摘要:

AbstractThis paper combines a new topology decomposition method of multistage MOS complex gates and the optimization technique for the transistor size. A method of automatic synthesis for the optimal circuit topology and the transistor size is proposed for a set of given finite topologies and for the given load capacitance and the maximum specified delay time.The procedure starts from the single‐stage complex logic circuit which is synthesized by the circuit synthesis program MoSyn [1]. By iterating the process called “cut,” the multistage circuit is constructed while restricting the number of transistors on the conduction path at the transistor circuit‐level. Then, the transistor size in the circuit is optimized for the several obtained multistage circuits using the two‐stage transistor size optimization method (MoSiz) [2, 3]. The area occupied by each circuit is evaluated.Finally, the circuit with the smallest circuit area is selected as the optimal solution. Circuit designs are actually attempted for several examples. Compared to the worst‐case circuit under the same load and delay conditions, the area is improved by 10 to 80 percent. It is verified that the optimal circuit topology depends on the given load capacitance and

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741201

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

年代:1991

数据来源: WILEY

摘要:

AbstractIn the design of logic circuits, it is not always true that the circuit constructed by the designer is the optimal one. From such a viewpoint, this paper proposes a method in which the first designed circuit is expanded backwardly, i.e., from the output back to the input, and more than one equivalent circuit of the same function is resynthesized and the one best satisfying the requirements is determined and adopted.In the proposed method, a fuzzy reasoning is introduced in the decision process. In this scheme, such requirements as the delay time, power consumption and the chip area are handled by the fuzzy reasoning. A selectability index known as “selection criterion value” is given to each generated circuit, and the objective logic circuit is selected according to this index.Such requirements as delay, etc., have different units and are often in a trade‐off relation. Therefore, these requirements are represented as relative values and are considered as circuit selection parameters in the fuzzy reasoning. Such parameterization enables easy understanding of the features of each circuit. It is easy also to decide which of the parameters of the trade‐off relation is to be emphasized in the selection

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741202

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

年代:1991

数据来源: WILEY

摘要:

AbstractIn the smearing process to suppress impulse noises and the pulse compression in long‐range radar, it is crucial to employ the finite binary sequence which minimizes the sidelobe of the autocorrelation function.This paper proposes a new generation algorithm for the finite binary sequence with a sharp autocorrelation function. The method is based on the fact that the autocorrelation function θ(n) of skew‐symmetric sequence is always zero whennis odd, and the Fourier expansion coefficient sequence of the complex exponential function is an uncorrelated sequence.First, the generating function is derived for the skew‐symmetric real‐valued sequence, for which the Fourier expansion coefficient sequence is an uncorrelated sequence. An algorithm is presented in detail, where the foregoing real‐valued sequence is quantized into a binary sequence, and the binary sequence minimizing the autocorrelation is derived with the finite delay coefficients of the generating function as the variables.In the past, no generation algorithm has been found which can derive the optimal skew‐symmetric binary sequence. It is shown that the proposed generation algorithm can derive all of the optimal skew‐symmetric binary sequence derived by Golay using the exhaustive method. It is shown also that all Barker sequences with off length

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741203

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

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper proposes a method for a numerical analysis of the bifurcation in the nonautonomous system containing hysteretic elements. Previously, the authors discussed the case where the characteristics of the hysteretic elements can be represented by Preisach's model, and proposed a method for steady‐state analysis of the nonautonomous system containing hysteretic elements.First, a method is presented to investigate the change of the steady‐state behavior with the variation of the system parameters by combining the proposed method and the continuation method. Then another method is presented in which the singular point on the characteristic curve (solution curve) is determined using the previously derived variational equations of the system. Finally, examples of analysis by the newly proposed method are presented, and the effects of the hysteresis loss and the ohmic loss on the bifurcation are compared. A remarkable difference between the two is indica

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741204

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

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper shows that the learning identification (the normalized LMS) algorithm can be expressed by a first‐order IIR low‐pass filter having rapidly varying coefficients as a function of output signal to be sent to an unknown system to be estimated. Based on the expression, this paper studies the estimation error of adaptive filters obtained by the learning identification algorithm. It is pointed out that the mean of estimation error given by the conventional analysis corresponds to the output fluctuation which can be computed by replacing varying coefficients of the lowpass filter with its arithmetic mean. However, the output fluctuation is affected by the time constant specified by the coefficients of the lowpass filter and it has a characteristic that it increases rapidly when time constant is short and decreases slowly when it is long. This means that the actual estimation error becomes larger than the result given by the conventional analysis.According to the analysis shown in this paper, it can be seen that the estimation error consists of elements for which the portion increased by the effect of time constant become fewer anti‐proportionally to the number of the tap, and those elements which increase at a constant rate independently of the number of the tap. It was shown also by simulation using white noise that the difference between the estimation error obtained in actual estimation operation which occurs when the number of the tap is small and the result given by the conventional analysis can be explained well by the analysis by simulation using white

