摘要:

AbstractThis paper considers the case where hysteresis is given by the Preisach model and discusses the stability analysis for the periodic solution in the nonautonomous system containing hysteretic elements. The behavior of the system containing hysteretic elements is affected by the history of the system until it arrives at the steady state.In this paper, it is shown first that even periodic solutions with the same hysteretic loop may have different variational systems for the steady‐state solution if the histories until arriving at the steady state are different. Next, two kinds of stability criteria are considered based on the difference of the history up to the steady state and the stability against the external disturbance is investigated. The dependence of the stability of the solution on the bifurcation of the periodic solution also is discussed. Finally, examples of numerical analysis are presented to verify the result of discussion

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760501

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

年代:1993

数据来源: WILEY

摘要:

AbstractModular multiplication:R=A · BmodN(whereA, B, N, andRare integers) is an essential operation used in public‐key cryptosystems such as RSA, El Gamal, and Rabin. Thus, if high‐speed modular multiplication circuits can be constructed, these cryptosystems can operate at high speeds. In this paper, we show how to construct, with a high‐speed modular multiplication circuit which employs parallel processing methods using systolic arrays, a circuit which performs modular exponentiation by repeated modular multiplication. In particular, we demonstrate its validity by using the RSA scheme as a first concrete example. Since a circuit using the method of this paper as its construction rule has simple and regular structure, it provides an optimal construction of a highspeed RSA chip in VLSI. The method is also applicable for a simple implementation of the RSA scheme with small‐sized chips. In this case, the number of chips needed by this method (the circuit size) allows the practical realization of proportionately higher speeds. Flexibility can be achieved for a change in the number of key bits by a corresponding increase or decrease in the number

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760502

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

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper proposes a design method for the FIR two‐channel perfect quadrature mirror filter (QMF) with the linear phase. The two‐channel perfect QMF can be designed by Vetterli's method, where a system of equations representing the condition for the perfect reconstruction of the signal is solved. The filter designed by this method, however, does not, in general, have good frequency characteristics.This paper presents the design for the two‐channel QMF with a perfect reconstruction and a good amplitude characteristic. The method is based on Vetterli's method, and a constraint to approximate the amplitude characteristic in the frequency domain is added to the condition of perfect reconstruction in time domain. Then Remez' algorithm is applied to the derived system of equations.The construction of the two‐channel perfect QMF, when the coefficient is quantized, also is discussed. Furthermore, a method is shown in which the two‐dimensional (2‐D) perfect QMF is designed by applying the McClellan transformation to the obtained 1‐D QMF. The condition for the McClellan transformation for the perfect reconstructi

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760503

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

年代:1993

数据来源: WILEY

摘要:

AbstractIn the fields of signal transmission and its processing, compensation of phase or group delay distortion is an important problem.This paper proposes an approximation method of group delay characteristic of one‐dimensional (1‐D) and 2‐D discrete‐time systems using an extended equation error function as its performance index. Since the phase approximation problem is inherently nonlinear, some iterative approaches have been proposed. Its disadvantage is in the increase of the amount of computation.Another method to transform group delay approximation problem to power spectrum approximation problem is presented. This indirect approach leads to the minimum squared error problem which is easily solved but does not yield a satisfactory result.In the first part of this paper, the 1‐D group delay approximation problem is formulated to a linear problem in group delay domain. Then we apply the quasi‐least mean squared method to it. In the latter part of this paper, the 1‐D method is extended to the 2‐D group delay approximation problem. Some examples are shown to verify the effectivenes

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760504

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

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper considers the controlled discrete event systems modeled by Petri nets with external input places. A maximal element in the set of permissive feedbacks is called a maximally permissive feedback. First, a simpler condition is derived for its unique existence which does not require constructing the set of permissive feedbacks.Next, a necessary and sufficient condition is derived for the reachable set under the unique maximally permissive feedback to be equal to the set of markings which satisfy the given predicate. Moreover, synthesis of the unique maximally permissive feedback is demonstrated for a simple manufacturing system.

