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Reveal the Incidence-Independent Frequency Shift in Acoustic Rotational Doppler Effect

Physical Review Letters 2024年第11期132卷

作者： Zhang, Chuanxin Jiang, Xue Ta, Dean Center for Biomedical Engineering School of Information Science and Technology Fudan University Shanghai200433 China State Key Laboratory of Integrated Chips and System Fudan University Shanghai200433 China

The Doppler effect is a universal wave phenomenon that has inspired various applications due to the induced frequency shift. In the case of the linear Doppler effect, the frequency shift depends on the incident frequency and angle. Here, we unveil the frequency shift dependence induced by the acoustic rotational Doppler effect in the wave-object scattering process. We experimentally demonstrate that this frequency shift is exclusively determined by the angular speed and rotational symmetry of the spinning scatterer while remaining independent of the incident angular momentum and angle. We derive the analytical relationship between the frequency shift and the scatterer's helicity, presenting a novel approach for helical feature recognition. The angle-independent nature of the frequency shift inherently prevents spectrum broadening and offers a solution for precise motion measurement through the rotational Doppler effect. This work provides a rigorous and comprehensive understanding of the acoustic Doppler effect, enriching its applications in helicity and motion detection. © 2024 American Physical Society.

关键词： Doppler effect

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Distributed differential evolution algorithm with adaptive parameters

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Kongzhi yu Juece/Control and Decision 2014年第4期29卷 701-706页

作者： Zhang, Chun-Mei Chen, Jie Xin, Bin School of Automation Ministry of Education Beijing Institute of Technology Beijing 100081 China Key Laboratory of Complex System Intelligent Control and Decision Ministry of Education Beijing Institute of Technology Beijing 100081 China School of Electronic Information Engineering Taiyuan University of Science and Technology Taiyuan 030024 China

An adaptive distributed differential evolution algorithm is proposed based on the change of the individual's fitness value. Firstly, the initial population is divided into several subpopulations. When the migration condition is satisfied, the best individual in each subpopulation will replace the worst individual of its neighbor subpopulations according to the Von Neumann topology. The migration mechanism among subpopulations enables the information to be communicated in the whole population. Meanwhile, the adaptive mechanism of F and CR is presented for assigning different F and CR to each individual according to the individual's fitness. Numerical results show that, the proposed algorithm is beneficial to explore the solution space, which can avoid the premature convergence and search the excellent solutions.

关键词： Optimization

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Performance analysis of polarimetric radar detectors

Performance analysis of polarimetric radar detectors

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International Symposium on Communications Control and Signal Processing (ISCCSP)

作者： Y. Yang S. P. Xiao D. J. Feng F. Zhao J. H. Yang L.T. Xu State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System National University of Defense Technology Changsha People's Republic of China

Choosing a polarimetric radar detector which exhibits well on detection performance and is easy to implement simultaneously is significant to the polarimetric radar target detection in reality. In this paper, we analyze and compare the detection performances and implementation difficulties of optimal polarimetric detector (OPD), polarimetric whitening filter (PWF), optimal span detector (OSD), polarimetric matched filter (PMF), polarimetric maximization synthesis detector (PMSD) and single channel detector (SCD) to find which one is optimal to be used in engineering. The clutter and target echoes in three polarimetric channels (HH, HV and VV) are modeled at first. Then we present the test statistics of the six detectors and analyze their implementation difficulties. We present the ideal detection performances of the six polarimetric detectors by Monte Carlo simulations. The results show that PWF, OSD and PMSD make a better compromise between ideal detection performance and implementation difficulty than other polarimetric detectors. Thus, we further compare the adaptive detection performances of PWF and OSD with the detection performance of PMSD under various circumstances. Simulation results demonstrate that PWF performs best and is optimal to be used in engineering.

关键词： Clutter Detectors Radar polarimetry Radar detection Matched filters Radar clutter

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A Novel Multi-Channel Phase Error Estimation Method Based On Stochastic Optimization For Tomographic Sar Autofocusing

A Novel Multi-Channel Phase Error Estimation Method Based On...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Muhan Wang Silin Gao Zhe Zhang Xiaolan Qiu Key Laboratory of Technology in Geo-Spatial Information Processing and Application System Aerospace Information Research Institute Chinese Academy of Sciences Beijing China Key Laboratory of Intelligent Aerospace Big Data Application Technology Suzhou Aerospace Information Research Institute Suzhou China University of Chinese Academy of Sciences Beijing China

Tomographic SAR (TomoSAR) technology has gained significant attention in recent years due to its three-dimensional imaging capability. However, in practical applications, phase errors between different channels can degrade the quality of three-dimensional imaging. Current state-of-the-art methods for phase error compensation based on autofocus techniques suffer from high computational complexity, making them unsuitable for large-scale three-dimensional imaging. In this paper, we propose a multi-channel phase error estimation method based on error back-propagation training optimization. By utilizing the TomoSAR model that incorporates phase errors from multiple channels, we construct a matrix containing the parameters to be estimated for inter-channel phase errors. Through stochastic gradient descent algorithm, we iteratively optimize the parameters of the phase error matrix, ultimately obtaining an estimation of the inter-channel phase errors. Experimental results validate the accuracy of the proposed method.

