摘要:

AbstractThis paper proposes a tracking filter to track the maneuvering target, controlled by the input which is unknown to the observer. The method estimates the constant component of the acceleration input, which is then utilized in the estimation and prediction of the position and the velocity. In the constant velocity, straight‐line motion, the acceleration of the moving target is only a perturbation of trajectory by turbulence, etc., which can be considered as a noise in the system. However, in circular motion, a considerably large acceleration is continuously added to the fluctuation. Consequently, the acceleration is divided into the system noise and the bias or deterministic input. The latter component is estimated under the assumption that it changes only slowly. The tracking filter is then constructed using the result of the above analysis to the estimation and prediction of the position and the velocity. The proposed tracking filter aims at the adaptation to the nonstationary motion of the maneuvering target and the tracking to both circular and straight line motions. The filtering can be generalized as a method of state estimation including the estimation of input, and one can expect other applications. Finally, the effectiveness of the proposed filter is demonstrated by a simulatio

ISSN:8756-6621    

DOI:10.1002/ecja.4410690701

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

年代:1986

数据来源: WILEY

摘要:

AbstractSince error correcting and detecting codes are used in many fields, the assessment of the code performance in actual communication environments is an important subject. A communication channel is expressed by a statistical model and the assessment is usually done by simulation and/or analysis method. However, conventional assessment methods are insufficient from the viewpoint of ease of handling, precision, etc. In this paper we present new methods for evaluating error‐correcting and error‐detecting codes. These evaluations make use of a new compound channel model which represents actual channels better than the channel models proposed previously. An exact analysis is used for computing the performances of codes. For these reasons, we can obtain reliable results. The time required for the evaluation is relatively small. Furthermore, their adaptability to various channels and codes is high and they are easy to use. Methods of evaluating the double encoding scheme, a well‐known scheme in CIRC, is also presented. Finally, some examples of evaluating codes by these methods are presented and their effectiveness is

ISSN:8756-6621    

DOI:10.1002/ecja.4410690702

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

年代:1986

数据来源: WILEY

摘要:

AbstractThis paper proposes an estimation method for the system parameters in the low‐frequency range of the direct‐radiator loudspeaker system. The system parameters considered in this paper are defined by the elements in the electrical and mechanical equivalent circuit in the low‐frequency range. In previous estimations of the system parameters, the impedance measurement was required for the driver speaker in the free space or in the standard box. On the other hand the proposed method can provide estimations for the system parameters, including the proper additional air mass and the effective volume of the box for the driver speaker and the passive radiator (drone cone or port), only by the measurement of the system impedance. Consequently, it is a practically useful method. The estimation is made by minimizing (optimizing) the evaluation function by the nonlinear optimization, which is composed of the square sum of the difference between the measured and calculated impedances at the voice‐coil terminals of the driver speaker at a finite number of discrete frequencies. Eight kinds of methods are examined for efficient estimation. By computer simulation and two examinations, the validity and usefulness of the method are indicated. Since the method can provide estimations of the true system parameters, it can present effective means for the system

ISSN:8756-6621    

DOI:10.1002/ecja.4410690703

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

年代:1986

数据来源: WILEY

摘要:

AbstractA three‐dimensional finite‐element method for determining the vector fields within a closed system containing inhomogeneous materials of arbitrary shape is described in terms of all three components of the magnetic field vector. One drawback associated with the powerful vector formulation is the appearance of spurious, nonphysical solutions. A modified functional has been introduced to reduce the spurious solutions. To show the validity and usefulness of this formulation, examples are computed for resonant frequencies of normal modes in a rectangular cavity partially loaded with dielect

ISSN:8756-6621    

DOI:10.1002/ecja.4410690704

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

年代:1986

数据来源: WILEY

摘要:

AbstractInformation processing in a biological system is more redundant than in a computer system, realizing real‐time processing, eventhough the individual processing speed is low. This paper discusses a neuron electronic model; it is considered the core of biological information processing that has application to engineering problems. The circuit is based on the element which uses a Λ‐shaped transistor, a three‐terminal voltage‐controlled negative‐resistance device, to realize both negative resistance and inductance. It is shown that a hardware neuron model can be constructed by a simple circuit. The existence of a threshold and the generation of action potential are discussed, together with other characteristics of the model. It is then shown that, by improving the Λ‐shaped transistor, a hardware neuron model can be constructed with the self‐organizing function with adjustable threshold. The model is compared with BVP and HH models. A hardware neuron model with K‐conductance characteristics of H‐H model is constructed, followed by the discussion of characteristics such as those for constant‐current stimulation. Through this analysis, it is demonstrated that the proposed model can well simulate the biological neuron, and has the potential to be applied

ISSN:8756-6621    

DOI:10.1002/ecja.4410690705

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

年代:1986

数据来源: WILEY

摘要:

