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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1031-1041页

作者： Bo Sun Xi Wu Xi Chen Zixiao Zou Qiang Li Bixing Ren School of Electrical Engineering Southeast UniversityNanjingChina State Grid Jiangsu Electric Power Company Limited Research Institute NanjingChina

In recent years,with increasing amounts of renewable energy sources connecting to power grids,sub-/super-synchronous oscillations(SSOs)occurred more *** to the time-variant nature of SsO magnitudes and frequencies,as well as the mutual interferences among SsO modes with close frequencies,the accurate parameter estimation of SsO has become a particularly challenging *** solve this issue,this paper proposes an improved spectrum analysis method by improving the window function and a spectrum correction method to achieve higher ***,by aiming at the sidelobe characteristics of the window function as evaluation criteria,a combined cosine function is optimized using a genetic algorithm(GA).Furthermore,the obtained window function is self-convolved to extend its excellent characteristics,which have better performance in reducing mutual interference from other SSO ***,a new form of interpolated all-phase fast Fourier transform(IpApFFT)using the optimized window function is proposed to estimate the parameters of *** method allows for phase-unbiased estimation while maintaining algorithmic simplicity and *** performance of the pro-posed method is demonstrated under various conditions,com-pared with other estimation *** results validate the effectiveness and superiority of the proposed method.

关键词： Sub-/Super-synchronous oscillation(SSO) window function parameter estimation interpolated all-phase fast Fourier transform(ApFFT)

Cosine-modulated window function-based staggered-grid finite-difference forward modeling

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Applied Geophysics 2017年第1期14卷 115-124,191页

作者：王建孟小红刘洪郑婉秋贵生中国地质大学(北京) 北京100083 中国科学院地质与地球物理研究所中国科学院油气资源研究重点实验室北京100049

The numerical dispersion and computational cost are high for conventional Taylor series expansion staggered-grid finite-difference forward modeling owing to the high frequency of the wavelets and the large grid intervals. In this study, the cosine-modulated binomial window function （CMBWF）-based staggered-grid finite-difference method is proposed. Two new parameters, the modulated time and modulated range are used in the new window function and by adjusting these two parameters we obtain different characteristics of the main and side lobes of the amplitude response. Numerical dispersion analysis and elastic wavefield forward modeling suggests that the CMBWF method is more precise and less computationally costly than the conventional Taylor series expansion staggered-grid finite-difference method.

关键词： Elastic wave staggered grid window function cosine modulate

Wavelet Variance Analysis of EEG Based on window function

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Chinese Journal of Biomedical Engineering(English Edition) 2014年第2期23卷 54-59页

作者： ZHENG Yuan-zhuang YOU Rong-yi School of Science Jimei UniversityFujian Province

A new wavelet variance analysis method based on window function is proposed to investigate the dynamical features of electroencephalogram(EEG).The exprienmental results show that the wavelet energy of epileptic EEGs are more discrete than normal EEGs, and the variation of wavelet variance is different between epileptic and normal EEGs with the increase of time-window width. Furthermore, it is found that the wavelet subband entropy (WSE) of the epileptic EEGs are lower than the normal EEGs.

关键词： wavelet variance EEG wavelet subband entropy (WSE) window function

Optimized staggered-grid finite-difference operators using window functions

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Applied Geophysics 2018年第2期15卷 253-260,363页

作者： Ren Ying-Jun Huang Jian-Ping Yong Peng Liu Meng-Li Cui Chao Yang Ming-Wei School of Geosciences China University of Petroleum Qingdao 266580 China Qingdao National Laboratory for Marine Science and Technology Qingdao 266071 China Department of Mathematics and Statistics University of Calgary Calgary Alberta T2N 1N4 Canada.

