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Diagonally loaded SMI algorithm based on inverse matrix recursion

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Journal of Systems Engineering and Electronics 2007年第1期18卷 160-163页

作者： Cao Jianshu wang xuegang Coll. of Electronic Engineering Univ. of Electronic Science and Technology Chengdu 610054 P. R. China

The derivation of a diagonally loaded sample-matrix inversion （LSMI） algorithm on the busis of inverse matrix recursion （***-IMR algorithm） is conducted by reconstructing the recursive formulation of covariance matrix. For the new algorithm, diagonal loading is by setting initial inverse matrix without any addition of computation. In addition, a corresponding improved recursive algorithm is presented, which is low computational complexity. This eliminates the complex multiplications of the scalar coefficient and updating matrix, resulting in significant computational savings. Simulations show that the LSMI-IMR algorithm is valid.

关键词： Robust adaptive beamforming Space-time adaptive processing (STAP) Diagonal loading Inverse matrix recursion

Deep neural network based classification of rolling element bearings and health degradation through comprehensive vibration signal analysis

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Journal of Systems Engineering and Electronics 2022年第1期33卷 233-246页

作者： KULEVOME Delanyo Kwame Bensah wang Hong wang xuegang School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313001China

Rolling element bearings are machine components used to allow circular movement and hence deliver forces between components of machines used in diverse areas of *** likelihood of failure has the propensity of increasing under prolonged operation and varying working ***, the accurate fault severity categorization of bearings is vital in diagnosing faults that arise in rotating *** variability and complexity of the recorded vibration signals pose a great hurdle to distinguishing unique characteristic fault *** this paper, the efficacy and the leverage of a pre-trained convolutional neural network(CNN) is harnessed in the implementation of a robust fault classification *** the absence of sufficient data, this method has a high-performance ***, a modified VGG16 architecture is used to extract discriminating features from new samples and serves as input to a *** raw vibration data are strategically segmented and transformed into two representations which are trained separately and *** proposed approach is carried out on bearing vibration data and shows high-performance *** addition to successfully implementing a robust fault classification model, a prognostic framework is developed by constructing a health indicator(HI) under varying operating conditions for a given fault condition.

关键词： bearing failure deep neural network fault classification health indicator prognostics and health management

Rolling bearing fault diagnostics based on improved data augmentation and ConvNet

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Journal of Systems Engineering and Electronics 2023年第4期34卷 1074-1084页

Convolutional neural networks(CNNs)are well suited to bearing fault classification due to their ability to learn discriminative spectro-temporal ***,gathering sufficient cases of faulty conditions in real-world engineering scenarios to train an intelligent diagnosis system is *** paper proposes a fault diagnosis method combining several augmentation schemes to alleviate the problem of limited fault *** begin by identifying relevant parameters that influence the construction of a *** leverage the uncertainty principle in processing time-frequency domain signals,making it impossible to simultaneously achieve good time and frequency resolutions.A key determinant of this phenomenon is the window function's choice and length used in implementing the shorttime Fourier *** Gaussian,Kaiser,and rectangular windows are selected in the experimentation due to their diverse *** overlap parameter's size also influences the outcome and resolution of the spectrogram.A 50%overlap is used in the original data transformation,and±25%is used in implementing an effective augmentation policy to which two-stage regular CNN can be applied to achieve improved *** best model reaches an accuracy of 99.98%and a cross-domain accuracy of 92.54%.When combined with data augmentation,the proposed model yields cutting-edge results.

关键词： bearing failure short-time Fourier transform prognostics and health management data augmentation fault diagnosis

IF signals simulation of three-dimensional radar

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Journal of Systems Engineering and Electronics 2008年第3期19卷 486-492页

作者： Zhang Wei wang xuegang Zhu Zhaoda Dept. of Electronic Engineering Nanjing Univ. of Aeronautics & Astronautics Nanjing 210016 P. R. China School of Electronic Engineering Univ. of Electronic Science and Technology of China Chengdu 610054 P. R. China

Based on the analysis of the principles of frequency-phase scanning 3-D （three-dimensional） radar and the scattering mechanism of 3-D radar, the target and clutter IF （intermediate frequency） signals model of frequencyphase scanning 3-D radar is presented. The IF signals model of different channels of 3-D radar is presented in one simple formula in which complex waveform effects are considered. The simulation results obtained during tests are also provided in the end.

关键词： simulation three-dimensional radar IF signal frequency-phase scanning.

Design and implementation of 1 GHz high speed data acquisition system

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Journal of Systems Engineering and Electronics 2009年第1期20卷 55-59页

作者： Zou Lin wang xuegang Qian Lu School of Electronic Engineering Univ. of Electronic Science and Technology of China Chengdu 610054 P. R. China

With the development of current electronic technology, numerous high-speed data acquisition systems provide a variety of potential benefits. This article describes a high-speed data acquisition system which consists of ECL logic and TTL logic devices, samples and stores data with a 1 GHz clock. This system is accomplished easily and works stably. A performance test of this system has been undertaken and the results show that the effective number of bits （ENOB） is more than 6.5 bits.

