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Frequency response identification with cascade relay feedback

INTERNATIONAL JOURNAL OF CONTROL 2000年第18期73卷 1647-1656页

作者： Wang, QG Zhang, Y Natl Univ Singapore Dept Elect Engn Singapore 119260 Singapore

The standard relay arrangement can only identify one point (on the process frequency response) from the resultant stationary oscillations. In this paper, a new technique for process frequency response identification is presented, which can identify multiple points on the process frequency response from a single relay feedback test. A new relay, called cascade relay, is proposed and it can effectively excite a process not only at the process critical frequency omega (c) but also at 0:5 omega (c) and 1: 5 omega (c). Guidelines for relay parameters selection are suggested. The process frequency response at multiple frequencies can be accurately estimated from one relay test using the fft algorithm. The proposed method is robust to noise and step-like load disturbance. The technique can also be easily extended to identify other frequency response points of interest. Simulation shows its effectiveness.

关键词： Pid controllers Proportional Integral Derivative Control Relay feedback relay cascades fft algorithm relay test frequency response

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ITERATIVE PROCEDURE FOR DESIGNING TWO-DIMENSIONAL FIR FILTERS

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ELECTRONICS LETTERS 1987年第3期23卷 131-133页

作者： CETIN, AE ANSARI, R Moore School of Electrical Engineering University of Pennsylvania Philadelphia USA

We describe a new iterative method to design two-dimensional linear-phase FIR filters with arbitrary magnitude characteristic. The procedure is simple and can be used easily in designing filters of large order. This method is based on the use of the method of projection on to convex sets and can be implemented using the fft algorithm.

关键词： convex sets fast Fourier transforms iterative methods two-dimensional digital filters linear-phase Digital filters two-dimensional FIR filters iterative method arbitrary magnitude characteristic projection fft algorithm

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AN EFFICIENT METHOD FOR COMPUTING THE CAPACITANCE MATRIX OF MULTICONDUCTOR INTERCONNECTS IN VERY HIGH-SPEED INTEGRATED-CIRCUIT SYSTEMS

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 1995年第1期43卷 225-227页

作者： LUO, SP LI, ZF Department of Electronic Engineering Shanghai Jiaotong University Shanghai China

A new method for computing the capacitance matrix of multiconductor interconnects with finite metallization thickness is developed. Converting the vertical wall of the rectangular conductors into the equivalent horizontal strips allows the Green's function in the spectral domain and the fft algorithm to be used, which makes the method more effective for computing capacitance matrix of the interconnects.

关键词： multiconductor capacitance Spectral domain Circuits and systems Green\'s function new methods fft algorithm

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Fast Fourier transform analysis of dynamic data: Sine wave stress-strain analysis of biological tissue

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PHYSICS IN MEDICINE AND BIOLOGY 1997年第3期42卷 537-547页

作者： Wang, L Bert, JL Okazawa, M Pare, PD Pinder, KL UNIV BRITISH COLUMBIA PULM RES LAB VANCOUVER BC V6T 1Z4 CANADA

We propose an improvement to the dynamic oscillation method using as an example the measurement of the tensile stiffness of the rabbit tracheal mucosal membrane. A sine wave oscillation technique was used to study the tissue mechanical properties. A mathematical model was developed using fast Fourier analysis. After mathematically eliminating the machine response, this analysis reveals the tissue frequency response over a wide range of frequencies. This study addresses the advantages of using Fourier analysis to interpret dynamic properties of biological tissue and provides a complete description of how to obtain the pure tissue response.

