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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： J.P. Gastellu-Etchegorry Y. Wang O. Regaieg T. Yin Z. Malenovsky Z. Zhen X. Yang Z. Tao L. Landier A. Al Bitar Deschamps N. Lauret J. Guilleux E. Chavanon B. Cao J. Qi A. Kallel Z. Mitraka N. Chrysoulakis B. Cook D. Morton Université de Toulouse CESBIO - UPS CNES CNRS IRD Toulouse France Earth System Science Interdisciplinary Center University of Maryland College Park MD USA School of Technology Environments and Design University of Tasmania Hobart Australia College of Geo-Exploration Science and Technology Jilin University Changchun China Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Beijing China Key Laboratory of Geographical Information Science East China Normal University Shanghai China CNES Toulouse France Beijing Forestry University Beijing China CRNS ATMS Sfax Tunisia Foundation for Research and Technology Hellas (FORTH) Heraklion Greece NASA Goddard Space Flight Center Greenbelt MD USA

ISBN: (数字)9781728163741

ISBN: (纸本)9781728163758

Physical models simulating the radiative budget (RB) and remote sensing (RS) observation of three-dimensional (3D) landscapes are critical to better understand human and natural components of the Earth system and further develop RS technology. DART is one of the most comprehensive 3D models of Earth-atmosphere optical radiative transfer (RT), from ultraviolet (UV) to thermal infrared (TIR). It simulates the optical signal of proximal, aerial and satellite imaging spectrometers and laser scanners, the 3D RB and solar induced chlorophyll fluorescence (SIF) signal, for any urban or natural landscape and any experimental or instrument configuration. It is freely available for research and teaching activities (https://***). Here, five recent advances are presented. 1) Atmosphere RT. 2) RT in non repetitive topography. 3) Monte Carlo modelling for fast RS image simulation of large landscapes. 4) SIF modelling for vegetation simulated as facets and turbid cells. 5) RS image inversion for mapping the optical properties of urban material and the urban radiative budget.

关键词： Atmospheric modeling Three-dimensional displays Terrestrial atmosphere Earth Satellites Computational modeling Surface topography

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Time-varying Characteristics of mmWave Channel based on the Clustered Sparsity Model

Time-varying Characteristics of mmWave Channel based on the ...

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IEEE Conference on Vehicular technology (VTC)

作者： Lijun Yang Haitao Lu Xinchao Ge Zhixin Sun Pan Cao School of Internet of Things Nanjing University of Posts and Telecommunications Nanjing China RAN System Design Dept. ZTE Corporation Shenzhen China Shenzhen Key Laboratory of 5G RAN Security Technology Research and Application Shenzhen China School of Modern Posts Nanjing University of Posts and Telecommunications Nanjing China School of Physics Engineering and Computer Science University of Hertfordshire Hatfield UK

A better understanding of the mmWave channel coherence time will play a significant role in both communication and sensing. Traditional literatures consider that the channel coherence time in mmWave communication will be very short due to high frequency, which makes the channel estimation more difficult. However, we believe that the propagation characteristics of the mmWave channel will affect its coherence time, i.e., channel sparsity may limit its time variability. In this paper, we investigate the time-varying nature of mmWave channel by analyzing its Doppler spread based on the clustered sparsity model. After the derivation of Doppler spectrum DPS and the simulation analysis based on the two-cluster channel, we found that the maximum angle between clusters and the power distribution between clusters are two main factors limiting the Doppler spread. Finally, the realistic mmWave NYUSIM model is used for Doppler spread comparative analysis with Clarke’s model and find that Doppler spread of NYUSIM channel is far less than that estimated based on Clarke’s model. Thus, it is demonstrated that even if the mmWave frequency is high, the clustered sparsity characteristics makes its channel coherence time not as short as thought intuitively, which is meaningful for mmWave vehicular sensing and communication.