The staggered-grid finite-difference （SGFD） method has been widely used in seismic forward modeling. The precision of the forward modeling results directly affects the results of the subsequent seismic inversion and migration. Numerical dispersion is one of the problems in this method. The window function method can reduce dispersion by replacing the finite-difference operators with window operators, obtained by truncating the spatial convolution series of the pseudospectral method. Although the window operators have high precision in the low-wavenumber domain, their precision decreases rapidly in the high-wavenumber domain. We develop a least squares optimization method to enhance the precision of operators obtained by the window function method. We transform the SGFD problem into a least squares problem and find the best solution iteratively. The window operator is chosen as the initial value and the optimized domain is set by the error threshold. The conjugate gradient method is also adopted to increase the stability of the solution. Approximation error analysis and numerical simulation results suggest that the proposed method increases the precision of the window function operators and decreases the numerical dispersion.

关键词： Staggered-grid finite-difference operator window function least squares numerical dispersion

Threshold flux-controlled memristor model and its equivalent circuit implementation

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Chinese Physics B 2014年第11期23卷 589-594页

作者：武花干包伯成陈墨 School of Eelctronic and Optical Engineering Nanjing University of Science and Technology School of Information Science and Engineering Changzhou University

Modeling a memristor is an effective way to explore the memristor properties due to the fact that the memristor devices are still not commercially available for common researchers. In this paper, a physical memristive device is assumed to exist whose ionic drift direction is perpendicular to the direction of the applied voltage, upon which, corresponding to the HP charge-controlled memristor model, a novel threshold flux-controlled memristor model with a window function is proposed. The fingerprints of the proposed model are analyzed. Especially, a practical equivalent circuit of the proposed model is realized, from which the corresponding experimental fingerprints are captured. The equivalent circuit of the threshold memristor model is appropriate for various memristors based breadboard experiments.

关键词： memristor window function equivalent circuit experiment

Convergence of FBP Algorithm for Tomography

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Acta Mathematicae Applicatae Sinica 2016年第4期32卷 963-968页

作者： Gang-rong QU School of Science Beijing Jiaotong University Beijing 100044 China Beijing Center for Mathematics and Information Interdisciplinary Sciences Beijing 100048 China

Filter back-projection （FBP） algorithms are available and extensively used methods for tomogra- phy. In this paper, we prove the convergence of FBP algorithms at any continuous point of image function, in L2-norm an... 详细信息

关键词： FBP algorithm convergence window function

A new family of windows——convolution windows and their applications

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Science China(Technological Sciences) 2005年第4期48卷 468-480页

作者： ZHANG Jieqiu1,2, LIANG Changhong1 & CHEN Yanpu3 1. Department of Applied Math. & Phys., College of Science, Airforce Engineering University, Xi’an 710051, China 2. National Key Laboratory of Antennas and Microwave Technology, Xidian University, Xi’an 710071, China 3. Computer Center, Xi’an Communication College, Xi’an 710106, China 1. Department of Applied Math. & Phys. College of Science Airforce Engineering University 710051 Xi’an China 2. National Key Laboratory of Antennas and Microwave Technology Xidian University 710071 Xi’an China 3. Computer Center Xi’an Communication College 710106 Xi’an China

A new family of windows is constructed by convolutions via a few rectangular windows with same time width and is thus referred to as convolution windows. The expressions of the second-order up to the eighth-order convolution windows in both the time and frequency domains are derived. Their applications in high accuracy harmonic analysis of periodic signals are investigated. Comparisons between the proposed windows and some known windows with the same width shows that, when the synchronous deviation of data sampling is slight, the proposed ones have the least effect of spectral leakage. Therefore, the new windows are well suited for high accuracy harmonic analysis and parameter estimation for periodic signals. The error analysis and computer simulations show that the estimation errors, corresponding to frequency, amplitude and phase of every harmonic component of a signal, are proportional to the pth power of the relative frequency deviation in case of the pth-order convolution window is applied to windowing signal of approximately p cycles. By introducing real time adjustment in sampling interval, the proposed algorithm can adaptively trace signal frequency and lead to less sampling synchronous deviation. The proposed approach has the advantages of easy implementation and high measure precision and can be used in harmonic analysis of quasi-periodic signals whose fundamental frequency drifts slowly with time.