关键词： Fourier analysis waves wide-range Strain analysis fft convolution dynamic characteristics fft algorithm Oscillations sin Fast Fourier transform Fourier Transform TISSUES (BIOLOGY)

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OPTIMAL EMBEDDINGS OF BUTTERFLY-LIKE GRAPHS IN THE HYPERCUBE

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MATHEMATICAL SYSTEMS THEORY 1990年第1期23卷 61-77页

作者： GREENBERG, DS HEATH, LS ROSENBERG, AL UNIV MASSACHUSETTS DEPT COMP & INFORMAT SCIAMHERSTMA 01003 VIRGINIA POLYTECH INST & STATE UNIV DEPT COMP SCIBLACKSBURGVA 24061

We present optimal embeddings of three genres of butterfly-like graphs in the (boolean) hypercube; each embedding is specified via a linear-time algorithm. Our first embedding finds an instance of the fft graph as a subgraph of the smallest hypercube that is big enough to hold it; thus, we embed then-level fft graph, which has (n+1)2 n vertices, in the (n+?log2(n+1)?)-dimensional hypercube, with unit dilation. This embedding yields a mapping of the pipelined fft algorithm on the hypercube architecture, which is optimal in all resources (time, processor utilization, load balancing, etc.) and which is on-line in the sense that inputs can be added to the transform even during the computation. Second, we find optimal embeddings of then-level butterfly graph and then-level cube-connected cycles graph, each of which hasn2 n vertices, in the (n+?log2 n?)-dimensional hypercube. These embeddings, too, have optimal dilation, congestion, and expansion. The dilation is 1+(n mod 2), which is best possible. Our embeddings indicate that these two bounded-degree approximations to the hypercube do not have any communication power that is not already present in the hypercube.

关键词： embedding Dilation Dilatation Hypercube Line graph Hypertrophy fft algorithm Optimal Butterfly Dilatation, Pathologic

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ANALYSIS OF THE MICROSTRIP YAGI ANTENNA BY AN ITERATIVE MPIE FORMULATION

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 1995年第3期8卷 123-124页

作者： BOKHARI, SA COSTACHE, GI Department of Electrical Engineering University of Ottawa 161 Louis Pasteur Ottawa Ontario K1N 6N5 Canada

The Letter presents a method for the rigorous analysis of the microstrip Yagi antenna. Using the mixed potential integral equation (MPIE) for patch antennas, the fft algorithm and the biconjugate gradient iterative method, the solution for the unknown current distribution on the patch is obtained in an efficient manner without requiring the storage of large matrices that typically arise in moment-method computations. Consequently, the scheme can deal with patches of arbitrary shapes and can handle a very large number of unknowns. Numerical results of input impedance and radiation patterns are compared with measured results. (C) 1995 John Wiley & Sons, Inc.

关键词： MICROSTRIP ANTENNA YAGI ANTENNA fft algorithm

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Amplitude spectral analysis of theta/alpha/beta waves in preterm infants

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PEDIATRIC NEUROLOGY 2006年第1期34卷 30-34页

作者： Okumura, A Kubota, T Tsuji, T Kato, T Hayakawa, F Watanabe, K Nagoya Univ Grad Sch Med Dept Pediat Showa Ku Nagoya Aichi 4668550 Japan Anjo Kosei Hosp Dept Pediat Anjo Japan Okazaki City Hosp Dept Pediat Okazaki Aichi Japan Aichi Shukutoku Univ Fac Med Welf Nagoya Aichi Japan

The aim of this study is to clarify the usefulness of amplitude spectral analysis for the evaluation of maturational changes of theta, alpha, and beta activities in preterm infants. We chose 10 healthy infants, who were born without complications other than prematurity, who were 29-30 weeks, 31-32 weeks, and 33-34 weeks of postconceptional age, respectively, at time of electroencephalogram recordings. Fast Fourier transform algorithm was applied for amplitude spectral analysis. The analyzed data were divided into five frequency bands: theta 14-6 Hz, theta 2 6-8 Hz, alpha 8-13 Hz, beta 1 13-20 Hz, and beta 2 20-30 Hz. The average amplitude of six segments with continuous patterns with high-voltage slow waves of preterm infants was calculated in each frequency band. A significant reduction of the amplitude along with postconceptional age was present in all leads in theta 1 and theta 2 bands. On the other hand, a significant correlation with postconceptional age was not observed in alpha, beta 1, or beta 2 bands. In conclusion, maturational electroencephalographic changes assessed by amplitude spectral analysis were prominent in theta activities and were not remarkable in alpha or beta activities. (c) 2006 by Elsevier Inc. All rights reserved.

