摘要:

AbstractSSBL (super‐short‐base‐line) is an acoustic reference system in which the angle of incidence (direction cosine) and the slant range of the acoustic wave are estimated to locate the source position. A new SSBL acoustic reference system differing from conventional systems is proposed. The new system uses a planar hydrophone array consisting of many hydrophone elements. When a maximum likelihood estimate is implemented for the direction cosine and slant range measured by a planar hydrophone array, the estimate is given so that the envelope of the spatial‐temporal correlation between the array output and the reference signals is maximized. When the short array condition is satisfied for a planar hydrophone array, this spatial‐temporal correlation is given by the temporal correlation, phase compensation and addition. We obtained the lower bound of the mean‐square error of estimates of the direction cosine and slant range and compared the performance of the system with that of conventional systems. For example, when a square planar array of 4 × 4 = 16 elements is used, system gains of about 16 dB for the direction cosine and 12 dB for the slant range ar

ISSN:8756-6621    

DOI:10.1002/ecja.4410650302

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

年代:1982

数据来源: WILEY

摘要:

AbstractA three‐level optimization algorithm is proposed for a large‐scale nonlinear programming problem with nonconvexity and block angular structures based upon the general duality theorem. In the three‐level optimization algorithm the augmented Lagrangian function as well as the auxiliary variables of the second term in the augmented Lagrangian function are introduced to resolve the so‐called duality gap and conversion is done to obtain an additively separable form. Then, an independent partial problem is solved and the dual function is determined by using the sum of the object functions in the partial problem. Further, an example of application with simple numerical data and nonconvexity is shown to confirm appropriateness of the proposed three‐level optimization

ISSN:8756-6621    

DOI:10.1002/ecja.4410650303

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe fact that a power spectrum is inversely proportional to frequency is of interest in the fields of engineering, physics, and physiology. This paper presents a theoretical design method for a network whose power spectrum response to noise is a good approximation to the so‐called 1/f‐response in a given frequency band between lower and upper limiting frequencies. The network is a filter whose transfer function to white noise is 1/√s. The input impedance of a cascade connection of semi‐elementary sections composed of symmetrical RC lattices whose image impedances are 1/√sis a close approximation to 1/√s. Design formulas and diagrams of the approximating function, showing the relationships between the parameters of the frequency band, the approximation and the degree of the approximating function are given. A filter whose transfer function is an approximating function is realized by a cascade of symmetrical RC lattices and an operational amplifier. An experimental test of a tenth degree filter shows good characteristics in the frequency band 1 Hz ‐ 100 kHz. It is shown that the approximating function is applicable in the design of a Wiener filter for the reduction of 1/

ISSN:8756-6621    

DOI:10.1002/ecja.4410650304

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

年代:1982

数据来源: WILEY

摘要:

AbstractAs a speech analysis method using the generalized cepstrum there is a method based on a generalized logarithmic function instead of a logarithmic function as an evaluation scale. This paper presents a speech synthesis system using the generalized cepstrum, which is defined as the Fourier coefficients of the generalized logarithmic spectrum. The direct approximated digital filter using the Padé approximation, which is the inverse function of the generalized logarithmic function, is used as a synthesis filter. Since this filter not only gives a good approximation of the desired generalized logarithmic spectrum by a generalized cepstrum but also since the values of generalized cepstra correspond to the filter coefficients as they are, it is easy to determine the synthesis filter coefficients. Since the synthesis system in this paper is fully compatible with the one based on the conventional cepstrum method, it is possible to synthesize speech by the generalized cepstrum without changing the speech synthesis system based on the conventional cepstrum method. Also, using this synthesis system, it is possible to synthesize speech by the conventional cepstrum method as a special case of this method. With proper choice of the parameters of the generalized logarithmic function, the synthesized speech by this method is of higher quality than that by the conventional cepstrum method

ISSN:8756-6621    

DOI:10.1002/ecja.4410650305

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

年代:1982

数据来源: WILEY

摘要:

AbstractIn general, when a signal with noise is applied to a nonlinear amplifier, the nonlinearity will suppress either the signal or the noise. This property is utilized in this paper; the input signal is applied to nonlinear and linear amplifiers and an output circuit forms their difference. It is found that such a circuit can markedly improve the signal‐to‐noise (S/N) ratio of an input signal containing strong noise. Simple saturation nonlinearity is produced by an elementxν(ν1 extension‐type nonlinearity characteristics result. A general type of noise is treated as a narrowband noise with a Weibull amplitude distribution. Analysis shows that when the Weibull coefficient is small, the use of the saturation characteristics of a nonlinear amplifier improves the S/N ratio considerably; when the Weibull coefficient is very large, neither extension‐ or saturation‐nonlinearity shows a marked difference. If the signal is contained in narrow‐band noise of constant amplitude, tests confirm the effectiveness

