摘要:

AbstractIn communication line systems, in general, failure correlation (dependency of communicational line (path) composing a system due to the existence of common‐caused failure mode) often occurs and dependent failure correlation between communication lines (paths) must inevitably be considered in many cases. A concrete example is in reliability analysis between communication terminals in communication cable lines linking two central terminals, a characteristic quantity analysis of reliability whenr‐fold common‐caused failures of neighboring lines occur. Thus, in this paper, we take a parallel redundant system given by common‐caused failure (r) and the number of communication lines (

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730401

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

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper aims for high reliability as well as reduction of hardware size, cost and development period for the time‐division multiplex access (TDMA) equipment, and proposes a new TDMA equipment architecture and modular construction. The fundamental approach employed in this paper is the digital realization of the analog circuit and the LSI implementation of the digital circuit. Then to realize TDMA equipment with a simple architecture and to realize a widely applicable LSI, TDMA equipment is reconstructed into a hardware‐oriented architecture. Based on the new architecture and the optimal function assignment to the modules, the following LSI and IC were developed. Six types for synchronization control, 11 types of LSI and IC for modulation‐demodulation (3 LSI, 4 MIC and 4 HIC), and 1 type of terrestrial network interface. By this development of LSI and IC, the hardware scale of TDMA equipment was reduced to one‐fifth, and the development period is reduced to one‐half compared with previous equipment. The maintenance‐free property is also achieved. The developed LSI and IC can be applied to various TDMA equipment in general with different TDMA frame and rate. For TDMA equipment to be developed in the future, the hardware‐scale and the development period can be reduced as

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730402

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe systolic array is a scheme for parallel processing and provides an architecture which is suited to a high‐speed operation. Consequently, the systolic array has been applied to the system for which the high‐speed processing is required, but not to the system for which the reduction of the circuit scale is required. This paper demonstrates that the principle of the systolic array can be applied as a means of reducing the circuit scale. By the proposed method, the circuit scale can be reduced in the system based on the systolic array, without an appreciable modification of the connection in the array and the control. This paper discusses the Reed‐Solomon (RS) coder‐decoder based on the systolic array as an example, and shows that the circuit scale can be reduced simply. By this system, the RS coder‐decoder can be realized in a simple way by the small circuit scale, corresponding to the processing speed of t

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730403

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn the resistance networkN, the potential of each vertex determined in reference to one vertex of the input vertex‐pair, where a unit current source is placed, can be expressed by using the topological formula as the ratio of the conditional 2‐tree conductance product sum to the tree conductance product sum ofN.It is a well‐known empirical law that the potential of the input vertex (equi‐valently, the input resistance) does not increase if any two vertices ofNare short‐circuited. However, no rigorous and simple algebraic proof including the potential variation of the input vertex is available, and such studies on an arbitrary vertex as its generalization have not been carried out. In this paper, the variations of vertex potentials by short‐circuiting two vertices ofNare formulated by using the topological process. If the formula obtained here is used, a necessary and sufficient condition can be provided for increase (or decrease) of any vertex potentials by short‐circuiting two vertices ofNbesides a proof of the fore‐mentioned empirical law. In addition, the following can readily be verified. If the potentials of two vertices ofNare equal, the potentials of any vertices do not change by short‐circuiting the two vertices. Even if a specific vertex potential does not change after short‐circuiting two vertices, the potentials of these two vertices are no

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730404

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

年代:1990

数据来源: WILEY

摘要:

AbstractA reliability analysis model is proposed for software products at their development stage from the Bayesian viewpoint, with emphasis on such software products as the usual mathematical software used discretely in time. In the proposed model, a single debugger is engaged in conducting software tests and in debugging a software product, where the significations of “single debugger” are as follows: the model does not consider the case where several software engineers conduct software tests and debugging for the same software product independently of each other to collate their respective detected bugs after the tests. On the basis of the proposed model, an optimum release problem for software products is also formulated. The proposed methods are demonstrated by presenting numerical examples to clarify their characterist