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Approaching the Fundamental Limit of Orbital-Angular-Momentum Multiplexing Through a Hologram Metasurface

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Physical Review Applied 2021年第6期16卷 064042-064042页

作者： Shuai S.A. Yuan Jie Wu Menglin L.N. Chen Zhihao Lan Liang Zhang Sheng Sun Zhixiang Huang Xiaoming Chen Shilie Zheng Li Jun Jiang Xianmin Zhang Wei E.I. Sha College of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China Department of Education of Anhui Province Ministry of Education and the Key Laboratory of Electromagnetic Environmental Sensing Anhui University Hefei 230039 China Department of Electrical and Electronic Engineering The University of Hong Kong Hong Kong Department of Electronic and Electrical Engineering University College London Torrington Place London WC1E 7JE United Kingdom Anhui Province Key Laboratory of Simulation and Design for Electronic Information System Hefei Normal University Hefei 230601 China School of Electronic Science and Engineering University of Electronic Science and Technology of China Chengdu 611731 China School of Information and Communications Engineering Xi’an Jiaotong University Xi’an 710049 China

Establishing and approaching the fundamental limit of orbital-angular-momentum (OAM) multiplexing are necessary and increasingly urgent for current multiple-input multiple-output research. In this work, we elaborate the fundamental limit in terms of independent scattering channels (or the degrees of freedom of scattered fields) through angular-spectral analysis, in conjunction with a rigorous Green’s function method. The scattering-channel limit is universal for arbitrary spatial-mode multiplexing, which is launched by a planar electromagnetic device, such as antenna, metasurface, etc., with a predefined physical size. As a proof of concept, we demonstrate both theoretically and experimentally the limit by a phase-only metasurface hologram that transforms orthogonal OAM modes to plane-wave modes scattered at critically separated angular-spectral regions. Particularly, a minimax optimization algorithm is applied to suppress angular-spectrum aliasing, achieving good performances in both full-wave simulation and experimental measurement at microwave frequencies. This work offers a theoretical upper bound and corresponding approach route for engineering designs of OAM multiplexing.

关键词： Angular momentum of light Polarization of light Spatial profiles of optical beams Devices Metamaterials Surfaces Holography Light scattering

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Surface morphology and stiffness of cartilage-like tissue repaired with a scaffold-free tissue engineered construct

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Journal of Biomechanical science and Engineering 2011年第1期6卷 40-48页

作者： Nansai, Ryosuke Suzuki, Takuya Shimomura, Kazunori Ando, Wataru Nakamura, Norimasa Fujie, Hiromichi Biomechanics Laboratory Graduate School of Engineering Kogakuin University 2665-1 Nakanomachi Hachioji Tokyo 192-0015 Japan Department of Orthopaedics Osaka University Graduate School of Medicine 1-1 Yamadaoka Suita Osaka 565-0871 Japan Faculty of System Design Tokyo Metropolitan University 6-6 Asahigaoka Hino Tokyo 191-0065 Japan Research Institute for Science and Technology Kogakuin University 2665-1 Nakanomachi Hachioji Tokyo 192-0015 Japan

We have been developing a new tissue engineering technique for cartilage repair using a scaffold-free tissue engineered construct (TEC) bio-synthesized from synovium-derived mesenchymal stem cells (MSCs). A round-shaped chondral defect of 8.5 mm in diameter and 2.0 mm in depth created on the medial condyle of immature (4-month-old) and mature (12-month-old) porcine femur was filled with the TEC. Six months after surgery, a cylindrically shaped specimen of 4 mm in diameter and 4-5 mm in depth was extracted. Stiffness measurements were carried out on the specimen using an AFM after the surface image of the specimen was obtained. The TEC-treated tissues exhibited more irregular surface as compared with normal cartilage, regardless of animal maturity. The stiffness of the superficial layer of the TEC-treated tissue was significantly lower than those of the normal cartilage, indicating 6.8±2.3 mN/m in the immature group and 8.8±2.3 mN/m in the mature group. Histological observation indicated that the defects were repaired with a hyaline cartilage-like tissue with positive Safranine O staining, regardless of animal maturity. However, the superficial layer of the repaired tissues was negatively stained with Safranine O. The present study suggests that the recovery of the superficial layer is delayed in both immature and mature animals although the treatment with TEC enhances the repair of partial chondral defects. © 2011 by JSME.

