenosis. The investigation is based on AI approach, the Levenberg–Marquardt algorithm (LMA), with back propagation Artificial Neural Network (ANN-BP). The mathematical model is developed in the form of partial differentia equations and transformed into ordinary differential equation by similarity scaling, and then numerically evaluated by a modified finite difference approach, the Keller-Box method. The suggested ANN-LMA accuracy is compared to the ML solution for boundary layer flow. Regression values indicate an excellent fit between the predictions and the real data. It is observed that the inclined magnetic angle affects the drag force and heat transfer rate. There is a 27.9% increase in the heat transfer rate for ternary nano-fluid. Conclusively, the non-linear interaction between the magnetic field and nanofluid flow may significantly enhance heat transfer rates, which could have potential applications in biomedical sciences. © 2025 Elsevier Ltd

关键词： Magnetic levitation

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AFDM-SCMA: A Promising Waveform for Massive Connectivity over High Mobility Channels

arXiv

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arXiv 2023年

作者： Luo, Qu Xiao, Pei Liu, Zilong Wan, Ziwei Nikolaos, Thomos Gao, Zhen He, Ziming The 5G & 6G Innovation Centre University of Surrey United Kingdom The School of Computer Science and Electronics Engineering University of Essex United Kingdom The School of Information and Electronics Beijing Institute of Technology Beijing100081 China The 5G & 6G Innovation Centre University of Surrey GuildfordGU2 7XH United Kingdom BIT Zhuhai519088 China The MIIT Key Laboratory of Complex-Field Intelligent Sensing BIT Beijing100081 China Jinan250307 China Jiaxing314019 China The Samsung Cambridge Solution Centre System LSI Samsung Electronics CambridgeCB4 0DS United Kingdom

This paper studies the affine frequency division multiplexing (AFDM)-empowered sparse code multiple access (SCMA) system, referred to as AFDM-SCMA, for supporting massive connectivity in high-mobility environments. First, by placing the sparse codewords on the AFDM chirp subcarriers, the input-output (I/O) relation of AFDM-SCMA systems is presented. Next, we delve into the generalized receiver design, chirp rate selection, and error rate performance of the proposed AFDM-SCMA. The proposed AFDM-SCMA is shown to provide a general framework and subsume the existing OFDM-SCMA as a special case. Third, for efficient transceiver design, we further propose a class of sparse codebooks for simplifying the I/O relation, referred to as I/O relation-inspired codebook design in this paper. Building upon these codebooks, we propose a novel iterative detection and decoding scheme with linear minimum mean square error (LMMSE) estimator for both downlink and uplink channels based on orthogonal approximate message passing principles. Our numerical results demonstrate the superiority of the proposed AFDM-SCMA systems over OFDM-SCMA systems in terms of the error rate performance. We show that the proposed receiver can significantly enhance the error rate performance while reducing the detection complexity. © 2023, CC BY.

关键词： Mean square error

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A more compact object detector head network with feature enhancement and relational reasoning

arXiv

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arXiv 2021年

作者： Zhang, Wenchao Fu, Chong Chang, Xiangshi Zhao, Tengfei Li, Xiang Sham, Chiu-Wing School of Computer Science and Engineering Northeastern University Shenyang110819 China Engineering Research Center of Security Technology of Complex Network System Ministry of Education China Key Laboratory of Intelligent Computing in Medical Image Ministry of Education Northeastern University Shenyang110819 China Baidu Smart Life Group NO. 10 Xibeiwang East Street Ke Ji Yuan Haidian District Beijing100193 China School of Computer Science University of Auckland New Zealand

Modeling implicit feature interaction patterns is of significant importance to object detection tasks. However, in the two-stage detectors, due to the excessive use of hand-crafted components, it is very difficult to reason about the implicit relationship of the instance features. To tackle this problem, we analyze three different levels of feature interaction relationships, namely, the dependency relationship between the cropped local features and global features, the feature autocorrelation within the instance, and the cross-correlation relationship between the instances. To this end, we propose a more compact object detector head network (CODH), which can not only preserve global context information and condense the information density, but also allows instance-wise feature enhancement and relational reasoning in a larger matrix space. Without bells and whistles, our method can effectively improve the detection performance while significantly reducing the parameters of the model, e.g., with our method, the parameters of the head network is 0.6× smaller than the state-of-the-art Cascade R-CNN, yet the performance boost is 1.3% on COCO test-dev. Without losing generality, we can also build a more lighter head network for other multi-stage detectors by assembling our method. Copyright © 2021, The Authors. All rights reserved.