关键词： Brain Electroencephalography Infant Premature 脑脑电描记术婴儿早产 Spectrum Analysis Hz fft algorithm Cerebrum Beta Rays Amplitude Electroencephalography

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Design of Multi-function Power Factor Instrument with STM32

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RECENT ADVANCES IN ELECTRICAL & ELECTRONIC ENGINEERING 2020年第6期13卷 925-932页

作者： Qi, Wenjuan Gao, Jixuan Wang, Zhongxian Heilongjiang Univ Sch Mech & Elect Engn POB 24474 XueFu St Harbin 150080 Peoples R China

Background: A multifunctional power factor device based on the fft algorithm has been designed. The digital panel can display power factor, voltage, current, frequency, phase angle, active power and reactive power. Objective: To solve the influence of the harmonic interference and the aperiodic component on the accuracy of power factor measurement. Method: In this paper, by combining a fixed-point 256-point fft algorithm and taking STM32 as the core microcontroller, the hardware circuit and the software program are designed respectively. The hardware circuit is tested and analyzed in practice. Among them, the hardware circuit mainly includes the main circuit design, STM32 control circuit design, EMI and second-order RC filter circuit design, sampling circuit design, and signal conditioning circuit design. The software program mainly includes the main program, AD conversion subroutine, voltage and current acquisition subroutine, LCD display subroutine and twirl factor array. fft algorithm is achieved by the table look-up method. Results: Finally, the hardware circuit is built and the software program is debugged to test the designed device. The experimental results show that the designed power factor instrument meets the task requirements under the different types of loads. Conclusion: After processing and analyzing the measurement results, it can be concluded that: under the pure resistive load, the maximal relative error of electrical parameters is 4.49%;and under the resistive inductive load, the maximal relative error of electrical parameters is 2.86%. Both results meet the design requirements.

关键词： Power factor device fft algorithm second-order RC filtering signal conditioning circuit aperiodic component STM32

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A NEW APPROACH TO THE FOURIER-ANALYSIS OF PERIODIC SIGNALS FOR THE MINIMIZATION OF THE PHASE ERRORS

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 1991年第4期40卷 694-698页

作者： FERRERO, A OTTOBONI, R UNIV CATANIA DIPARTIMENTO ELETTR ELETTRON & SISTEMI-95125 CATANIAITALY

The paper deals with the methods employed to reduce the errors in the determination of the harmonic phase of periodic signals by means of digital techniques. The genesis of these errors is discussed and an original method is proposed to minimize them while keeping the computation burden comparable with that of the classic fft algorithm. The results of some experimental work done to verify the proposed method are reported, showing that the phase errors can be reduced by up to two decades with respect to those typical of the usual methods.

关键词： phase error discrete Fourier transform DIGITAL TECHNIQUES PERIODIC SIGNAL Fourier analysis fft algorithm Phase

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Pretreatment for 2D Astronomical Spectrum Images with Low S/N before the Spectra Extracting

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PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC 2009年第875期121卷 54-58页

作者： Zhu, Zhangqin Wang, Chong Ye, Zhongfu Univ Sci & Technol China Inst Stat Signal Proc Hefei 230027 Peoples R China

It is difficult to extract multiple overlapping spectra accurately from low signal-to-noise ratio (S/N) 2D astronomical spectrum images. A pretreatment method is proposed in this article to deal with the problem. The combining of the empirical mode decomposition (EMD) algorithm and the fast Fourier transform (fft) algorithm is used to weaken the effect of the noise of low S/N astronomical spectrum images in order to get more accurate information on spectrum contours. At the end of this paper, experiments for different full width at half-maximum (FWHM) of point-spread functions (PSFs) are presented to demonstrate the effectiveness of the proposed method.

关键词： EMPIRICAL MODE DECOMPOSITION SINGLE IMAGES Spectra Empirical mode decomposition Pretreatment fft algorithm Noise effects supernovas

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