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Micro-Doppler feature extraction of micro-rotor UAV under the background of low SNR 被引量:5
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作者 HE Weikun SUN Jingbo +1 位作者 ZHANG Xinyun LIU Zhenming 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第6期1127-1139,共13页
Micro-Doppler feature extraction of unmanned aerial vehicles(UAVs)is important for their identification and classification.Noise and the motion state of the UAV are the main factors that may affect feature extraction ... Micro-Doppler feature extraction of unmanned aerial vehicles(UAVs)is important for their identification and classification.Noise and the motion state of the UAV are the main factors that may affect feature extraction and estimation precision of the micro-motion parameters.The spectrum of UAV echoes is reconstructed to strengthen the micro-motion feature and reduce the influence of the noise on the condition of low signal to noise ratio(SNR).Then considering the rotor rate variance of UAV in the complex motion state,the cepstrum method is improved to extract the rotation rate of the UAV,and the blade length can be intensively estimated.The experiment results for the simulation data and measured data show that the reconstruction of the spectrum for the UAV echoes is helpful and the relative mean square root error of the rotating speed and blade length estimated by the proposed method can be improved.However,the computation complexity is higher and the heavier computation burden is required. 展开更多
关键词 micro-rotor unmanned aerial vehicle(UAV) low signal to noise ratio(SNR) MICRO-DOPPLER feature extraction parameter estimation
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Performance Analysis of Two CFAR Detectors in Clutter Edge Situation 被引量:1
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作者 He You Department of Electronic Engineering, Naval Aeronautical Engineering Academy Yantai 264001, P. R. China Guan Jian Department of Electronic Engineering, Tsinghua University, Beijing 100084, R R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2001年第2期44-51,共8页
This paper studies the performance of the GOSGO and GOSSO CFAR detectors [1] in clutter edge situation. The authors derive the analytic expressions of the false alarm probabilities in that situation, analyze their per... This paper studies the performance of the GOSGO and GOSSO CFAR detectors [1] in clutter edge situation. The authors derive the analytic expressions of the false alarm probabilities in that situation, analyze their performances against clutter edge, and compare them with the OS, CA, GO and SO detectors. The results show that GOSGO possesses better performance than GO for countering clutter, but the performance of GOSSO is very unideal. 展开更多
关键词 Alarm systems Clutter (information theory) Gaussian noise (electronic) signal to noise ratio White noise
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Signal recovery method based on co-prime array
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作者 Shuang Qiu Weixing Sheng +2 位作者 Xiaofeng Ma Yubing Han Renli Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第2期224-234,共11页
A signal waveform recovery method based on the co-prime array is investigated to extract the waveform of the desired signal from spatial interferences in narrowband scenarios. The direction of arrivals (DOAs) of the d... A signal waveform recovery method based on the co-prime array is investigated to extract the waveform of the desired signal from spatial interferences in narrowband scenarios. The direction of arrivals (DOAs) of the desired signal and interference signals are estimated with the compressive sensing approach based on angle grids, and the signal power together with the noise power are estimated. Thereafter, a modified steepest descent (SD) method is derived to recover the waveform of the desired signal and interferences utilizing the estimated power and directions. The recovered waveform of the desired signal is the output of the proposed method. The situation in which the signals are not on the predefined angle grids is also considered. The DOAs estimated via the predefined angle grids are corrected based on the maximum likelihood (ML) angle estimation. Compared to the existing beamforming methods on co-prime array, the proposed method can obtain the waveform of the desired signal. Simulation results demonstrate that the proposed method can achieve good performance in signal waveform recovery and output signal to noise ratio. © 2017 Beijing Institute of Aerospace Information. 展开更多
关键词 Compressed sensing Maximum likelihood Maximum likelihood estimation RECOVERY signal reconstruction signal to noise ratio
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Optimizing electrophoretic deposition conditions for enhancement in electrical conductivity of carbon fiber/carbon nanotube/epoxy hybrid composites 被引量:1
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作者 王一奇 BYUN Joon-hyung +1 位作者 KIM Byung-sun SONG Jung-il 《Journal of Central South University》 SCIE EI CAS 2012年第11期3017-3022,共6页
The effectiveness of optimizing electrical conductivity of carbon fiber/carbon nanotube (CNT)/epoxy hybrid composites via Taguchi method was demonstrated. CNTs were induced on carbon fabric by electrophoretic deposi... The effectiveness of optimizing electrical conductivity of carbon fiber/carbon nanotube (CNT)/epoxy hybrid composites via Taguchi method was demonstrated. CNTs were induced on carbon fabric by electrophoretic deposition (EPD) technique. The essential deposition parameters were identified as l) the deposition time, 2) the deposition voltage, 3) the mass fraction of CNTs in suspension, and 4) the distance between the electrodes. An experimental design was then performed to establish the appropriate levels for each factor. An orthogonal array of L9 (34) was designed to conduct the experiments. Electrical conductivity results were collected as the response. The relative influences of design parameters on the response were discussed. Using the model, signal to noise (S/N) ratio and response characteristics for the optimized deposition parameter combination were predicted. The results show clearly that the optimum condition of electrophoretic deposition (EPD) process improves the electrical conductivity of carbon/epoxy hybrid composites. 展开更多
关键词 design of experiment electrophoretic deposition carbon nanotube Taguchi method signal to noise (S/N) ratio analysisof variance (ANOVA)
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On the Small SNR Processing Ability of IR Point Target Detection
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作者 Song, Liuping Sun, Zhongkang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1993年第3期28-36,共9页
Three-dimensional (3-D) matched filtering has been suggested as a powerful processing technique for detecting weak, moving IR point target immersed in a noisy field. Based on the theory of the 3-D matched filtering an... Three-dimensional (3-D) matched filtering has been suggested as a powerful processing technique for detecting weak, moving IR point target immersed in a noisy field. Based on the theory of the 3-D matched filtering and the optimal linear processing, the optimal point target detector is being analyzed in this paper. The performance of the detector is introduced in detail. The results provide a standard reference to evaluate the performance of any other point target detection algorithms. 展开更多
关键词 ALGORITHMS Correlation detectors Digital signal processing Image processing signal detection signal to noise ratio Systems analysis Three dimensional
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An Adaptive Method of Image CompressionBased on Wavelet Analysis
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作者 Xu Hao Dept. of Biomedical Engineering, Shanghai Jiaotong University, 200030, P. R. China Yu Jun Dept. of Computer and Engineering, Hangzhou University of Commerce, 310035, P. R. China Yao Min Dept. of Computer, Zhejiang University, Hangzhou 310028, P. R. 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2001年第1期53-58,共6页
Through research for image compression based on wavelet analysis in recent years, we put forward an adaptive wavelet decomposition strategy. Whether sub-images are to be decomposed or not are decided by their energy d... Through research for image compression based on wavelet analysis in recent years, we put forward an adaptive wavelet decomposition strategy. Whether sub-images are to be decomposed or not are decided by their energy defined by certain criterion. Then we derive the adaptive wavelet decomposition tree (AWDT) and the way of adjustable compression ratio. According to the feature of AWDT, this paper also deals with the strategies which are used to handle different sub-images in the procedure of quantification and coding of the wavelet coefficients. Through experiments, not only the algorithm in the paper can adapt to various images, but also the quality of recovered image is improved though compression ratio is higher and adjustable. When their compression ratios are near, the quality of subjective vision and PSNR of the algorithm are better than those of JPEG algorithm. 展开更多
关键词 Adaptive algorithms Image coding Image quality signal to noise ratio Wavelet transforms
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