AbstractIt is well known that a flexuraltorsional quartz crystal resonator which couples a torsional mode vibration to a flexural mode vibration, has a cubic curve in frequency temperature characteristics as well as an AT cut quartz crystal resonator. This paper describes the frequency‐temperature characteristics of a tuning fork‐type quartz crystal resonator which couples the torsional mode vibration to the flexural mode vibration and the estimated results of the various constants for the resonator manufactured for trial experiments. First, a secular equation coupled the torsional mode vibration to the flexural mode vibration is calculated. From the secular equation, frequency‐temperature characteristics for the flexural‐torsional mode tuning fork‐type resonator have been analyzed theoretically, specifically concerning a relationship of the resonant frequency, the frequency‐temperature coefficients vs. thickness, a normalized frequency and a cut angle. Next, by manufacturing tuning fork‐type flexural‐torsional quartz crystal resonators, the calculated values are compared with the experimental values, at the same time, the various constants of the resonators manufactured for trial experiments are estimated. As a result, it is confirmed that tuning fork‐type flexural‐torsional quartz crystal resonators with excellent frequency‐temperature characteristics, low‐crystal impedance, and a high qual

ISSN:8756-6621    

DOI:10.1002/ecja.4410690706

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

年代:1986

数据来源: WILEY

摘要:

AbstractMost of the common sounds in our daily life change their frequencies transiently, and it is important in engineering applications such as voice recognition and instrument tone discrimination to find a correspondence between the physical properties of these sounds of changing frequency and human perception. This paper reports on the experimental study of masking by tone bursts of changing frequency as an effort toward clarifying such dynamic auditory perception. First, using artificial formant stimuli the masking patterns for continuous tones were measured with the formant frequency changed discontinuously. The results showed masking overshoot at the formant transition and forward and backward masking phenomena, which suggests a characteristic extraction of the voice formant transition in the auditory system. Next, using various combinations of artificial formant and “bridge” tones as the masker, the masking patterns for continuous tones mixed with the masker at various phases were measured. As a result it became clear that the resultant pattern is not a simple addition of individual maskings by the component tones and shows relatively sharp bandpass filter characteristics in the critical band of the auditory system. This suggests the existence of a special processing mechanism for compound consonants in the auditory sys

ISSN:8756-6621    

DOI:10.1002/ecja.4410690707

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

年代:1986

数据来源: WILEY

摘要:

AbstractAnalytical results by the integral equation method are described for the problem of electromagnetic scattering from perfectly conducting polygonal cylinders with TE and TM wave incidence. This approach is extended to the case of TE wave scattering by a set of perfectly conducting polygonal cylinders. In the presence of several conducting cylinders the mutually interacting surface current densities are used for deriving the integral equations. The latter are reduced to simultaneous equations by step function approximations of the current distributions. Numerical examples include the surface current distributions on a concave conducting cylinder and multiple rectangular cylinders and their scattering patterns as well as the near field distributions, which have not been evaluated extensively to date. It is found that a strong standing wave is caused in the electric field between the rectangular cylinders due to multiple scattering. To confirm validity of the theory, a model experiment is performed at microwave frequency. It is confirmed that the theoretical experimental results are in good agreement. The results of the present paper provide a calculation model for wave propagation in an urban community. They can be used as a basis of such propagation.

ISSN:8756-6621    

DOI:10.1002/ecja.4410690708

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

年代:1986

数据来源: WILEY

摘要:

AbstractIn conventional radio interference measuring apparatus, the direct‐QP detection method is used. In this method, intermediate frequency output is added directly to a quasi‐peak detector to obtain an output corresponding to the quasi‐peak level of the interference. However, a new type of QP detection method has recently been used in the radio interference measuring apparatus as demonstrated in the spectrum analyzer with the quasi‐peak detection capability. In this method, the intermediate frequency output is first added to an envelope detector and then to quasi‐peak detector. But it is not yet known if this measuring apparatus with its combination of detector, the envelope‐QP detector, satisfies all standards, including present CISPR specifications. The latter is determined based on the response characteristics of the direct‐QP detector system. In this paper, theoretical computer comparison has been made between the direct‐QP detector system and the envelope‐QP detector system to study responses to Gaussian noise and the repeated pulse input. It is found that the measuring apparatus with an envelope QP detector does not easily satisfy the present CISPR specifications. To improve the response characteristics of this new apparatus having the envelope‐QP detector, guidelines, have been indicated for the bandwidth and the charge and disch

ISSN:8756-6621    

DOI:10.1002/ecja.4410690709

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

年代:1986

数据来源: WILEY

摘要:

AbstractFM demodulators using Digital Signal Processing (DSP) are smaller and more reliable than conventional analog FM demodulators. The authors have already proposed an improved tangent‐type FM demodulator (I‐TAN) capable of extending the demodulation range without introducing distortion.This paper proposes a new range‐extended TAN‐type FM demodulator (RE‐TAN) capable of extending the demodulation range for wideband FM signal without increasing the sampling rate.The range can be extended incrementally by increasing the number of stages of the range extender proposed in t

ISSN:8756-6621    

DOI:10.1002/ecja.4410690710

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

年代:1986

数据来源: WILEY