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Robust adaptive radar beamforming based on iterative training sample selection using kurtosis of generalized inner product statistics

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Journal of Systems Engineering and Electronics 2024年第1期35卷 24-30页

作者： tian jing ZHANG Wei School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Electromagnetic Space Security Chengdu 610036China

In engineering application,there is only one adaptive weights estimated by most of traditional early warning radars for adaptive interference suppression in a pulse reputation interval(PRI).Therefore,if the training samples used to calculate the weight vector does not contain the jamming,then the jamming cannot be removed by adaptive spatial *** the weight vector is constantly updated in the range dimension,the training data may contain target echo signals,resulting in signal cancellation *** cope with the situation that the training samples are contaminated by target signal,an iterative training sample selection method based on non-homogeneous detector(NHD)is proposed in this paper for updating the weight vector in entire range *** principle is presented,and the validity is proven by simulation results.

关键词： adaptive radar beamforming training sample selection non-homogeneous detector electronic jamming jamming suppression

Color reproduction for noisy CFA data using directional cycle-spinning

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Journal of Systems Engineering and Electronics 2011年第3期22卷 528-533页

作者： Weiyu Yu jing tian Yonghao Xiao School of Electronic and Information Engineering South China University of TechnologyGuangzhou 510640P.R.China Provincial Key Laboratory for Computer Information Processing Technology School of Computer Science and TechnologySoochow UniversitySuzhou 215006P.R.China School of Electrical and Electronic Engineering Nanyang Technological UniversityNanyang Avenue 639798Singapore

This paper addresses color filter array（CFA） color reproduction problem where the aim is to utilize an image captured by the CFA to produce an image with full color ***,conventional subband synthesis based color reproduction techniques do not consider the noise during image acquisition and assume that the CFA data are *** tackle the noisy CFA data,a novel approach is proposed by inserting a subband denoising scheme into the conventional subband synthesis ***,conventional subband synthesis based techniques exploit the decimated wavelet transform that is not shift-invariant and could result in ringing artifacts in the *** alleviate these artifacts,the directional cycle-spinning（DCS） technique is ***,a new cycle-spinning pattern is proposed according to the sampling pattern of the Bayer CFA *** experiments are conducted to demonstrate that the proposed approach outperforms several approaches.

关键词： color filter array(CFA) cycle-spinning denoising.

A Novel Parameter Estimation Algorithm for DSSS Signals Based on Compressed Sensing

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Chinese Journal of Electronics 2015年第2期24卷 434-438页

作者： WU Shuang tian jing CUI Wei Radar Research Laboratory School of Information and ElectronicsBeijing Institute of Technology

A novel parameter estimation algorithm based on Compressed sensing(CS) for the Direct sequences spread spectrum(DSSS) signals in high dynamic environments is proposed. In this algorithm, Fractional Fourier transform(Fr FT) is first employed to estimate Doppler frequency rate, followed by the quadric phase term compensation. The compensation results are divided into several segments with equal length and coherent integration is carried out within each segment respectively. A convex optimization algorithm is applied to estimate the velocity and initial range of the target simultaneously based on the sparsity of target in the code phase domain. The proposed algorithm is capable of overcoming the limitation of Doppler frequency ambiguity and obtaining the accurate parameter estimates without correcting the code phase drift. Simulation results are presented to demonstrate the validity of the proposed algorithm.

关键词： Compressed sensing(CS) Fractional Fourier transform(Fr FT) Direct sequences spread spectrum(DSSS) Doppler frequency ambiguity

Theoretical Study on Mechanism of Reaction of OH with HO2NO2

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Chinese Journal of Chemical Physics 2008年第1期21卷 32-38页

作者： Yan tian tian-jing He Li He Fan-chen Liu Dong-ming Chen Department of Chemical Physics University of Science and Technology of China Hefei 230026 China Department of Electronic Science and Technology University of Science and Technology of ChinaHefei 230025 China School of Science Anhui Agricultural University Hefei 230036 China

The reaction of HO2NO2 （peroxynitric acid, PNA） with OH was studied by the hybrid density functional B3LYP and CBS-QB3 methods. Based on the calculated potential energy surface, five reaction channels, H20＋NO2＋O2, HOOH＋NO3, NO2＋HO3H, HO2＋HONO2 and HO2＋HOONO, were examined in detail. The major reaction channel is PNA＋OH→M1→TS1→H2O＋NO2＋O2. Taking a pre-equilibrium approximation and using the CBS-QB3 energies, the theoretical rate constant of this channel was calculated as 1.13×10-12 cm^3/（molecule s） at 300 K, in agreement with the experimental result. Comparison between reactions of HOONO2＋OH and HONO2＋OH was carried out. For HOR＋OH reactions, the total rate constants increase from R=NO2 to R=ONO2, which is consistent with experimental measurements.

关键词： Reaction Peroxynitric acid ab initio calculation Rate constant

PHOTO-INDUCED GRAFT POLYMERIZATION OF ACRYLAMIDE ON POLYPROPYLENE MEMBRANE SURFACE IN THE PRESENCE OF DIBENZYL TRITHIOCARBONATE

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Chinese Journal of Polymer Science 2007年第2期25卷 221-226页

作者： Qian Yang jing tian Zhi-kang Xu Institute of Polymer Science and Key Laboratory of Macromolecule Synthesis and Functionalization （Ministry of Education） Zhejiang University Hangzhou 310027 China

Ultraviolet （UV）-induced graft polymerization of acrylamide （AAm） on polypropylene substrates was successfully conducted using dibenzyl trithiocarbonate （DBTTC） as photoinitiator. It was confirmed by chemical analysis and surface morphology observation with attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. A possible mechanism for this graft process was presented, which suggested that, under UV irradiation, the C： S bond in DBTTC could split and abstract a hydrogen from the polypropylene surface and a surface free radical was then formed, and initiated the graft polymerization of AAm.