关键词： Surface morphology

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Incorporating Steering Constraints in AGV Path Planning Through Graph Augmentation

Incorporating Steering Constraints in AGV Path Planning Thro...

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Fully Actuated system Theory and Applications (CFASTA), Conference on

作者： Liming Zhang Zhimin Han Bo Wang Zhiyun Lin Xiangdong Xu School of Automation Hangzhou Dianzi University Hangzhou P. R. China Zhejiang CoTEK Robotics Co. Ltd Hangzhou P. R. China Shenzhen Key Laboratory of Control Theory and Intelligent Systems School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen P. R. China Peng Cheng Laboratory Shenzhen P. R. China Wenzhou Institute of Industry & Science Wenzhou P. R. China

ISBN: (数字)9798350373691

ISBN: (纸本)9798350373707

In this paper, we introduce an innovative method for the orientation-specific path planning of an Automated Guided Vehicle (AGV) with steering constraints, such as unmanned forklifts. Traditional shortest-path algorithms, which solely consider distance or travel time, are unsuitable for tasks where the AGV’s orientation is crucial. To address this, we have created an augmented graph that inherently incorporates the AGV’s steering constraints and orientation. By utilizing this enhanced graph structure, conventional shortest-path algorithms can be employed to ascertain a path that takes the AGV’s orientation into account. This novel method facilitates more adaptable and secure path planning, while preserving the immediacy required for real-time path planning execution.

关键词： Remotely guided vehicles Path planning Real-time systems Task analysis Standards Robots

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Eddy Current Pulsed Thermography for Gear Fatigue Evaluation:An open access database and its applications

Eddy Current Pulsed Thermography for Gear Fatigue Evaluation...

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第十届全国无损检测学术年会

作者： Ai Jun Yin Gui Yun Tian Liang Chen Jishan Zhang Brian Shaw State Key Laboratory of Mechanical Transmission College of Mechanical Engineering Chongqing Universi School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu61 School of Electrical and Electronic Engineering Newcastle UniversityNewcastle upon TyneNE1 7RUUni Design unit School of Mechanical Engineering and SystemNewcastle UniversityNewcastle upon TyneNE1

Pulsed eddy current (PEC) technique generates responses over a wide range of frequencies, containing more spectral coverage than traditional eddy current *** current pulsed thermography (ECPT), a newly developed non-destructive testing (NDT) technique, has advantages such as rapid inspection of a large area within a short time, high spatial resolution, high sensitivity and stand-off measurement *** paper investigates ECPT for the evaluation of gear fatigue *** paper proposes a statistical method based on single channet blind source separation to extract details ot gear *** discussion of transient thermal distribution and patterns of fatigue contact surfaces as well as the non-contact surfaces have been *** addition, the measurement for gears with different cycles of fatigue tests by ECPTand the comparison results between ECPT with magnetic Barkhausen noise (MBN) have been *** comparison shows the competitive capability of ECPT in fatigue *** open access database of ECPT for gear fatigue evaluation is provided, and freely obtained to further analysis for gear fatigue evaluation.

关键词： Eddy current pulsed thermography Gear fatigue Evaluation Non-destructive testing

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Why To Model Remote Sensing Measurements In 3d? Recent Advances In Dart: Atmosphere, Topography, Large Landscape, Chlorophyll Fluorescence And Satellite Image Inversion

Why To Model Remote Sensing Measurements In 3d? Recent Advan...