关键词： Object detection

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Optimization of Missile Path Planning Based on APMO-HV Algorithm

Optimization of Missile Path Planning Based on APMO-HV Algor...

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2019 IEEE International Conference on Unmanned systems, ICUS 2019

作者： Zhang, Hu Wang, Shuai Liu, Tonglin Zhou, Aimin Zhang, Yi Beijing Electro-mechanical Engineering Institute Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing China Changzhou University School of Mechanical Engineering Changzhou China East China Normal University Shanghai Key Laboratory of Multidimensional Information Processing School of Computer Science and Technology Shanghai China

ISBN: (纸本)9781728137926

In this paper, with considerations of low efficiency of missile path planning (MPP) by traditional aggregation technology, it uses affinity propagation based multi-objective evolutionary algorithm with hypervolume environment selection (APMO-HV) to solve the problem of MPP after establishing the MPP model. The experimental part compares and analyzes APMO-HV with six state-of-the-art algorithms, and applies it to address the MPP problem. The experimental results show that compared with the other six algorithms, APMO-HV has achieved the best solution performance in both the GLT test suite and MPP problem. This not only validates the effect of the proposed algorithm, but also enriches and improves the research results of MPP. © 2019 IEEE.

关键词： Evolutionary algorithms

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Time-resolved ARPES of excitons in a 2D semiconductor

Time-resolved ARPES of excitons in a 2D semiconductor

引用

Conference on Lasers and Electro-Optics (CLEO)

作者： Julien Madéo Michael K. L. Man Chakradhar Sahoo Marshall Campbell Vivek Pareek E Laine Wong Abdullah Al-Mahboob Nicholas S. Chan Arka Karmakar Bala Murali Krishna Mariserla Xiaoqin Li Tony F. Heinz Ting Cao Keshav M. Dani Femtosecond Spectroscopy Unit Okinawa Institute of Science and Technology Okinawa Japan School of Physics University of Hyderabad Hyderabad Telangana India Center for Complex Quantum System the University of Texas at Austin Austin TX U.S.A Indian Institute of Technology Jodhpur Rajasthan India Stanford University Stanford California U.S.A. SLAC National Accelerator Laboratory Menlo Park California USA University of Washington Seattle WA U.S.A

We use a table-top time-resolved ARPES based on a MHz XUV source to directly observe direct and momentum-forbidden excitons in the full first Brillouin zone of WSe 2 monolayer and measure their ultrafast dynamics.

ISBN: (纸本)9781943580910

关键词： Semiconductor device measurement Excitons Semiconductor lasers Scattering Measurement by laser beam Lasers and electrooptics Laser excitation

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Performance analysis of moving ship target signal integration and detection in geosynchronous synthetic aperture radar

Performance analysis of moving ship target signal integratio...

引用

IET International Radar Conference 2018, IRC 2018

作者： Zhang, Ying Dong, Xichao Xiong, Wei Hu, Cheng Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing101416 China Radar Research Lab School of Information and Electronics Beijing Institute of Technology Beijing100081 China Ministry of Education Beijing100081 China

Geosynchronous synthetic aperture radar (GEO SAR) has the characteristics of wide coverage and short revisit time, which makes GEO SAR moving target indication more valuable than other platforms. This article analyses the influence of moving target on 'Stop-and-Go' error in GEO SAR, and then the accurate slant range model of moving target is constructed. The signal-to-noise ratio of the raw data echoes for moving ship target is very low because of the high satellite orbit altitude, so it cannot be detected by constant false alarm detection. Based on the accurate slant range model of moving target in GEO SAR, three kinds of integration methods are reconstructed, including moving target detection, Radon transform and generalised Radon Fourier transform (GRFT). The performance of these methods is compared through numerical simulation. GRFT can provide the best detection performance in a reasonable integration time. © 2019 Institution of Engineering and technology. All rights reserved.