关键词： signal processing harmonic analysis window function convolution window synchronous error spoctral leakage

Testing Jitter on PLL Clocks Based on Analysis of Instantaneous Phase

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Tsinghua Science and Technology 2007年第S1期12卷 101-104页

作者：朱彦卿何怡刚方葛丰阳辉齐绍忠刘惠 College of Electrical and Information Engineering Hunan University

A novel method based on the analysis of instantaneous phase is proposed to extract the jitter on phase-locked loops output clock. The method utilizes the Hilbert transform to extend the real signal of PLLs output into an analytic signal, and the implementation of Hilbert transform is based on the Fourier transform windowed with Hamming window. Then, the jitter of clock is extracted from the instantaneous phase of analytic signal. The experimental results of simulations validate that the proposed method can effectively extract the jitter on PLL clock, and it has better performance by comparing the sinusoidal jitter extraction results with the other methods.

关键词： phase-locked loops (PLLs) jitter Hilbert transform window function

Comparative analysis of memristor models and memories design

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Journal of Semiconductors 2018年第7期39卷 92-103页

作者： Jeetendra Singh Balwinder Raj VLSI Lab Department of ECE Dr.B.R.Ambedkar National Institute of Technology Jalandhar

The advent of the memristor breaks the scaling limitations of MOS technology and prevails over emerging semiconductor devices. In this paper, various memristor models including behaviour, spice, and experimental are investigated and compared with the memristor＇s characteristic equations and fingerprints. It has brought to light that most memristor models need a window function to resolve boundary conditions. Various challenges of availed window functions are discussed with matlab＇s simulated results. Biolek＇s window is a most acceptable window function for the memristor, since it limits boundaries growth as well as sticking of states at boundaries. Simmons tunnel model of a memristor is the most accepted model of a memristor till now. The memristor is exploited very frequently in memory designing and became a prominent candidate for futuristic memories. Here, several memory structures utilizing the memristor are discussed. It is seen that a memristor-transistor hybrid memory cell has fast read/write and low power operations. Whereas,a 1 T1 R structure provides very simple,nanoscale,and non-volatile memory that has capabilities to replace conventional Flash memories. Moreover, the memristor is frequently used in SRAM cell structures to make them have non-volatile memory. This paper contributes various aspects and recent developments in memristor based circuits, which can enhance the ongoing requirements of modern designing criterion.

关键词： memristor modeling window function nonlinear non-volatile memory

High-Speed Parallel Matched Filter Designing and FPGA Implementation

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Wuhan University Journal of Natural Sciences 2010年第4期15卷 335-339页

作者： ZHANG Qinglin, CHEN Shuzhen, LUO Yijun, WANG Shan School of Electronic Information, Wuhan University, Wuhan 430072, Hubei, China School of Electronic Information Wuhan University Wuhan Hubei China

Matched filter is one of the key technologies to achieve high-speed data transmission. In this paper,a parallel finite-impulse response (FIR) filter structure based on polyphase filter-ing is used to achieve high-speed matched filter in quadrature phase-shift keying (QPSK) demodulation up to 800 Mb·s-1. First,a window function is employed of to obtain impulse response of matched filter. Second,the high-speed parallel FIR structure is presented based on polyphase filtering. Then,the filter with EP2S180F1020 on the Quartus II 7.2 platform is achieved. The final results show that the design is correct and can implement high-speed matched filtering,wherein the equivalent frequency of which is up to 2 037 MHz. In addition,this scheme is easy to real-ize,which brings great value to the application of this filter in high-speed matched filters design in demodulation systems.

关键词： parallel matched filter finite-impulse response (FIR) window function polyphase filtering field programmable gate array