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International Conference on Advanced Technologies for Signal and Image Processing (ATSIP)

作者： J.P. Gastellu-Etchegorry Y. Wang O. Regaieg T. Yin Z. Malenovsky Z. Zhen X. Yang Z. Tao L. Landier A. Al Bitar Deschamps N. Lauret J. Guilleux E. Chavanon B. Cao J. Qi A. Kallel Z. Mitraka N. Chrysoulakis B. Cook D. Morton Université de Toulouse CESBIO - UPS CNES CNRS IRD Toulouse France Earth System Science Interdisciplinary Center University of Maryland College Park MD 20740-3823 USA School of Technology Environments and Design University of Tasmania Hobart Australia College of Geo-Exploration Science and Technology Jilin University Changchun China Chinese Academy of Sciences Institute of Remote Sensing and Digital Earth Beijing China Key Laboratory of Geographical Information Science East China Normal University Shanghai China CNES 18 Av. Belin Toulouse France Beijing Forestry University Beijing China CRNS ATMS Sfax Tunisia Foundation for Research and Technology Hellas (FORTH) Heraklion Greece NASA Goddard Space Flight Center Greenbelt USA

ISBN: (数字)9781728175133

ISBN: (纸本)9781728175140

Remote sensing (RS) dedicated to the study of land surfaces benefits from more and more advanced sensors. However, the interpretation of RS data is often is often inaccurate due to the complexity of the observed land surfaces. Therefore, RS models, in particular physical models, that simulate RS observations of the three-dimensional (3D) landscapes are critical to correctly interpret RS data. DART is one of the most comprehensive 3D models of Earthatmosphere optical radiative transfer (RT), from ultraviolet (UV) to thermal infrared (TIR). It simulates the optical signal of proximal, aerial and satellite imaging spectrometers and laser scanners, the 3D RB and solar-induced chlorophyll fluorescence (SIF) signal, for any urban or natural landscape and any experimental or instrument configuration. It is freely available for research and teaching activities (***). After illustrating three significant sources of inaccuracy in RS interpretation, five recent DART advances are presented: RT in the atmosphere and topography, fast RS image simulation of large landscapes, SIF modelling, and satellite image inversion.

关键词： Atmospheric modeling Three-dimensional displays Reflectivity Surface topography Sun Forestry Solid modeling

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Developing a prototype concurrent design tool for composite topside structures

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NAVAL ENGINEERS JOURNAL 1997年第3期109卷 279-290页

作者： Dirlik, S Hambric, S Azarm, S Marquardt, M Hellman, A Bartlett, S Castelli, V Steve Dirlik:began his career at the Naval Surface Warfare Center Carderock Division in 1981 as an aerospace engineer co-op student. He completed his bachelor of science degree in aeropace and ocean engineering from Virginia Polytechnic Institute and State University in 1985 and his master of science degree in aerospace engineering from the University of Maryland in 1990. Mr. Dirlik recently completed a master of science program in applied physics at The Johns Hopins University and currently works in the Radar Cross Section and Target Physics Branch of the Signatures Directorate at the Naval Surface Warfare Center Corderoke Division. He has worked on Navy low observable programs since 1990. Stephen Hambric:is a research associate at the Applied Research Laboratory at The Pennsylvania State University. He received his B. S. and M.S. degree in mechanical engineering from Virginia Polytechnic Institute and State University and his D. Sc. in mechnical engineering from the George Washington University. He has worked on several computer aided multidiscikplinary design and optimization projects over the years including an automated propeller design system and a structural acoustic optimization capability. Dr. Shpour Azarm:is currently working as an associate professor with the Design and Manufacturing Group of the Department of Mechanical Engineering at the University of maryland at College Park. Dr Azarm's expertise is in the areas of optimization-based designed and concurrent design and optimization of multidisciplinary systems. He was a consultant at Black & Decker Corporation (summer 1996) and worked as a Navy senior summer faculty fellow (summer 1995) and a NASA summer faculty fellow (summer 1994). He was a visiting scientist at NASA Langley Research Center for Multidisciplinary Analysis and Applied Structural Optimzatiom at the University of Siegen in Germany (spring 1992) and the Design Institute of the Technical University of Denmark (summer 1990). Dr Azarm was an associate technical editor of the ASME Jour