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730405

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

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper describes a new method for designing two‐dimensional (2‐D) digital filters with complex coefficients having circularly symmetric and fan characteristics by applying variable transformation (spectral variable) to one‐dimensional (1‐D) IIR digital filters with complex coefficients. A 2‐D digital filter with complex coefficients has an advantage in that it can increase greatly the degree of freedom for design, since once it satisfies the design specification partly in the frequency plane, its characteristics can be arbitrary in other regions.Here, a design method is proposed which makes positive use of this property of the complex coefficient digital filters. Since we have introduced the complex coefficient filters into spectral transformation functions and 1‐D prototype filters, there is no constraint on cutoff frequency (radius) accomplishable in circularly symmetric filters. In fan filters even a characteristic that has been difficult to design unless one uses optimization techniques, has become easy to design by means of variable transformation without using any optimization techniques. Moreover, the stability of the resulting IIR filters is guaranteed in simple

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730406

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn equations describing switched‐capacitor (SC) circuits, the switching equation of some switching instant is represented byv+c=F·v−c+G·u+. Historically, the transformation matricesFandGhave been obtained by the limiting method, in which each switching resistance approaches infinity or zero. This method derives the transformation matricesFandGdirectly. But it has numerical instability for large‐scale SC circuits, because Frame's method is used. In this paper, we propose two methods to obtain the transformation matrixFfrom a characteristic matrixC.The first method is the Danielevsky's method, and the second is the backward Euler method. We also propose another method to transformFtoGby means of characteristic matrices given by circuit topology, by relation of zero input and the zero state responses. The results of the simulation are represented by a si

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730407

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn a network operated under a certain system management to make the topological structure invariant for insertion of a newly arising node, accompanied by the increase of the number of users or extension of the system scale, some modifications of the node connection must be required. In a fourth‐degree chordal‐ring network which is known to have a disadvantage with respect to diameter minimization although management software is easy, the forementioned system modification is expected to be required relatively less frequently. This paper presents a new measure for system modification for a chordalring network by formulating modifications of node connection required for the change of the number of no

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730408

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

年代:1990

数据来源: WILEY

摘要:

AbstractFrom the measurement of a reflected voltage waveform from a biological body for a step‐like voltage waveform, the frequency characteristics of the complex relative permittivity are studied and the following results are obtained: (1) if the blood flow and sweating are normal, the value of tanδ in the mouth is 4 ‐ 6 at about 10 MHz because electrochemical materials are contained in a large quantity. At frequencies below 100 MHz, the value is larger than those at the face, upper arms, legs and torso and its decrease with respect to frequency is larger. The back of the foot and the thenar have relative permittivities and tanδ's lower than other parts and hence are suitable for measurement of emotion functions; (2) in a physical exercise which causes a change in blood condition without sweating, the value of tanδ in the moving part increases as the number of motions is increased. In addition, the frequency characteristics below 1 GHz change significantly. The value of tanδ in the portion not related to the motion increases even after termination of the motion. Hence, the effect of the exercise can be evaluated from tanδ; and (3) as sweating progresses, the reduction of the permittivity becomes significant at frequencies below 100 MHz while the increase of tanδ is significant below 1 GHz. Hence, the sweating activity can be evaluated from the complex relative per

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730409

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

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper proposes a new construction method for 2‐D IIR digital filters with all‐pass subfilters as components. Recently, numerous studies have been made to construct digital filters by combining all‐pass characteristics. This paper is based on the construction by a parallel connection of an all‐pass subfilter and delay element, which can realize approximately the linear phase characteristic. First, the basic design for 1‐D digital filters as well as its properties are described. Then the theory for the 1‐D case is extended to the 2‐D case, and a new construction method for 2‐D digital filters with low‐pass characteristics with circular symmetry is shown. The proposed method features the following. The phase characteristic is approximately linear in the passband. The filter can be realized with a smaller number of multipliers than in the traditional method. The coefficient s

ISSN:1042-0967    

DOI:10.1002/ecjc.4430730410

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

年代:1990

数据来源: WILEY