关键词： A/D converter high-speed data acquisition system effective number of bits.

Space-time clutter model for airborne bistatic radar with non-Gaussian statistics

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Journal of Systems Engineering and Electronics 2009年第2期20卷 283-290页

作者： Duan Rui wang xuegang Jiang Chaoshu Chen Zhuming Dept.of Electronic Engineering Univ. of Electronic Science and Technology of China Chengdu 610054 P. R. China

To validate the potential space-time adaptive processing （STAP） algorithms for airborne bistatic radar clutter suppression under nonstationary and non-Gaussian clutter environments, a statistically non-Gaussian, space-time clutter model in varying bistatic geometrical scenarios is presented. The inclusive effects of the model contain the range dependency of bistatic clutter spectrum and clutter power variation in range-angle cells. To capture them, a new approach to coordinate system conversion is initiated into formulating bistatic geometrical model, and the bistatic non-Gaussian amplitude clutter representation method based on a compound model is introduced. The veracity of the geometrical model is validated by using the bistatic configuration parameters of multi-channel airborne radar measurement （MCARM） experiment. And simulation results manifest that the proposed model can accurately shape the space-time clutter spectrum tied up with specific airborne bistatic radar scenario and can characterize the heterogeneity of clutter amplitude distribution in practical clutter environments.

关键词： airborne bistatic radar clutter model geometry non-Gaussian

Krylov subspace method based on data preprocessing technology

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Journal of Systems Engineering and Electronics 2008年第6期19卷 1063-1069页

作者： Tang Bin wang xuegang Zhang Chaoshen Chen Kesong School of Electronic Engineering Univ. of Electronic Science and Technology of China Chengdu 610054 P. R. China Chengdu Aircraft Design & Research Inst. Chengdu 610041 P. R. China

The performance of adaptive beamforming techniques is limited by the nonhomogeneous clutter scenario. An augmented Krylov subspace method is proposed, which utilizes only a single snapshot of the data for adaptive processing. The novel algorithm puts together a data preprocessor and adaptive Krylov subspace algorithm, where the data preprocessor suppresses discrete interference and the adaptive Krylov subspace algorithm suppresses homogeneous clutter. The novel method uses a single snapshot of the data received by the array antenna to generate a cancellation matrix that does not contain the signal of interest （SOI） component, thus, it mitigates the problem of highly nonstationary clutter environment and it helps to operate in real-time. The benefit of not requiring the training data comes at the cost of a reduced degree of freedom （DOF） of the system. Simulation illustrates the effectiveness in clutter suppression and adaptive beamforming. The numeric results show good agreement with the proposed theorem.

关键词： adaptive beamforming Krylov subspace conjugate gradient algorithm nonhomogeneous clutter clutter suppress

Efficient structures for wideband digital receiver

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Journal of Systems Engineering and Electronics 2006年第3期17卷 483-486页

作者： wang Hong Lu Youxin wang xuegang Wan Yonglun Univ. of Electronic Science and Technology of China Chengdu 610054 P. R. China

Digital receivers have become more and more popular in radar, communication, and electric warfare for the advantages compared with their analog counterparts. But conventional digital receivers have been generally considered impractical for bandwidth greater than several hundreds MHz. To extend receiver bandwidth, decrease data rate and save hardware resources, three novel structures are proposed. They decimate the data stream prior to mixing and filtering, then process the multiple decimated streams in parallel at a lower rate. Consequently it is feasible to realize wideband receivers on the current ASIC devices. A design example and corresponding simulation results are demonstrated to evaluate the proposed structures.

关键词： digital receiver digital down-converter postpositional mixer structure least common multiple structure double frequency transfer structure.

Study of ultra-wideband radar signals-generated technology using two-channel signal generator

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Journal of Systems Engineering and Electronics 2007年第4期18卷 710-715页

作者： Wan Yonglun Lu Youxin Si Qiang wang xuegang Cao Guangping Southwest China Inst. of Electronic Technology Chengdu 610036 P. R. China Coll. of Electronic Engineering Univ. of Electronic Science and Technology of China Chengdu 610054 P.R. China

Synthesis of ultra-wideband （UWB） linear frequency modulation radar signals is a very important technology for microwave imaging, target identification and detection of low radar-cross-section （RCS） targets. A new method of UWB radar signals generation with two-channel signal generator is presented. The realization structure is given; the principle and errors of signal synthesis are analyzed. At the same time, an automatic .adjustment measure of signal phase is proposed because of phase discontinuity of waveform in this method. The simulation experiment and analysis results indicate that radar signals with large instantaneous bandwidth can be generated by means of this method on the condition that the high-speed digital devices are limited.

关键词： UWB DDS LFM two-channel signal generator pulse compression