A prototype concurrent engineering tool has been developed for the preliminary design of composite topside structures for modern navy warships. This tool, named GELS for the Concurrent Engineering of Layered Structures, provides designers with an immediate assessment of the impacts of their decisions on several disciplines which are important to the performance of a modern naval topside structure, including electromagnetic interference effects (EMI), radar cross section (RCS), structural integrity, cost, and weight. Preliminary analysis modules in each of these disciplines are integrated to operate from a common set of design variables and a common materials database. Performance in each discipline and an overall fitness function for the concept are then evaluated. A graphical user interface (GUI) is used to define requirements and to display the results from the technical analysis modules. Optimization techniques, including feasible sequential quadratic programming (FSQP) and exhaustive search are used to modify the design variables to satisfy all requirements simultaneously. The development of this tool, the technical modules, and their integration are discussed noting the decisions and compromises required to develop and integrate the modules into a prototype conceptual design tool.

关键词： Warships

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Time-dependent fatigue reliability estimation and optimal design of scraper chains under corrosive wear effect

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Mechanics Based design of Structures and Machines 2024年第10期52卷

作者： Shuai Li Zhencai Zhu Hao Lu Yujun Xue Gang Shen a School of Mechatronics Engineering Henan University of Science and Technology Luoyang Chinab Henan Key Laboratory for Machinery Design and Transmission System Henan University of Science and Technology Luoyang Chinac Longmen Laboratory Luoyang China d School of Mechatronic Engineering Jiangsu Key Laboratory of Mine Mechanical and Electrical Equipment China University of Mining and Technology Xuzhou China

Fatigue damage is one of the main failures of the scraper chain. Moreover, corrosive wear has a detrimental effect on fatigue crack propagation. It is so essential to study the fatigue reliability of the scraper chain considering the interaction of corrosive wear and fatigue. This paper is intended to propose a reliability-based estimation and optimal design of the scraper chain considering the performance degradation of the scraper chain under the interaction of corrosive wear and fatigue. First, the dynamic model of the scraper conveyor is established based on the finite element method. Second, Paris Low is used to empirically describe the occurrence of cracking with corrosion effects. Furthermore, the time-dependent reliability of scraper chains under the interaction of the corrosive wear and fatigue crack propagation is addressed by the fourth-moment saddlepoint approximation (FMSA) method, and the reliability-based design optimization (RBDO) of the scraper chain is then carried out. Finally, the applicability of the proposed method is verified by the SGZ1000/1400 scraper conveyor.

关键词： Fatigue reliability scraper chain saddlepoint approximation reliability based design optimization

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synchronization of coupled reaction-diffusion neural networks with mixed delays

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Complexity 2016年第S2期21卷

作者： Ping He Yangmin Li Department of Electromechanical Engineering Faculty of Science and Technology University of Macau Taipa Macao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin China

The reaction-diffusion neural network is often described by semilinear diffusion partial differential equation (PDE). This article focuses on the asymptotical synchronization and synchronization for coupled reaction-diffusion neural networks with mixed delays (that is, discrete and infinite distributed delays) and Dirichlet boundary condition. First, using the Lyapunov–Krasoviskii functional scheme, the sufficient condition is obtained for the asymptotical synchronization of coupled semilinear diffusion PDEs with mixed time-delays and this condition is represented by linear matrix inequalities (LMIs), which is easy to be solved. Then the robust synchronization is considered in temporal-spatial domain for the coupled semilinear diffusion PDEs with mixed delays and external disturbances. In terms of the technique of completing squares, the sufficient condition is obtained for the robust synchronization. Finally, a numerical example of coupled semilinear diffusion PDEs with mixed time-delays is given to illustrate the correctness of the obtained results. © 2016 Wiley Periodicals, Inc. Complexity 21: 42–53, 2016

关键词： asymptotical synchronization synchronization coupled reaction-diffusion neural networks linear matrix inequality (LMI) partial differential systems (PDSs) mixed delays

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