摘要:

AbstractSpectral matching is a powerful method of calculating the distance between two frames in speech data which is used in speech analysis, speech recognition and the evaluation of speech quality. Since the introduction of LPC [linear prediction coefficient] analysis, several LPC spectral matching measures have been proposed. It is widely known that human hearing has greater sensitivity in the low‐frequency region than in the high‐frequency region. However, it is impossible to assign frequency weighting using conventional LPC spectral matching measures. This paper proposes two types of frequency weighted LPC spectral matching. The first method is applicable only to the peak weighted measure, while the second is applicable to a more general LPC spectral matching measure. The theoretical relation between these two types of frequency weighting methods is discussed and vowel identification experiments are carried out to examine the effectiveness of these methods. It is seen that the first method is effective in assigning the same frequency weighting to all frames and the second method is effective in assigning different frequency weightings to frames with different phonemic reference patte

ISSN:8756-6621    

DOI:10.1002/ecja.4400651202

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

年代:1982

数据来源: WILEY

摘要:

AbstractTo perform a two‐dimensional analysis of a monolithic filter (MCF), the distributed parameter analysis based on an approximate two‐dimensional model and the coupled oscillation analysis based on a variational method are used widely. However, the error in the first method is large for a conventional MCF which is designed to prevent nonharmonic higher‐order vibration. This is because approximations are introduced to the displacement distribution. In the second method, the distributed parameter characteristics of an MCF cannot be estimated because it is equivalent to that based on an approximate coupling circuit with lumped elements. This paper introduces a more rigorous distributed parameter method for MCF's based on the mode matching technique. This analysis can also be applied to an MCF with two‐dimensionally placed electrodes. First, the coupling coefficient of a two‐dimensionally placed two‐electrode pair and the filter characteristics of a one‐dimensionally placed three‐electrode pair MCF are analyzed. It is confirmed that the present method evaluates correctly the distributed parameter characteristics of an MCF with a weak energytrapping capability. The conventional methods cannot be applied to this kind of MCF. Next, as an example of MCF's with two‐dimensionally placed electrodes, we treat a four‐electrode pair MCF with an attenuation pole on the high‐frequency side. It is shown that the filter characteristic obtained by the present method can realize the distributed parameter characteristics that cannot be analyzed by the conventional methods. Thus the usefulness of this method for distributed parameter analysis of MCF's with two‐dimensionally placed

ISSN:8756-6621    

DOI:10.1002/ecja.4400651203

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

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper deals with the dynamic flow problem in the time‐optimal transmission of time‐variant input particle flow streams through the time‐invariant networks with edge capacitycand edge delayd. The minimum‐cost static flow problem is first solved by the successive assignment method to obtain the routing informationi= 1, 2,…,k}, wherepiis thei‐th minimum‐cost path, Δiis the maximum flow augmentation is the cost. The routing information is next used to find an algorithm for constructing the maximum flow and preserving time optimality. In the first half of the paper a solution is found for the case in which both time and flow are discrete; in the second half, the result is extended to the case in which time and flow

ISSN:8756-6621    

DOI:10.1002/ecja.4400651204

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

年代:1982

数据来源: WILEY

摘要:

AbstractThis paper presents a synthesis method for LC filters using switched‐capacitor simulations. The relation between the structure of the original LCR circuits and the synchronization of node voltages in an SCF simulating the original circuit is first investigated and a synthesis method is then derived for a low‐pass filter using the resu

ISSN:8756-6621    

DOI:10.1002/ecja.4400651205

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

年代:1982

数据来源: WILEY

摘要:

AbstractDouble encoding is a method by which a new code is constructed by twofold encoding with two codes. Using this method, a code with excellent error‐correcting capabilities can be constructed from relatively simple codes. The decoding can also be made simpler compared with a single code with the same code length and the same error‐correcting performance. Both random and burst errors can be corrected. This paper describes a general, practical decoding method for use in a double‐encoding system. Algebraic decoding is used in both the first and the second stages, but the detailed information obtained in the first decoding is fully utilized in the second stage: the usual error‐correcting method is applied in the first decoding and a Chase algorithm is applied in the second decoding. A decoding system which is a practical simplification of the above method is also proposed. The proposed methods are compared with widely‐used conventional systems in terms of the decoding error rate; it is shown that the decoding error rate can drastically be

ISSN:8756-6621    

DOI:10.1002/ecja.4400651206

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

年代:1982

数据来源: WILEY

摘要:

AbstractIn many cases in electrostatic or acoustic field analysis, the infinite region must be considered; this is difficult to handle by the usual finite‐element method. As a means to handle such cases, the region containing sources and complex configurations are considered as the finite region, and the rest as the infinite region. Then, the usual finite‐element method is applied to the finite region, and the infinite region is partitioned into infinite elements. Two types of infinite element have been proposed: by Bettes‐Zienkiewicz and a hybrid type by Pian‐Moriya. The former does not depend on the model, being general in nature, but integration over the infinite region and the determination of the attenuation parameter are required. In contrast, the latter type of infinite element utilizes the general solution of the system equation in the element, which provides a more accurate solution. Furthermore, since the element is of the boundary type, the integration is generally easier than in the former case. The bandwidth of the discrete equation is the same as that of the finite region. This paper considers Poisson and Helmholtz equations and formulates the three‐dimensional parametric element. As computational examples, simple models for the two‐dimensional electrostatic problem, and two‐ and three‐dimensional acoustic radiation problems are considered as computational examples, and the two types of infinite elements are compare

ISSN:8756-6621    

DOI:10.1002/ecja.4400651207

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

年代:1982

数据来源: WILEY

摘要:

AbstractConductor and dielectric losses in a coplanar waveguide are analyzed and the results are verified experimentally. Since the waveguide is made of two conductors, TEM transmission is assumed and the Laplace equation for the potential distribution in the waveguide cross section is solved. From the resultant potential distributions, the current distributions on the conductor surfaces and the conductor loss are obtained. We also obtain the effective dielectric constant, which expresses the electrical effect exerted on the waveguide by the dielectric substrate. From this quantity, the dielectric loss is derived. The Laplace equation is solved numerically on a computer using the successive overrelaxation method. Only one quarter of the cross section is analyzed due to symmetry, so that computation time and memory requirements are reduced. The experiment verification of these results involves measurement of Q of a resonator consisting of a coplanar waveguide. The difference between the theoretical and experimental values is less than 25% for the conductor loss and less than 6% for the dielectric loss.

ISSN:8756-6621    

DOI:10.1002/ecja.4400651208

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

年代:1982

数据来源: WILEY

摘要:

AbstractExtraordinary traffic phenomena caused by network failures, disasters and social accidents cause remarkable deterioration of the network throughput and service grade. Algorithms of traffic control, e.g., originating traffic control, code blocking control, alterante route control and time‐out control, have been investigated and some of them have been implemented as countermeasures.This paper studies analytically the mechanism of congestion and traffic handling behavior of the telecommunication network for focused extraordinary traffic overload in a two‐stage hierarchical network, using an exchange model which has limited call handling capacity. The congestion at every part of the network can be explained by several factors: network configuration; traffic flow pattern of the extraordinary overload; maximum call handling capacity of exchanges; and the number of channels of the links. The increase of repeated calls arising as the result of congestion at exchanges is one of the dominant factors reducing the throughput of the netw

ISSN:8756-6621    

DOI:10.1002/ecja.4400651209

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

年代:1982

数据来源: WILEY

摘要:

AbstractA theoretical analysis and experiments on one‐ and two‐element ring antennas in an isotropic compressible plasma are repeated. First, a two‐element ring antenna connected to the inner and outer conductors of a coaxial feeder is analyzed by decomposing the system into a zero phase type and a positive phase type. The analysis uses Fourier series expansion. Numerical results reveal that in both one‐ and two‐element systems the current is approximated by a triangular distribution, i.e., a charge with a uniform distribution, if the ring diameter is much smaller than the free space wavelength. In the case of two‐element systems, the charge distributions of elements #1 and #2 are out of phase. The input impedance of the two‐element ring is much smaller than that of the one‐element system. The measured and calculated radiation patterns of a one‐element ring for the electron plasma wave agree well except near θ = 90°. The side‐lobe level of the two‐element ring is much lower than that of the one‐element ring and the radiation characteristics are much improved. It is theoretically and experimentally confirmed that the radiation efficiency of the two‐element ring is much better than that of the one‐element r

ISSN:8756-6621    

DOI:10.1002/ecja.4400651210

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

年代:1982

数据来源: WILEY

摘要:

AbstractHyperthermia is now recognized as an effective means for cancer therapy, and many reports on the irradiation of biological subjects by electromagnetic waves to produce dielectric heating and hyperthermia have been reported. Although it is desirable in hyperthermia selectively to heat the cancer tissue, it is difficult to estimate the heat distribution in the subject owing to insufficient analysis of the electromagnetic field distribution in the irradiated subject. At present it is not yet possible to control the temperature distribution in the biological subject. In electromagnetic wave hyperthermia, microwaves are effective from the viewpoint of efficiency or selective heating. On the other hand, it is difficult to heat a cancer in deep tissue because of reduced penetration of the microwaves into the subject. This paper shows experimentally and by theoretical analysis, using a microwave lens geometrically designed to produce a focused cylindrical wave as the applicator, that selective heating is possible for tissue 10 to 40 percent deeper than with planar wave. It is shown that the microwave lens applicator is effective for the heating of biological tissues.

ISSN:8756-6621    

DOI:10.1002/ecja.4400651211

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

年代:1982

数据来源: WILEY