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Rice lodging disaster monitoring method based on multi-source remote sensing data

Rice lodging disaster monitoring method based on multi-sourc...

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2022 International Conference on Geographic information and Remote Sensing technology, GIRST 2022

作者： Dai, Xuemei Chen, Shuisen Jiang, Hao Nainarpandian, Chandrasekar Guangzhou Institute of Geography Guangdong Academy of Sciences Key Lab of Guangdong for Utilization of Remote Sensing and Geographical Information System Guangdong Open Laboratory of Geospatial Information Technology and Application Research Center of Guangdong Province for Engineering Technology Application of Remote Sensing Big Data Guangzhou China Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Centre for Geotechnology Manonmaniam Sundaranar University Tamil Nadu Tirunelveli627012 India

ISBN: (纸本)9781510662186

Lodging is a major yield-limiting factor in rice. Accurate assessment of rice lodging is essential for yield damage estimation, agricultural insurance claims settlement and subsequent management decisions. This study aims to explore the effect of lodging on backscatter/coherence and spectral reflectance derived from Sentinel-1 and Sentinel-2 data. Based on this, an extraction method of lodging rice distribution using multi-source remote sensing data was proposed. The results showed that: (a) The lodging area of rice could be effectively extracted from dual-polarization Sentinel-1 image data with an accuracy of 87.87%;(b) The vegetation indices (NDVI, DVI and LSWI) extracted by Sentinel-2 are sensitive to lodging rice. Based on a certain threshold, lodging rice can be effectively extracted with an accuracy of 87.5%. Our findings demonstrate the potential of Sentinel data for near real-time detection of the rice lodging. © 2023 SPIE.

关键词： Polarization

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SASO: Joint 3D Semantic-Instance Segmentation via Multi-scale Semantic Association and Salient Point Clustering Optimization

arXiv

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arXiv 2020年

作者： Tan, Jingang Chen, Lili Wang, Kangru Peng, Jingquan Li, Jiamao Zhang, Xiaolin Bionic Vision System Laboratory State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China University of Chinese Academy of Sciences Beijing China School of Information Science and Technology ShanghaiTech University Shanghai China

We propose a novel 3D point cloud segmentation framework named SASO, which jointly performs semantic and instance segmentation tasks. For semantic segmentation task, inspired by the inherent correlation among objects in spatial context, we propose a Multi-scale Semantic Association (MSA) module to explore the constructive effects of the semantic context information. For instance segmentation task, different from previous works that utilize clustering only in inference procedure, we propose a Salient Point Clustering Optimization (SPCO) module to introduce a clustering procedure into the training process and impel the network focusing on points that are difficult to be distinguished. In addition, because of the inherent structures of indoor scenes, the imbalance problem of the category distribution is rarely considered but severely limits the performance of 3D scene perception. To address this issue, we introduce an adaptive Water Filling Sampling (WFS) algorithm to balance the category distribution of training data. Extensive experiments demonstrate that our method outperforms the state-of-the-art methods on benchmark datasets in both semantic segmentation and instance segmentation tasks. Copyright © 2020, The Authors. All rights reserved.

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Robotic Trajectory Planning for Non-Destructive Testing Based on Surface 3D Point Cloud Data 7

Robotic Trajectory Planning for Non-Destructive Testing Base...

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2021 7th International Forum on Manufacturing technology and Engineering Materials, IFEMMT 2021

作者： Zhang, Zhen Zhang, Hualiang Yu, Xiaolong Deng, Yongsheng Chen, Zheng School of Mechanical Engineering and Automation Northeastern University Shenyang China Key Laboratory of Industrial Control Network and System Shenyang Institute of Automation Chinese Academy of Sciences Shenyang China Hangzhou Innovation Institute Beihang University Hangzhou China School of Information Engineering Shenyang University of Chemical Technology Shenyang China

Robotics has been widely used in the field of non-destructive testing in recent years. However, for complex surfaces, manual teaching or offline programming is time-consuming and difficult to ensure high precision for non-destructive testing robot trajectory planning. Therefore, this work proposes a new method to generate non-destructive testing trajectory of the robot based on the pre-processed point cloud data. The workpiece surface is measured by 3D sensor to obtain the point cloud data. The trajectory line on workpiece surface is obtained by slicing pre-processed point cloud data. The dense trajectory points are obtained by isometric discretizing trajectory lines, and then they are compressed by Douglas-Peucker algorithm. The Principal Component Analysis (PCA) method is used to estimate the normal vector of the optimized trajectory points and unify their orientation. The pose of non-destructive testing robot can be obtained by biasing the trajectory points along their normal vectors finally. © Published under licence by IOP Publishing Ltd.