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760505

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

年代:1993

数据来源: WILEY

摘要:

AbstractTwo methods have been proposed for calculating the block orthogonal projection algorithm using the Moore‐Penrose generalized inverse matrix. One is the conjugate gradient method, and the other is the block adaptive algorithm composed of the Gram‐Schmidt orthogonalization and the learning identification. Both computation methods are suited to the high‐speed estimation of the optimal coefficients with a small computational complexity. However, the operation may become very unstable due to the effects of observation error, quantization error, and other factors.This paper proposes a method of realizing the block orthogonal projection algorithm with the learning identification, where the orthogonal basis of the space spun by the state matrix in the block adaptive filter is used as the direction of modification. A feature of this method is that the orthogonal basis is calculated using the orthogonal projection matrix. Computer simulation shows that the proposed adaptive algorithm realizes a very stable operation without being affected by either the quantization error, the operational error, or the observation

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760506

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

年代:1993

数据来源: WILEY

摘要:

AbstractA derivation of the Riccati equation giving a necessary and sufficient condition forH∞control by state feedback is presented. It is proved by solving the LQ‐max problem which is equivalent to the satisfaction condition (H∞norm constraint condition) such that the uniform norm ∣Tvz∣ of a transfer operatorTfrom the disturbancevto the controlled outputzis kept below a prescribed γ.Based on the state space representation, the proof is achieved by extending optimal regulator theory. While normal proofs are based fundamentally on the analysis of theH∞norm in the frequency domain, it is performed fully in the time domain. This paper provides a direct and self‐c

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760507

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

年代:1993

数据来源: WILEY

摘要:

AbstractA length extensional mode quartz crystal resonator of small size and good antishock performance and which functions at relatively low frequencies of 200 kHz to 1.536 MHz has been used in pagers and IC cards. An on/off repetition in quartz resonators of this type is common and therefore the start‐up transient performance becomes important.This paper describes a length extensional mode quartz crystal resonator with plural vibration bars which has a short start‐up time. The objective of this paper is to clarify both theoretically and experimentally motional inductanceL1, frequency characteristics and temperature dependence of resonance frequency, and also electric properties of the resonator.Motional inductanceL1is derived first. Especially,L1is found theoretically to be inversely proportional to the number of bars. Next, a vibration analysis of bars and supporters is made by taking into account the lateral motions based on an energy method and then a frequency equation is derived. The frequency characteristics, temperature dependence of resonance frequency, and electric properties are analyzed and compared with experimental results. The calculated results are found to be in agreement with the experimental ones. Finally, it is shown that a length extensional mode quartz resonator exhibits a short start‐up time, sinceL1andR1are compared to the single‐bar case. Such resonators are believed to be manufactured in a small form and also exhibit a good anti‐shock performance since vibrational and supporting portions can be made as one solid body by an etchi

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760508

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

年代:1993

数据来源: WILEY

摘要:

AbstractThe circuit with zero sensitivity at the matching points is desirable in the sense that a very low sensitivity can be expected in the passband. It should also be noted that the wave digital filter (WDF) with a II‐cascade structure has the advantage that the sensitivity in the stopband is lower than WDF with aT‐cascade structure. However, the synthesis method has not been known for WDF with a II‐cascade structure with the zero amplitude sensitivity at the matching points which can realize an arbitrary transfer function. This paper is an attempt to realize such a WDF.First, it is shown what type of sections should be used as the reference section of a doubly resistor‐terminated reactance filter. The two terminating resistances are set equal to avoid the situation where the sensitivity at the matching point turns out to be nonzero because of the effect of the terminating resistance ratio. Then the replacement of the multiplier is shown so that the forementioned state is maintained, even if the multiplier coefficients are quantized.It is shown that WDF exists corresponding to each section, where the forementioned replacement can be applied and the structural boundedness is retained even after the coefficients are quantized. As a result, it is shown that WDF actually exists with a II‐cascade structure with the zero amplitude sensitivity at the matching points which can realize an arbitrary transfer

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760509

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

年代:1993

数据来源: WILEY

摘要:

AbstractAn ultrasonic system for measuring a leaky surface acoustic wave (SAW) velocity is described. A leaky SAW transducer consisting of a piezoelectric ceramic thin plate, an interdigital transducer (IDT), and a fused quartz plate is used in this system. A longitudinal wave which is reradiated from a test sample surface into a water layer is detected as electric signals having different delay times received at two different IDTs placed on a substrate surface. A phase difference between two delayed signals depends on the leaky SAW velocity. It is essential in this measurement method that an incident angle of an ultrasonic beam be nearly equal to the Rayleigh angle. The present method using a layered structure leaky SAW transducer has the advantage of a wider range of detecting SAW velocities, compared to a conventional single‐layer SAW one. Experimental results for a 128° rotated Y‐cut‐X propagation LiNbO3plate and a glass plate are discussed. The layered structure leaky SAW transducer is useful for nondestructive evaluation of piezoelectric as well as nonpiezoelectric subs

ISSN:1042-0967    

DOI:10.1002/ecjc.4430760510

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

年代:1993

数据来源: WILEY