摘要:

AbstractThis paper discusses a method in which the impulse response of the digital filter in PARCOR speech synthesizer is used as a musical tone. the following items are discussed. (1) Creation of musical tone‐scale by pole frequency of digital filter. (2) the effect of operational accuracy on the quality of a musical tone, which is an important factor in determining the size of the circuit. (3) Improvement of the quality of the musical tone. For the present circuit size where the word length of k‐parameters is 10 bits and the operational bit length is 14, the sinusoidal wave above C4 has the sufficiently accurate pitch frequency, and there is no problem in creating the musical tone scale. However, it was seen that the impulse response is attenuated in a short period, and a musical tone with practicable envelope characteristics cannot be obtained. As a method to solve this difficulty, a method is proposed whereby the lower bits are rounded‐up in the multiplier output of the filter circuit. the effectiveness of the proposed method has been verified. By this scheme, a PARCOR speech synthesis LSI has been realized which can generate sinusoidal waves of various kinds of envelopes as well as musical

ISSN:8756-6621    

DOI:10.1002/ecja.4400671202

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe problem of finding all s‐t acyclic graphs between two given vertices of a digraph is interesting in relation to the evaluation of the reliability of a communication network. There is already an algorithm which generates all s‐t acyclic digraphs without duplication by opening an arc or a set of arcs one by one starting with a given graph. But the efficiency of that algorithm decreases when the number of cycles in the graph becomes large. This paper proposes an algorithm which generates s‐t acyclic graphs without duplication by combining s‐t paths obtained by a depth‐first search. Compared with the existing algorithms (i) the execution time of this algorithm is not affected much by the number of arc disjoint cycles of the graph; (ii) when the generation is stopped at an arbitrary level i, all the s‐t acyclic graphs composed of paths of length i or less will have been generated. Thus they can be used to approximate the

ISSN:8756-6621    

DOI:10.1002/ecja.4400671203

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

年代:1984

数据来源: WILEY

摘要:

AbstractA number of research reports has been presented on the noise suppression signal processings as one of the important technical problems. Although a reduction feeling of the noise level can be obtained by the conventional method using the one‐point received signal, it has been pointed out that the program of improving the articulation is not sufficient. to solve this problem, we propose a noise suppression signal processing method using two‐point received signals. As the first step, the noise suppression method is discussed assuming that the desired signal is uncorrelated to the noise. It is shown that the noise suppression filter, which is the optimum in the sense of least‐mean‐square error, is obtained from the correlation coefficients between the frequency components of the two‐point received signals. Then a method is shown in which the two‐point receiving noise suppression system can be constructed using FET based on the proposed principle. Finally, to verify the effectiveness of the proposed processing, the method is applied to the two‐point received speech under room noise. the articulation tests were performed for the processed and unprocessed speeches. As a result, it was seen that the syllable articulation score could be improved by 4 to 10 percent when the correlation coefficient between the two‐point received signals of the noise is 0.1 or less and that of the speech

ISSN:8756-6621    

DOI:10.1002/ecja.4400671204

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

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper examines the splicing loss due to axis misalignment in the splicing of single‐mode optical fibers using direct core monitoring and discusses the methods for reducing such loss and the techniques for estimating it. Axis misalignment is strongly dependent on the offset between the monitoring location and the actual position due to the fiber lens effect and core eccentricity as well as on the precision of the core monitoring system. Taking into consideration the indeterminateness of the relative position of the fibers, we analyze this relationship by means of a statistical technique and, using a direct core monitoring system with transmitted light, verify the appropriateness of the theory by means of experimental studies. Further, it is shown that it is necessary to reduce the alignment error due to core eccentricity and that it is possible to align the cores to a precision of better than 0.5 μm by correcting the core center position from the observed eccentricity. In addition, by considering the surface tension effects during fusion we can explain the relationship to axis shift before and after splicing and, if the axis alignment precision is given prior to splicing, we can estimate the splicing loss distribution. We also show that it is theoretically possible to achieve an average splicing loss of less than 0.1 dB with single‐mode fibers using this direct core monitoring method when the axes are aligned to within 0.

ISSN:8756-6621    

DOI:10.1002/ecja.4400671205

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

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper provides the results of theoretical and experimental studies to realize a broadband quasi‐optical diplexer with polarization‐independent characteristics, using multilayer rectangular metal meshes. A rectangular metal mesh is usually used in the inductive region below the mesh resonant frequency. In the theoretical analysis based on the mode matching method, it is concluded that the anomalous resonance of the mesh appearing below mesh resonant frequency in TM oblique incidence is caused by the higher‐order modes generated on the metal mesh surface. This phenomenon can not be explained by the equivalent circuit analysis, in which metal mesh is decomposed to two orthogonal metal strip gratings. A bricktype rectangular metal mesh is proposed in which the anomalous resonance can be eliminated from the operating frequency region. It is shown theoretically and experimentally that one can realize a new metal mesh of which the transmission characteristics below the mesh resonance do not vary in accordance with the incident polarization mode. A design method of quasi‐optical diplexer using this brick‐type metal mesh is described and the experimental results of the filter designed for diplexing the six, 4 GHz and fourteen, 11 GHz signals are reported. It is confirmed that broadband diplexing is possible with a stacked rectangular metal mesh and that the design method is l

