摘要:

AbstractThe nonuniform line containing the binomial‐form transmission line of odd order can be approximated by the lumped‐distributed circuit at frequencies below π/2 (rad) in electrical length. The rigorous solution for telegraph equation of odd‐order binomial‐form lines with the characteristic impedance given by (ax±b)±n(where a and b are constant and n is odd number) is derived and the approximate solution is obtained for a case where four‐terminal constants of the linear taper line with n=1 are truncated at finite terms. It is shown that the linear taper line can be approximated by the lumped‐distributed circuit at frequencies below π/2 (rad) in electrical length. Next, Kuroda's identity is applied to the lumped nonuniform distributed circuit consisting of the linear taper line and lumped reactance to show that the nonuniform line containing binomial‐form transmission lines can be obtained as a cascade connection of the linear taper line and lumped reactance. Finally, the nonuniform line is approximated by the lumped‐distributed circuit at frequenc

ISSN:8756-6621    

DOI:10.1002/ecja.4410640802

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe periodic solution of polynomial nonlinear equations is derived based on Galerkin's procedure. An algorithm for evaluating deterministic equations and elements of Jacobian matrices is presented. This algorithm enables one to determine a periodic solution and to reduce the computation time and procedure. The result is applied successfully to periodic solutions of Duffing's equation, Van der Pols' equation, the pendulum equation, Minorsky's equation, the population growth model with time lag and the difference equation.

ISSN:8756-6621    

DOI:10.1002/ecja.4410640803

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

年代:1981

数据来源: WILEY

摘要:

AbstractGraph theoretic algorithms often are evaluated by their behaviors on random graphs. This paper attempts to find graphs which can be used to evaluate heuristic algorithms for the minimum feedback are set problem. For these graphs the following properties are required: (i) ease in generating, (ii) their minimum feedback are sets are known. Here we consider directed star polygons (DSP). First, we show that a DSP can be represented by a set of integers (symbols) indicating the number of its vertices and its interconnection structure. Then we discuss transformations of symbols, equivalent symbols, connectivities and a method of obtaining an equivalent class of DSP. Also, we discuss the relationships between symbols of DSP and its feedback are sets. In the case of degree equal to 4, the problem of finding a minimum feedback are set and its density is equivalent to that of finding the maximum number of are disjoint cycles or a symbol the sum of whose elements is the smallest.

ISSN:8756-6621    

DOI:10.1002/ecja.4410640804

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

年代:1981

数据来源: WILEY

摘要:

AbstractTwo types of speech compression systems which use a set of precalculated inverse filters (the inverse filter codebook) are studied. The information theoretic ideas of universal coding and block quantization motivated the use of the inverse filter code‐book. The first system finds the indices of the best matching inverse filter, the gain and the pitch interval for each frame of the input speech signal. In this case, a system operating at 800 bit/s for speech sampled at 8 kHz is adopted as the basic system. The second system is a waveform encoder which uses the inverse filter code‐book and tree searching. The system uses a single tree search, which is an improved version of the parallel tree search presented by the author, and a system of 8,875 bit/s is adopted as the basic device. Application of the inverse filter codebook is effective in achieving rate reduction and/or decreasing the system complexity.The first system falls into the class of vocoders and the second is a waveform encoder. The data rates of the two differ considerably, yet both types of systems are necessary. An example explaining this fact is also given in the t

ISSN:8756-6621    

DOI:10.1002/ecja.4410640805

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

年代:1981

数据来源: WILEY

摘要:

AbstractA technique of measuring millimeterwave reflection coefficients by using a T junction is proposed. This technique does not require a tuning procedure and frequency conversion. The measurement circuit is composed of a T junction and power meter, where system constants of the circuit are calibrated in advance by using a sliding short. The standard waveguides are used to shift the phase angle of the reflection coefficients of a load under test and the unknown reflection coefficient is computed from the powermeter reading. The measurement result at 34.0 GHz indicates the validity of this technique. The error was estimated as about 2.7% at the 0.3 magnitude of the reflection coefficient.

