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SHORT-STEP-STUB CHEBYSHEV IMPEDANCE TRANSFORMERS

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 1986年第8期34卷 863-868页

作者： VANDERWALT, PW Department of Electrical and Electronic Engineering University of Stellenbosch Stellenbosch South Africa

A transfer function for short-step impedance transforming filters consisting of short cascaded TEM transmission-line sections and at least one commensurate length open-circuit stub is described. Element values are given for a particular family of octave-bandwidth short-step transformers that are much more compact than existing short-step transformers.

关键词： Chebyshev approximation Transformers Impedance Stripline Bandwidth density estimation robust algorithm Transfer functions Filters Microwave integrated circuits

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AUTOMATED RECORDING OF LETTUCE ROOT ELONGATION AS AFFECTED BY AUXIN AND ACID PH IN A NEW RHIZOMETER WITH MINIMUM MECHANICAL CONTACT TO ROOTS

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PLANT AND CELL PHYSIOLOGY 1986年第8期27卷 1475-1487页

作者： TANIMOTO, E WATANABE, J NAGOYA CITY UNIV COLL GEN EDUC PHYS LAB MIZUHO KU NAGOYA AICHI 467 JAPAN

The elongation of many lettuce [Lactuca sativa] roots was separately recorded at the same time by a new rhizometer with minimum mechanical contact to root tips. The apparatus was operated by a microcomputer system interfaced with field-effect transistor circuits. Elongation responses of intact seedling roots (ISR), decotylized seedling roots (DSR) and excised apical roots (EXR) to different concentrations of H+ and IAA were compared. A pH 4-induced acid growth was observed only in DER and EXR, whereas a pH 3-induced one was observed in all roots. Duration of pH 3-induced elongation was shorter in ISR than in DSR and EXR. Growth curves suggested that ISR is more susceptible to acid-injury than EXR. The maximum acid growth was obtained to pH 2.5 in EXR which is comparable to thick roots of maize [Edwards and Scott (1974) Planta 119:2]. Indole-3-acetic acid showed growth inhibition at concentration higher than 10-8 M which is comparable to other reports on thick roots. It is concluded that fine lettuce roots have the same magnitude of sensitivity to external concentration of H+ and IAA as thick roots. It is also suggested that root excision or decotylization make roots less susceptible to acid-injury, resulting in greater acid-growth of EXR. Further characteristics and application of the new rhizometer are discussed.

关键词： Root PH mechanical contact Auxins Indoleacetic Acids ISR growth inhibitory concentration Lettuce Automated recording Elongation recording density estimation robust algorithm Comparable dynamic shear rheometer

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MODERN SINGLE-SIDEBAND EQUIPMENT OF THE NETHERLANDS POSTALS TELEPHONE AND TELEGRAPH

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PROCEEDINGS OF THE INSTITUTE OF RADIO ENGINEERS 1948年第8期36卷 970-980页

作者： VANDERWYCK, CTF Radio Laboratory of the Dutch Postal Telegraph and Telephone Service The Hague Netherlands

After we introduction, a short description is given of the equipment developed before 1940, followed by a survey of the principles of the modern equipment. The way in which the automatic tuning in the receiver in accomplished is described in detail. A summary is given of the advantages of the modern equipment with respect to the earlier art. In an appendix, some theoretical considerations are given with respect to the automatic tuning control; particularly, the conditions for a stable circuit are derived.

关键词： Telephony Telegraphy Circuit optimization Frequency Radio transmitters Automatic control Laboratories Filters Oscillators density estimation robust algorithm

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UNIFORM DISTRIBUTION OF PRIME POWERS AND SETS OF RECURRENCE AND VAN DER CORPUT SETS IN Z^k

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ISRAEL JOURNAL OF MATHEMATICS 2014年第2期201卷 729-760页

作者： Bergelson, Vitaly Kolesnik, Grigori Madritsch, Manfred Son, Younghwan Tichy, Robert Ohio State Univ Dept Math Columbus OH 43210 USA Calif State Univ Los Angeles Dept Math Los Angeles CA 90032 USA Graz Univ Technol Dept Anal & Computat Number Theory A-8010 Graz Austria

We establish new results on sets of recurrence and van der Corput sets in Z(k) which refine and unify some of the previous results obtained by Sarkozy, Furstenberg, Kamae and Mendes France, and Bergelson and Lesigne. ... 详细信息

关键词： UNIFORM DISTRIBUTION PRIME POWERS VAN DER CORPUT SETS IN Z~k density estimation robust algorithm Uniform distribution Uniforms SETTING Relapse

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DETECTION OF A DISTRIBUTED TARGET

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 1971年第5期AES7卷 922-&页

作者： VANDERSP.GA Physics Laboratory National Defence Research Organization The Hague Netherlands

The influence of increasing range resolution on the detectability of targets with dimensions greater than the resolution cell is studied. An N-cell target model is assumed, which contains k reflecting cells, each reflecting independently according to the same Rayleigh amplitude distribution. It will be referred to as the (N,k) target. Detection based on one transmitted pulse is performed against a background of white normal noise. Detection in stationary clutter is also considered. The optimum detector is obtained but, in view of its complexity, the performance of a simpler detector, the square-law envelope detector with linear integrator (SLEDLI), is analyzed, and a formula for the probability of detection is obtained. Graphs are presented which show the probability of detection as a function of signal-to-noise ratio (SNR) for various values of N k, and false alarm probability. For N/k not too large it is shown that the SLEDLI is near optimum.