ISSN:8756-6621    

DOI:10.1002/ecja.4400671206

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe carried traffic estimate errors for delay system models are analyzed. Particular attention is given to the traffic models for the switching machine control equipment. It is known that the holding time distribution of the switching machine control equipment is one whose coefficient of variation is less than 1 (exponential distribution). Therefore this paper emphasizes the analysis of the effect of the holding time distribution on the estimate errors. First, the carried traffic estimate errors for M/D/S queue and M/M/S queue are analyzed and it is shown that the estimate errors for the M/D/S queue are always smaller than those for the M/M/S queue for any fixed utilization. As a result, it is conjectured that as the coefficients of variations for the holding time distributions increase, the estimate errors also increase. In the latter part, this conjecture is justified for one server model M/G/1 queue. In analyzing the carried traffic estimate errors for M/G/1 queue, the approximation of the busy period distribution by an hyperexponential distribution is proposed, and its estimation accuracy and its applicable range are studied.

ISSN:8756-6621    

DOI:10.1002/ecja.4400671207

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

年代:1984

数据来源: WILEY

摘要:

AbstractA design method of radiation‐suppressed high‐Q dielectric resonators with a metal cap loaded above a dielectric material with high dielectric constant is studied. For exact evaluation of the effect of the radiation‐suppressing metal cap, a semispherical dielectric resonator model with simplified boundary conditon of the metal cap is introduced. As a result, it is found that there exist two modes in this resonator, a dielectric resonator mode and a hollow cavity mode, depending on the size (diameter) of the metal cap, and almost constant resonant frequencies for the change of metal cap size and high unloaded Q factors are obtained in the dielectric resonator mode by selecting the cap size on the optimum range. the validity of the analysis result is confirmed by experiment. Moreover, the resonant frequency and its temperature variation for a cylindrical resonator are studied and it is found that the frequency variation does not depend on the material of the metal cap but greatly depends on the temperature coefficient of the high‐constant dielectric material

ISSN:8756-6621    

DOI:10.1002/ecja.4400671208

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

年代:1984

数据来源: WILEY

摘要:

AbstractCompact and low‐cost video coding equipment is indispensable for the economical realization of visual communication services such as traffic monitoring entertainment relay, etc. This paper describes an LSI oriented coding algorithm which is effective for the compact and economical realization of intra‐frame coding equipment. First, an intra‐frame combinational difference coding algorithm is proposed. the encoded picture quality obtained using this coding algorithm is sufficient even for complicated scenes of TV signals. the predictive coding circuit LSIs for realizing this coding algorithm are also developed. Moreover, the variablelength word multiplexing circuit is shown to be suitable for LSI, and LSIs for this are also developed. Furthermore, coding equipment using the coding algorithm and the LSIs were developed, and its compactness is confirmed. A coding experiment was performed by using the developed equipment and it is shown that the equipment is capable of transmitting good quality ITV signals at a 32‐Mb

ISSN:8756-6621    

DOI:10.1002/ecja.4400671209

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

年代:1984

数据来源: WILEY

摘要:

AbstractVarious proposals have been made in recent years with regard to hybrid power supply systems for communication system applications. the main common feature of such systems is the incorporation of two or more kinds of power sources. In this paper we first discuss the concept of hybrid systems and then describe experimental results obtained with a triple hybrid system incorporating a wind‐power generator, solar cells and Diesel generating equipment. It is then shown that the continuous time distribution of natural energy in the nonenergized state follows an exponential function. We apply a mathematical model which is in good agreement with the experimental results and develop a theory for derivation of the required storage battery capacity as well as the power to be applied by the Diesel generators. Then, applying this design method to various systems, we present a quantitative analysis of the complementary relationship between wind power and solar illumination and show that the triple hybrid system is most economica

ISSN:8756-6621    

DOI:10.1002/ecja.4400671210

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

年代:1984

数据来源: WILEY

摘要:

AbstractA target‐facing type sputtering apparatus which can deposit three‐layer films on a long film base continuously, is constructed. Using this apparatus, a Co‐Cr perpendicular magnetic recording medium is formed continuously to obtain the following results.(1)A Co‐Cr film with deposition rate of more than 0.4 μm/min is obtained with fine structure and good C‐axis orientation.(2)When the tape substrate is advanced and the Co‐Cr film is deposited continuously, deterioration of the film C‐axis orientation results from oblique incidence of the sputtered particles at the time of initial deposition.(3)the properties (such as C‐axis orientation and the magnetic characteristics) of initially deposited film dominates the characteristics of film as a whole.(4)the (111) oriented permalloy film is used as base soft magnetic layer, and the Co‐Cr film is deposited on this film. Orientation of Co‐Cr film is decided by (111) orientation of the permalloy film.(5)the temperature of the substrate surface during deposition changes greatly according to the substrate thickness and the applied tensile force on the substrate, thereby changing the film magnetic characteristics. the Co‐Cr perpendicular magnetic recording medium with desired magnetic characteristics and good C‐axis orientation can be formed continuously at high speed by controlling the substrate temperature and by suppressing the oblique incidence of

ISSN:8756-6621    

DOI:10.1002/ecja.4400671211

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

年代:1984

数据来源: WILEY