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Overview of radar detection methods for low altitude targets in marine environments

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Journal of Systems Engineering and Electronics 2024年第1期35卷 1-13页

作者： YANG Yong YANG Boyu school of Electronic Science National University of Defense TechnologyChangsha 410073China

In this paper,a comprehensive overview of radar detection methods for low-altitude targets in maritime environments is presented,focusing on the challenges posed by sea clutter and multipath *** performance of the radar detection methods under sea clutter,multipath,and combined conditions is categorized and summarized,and future research directions are outlined to enhance radar detection performance for low-altitude targets in maritime environments.

关键词： radar sea clutter multipath scattering detection low altitude target

Residual subsidence time series model in mountain area caused by underground mining based on GNSS online monitoring

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International Journal of Coal Science & Technology 2024年第2期11卷 173-186页

作者： Xugang Lian Lifan Shi Weiyu Kong Yu Han Haodi Fan school of Mining Engineering Taiyuan University of TechnologyTaiyuanChina

The residual subsidence caused by underground mining in mountain area has a long subsidence duration time and great potential harm,which seriously threatens the safety of people's production and life in the mining ***,it is necessary to use appropriate monitoring methods and mathematical models to effectively monitor and predict the residual subsidence caused by underground *** with traditional level survey and InSAR(Interferometric Synthetic Aperture radar)technology,GNSS(Global Navigation Satellite System)online monitoring technology has the advantages of long-term monitoring,high precision and more flexible monitoring *** empirical equation method of residual subsidence in mining subsidence is effectively combined with the rock creep equation,which can not only describe the residual subsidence process from the mechanism,but also predict the residual ***,based on GNSS online monitoring technology,combined with the mining subsidence model of mountain area and adding the correlation coefficient of the compaction degree of caving broken rock and the Kelvin model of rock mechanics,this paper constructs the residual subsidence time series model of arbitrary point on the ground in mountain *** the example,the predicted results of the model in the inversion parameter phase and the dynamic prediction phase are compared with the measured data *** results show that the model can carry out effective numerical calculation according to the GNSS monitoring data of any point on the ground,and the model prediction effect is good,which provides a new method for the prediction of residual subsidence in mountain mining.

关键词： Underground mining in mountain area Residual subsidence GNSS online monitoring Mathematical model Subsidence prediction

Machine learning-based comparison of factors influencing estimated glomerular filtration rate in Chinese women with or without nonalcoholic fatty liver

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World Journal of Clinical Cases 2024年第15期12卷 2506-2521页

作者： I-Chien Chen Lin-Ju Chou Shih-Chen Huang Ta-Wei Chu Shang-Sen Lee Department of Nursing Kaohsiung Armed Forces General HospitalKaohsiung 802Taiwan Department of Obstetrics and Gynecology Tri-Service General HospitalNational Defense Medical CenterTaipei 114Taiwan Chief Executive officer's Office MJ Health Research FoundationTaipei 114Taiwan Department of Urology Taichung Tzu Chi HospitalBuddhist Tzu Chi Medical FoundationTaichung 427Taiwan school of Medicine Tzu Chi UniversityHualian 970Taiwan Department of Urology Tri-Service General HospitalNational Defense Medical CenterTaipei 114Taiwan

BACKGROUND The prevalence of non-alcoholic fatty liver(NAFLD)has increased *** with NAFLD are known to have higher chance for renal function *** past studies used traditional multiple linear regression(MLR)to identify risk factors for decreased estimated glomerular filtration rate(eGFR).However,medical research is increasingly relying on emerging machine learning(Mach-L)*** present study enrolled healthy women to identify factors affecting eGFR in subjects with and without NAFLD(NAFLD+,NAFLD-)and to rank their *** To uses three different Mach-L methods to identify key impact factors for eGFR in healthy women with and without *** A total of 65535 healthy female study participants were enrolled from the Taiwan MJ cohort,accounting for 32 independent variables including demographic,biochemistry and lifestyle parameters(independent variables),while eGFR was used as the dependent *** from MLR,three Mach-L methods were applied,including stochastic gradient boosting,eXtreme gradient boosting and elastic *** of estimation were used to define method accuracy,where smaller degree of error indicated better model *** Income,albumin,eGFR,High density lipoprotein-Cholesterol,phosphorus,forced expiratory volume in one second(FEV1),and sleep time were all lower in the NAFLD+group,while other factors were all significantly higher except for smoking ***-L had lower estimation errors,thus outperforming *** Model 1,age,uric acid(UA),FEV1,plasma calcium level(Ca),plasma albumin level(Alb)and T-bilirubin were the most important factors in the NAFLD+group,as opposed to age,UA,FEV1,Alb,lactic dehydrogenase(LDH)and Ca for the *** the importance percentage was much higher than the 2nd important factor,we built Model 2 by removing *** The eGFR were lower in the NAFLD+group compared to the NAFLD-group,with age being was the most important impact factor in both groups of he