关键词： Numerical methods

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New nitinol endovascular stent-graft system for abdominal aortic aneurysm with finite element analysis and experimental verification

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Rare Metals 2019年第6期38卷 495-502页

作者： Xiao-Chen Zhou Fan Yang Xiao-Yan Gong Ming Zhao Yu-Feng Zheng Zhi-Li Sun Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China Beijing Percutek Therapeutics Co. Ltd.Beijing 102600China Suzhou Innomed Medical Device Co. Ltd.Suzhou 215123China Schlumberger Technology Corporation HoustonTX 77054USA State Key Laboratory for Turbulence and Complex System College of EngineeringPeking UniversityBeijing 100871China

Abdominal aortic aneurysm(AAA) is one of the most common and catastrophic manifestations of the acute aortic syndrome that can be treated with endovascular aneurysm repair(EVAR) which requires a specially designed stent-graft *** this work, a self-expanding nickel–titanium(nitinol) stent-graft system is aiming at AAA using finite element analysis(FEA) methods to analyze both fatigue behaviors and radial *** on the systematic analysis of the parametric variations, a final stent-graft system was developed by the selection and arrangement of the individual stent components, targeting an optimal performance for the treatment of *** tests, animal tests and clinical trials were carried out to confirm the *** animal trials and clinical trials showed comparable curative effects with Medtronic Endurant stent-graft(SG) systems.

关键词： Nitinol Stent-graft system Abdominal aortic aneurysm Fatigue safety factor Radial force Finite element analysis

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Subnormal Distribution Derived From Evolving Networks With Variable Elements

引用

IEEE TRANSACTIONS ON CYBERNETICS 2018年第9期48卷 2556-2568页

作者： Feng, Minyu Qu, Hong Yi, Zhang Kurths, Juergen School of Computer Science and Engineering University of Electronic Science and Technology of China Chengdu China College of Computer Science Sichuan University Chengdu China Institute for Complex System and Mathematical Biology University of Aberdeen Aberdeen U.K.

During the past decades, power-law distributions have played a significant role in analyzing the topology of scale-free networks. However, in the observation of degree distributions in practical networks and other nonuniform distributions such as the wealth distribution, we discover that, there exists a peak at the beginning of most real distributions, which cannot be accurately described by a monotonic decreasing power-law distribution. To better describe the real distributions, in this paper, we propose a subnormal distribution derived from evolving networks with variable elements and study its statistical properties for the first time. By utilizing this distribution, we can precisely describe those distributions commonly existing in the real world, e.g., distributions of degree in social networks and personal wealth. Additionally, we fit connectivity in evolving networks and the data observed in the real world by the proposed subnormal distribution, resulting in a better performance of fitness.

关键词： Degree distribution evolving networks Gibrat's law power-law distribution probability theory

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Transient Fault Diagnosis Algorithm based on Feature Classification and Its Application in High-Power Laser facility

Transient Fault Diagnosis Algorithm based on Feature Classif...

引用

Chinese Control and Decision Conference, CCDC

作者： Qiang Ren Hang Gao Hailei Ren Baoran An Tianyou Yun Xiaoli Wang Institute of Computer Application China Academy of Engineering Physics Mianyang State Key Laboratory of Complex Electromagnetic Environmental Effects on Electronics and Information System College of Electronic Science and Technology National University of Defense Technology Changsha Institute of Fluid Physics China Academy of Engineering Physis MianYang China

ISBN: (数字)9781728158556

ISBN: (纸本)9781728158563

High-power laser facility plays an import role both in scientific research and military application, and the occurred faults are usually transient. In this paper, a transient fault diagnosis algorithm based on feature classification is proposed, and the algorithm has been applied in the high-power laser facility. The method extracts the features of input data with an autoencoder network. And based on the extracted features, a multi-layer full connection neural network is adopted for fault diagnosis. By comparing the results with those obtained by traditional fault diagnosis methods, the performance of the algorithm has been verified.

关键词： Feature extraction Fault diagnosis Circuit faults Neural networks Principal component analysis Kernel Transient analysis

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