关键词： Envelope detectors Radar detection Signal resolution Energy resolution White noise Clutter density estimation robust algorithm Physics Laboratories Background noise

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PERMANENT-MAGNET OPERATING-CONDITIONS IN SOME ELECTRICAL MACHINES - INFLUENCE OF THE FIELD INTENSITY AND ANGLE

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IEEE TRANSACTIONS ON MAGNETICS 1995年第3期31卷 1805-1808页

作者： MERLE, R YONNET, JP DIOP, A BINESTI, D ELECT FRANCE DERF-93206 ST DENISFRANCE ELECT FRANCE DERF-77250 MORET SUR LOINGFRANCE

From measurements on NdFeB permanent magnets and numerical simulation of 3 types of electrical machines, this paper presents a good representation of the behavior of these magnets in various operating conditions.

关键词： Permanent magnets Magnetic field measurement Coercive force Electromagnetic wave polarization Electromagnets density estimation robust algorithm Numerical simulation Circuits Magnetic hysteresis Saturation magnetization

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Unsupervised Land Cover Change estimation Using Region Covariance Estimates

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IEEE GEOSCIENCE AND REMOTE SENSING LETTERS 2019年第3期16卷 347-351页

作者： Olding, W. C. Olivier, J. C. Salmon, B. P. Kleynhans, W. Univ Tasmania Sch Engn Hobart Tas 7005 Australia CSIR Meraka Inst Remote Sensing Res Unit ZA-0081 Pretoria South Africa

In this letter, we demonstrate the utility of estimating a probabilistic model of the underlying seasonal and interannual variations experienced by land cover time series in a given geographical region. Time series that deviate from these trajectories due to the human-induced change appear as outliers and can be detected using their Mahalanobis distance from the mean under the joint distribution of time samples. We apply this model to a collection of pixel time series acquired by the Moderate Resolution Imaging Spectroradiometer platform over Limpopo province, South Africa, for the task of identifying human settlement expansion. For estimation of the time of change, we present a hypothesis testing approach that tests for a decrease in correlation between samples before and after the change. This was found to be highly effective, yielding a mean absolute error of 52 days.

关键词： Change detection algorithms covariance matrices density estimation robust algorithm remote sensing time series analysis

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THE TRUE DIMENSION OF CERTAIN BINARY GOPPA CODES

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IEEE TRANSACTIONS ON INFORMATION THEORY 1990年第2期36卷 397-398页

作者： VANDERVLUGT, M Department of Mathematics and Informatics Leiden University Leiden Netherlands

By applying a result from algebraic geometry due to E. Bombieri (Amer. J. Math., vol.88, p.71-105, 1966), the true dimension of certain binary Goppa codes is calculated. The results lead in many cases to an improvemen... 详细信息

关键词： Reed-Solomon codes density estimation robust algorithm Polynomials Mathematics Informatics Linear code Binary codes

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Inversion of the Van der Monde matrix

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IEEE SIGNAL PROCESSING LETTERS 1996年第4期3卷 119-120页

作者： Neagoe, VE Department of Electronics and Telecommunications Polytechnic University of Bucharest Bucharest Romania

In this letter we deduce an analytical formula for inversion of a complex Van der Monde matrix. It has applications in signal reconstruction, spectral estimation, system identification, as well as in other important signal processing problems. Since till now the inversion of such a matrix has been performed by approximations, we further deduce an exact inversion formula.

关键词： density estimation robust algorithm Signal processing Discrete Fourier transforms Signal reconstruction System identification Senior members Polynomials Algebra Interpolation

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PEAK FACTOR MINIMIZATION USING A TIME-FREQUENCY DOMAIN SWAPPING algorithm

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 1988年第1期37卷 145-147页

作者： VANDEROUDERAA, E SCHOUKENS, J RENNEBOOG, J Dienst ELEC Faculteit Togepaste Wetenschappen Vrije Universiteit Brussel Brussels Belgium Vrije Univ. Brussel Belgium

An algorithm is presented to minimize the peaks in the time domain of bandlimited Fourier signals. This method has the ability to compress signals effectively without disturbing their spectral magnitudes. A computationally efficient algorithm is presented that leads to strongly compressed signals (crestfactors of 1.41 compared to 1.67). The method is applicable not only to flat spectrum magnitudes but to any frequency domain energetic distribution.< >

关键词： Minimization methods Time frequency analysis density estimation robust algorithm Frequency measurement Frequency response Transfer functions Linear systems System testing Quantization PSNR

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