关键词： non-alcoholic fatty liver Estimated glomerular filtration rate Machine learning Chinese women

Modulated-ISRJ rejection using online dictionary learning for synthetic aperture radar imagery

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Journal of Systems Engineering and Electronics 2024年第2期35卷 316-329页

作者： WEI Shaopeng ZHANG Lei LU Jingyue LIU Hongwei College of Oceanography and Space Informatics China University of Petroleum(East China)Qingdao 266580China school of Electronics Engineering Xidian UniversityXi’an 710071China school of Electronics and Communication Engineering Shenzhen Campus of Sun Yat-sen UniversityGuangzhou 518107China school of Computer Science and Technology Xidian UniversityXi’an 710071China

In electromagnetic countermeasures circumstances,synthetic aperture radar(SAR)imagery usually suffers from severe quality degradation from modulated interrupt sampling repeater jamming(MISRJ),which usually owes considerable coherence with the SAR transmission waveform together with periodical modulation *** paper develops an MISRJ suppression algorithm for SAR imagery with online dictionary *** the algorithm,the jamming modulation temporal properties are exploited with extracting and sorting MISRJ slices using fast-time *** dictionary learning is followed to separate real signals from jamming *** the learned representation,time-varying MISRJs are suppressed *** simulated and real-measured SAR data are also used to confirm advantages in suppressing time-varying MISRJs over traditional methods.

关键词： synthetic aperture radar(SAR) modulated interrupt sampling jamming(MISRJ) online dictionary learning

Wideband radar cross-section reduction by a double-layer-plasma-based metasurface

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Plasma Science and Technology 2024年第6期26卷 159-168页

作者：赵智明李小平董果香刘旭牟相超 school of Aerospace Science and Technology Xidian UniversityXi’an 710126People’s Republic of China

Reduction of the radar cross-section(RCS) is the key to stealth technology. To improve the RCS reduction effect of the designed checkerboard metasurface and overcome the limitation of thinlayer plasma in RCS reduction technology, a double-layer-plasma-based metasurface—composed of a checkerboard metasurface, a double-layer plasma and an air gap between them—was investigated. Based on the principle of backscattering cancellation, we designed a checkerboard metasurface composed of different artificial magnetic conductor units;the checkerboard metasurface can reflect vertically incident electromagnetic(EM) waves in four different inclined directions to reduce the RCS. Full-wave simulations confirm that the doublelayer-plasma-based metasurface can improve the RCS reduction effect of the metasurface and the plasma. This is because in a band lower than the working band of the metasurface, the RCS reduction effect is mainly improved by the plasma layer. In the working band of the metasurface,impedance mismatching between the air gap and first plasma layer and between first and second plasma layers cause the scattered waves to become more dispersed, so the propagation path of the EM waves in the plasma becomes longer, increasing the absorption of the EM waves by the plasma. Thus, the RCS reduction effect is enhanced. The double-layer-plasma-based metasurface can be insensitive to the polarization of the incoming EM waves, and can also maintain a satisfactory RCS reduction band when the incident waves are oblique.

关键词： stealth technology radar cross-section(RCS)reduction backscattering cancellation double-layer-plasma-based metasurface

Scale effect removal and range migration correction for hypersonic target coherent detection

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Journal of Systems Engineering and Electronics 2024年第1期35卷 14-23页

作者： WU Shang SUN Zhi JIANG Xingtao ZHANG Haonan DENG Jiangyun LI Xiaolong CUI Guolong school of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

The detection of hypersonic targets usually confronts range migration(RM)issue before coherent integration(CI).The traditional methods aiming at correcting RM to obtain CI mainly considers the narrow-band radar ***,with the increasing requirement of far-range detection,the time bandwidth product,which is corresponding to radar’s mean power,should be promoted in actual ***,the echo signal generates the scale effect(SE)at large time bandwidth product situation,influencing the intra and inter pulse integration *** eliminate SE and correct RM,this paper proposes an effective algorithm,i.e.,scaled location rotation transform(ScLRT).The ScLRT can remove SE to obtain the matching pulse compression(PC)as well as correct RM to complete CI via the location rotation transform,being implemented by seeking the actual rotation *** to the traditional coherent detection algorithms,Sc LRT can address the SE problem to achieve better detection/estimation *** last,this paper gives several simulations to assess the viability of ScLRT.