ISSN:8756-6621    

DOI:10.1002/ecja.4410650306

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

年代:1982

数据来源: WILEY

摘要:

AbstractVarious characteristics are compared and studied for three typical phase‐locked loops: the first‐order loop, the imperfect second‐order loop and the perfect second‐order loop in the presence of large interfering signals. Comparison of these characteristics requires that the pull‐in range for the first‐order loop and the imperfect second‐order loop be made equal, and that the natural angular frequency and damping coefficient be made equal for the imperfect second‐order loop and perfect second‐order loop.The average value and variance of the error angular frequency, the average value of the output angular frequency and the phase jitter, as well as the synchronizing limit to the signals of the phase‐locked loops are determined in this analysis by the harmonic balance method and verified by computer simulation. Furthermore, the synchronization characteristics for the initial phase variations of the phase‐locked loops are determined by computer simulation, and compared and studied mutually. As a result, it is found that the imperfect second‐order loop shows the best synchronization characteristic in the presence of a l

ISSN:8756-6621    

DOI:10.1002/ecja.4410650307

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

年代:1982

数据来源: WILEY

摘要:

AbstractWindow allocation is an important issue in the design of a packet switching network using window flow control scheme. Most of the research in the past applied to loss system which omitted the waiting (delay) time external to the network. This paper deals with waiting (delay) systems which take into account both the external waiting time and internal delay time. For convenience in the simulation, the time required to send ACK message is assumed negligible. The results indicate that if the window size is about the same as the average number of packets outstanding on the logical channel with no‐control, then the window flow control scheme renders a shorter delay than the no‐control scheme in spite of the external waiting time. The window flow control scheme remains effective even in the expanded networks, and networks using the ACK scheme of the X.25 proto

ISSN:8756-6621    

DOI:10.1002/ecja.4410650308

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe mathematical representation method of treating oscillators was first suggested by van der Pol. Many analyses of oscillators have been conducted employing this method. However, analytical models of oscillators still have some inadequacies. This paper deals with the sinusoidal output wave form of the oscillator and presents the mathematical representation of oscillator properties in a simple but very practical manner. We shall explain how the coefficients in the formulas can be determined from several of the measured points on the Rieke diagram, which is a popular form for the representation of microwave oscillator properties. We shall also give a couple of practical examples.Previously, oscillator properties have been described in graphical form due to the nonlinearity of the device, but they can be described by several numerical values when a mathematical representation is used; with the help of computers, this simplifies considerably the design of oscillator circuits.

ISSN:8756-6621    

DOI:10.1002/ecja.4410650309

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

年代:1982

数据来源: WILEY

摘要:

AbstractThe fact that the pulse response of a transistor circuit is accompanied by a phase delay is well known. The quantity β(s), which plays the role of the frequency response of α(s), is expressed in terms of polynomials and the transformation formulas are obtained by introducing a state variable into β(s). After α(s) is set equal tod0e−sm/ωa, this transformation gives a response that agrees satisfactorily with measurement. This is true even when the measured pulse response has a phase delay from the start of response to the steady state conditions. This paper also gives the phase delay element value. When the delay time contained in the element is compared tom/ωα obtained from the response, the delay time of the pulse response can be directly determined within the phase interval from 45° to 90°. In addition, the relationship between the location of centroid of the impulse response coordinate axis and the 50% rise time of the indicial response and the carrier transit time is also in

ISSN:8756-6621    

DOI:10.1002/ecja.4410650310

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

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper describes the design and observed performance of a 2‐modulus prescaler MSI developed for a pulse‐swallowing variable frequency divider at 1 GHz. The output of the final stage is fed directly back to the first stage to achieve high‐speed operation. The operating speed is 1 GHz for a source voltage of 5 ± 0.5 V and ambient temperature from −40 to +85 C; the maximum speed is 1.3 GHz. The power consumption is 400 ‐ 450 mW. The frequency division ratio is 1/64 and 1/65. Series gate ECLs are used for the basic circuit and the logic amplitude is 0.5 V. The chip size is 1.78 × 2.08 mm2and includes 285 transistors and 170 resistors. Transistors with emitter size of 3 × 5 μm2and qualityn‐type resistors are used in the hig

ISSN:8756-6621    

DOI:10.1002/ecja.4410650311

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

年代:1982

数据来源: WILEY