关键词： Nondestructive examination

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Doppler Cycle Slip Detection and Repair of Low Sampling Rate

Doppler Cycle Slip Detection and Repair of Low Sampling Rate

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International Conference on Digital Home (ICDH)

作者： Yuanfa Ji Xizi Jia Xiyan Sun Suqing Yan Sunyong Wu Shouhua Wang Xingli Gan Guangxi Experiment Center of Information Science Guilin University of Electronic Technology Guilin China Guangxi Key Laboratory of Precision Navigation Technology and Application Guilin University of Electronic Technology Guilin China State key laboratory of satellite navigation system and equipment technology Shijiazhuang China

In the cycle slip detection and repair of satellite navigation and positioning, the Doppler observation is protected from the cycle slip, which can assist the carrier phase data for cycle slip detection. However, as the sampling rate decreases, the correlation between the errors of the epochs also decreases, and the cycle slip detection capability is significantly reduced. To solve this problem, the author proposes a method of detecting and repairing Doppler cycle slip for low sampling rate. The method first uses the Lagrange interpolation algorithm to interpolate the low sampling rate Doppler observations to the 1s sampling interval, and performs polynomial fitting on the interpolated values to obtain Doppler values with less noise. Finally, the Doppler value extrapolated by the polynomial fit is subtracted from the interpolated Doppler value to obtain the cycle slip value. The simulation example that using GPS data for solution analysis shows that the detection accuracy of the new method is about 3 times and 4 times higher than the 5s and 10s sampling interval of the traditional Doppler integration method, and the detection accuracy is increased by 20% and 30% respectively.

关键词： Doppler effect Interpolation Maintenance engineering Fitting Global Positioning system Extrapolation

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Modeling the dynamics of urban growth using multinomial logistic regression: A case study of Jiayu county, Hubei province, China

Modeling the dynamics of urban growth using multinomial logi...

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Geoinformatics 2008 and Joint Conference on GIS and Built Environment: The Built Environment and Its Dynamics

作者： Yu, Nong Qingyun, Du Kun, Wang Lei, Miao Weiwei, Zhang School of Resource and Environmental Science Wuhan University 129 Luoyu Road Wuhan 430079 China Key Laboratory of Geographic Information System Ministry of Education Wuhan University 129 Luoyu Road Wuhan 430079 China College of Informatics and Software Technology South China Agriculture University Guangzhou 510642 China

Urban growth modeling, one of the most important aspects of land use and land cover change study, has attracted substantial attention because it helps to comprehend the mechanisms of land use change thus helps relevant policies made. This study applied multinomial logistic regression to model urban growth in the Jiayu county of Hubei province, China to discover the relationship between urban growth and the driving forces of which biophysical and socialeconomic factors are selected as independent variables. This type of regression is similar to binary logistic regression, but it is more general because the dependent variable is not restricted to two categories, as those previous studies did. The multinomial one can simulate the process of multiple land use competition between urban land, bare land, cultivated land and orchard land. Taking the land use type of Urban as reference category, parameters could be estimated with odds ratio. A probability map is generated from the model to predict where urban growth will occur as a result of the computation. © 2008 SPIE.

关键词： Geographic information systems

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Analytical Models for QoT Estimations in Super-C and Super-C + L Bands Optical Transmission systems

Analytical Models for QoT Estimations in Super-C and Super-C...

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2023 Conference on Lasers and Electro-Optics, CLEO 2023

作者： Yan, Baoluo Sun, Yijun Zhou, Ziwen Liu, Hong Wang, Hongya Huan, Chen Zhao, Zhiyong Feng, Lipeng Zhang, Anxu Feng, Zhenhua Shi, Hu WDM System Department Wireline Product R&D Institute ZTE Corp. Beijing100029 China State Key Laboratory of Mobile Network and Mobile Multimedia Technology 518055 China School of Software Engineering Chongqing University of Posts and Telecommunications Chongqing400065 China School of Optical and Electronic Information Wuhan National Laboratory for Optoelectronics Optics Valley Laboratory Huazhong University of Science and Technology Wuhan China China Telecom Research Institute Beijing102209 China

We propose a novel physical model-based QoT estimation with achieved OSNR estimation error 1.5 dB in primary paths and OSNR prediction error 1.76 dB in unestablished lightpaths for both super-C bands and super-C+L ban... 详细信息

ISBN: (纸本)9781957171258

关键词： Light transmission

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