关键词： hypersonic target detection coherent integration(CI) scale effect(SE)removal range migration(RM)correction scaled location rotation transform(ScLRT)

Construction of enhanced multi-polarization and high performance electromagnetic wave absorption by self-growing ZnFe_(2)O_(4)on Cu_(9)S_(5)

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1922-1934页

作者： Wenxiong Chen Honglong Xing school of Chemical Engineering Anhui University of Science and TechnologyHuainan 232001China

The development of 3D structural composites with electromagnetic(EM)wave absorption could attenuate EM ***,magnetized flower-like Cu_(9)S_(5)/ZnFe_(2)O_(4)composites were fabricated through a multistep hydrothermal *** crystallographic and surface phase chemical information,morphological structure,and magnetic and EM parameters of the composites were *** prepared Cu_(9)S_(5)/ZnFe_(2)O_(4)composites have multiple loss paths for EM waves and present an overall 3D flower-like *** Cu_(9)S_(5)/ZnFe_(2)O_(4)composites exhibit a minimum reflection loss of-54.38 dB and a broad effective absorption bandwidth of 5.92 *** magnetization,ZnFe_(2)O_(4)particles are self-assembled and grown on the surfaces of Cu_(9)S_(5).Such a modification is conducive to the generation of additional cross-linking contact sites and the effective introduction of a large number of phase interfaces,crystalline defects,special three-dimensional flower-like structures,and magneto-electrical coupling loss ***,the synergistic effect of multiple loss strategies effectively improves EM wave absorption by the *** work can provide a strategy for the use of magnetizationmodified sulfide composite functional materials in EM wave absorption.

关键词： self-assembled material electromagnetic wave absorption enhanced multi-polarization effect Cu_(9)S_(5)/ZnFe_(2)O_(4)composites radar cross-section

Single-pixel 3D imaging based on fusion temporal data of single-photon detector and millimeter-wave radar

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Chinese Optics Letters 2024年第2期22卷 172-179页

作者：赖廷钦梁晓琳朱毅吴欣怡廖联烨袁雪林苏萍孙仕海 school of Electronics and Communication Engineering Sun Yat-sen UniversityShenzhen 518107China Shenzhen Campus of Sun Yat-sen University Shenzhen 518107China Tsinghua Shenzhen International Graduate school Tsinghua UniversityShenzhen 518055China

Recently,there has been increased attention toward 3D imaging using single-pixel single-photon detection(also known as temporal data)due to its potential advantages in terms of cost and power ***,to eliminate the symmetry blur in the reconstructed images,a fixed background is *** paper proposes a fusion-data-based 3D imaging method that utilizes a single-pixel single-photon detector and millimeter-wave radar to capture temporal histograms of a scene from multiple ***,the 3D information can be reconstructed from the one-dimensional fusion temporal data by using an artificial neural *** the simulation and experimental results demonstrate that our fusion method effectively eliminates symmetry blur and improves the quality of the reconstructed images.

关键词： single-pixel imaging single-photon imaging millimeter-wave radar neural network

The Adjustment Analysis Method of the Active Surface Antenna Based on Convolutional Neural Network

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Research in Astronomy and Astrophysics 2024年第6期24卷 294-306页

作者： You Ban Shang Shi Na Wang Qian Xu Shufei Feng school of Mechanical Engineering Xinjiang UniversityUrumqi 830017China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China school of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Active surface technique is one of the key technologies to ensure the reflector accuracy of the millimeter/submillimeter wave large reflector *** antenna is complex,large-scale,and high-precision equipment,and its active surfaces are affected by various factors that are difficult to comprehensively deal *** this paper,based on the advantage of the deep learning method that can be improved through data learning,we propose the active adjustment value analysis method of large reflector antenna based on deep *** method constructs a neural network model for antenna active adjustment analysis in view of the fact that a large reflector antenna consists of multiple panels spliced *** on the constraint that a single actuator has to support multiple panels(usually 4),an autonomously learned neural network emphasis layer module is designed to enhance the adaptability of the active adjustment neural network *** classical 8-meter antenna is used as a case study,the actuators have a mean adjustment error of 0.00252 mm,and the corresponding antenna surface error is0.00523 *** active adjustment result shows the effectiveness of the method in this paper.

关键词： techniques:radar astronomy telescopes methods:analytical methods:numerical