ISSN:8756-6621    

DOI:10.1002/ecja.4410640806

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

年代:1981

数据来源: WILEY

摘要:

AbstractSince a PCM transmission path can carry voice signals in one direction, the time‐division switching network at any PCM telephone exchanges employs a four‐wire configuration. Therefore, a pair of paths is required to form one connection. A general way of preparing such pairs is to establish the pair relationships between switches or links in the switching networks and to create paths automatically based upon those relationships. Having implemented these pair relationships, the blocking probability, the amount of path hunting and the required amount of control hardware for switching networks can be reduced considerably. Pair relationships are quite important in the efficient composition of time‐division switching networks. However, no general theory exists yet for the pair relationships. This report presents an overall study on the pair relationships in time‐division switching networks. First, we define the pair relationships and classify them into several forms and then present practical examples. We then describe how to compose the more important pair relationships and briefly review the connection patterns that are produced by forming the pair relationships and modifying link connection patterns. Finally, we explain how to compose favorable pair relationships based on the above study conc

ISSN:8756-6621    

DOI:10.1002/ecja.4410640807

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

年代:1981

数据来源: WILEY

摘要:

AbstractScattering of a plane wave (E wave) by a thick lossy semiinfinite dielectric slab with conductivity σ is evaluated by Fourier transform. The formal solution of the scattered field is derived by the Wiener‐Hopf method. The result is applicable to the cases of lossless media (σ = 0) and perfect conductors (σ → ∞). The scattered far field is evaluated by the saddle point method. The integral along the branch‐cut in the formal solution is evaluated numerically and the effects of the medium loss, slab thickness, and the incident angle on the scattered far field ar

ISSN:8756-6621    

DOI:10.1002/ecja.4410640808

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

年代:1981

数据来源: WILEY

摘要:

AbstractA multiple communication bus network (MCNET) is proposed as a structure for a nationwide trunk network and its optimum method of circuit regulation and size of the network are discussed. MCNET is a network in which uniform, large‐capacity transmission paths achieve bus connection of plural exchange offices in a region and in which interoffice traffic is directly switched on transmission paths in bus form. Between different regions, the network is hierarchically structured with representative exchanges in regions and bus‐formed transmission paths between them. This paper describes the fundamental concepts and network structure. The circuit regulation method by which circuits are assigned semipermanently to each originating exchange is advantageous with respect to adantability for traffic loading and ease of regulation. The capacities of the MCNET are investigated by introducing a “traffic diffusion index” and it is concluded that the erlang capacities for the RA, DA and TA switching systems are in the ranges of some ten thousands to hundred thousands, from ten thousand to some ten thousands and from six thousand to nine thousands, respectively, and that the capacities of the transmission paths are also in erlang ranges of from 300 thousand to one million, from 200 thousand to 600 thousand and from 40 thousand to 60 th

ISSN:8756-6621    

DOI:10.1002/ecja.4410640809

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

年代:1981

数据来源: WILEY

摘要:

AbstractComputer analysis is performed for coplanar waveguides with finite conductor thickness. Such line parameters as the characteristic impedance and effective filling fraction are obtained. Experimental verification is given for the characteristic impedance.Assuming that the line cross section is approximately symmetrical, Laplace's equation is solved by a successive over‐relaxation method for one quarter of the cross section. The characteristic impedance obtained by this approximate method is compared with that obtained by analysis of one half of the cross section with rigorous symmetry and the difference is found to be less than 0.27%. Experimental verification of the characteristic impedance is conducted by correcting the discontinuity between the measurement setup and the line to be measured. The difference between the analytical and experimental results is less than 10%. Approximate analysis by the present method is thus sufficiently accurate. The size of the storage locations in the computer is reduced and the processing time is shortene

ISSN:8756-6621    

DOI:10.1002/ecja.4410640810

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe double orthogonality of spheroidal wave functions has been used in pattern synthesis. However, because of difficulty in calculating spheroidal wave functions and in determining double orthogonality, its application to pattern synthesis is limited. In this paper, a new eigenintegral equation is derived to obtain general doubly orthogonal function systems in which the integral section and weighting functions can be determined freely. The new doubly orthogonal functions are applied for pattern synthesis under constraints.

ISSN:8756-6621    

DOI:10.1002/ecja.4410640811

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

年代:1981

数据来源: WILEY