关键词： Graft polymerization Surface modification Acrylamide Trithiocarbonate UV.

Long term integration algorithm for high-dynamic targets

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Journal of Systems Engineering and Electronics 2016年第5期27卷 979-985页

作者： Gang Yang Haikun Luo jing tian Siliang Wu School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Remote Sensing Equipment Beijing 100854China Science and Technology on Electronic Information Control Laboratory Chengdu 610036China

A new long term integration algorithm is proposed forhigh-dynamic targets, which can resolve the problems of spectrumspread, frequency walk and pseudorandom noise （PRN）code phase curvature caused by the motion of targets. This algorithmfirst applies a keystone transform based improved discretepolynomial-phase transform （KT-IDPT） to estimate the Dopplerchirp rate. Then, based on the estimated Doppler chirp rate,dechirping and envelope translation are performed on the partialcorrelation results to correct the spectrum spread and the codephase curvature. The simulation results demonstrate that the proposedmethod has low integration loss and computational burden.

关键词： High-dynamic target long term integration motioncompensation.

Fabrication of three-dimensional WO_(3)/ZnWO_(4)/ZnO multiphase heterojunction system with electron storage capability for significantly enhanced photoinduced cathodic protection performance

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Journal of Materials Science & Technology 2021年第31期90卷 183-193页

作者： Chang Feng Zhuoyuan Chen jing tian Jiangping jing Li Ma Jian Hou Key Laboratory of Marine Environmental Corrosion and Bio-fouling Institute of OceanologyChinese Academy of SciencesQingdao 266071China State Key Laboratory for Marine Corrosion and Protection Luoyang Ship Material Research InstituteQingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China

A novel three-dimensional hierarchical WO_(3)photoelectrode was prepared by solvothermal method,and ZnO was deposited on its surface by electrochemical *** WO_(3)/ZnWO_(4)/ZnO multiphaseheterojunction photoelectrode was prepared by further annealing treatment to explore the photoinduced cathodic protection(CP)*** with WO_(3)and ZnO,the photoinduced CP and electron storage capacity performance of WO_(3)/ZnWO_(4)/ZnO is significantly improved in 3.5%NaCl solution without adding any hole *** electron storage capacity of the WO_(3)/ZnWO_(4)/ZnO heterojunction makes it possible to continuously protect metallic materials in the dark after switching off the light,which can realize long-term and effective photoinduced CP.

关键词： WO_(3)/ZnWO_(4)/ZnO Multiphase-heterojunction photoelectrode Three-dimensional hierarchical structure Photoinduced cathodic protection Electron storage capacity

Deep Fault Diagnosis for Rotating Machinery with Scarce Labeled Samples

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Chinese Journal of Electronics 2020年第4期29卷 693-704页

作者： ZHANG jing tian jing WEN Tao YANG Xiaohui RAO Yong XU Xiaobin School of Automation Hangzhou Dianzi University School of Electronic and Information Engineering Beijing Jiaotong University School of Mathematics and Statistics Henan University Hofon Automation Co. Ltd

Early and accurately detecting faults is crucial for the modern manufacturing *** proposed a novel Deep fault diagnosis(DFD) method for rotating machinery with scarce labeled samples.A spectrogram of the raw vibration signal is calculated by applying a Short-time Fourier transform(STFT).Several candidate Support vector machine(SVM) models are trained with different combinations of features in the feature pool with scarce labeled *** evaluating the pretrained SVM models on the validation set, the most discriminative features and best-performed SVM models can be selected, which are used to make predictions on the unlabeled *** predicted labels reserve the expert knowledge originally carried by the SVM *** are combined together with the scarce fine labeled samples to form an Augmented training set(ATS).Finally,a novel 2D deep Convolutional neural network(CNN)model is trained on the ATS to learn more discriminative features and a better *** results on two fault diagnosis datasets demonstrate the effectiveness of the proposed DFD.

关键词： Fault diagnosis Deep CNN Spectrograms Knowledge-transferring

Intercomparison of two trapezoid-based soil moisture downscaling methods using three scaling factors

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International Journal of Digital Earth 2019年第4期12卷 485-499页

作者： jing tian Xiangzheng Deng Hongbo Su Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographical Sciences and Natural Resources Research(IGSNRR)Chinese Academy of Sciences(CAS)BeijingPeople’s Republic of China Center for Chinese Agricultural Policy Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China Department of Civil Environmental and Geomatics EngineeringFlorida Atlantic UniversityBoca RatonFLUSA

This paper compared two soil moisture downscaling methods using three scaling *** 3 soil moisture product of advanced microwave scanning radiometer for EOS(AMSR-E)is downscaled from 25 to 1 *** downscaled results are compared with the soil moisture observations from polarimetric scanning radiometer(PSR)microwave radiometer and field *** results show that(1)the scaling factor of normalized soil thermal inertia(NSTIs)and vegetation temperature condition index(VTCI)are better than soil evaporative efficiency in reflecting soil moisture;(2)for method 1,NSTIS is the best in the downscaling of soil *** method 2,VTCI is the best;(3)no significant differences of the correlation coefficients(R2)and the biases were found between the two methods for the same scaling ***,method 2 shows a better potential than method 1 in the time-series applications of the downscaling of soil moisture;(4)compared with the relationship between the area-averaged soil moisture of AMSR-E and that of PSR,R2 of the 6 sets of the downscaled soil moisture almost do not decrease,which suggests the validity of the downscaling of soil moisture with the two downscaling methods using the three scaling factors.

关键词： Soil moisture downscaling trapezoid-based method scaling factor