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741205

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

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper proposes a method for designing an FIR digital filter which extracts an object moving in a fixed direction at a fixed speed on a plane (linear trajectory signal) with some margins concerning direction and speed independently. Signals to be considered are 3‐D signals on the 2‐D space‐time coordinates.The method herein enables processing by FIR‐type prototype filter of cubic‐symmetric characteristics by rotating signal data and designing a prototype filter in the digital domain directly. Since this design method is not based on optimization design such as an iterative algorithm but finds filter coefficients in an analytical manner, the computation time is extremely short. In addition, since it is a direct design in the digital domain, it does not requires‐ztransformation such as bilinear transformation and thus it is not affected by distortion caused by it. Moreover, because of the FIR type its feature is that we do not need to consider a stability check or phase

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741206

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

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper discusses the optimal design of linear‐phase three‐dimensional (3‐D) FIR digital filters in the least‐square sense. The design procedure is as follows. The linear‐phase 3‐D polynomial which is symmetric with respect to the origin is decomposed into four polynomials from the viewpoint of the symmetry (cubic symmetry, ω1and ω2axes skew symmetry, ω2and ω3, axes skew symmetry and ω1and ω3axes skew symmetry). Each of those resulting polynomials is then used as the filter model. Next, the filter parameters are determined analytically so as to minimize the square errors between the actual magnitude response of the filter and the ideal magnitude response.Finally, two numerical examples are given to demonstrate the validity of the theory. The proposed method allows us to reduce the computational complexity in the design since it is not necessary to use various optimization procedures or to calculate the inverse matrix. The filter with the desired response can be designe

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741207

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe objective of this paper is to provide a miniature quartz crystal resonator with a frequency around 1 MHz. Here, a new G‐type crystal resonator made of the vibrational portion and the supporting portion is presented. The frequency constant, frequency‐temperature characteristic and electrical characteristics are investigated theoretically and experimentally. The study is conducted with a view to realizing a small quartz crystal resonator superior in the frequency‐temperature characteristics and the electrical characteristics.First, the vibration analysis or the experimental investigation is carried out for the case of supporting portions in the length or width direction of the vibrational portion. It is understood that there exists a zero temperature coefficient in either case and that the series resistanceR1is smaller for the structure with a supporting portion in the width direction. With the cut angles ø =‐60 ∼−70°, and θ = 45° in the present resonator, the frequency constant is much smaller than the one in the GT cut. It is shown that a small quartz crystal resonator can be realized at frequen

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741208

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

年代:1991

数据来源: WILEY

摘要:

AbstractWhen a switched capacitor (SC) filter is made in an LSI form, it is important to reduce the total capacitance for reduction of the chip size, improve high‐frequency operation, and reduce power consumption. The total capacitance can be reduced by reducing the total capacitance when the minimum capacitance, is normalized to unity andyis the miniaturization of the capacitors on the chip. When the capacitor is made smaller, the error in the capacitance ratio increases so that the transfer characteristics of the SC filter are varied. To minimize the effect of this error, a circuit with a low element sensitivity is needed.In this paper, for a cascaded SC filter frequently used as a standard circuit, general conditions have been derived that must be satisfied by the pairing and order of the zeros and poles. First, the element sensitivity of the transfer function of the second‐order SC circuit is derived. Next, based on this result, the formula is derived which represents the element sensitivity of the transfer function of the cascaded SC filter. Based on this formula, the condition is derived for the pairing and order of the zeros and poles to reduce the element sensitivity.From the present study, it is found that the element sensitivity can be reduced by pairing nearby zeros with a highQpole and that the element sensitivity is independent on the order of poles and zeros. It is found also that the element sensitivity increases in proportion to the cutoff frequency of the filter. The foregoing results are confirmed by the simulation using 11‐th order low‐pass and high‐pas

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741209

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

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper discusses the speech recognition based on the time course of the local peak of the spectrum such as the formant, which has been considered important in the phoneme perception. A measure for the dynamical behavior of the spectrum is proposed based on the functional model of the FM‐neuron which is shown to exist in auditory physiology.First, the FM‐neuron is modeled as a time‐frequency filter for the spectral time‐series which responds only to the shift of the local peak frequency of the spectrum with the discrimination function for the shift direction. Then the measure to represent the difference of the output from the FM‐neuron model is derived based on the cepstral expansion of the spectrum. The measure is called the spectral movement similarity.It is shown that the spectral movement similarity on the auditory nonlinear frequency axis can be realized equivalently by the frequency weighting. A spoken word recognition experiment is conducted employing the dynamic time warping (DTW) using the spectral movement similarity. It is shown also that the recognition error is reduced greatly by combining the proposed measure and the traditional spectral distance compared to the case where only the traditional spectral distance is used. This improvement is more remarkable when the cepstral distance is used as the spectral distance, with the recognition error being reduced to o

ISSN:1042-0967    

DOI:10.1002/ecjc.4430741210

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

年代:1991

数据来源: WILEY