摘要:

AbstractA study has been conducted on band‐limited waves f(t) of bandpass type, the Fourier spectrum F(ω) of which is identically zero outside an occupied band ωτ<∥ω∥<ωτ + ωb. Based on this study, we have obtained the following results: first, when an interpolation of a wave is attempted using a set of even‐numbered samples periodically repeated on both sides of the time axis at a mean distance between samples π/ωb (which in general are arranged ununiformly), the necessary and sufficient condition for said samples to restore a desired band‐limited wave having the same occupied bandwidth is demonstrated; second, a concrete formula of interpolation using a set of the prescribed type that satisfies the necessary and sufficient condition above, is introduced. Then a proof that demonstrates the impossibility that a formula which permits a set of samples of an odd number is periodically repeated at a mean interval of π/ωb to restore any desired band‐limited wave having the prescribed occupied bandwidth on the basis of interpolation unless ωτ or ωbsatisfies a special condition. Finally, relations between the possibility of interpolation and combinations of ωτ and ωbfor sample positions restricted to a certain extent if the mean interval between sampling points is sho

ISSN:8756-6621    

DOI:10.1002/ecja.4410690101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractLC simulation by active RC circuits generally requires an equal or a higher number of active elements than the order of the filter. This is one of the main difficulties that delays their practical applications as compared to cascade realizations. This paper proposes a method to simulate impedance‐scaled LCR filters using an equal or a lower number of voltage followers than the number of nodes in the original LCR filter. The influence of the imperfections of the voltage followers is also investigated. As simple examples, a 4th‐order bandpass filter and a 4th‐order lowpass filter are realized. Measurements and sensitivity analysis are performed on the 4th‐order bandpass filter and the results demonstrate the high performances of the method as compared to the other

ISSN:8756-6621    

DOI:10.1002/ecja.4410690102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractVehicle behavior of a PRT (Personal Rapid Transit system) multiberth station has already been analyzed as a continuous time system under the assumption of Poisson vehicle arrival and exponential passenger loading and unloading time [2]. However, it is more realistic to model it as a discrete time system considering a widely used point‐follower control. Thereby a general passenger loading and unloading time can be easily treated. An off‐line station with two berths in PRT, in which vehicles move on a guideway under point‐follower control, is modeled and analyzed as a discrete‐time Markov chain in this paper. The state quantity is defined based on the physical state of two berths at the arrival instance of a cell. First it is shown that the inter‐entrance time can be calculated numerically for a general passenger loading and unloading time. Then, several measures of the station behavior such as mean inter‐entrance time, entrance frequency and entrance factor are analytically obtained for the case of fixed passenger loading and unloading time, the opposite of the exponential distribution. The differences between two berths and one berth are discussed by showing numeric

ISSN:8756-6621    

DOI:10.1002/ecja.4410690103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractIn this paper, it is assumed that the ambiguous requirement and desired level of the decisionmaker for the objective functions in the multiobjective nonlinear programming problem can be quantified by eliciting the corresponding membership functions interactively. Then the region for the desired solution, called fuzzy satisficing region, is specified for the membership function by a membership value (required membership value) which is the minimum‐required value to be achieved, and another membership value (desired membership value), which should desirably be achieved. For such a fuzzy satisficing region of the decisionmaker, the penalty and the barrier functions are used to maximize the overachievement for the required membership value, and to minimize the underachievement for the desired membership value. In this way, the Pareto‐optimal solution for the specified fuzzy satisficing region is presented to the decisionmaker. The decisionmaker is either satisfied with the achieved Pareto‐optimal solution, or updates, on subjective basis, the required and the desired membership values. By reducing the fuzzy satisficing region in this way, it is possible eventually to derive the solution satisfactory to the decisionmaker from the set of Pareto‐optimal solutions for the given problem, through relatively simple interactive processes. An interactive computer program is constructed based on the proposed method, and an example for the course of interaction is shown for a numerical

ISSN:8756-6621    

DOI:10.1002/ecja.4410690104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractIn the transfer function with zeros restricted on the imaginary axis of S‐plane the phase characteristic is essentially determined by that of the denominator polynomial. As long as the denominator polynomial is a Hurwitz polynomial, the tangent of its phase characteristic, i.e., the ratio of the imaginary part (odd part) to the real part (even part), is a reactance function. This paper proposes a waveform approximation method which approximates the phase tangent of the Fourier transform of the object waveform by a reactance function using an optimization technique. The Hurwitz polynomial, which is the sum of the numerator and denominator of the reactance function, is adopted as the denominator polynomial of the approximate transfer function. The numerator polynomial of the approximate transfer function is derived by adjusting the zeros on the imaginary axis by an optimization technique to approximate the amplitude of the Fourier transform of the object waveform. An evaluation measure in the proposed approximation method is presented, describing its problems and physical implications. It is shown that the proposed method can provide a satisfactory approximation for symmetrical waveforms. For asymmetrical waveforms it is shown that the approximation can be improved by adding a delay time. An appropriate weighting function is proposed for the evaluation measure. Lastly, the proposed method is compared with other methods of approximatio

ISSN:8756-6621    

DOI:10.1002/ecja.4410690105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractThis paper proposes a new solution concept, based on the minimization, following the lexicographical order, of the complaint differences among coalitions in a cooperative n‐person game in characteristic function form. Such a solution minimizing the maximum complaint difference can be obtained as the pay‐off vector as the inequality constraints sequentially. A discussion is made on the pay‐off vector, which minimizes in the lexicographical order the complaint differences, taking the characteristics of the coalitions into consideration. Then as a method which can solve the formulated linear programming problem with less computational burden, an algorithm involving the relaxation method is proposed. A computer program was constructed and is applied to the cooperative water resource development pr

ISSN:8756-6621    

DOI:10.1002/ecja.4410690106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractChua and Tang reported a method based on the Volterra series to find the amplitude and frequency of the unknown fundamental wave component of a steady‐state oscillation resembling a sinusoidal wave generated in a self‐starting oscillation circuit. In the present paper, the method is used to find the higher‐order terms so that the harmonic components generated from the term related to the determination of the fundamental component can be found relatively easily. Formulas for the determination of such quantities are derived. Next, this method is used for the analysis of the van der Pol oscillator for which the detailed nature of the solution is available. The validity and the limitation of the application are studied. From the results, it is shown that reasonably accurate solutions can be derived for an oscillation waveform close to a sinusoid as well as a distorted one containing harmonic components. In this method there is no need to derive the differential equation for the oscillator. Insteady, only the algebraic equation found from the circuit diagram must be solved. Finally, this characteristic is used for analysis of an RC phase shift oscil

ISSN:8756-6621    

DOI:10.1002/ecja.4410690107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractIn earlier papers, we proposed a circularly polarized printed array antenna composed of strips and slots (CP‐PASS). We showed that it possessed good properties such as a good axial ratio, a relatively high gain, and had sufficient frequency bandwidths. The purpose of this paper is to obtain a practical design method for CP‐PASS in order to realize a desired radiation pattern or to increase further its antenna gain. First, an equivalent circuit model of a basic element set of CP‐PASS is represented taking into account interelement couplings and a feed line loss. On the basis of the equivalent circuit model, design conditions of circular polarization and input impedance matching are formulated for a normal use of CP‐PASS. Second, satisfying the above conditions, a procedure for determination of an arrangement, dimensions and input impedance of the elements is described to realize desired antenna properties. Numerical examples of CP‐PASS with uniform aperture distributions are shown to clarify its fundamental characteristics. Third, a practical method for determination of the element lengths and coupling gaps is described on the basis of the basic radiating‐element characteristics obtained before. Finally, to demonstrate the validity of the design method presented here, a Chebyshevarray CP‐PASS consisting of four element sets is designed and tested

ISSN:8756-6621    

DOI:10.1002/ecja.4410690108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractAn adaptive multistage vector quantizing system is proposed for highly efficient picture coding method and its coding performances are investigated. This system contains a multistage vector quantizer which means that comparatively large picture blocks are quantized first, then the remaining quantization error is quantized in smaller blocks, gradually refining the resolution at subsequent stages. That is, a rough picture is coded first and finer structures are coded later. Computer simulation studies on several picture samples demonstrate the excellent processing efficiency of the proposed method in comparison with conventional vector quantizers.

ISSN:8756-6621    

DOI:10.1002/ecja.4410690109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractA PN (Pseudonoise) code is often used for ranging systems, measurements or clock transmission, etc. Signal transmission using the PN code is effective even at low SNR. The delay‐lock loop is an effective circuit to detect PN code in such large noise, and is used widely. However, in the discriminator characteristic of conventional DLL, the range where the loop control signal can be gained is extremely narrow. Therefore, if the loop once loses lock for noise or for any reason, a large time is required for resynchronization. To compensate the fault of DLL, this paper proposes the improved DLL (IDLL‐1) with extended range of discriminator characteristic. Tracking performances are evaluated theoretically for a first‐order loop, and experimentally for a second‐order loop. Furthermore, the more improved DLL (IDLL‐2), which consists of IDLL‐1 and simple circuits, is proposed. Performance evaluation is done by experiments and

ISSN:8756-6621    

DOI:10.1002/ecja.4410690110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY