摘要:

AbstractRecent developments in computer technology have enabled the real‐time treatment of signal processing with a large amount of computation which had been considered to be impossible. Moreover, with the development of LSI technology, it has become possible to speed up the execution of the algorithms by parallel computing hardware.This paper discusses a parallel architecture for the recursive least square method of system identification fitted for VLSI. Ifnis the order of system to be identified, the complexityT(n)required for updating the estimate at each measurement isTs(n)=o(n2), using a single serial processor. However, it can be reduced toTp(n) = o(n)by using the architecture consisting of (2n+ 6) elementary processors and a set of delay units. Moreover, we discuss a method to speed upp‐time updates fromTs(n, p) = o(n2p)toTM(n, p) = o(n + p)usingo(np)elementary processors by vectorizing the measureme

ISSN:8756-6621    

DOI:10.1002/ecja.4410700401

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

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper presents a general formula for the number of spanning trees in an iterative graph. This graph is obtained by connecting k m‐cycles Cmand k n‐complete graphs Knby branch‐contact or by point‐contact into ladder, prism, wheel, step, sector or mill‐wheel types, and 2 × k of them into a lattice type, respectively. A conventional method using a determinant with k, m and n as parameters is used to determine the number of trees in these iterative graphs. In this method there are many cases where the expansion of the determinant is not easy. Thus as an alternative method for such cases we introduce for the first time an electrical network calculation method for driving point resistance conductance in a unit resistance network whose interconnection structure is represented by a graph. In addition, we introduce a series parallel partition method of branches of a graph, so that the derivation of a general formula for the number of trees in an iterative graph is simplified. Then for individual iterative graphs, we show concrete examples and the results of the determination method obtained by mixing the above‐mentioned three methods a

ISSN:8756-6621    

DOI:10.1002/ecja.4410700402

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe routing requirement in the channel routing problem for automatic wire routing in the interior of LSI is realizable if the constraint graph contains no cycle. Otherwise, the trunks for several appropriate nets must be divided into pieces. In this paper we modify a routing requirement with cyclic conflicts into one without them by dividing trunks into two parts. First we define a directed bipartite graphGto represent the routing requirement. A set of vertices in a strongly connected component inGis called a crowded set. It is shown that a routing requirement is realizable if there exists no crowded set inG. On the other hand, in the presence of a crowded set we define a method of dividing a netncontained in the crowded set into two subnetsn' andn'' at some terminal position. Ifn' andn'' are not contained in any crowded set in the graph modified by division, we say that the division is effective. We then present a necessary and sufficient condition for the existence of effective division. Further, a semi‐effective division is defined to deal with the case where there is no effective division and then the routability for the channel routing problem is discusse

ISSN:8756-6621    

DOI:10.1002/ecja.4410700403

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

年代:1987

数据来源: WILEY

摘要:

AbstractFrom a microscopic viewpoint in consideration of the loading control of work‐pieces and the machine layout, the dynamic behavior of a single‐stage transfer‐type automated manufacturing system with two same‐type machine tools placed in parallel at both sides of a loop conveyor is modeled and analyzed. The processing time obeys a general distribution and to avoid the collision, workpieces are assigned at random to moving slots at regular intervals on the conveyor. The state is defined on the basis of the physical states of the two machines at the arrival epoch of each slot and the system behavior is formulated as a Markov chain. Performance measures such as production rate and inflow rate are obtained by finding the equilibrium state probabilities. Especially, in case of exponential processing time distribution, their explicit expressions are derived. Numerical examples are shown and the difference between the two‐machine parallel system and the two‐machine series system [5] is discussed. Moreover, the production rates for the cases of normally distributed processing time and fixed processing time are calculated numerically and then the validity of the analysis results under the exponential assumption i

ISSN:8756-6621    

DOI:10.1002/ecja.4410700404

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

年代:1987

数据来源: WILEY

摘要:

AbstractA lattice filter has several advantageous properties for adaptive applications. The gradual increase of the degree of estimation by the regular repetition of the adaptation module is particularly advantageous for hardware realization. In this paper, this adaptation module is called a lattice element and a method is proposed for the design of adaptive filters using such lattice elements. The efficiency of this method is demonstrated by the derivation of orthogonalizing and biorthogonalizing filters. The operation of these filters is tested by computer simulation and some problems arising at higher‐order filters are pointed ou

ISSN:8756-6621    

DOI:10.1002/ecja.4410700405

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

年代:1987

数据来源: WILEY

摘要:

AbstractPerfect AN codes are those with the least redundancy under constant code length and error correcting capability. The existence of perfect codes has been studied for generalized r‐ary represented AN codes and symmetric multivalue represented AN codes to apply them to multivalued arithmetic circuits. In this paper we define single‐error‐correcting perfect BCN (Binary Coded Decimal)‐AN codes and obtain the conditions under which the perfect BCN‐AN codes exist. These conditions do not depend on the weight sequence itself used in BDC representation of code words, but on the class to which the weight sequence belongs. By using these conditions we prove that for some classes of the BCD representation including (8421) representation there exists no perfect BCD‐AN code. For some of the remaining classes we obtain examples of generators of perfect BCD‐AN codes through exhaustiv

ISSN:8756-6621    

DOI:10.1002/ecja.4410700406

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

年代:1987

数据来源: WILEY

摘要:

AbstractRecently, progress in the high‐density wiring technique on a printed circuit board (PCB) has been remarkable. Thus the problem of malfunctions due to crosstalk noise occurring on the signal line must be addressed. The authors have been developing the noise estimation system for PCB named NESSY and a program to calculate the capacitance of multiconductor system (CALCAP). In NESSY, the wiring pattern is divided into small segments, which comprise the equivalent element circuit. The partial capacitance of the printed pattern is calculated by solving the integral equation and using the image method in CALCAP. The crosstalk analysis of equivalent circuit was made by the circuit simulation program.Among the results of this analysis, crosstalk noise using the partial element equivalent circuit (PEEC) agrees quite well with the measurement. The crosstalk noise should be anticipated by the close coupling theory in the case of frequently used wiring (both the width of signal line and line spacing are less than 1 mm). The crosstalk noise voltage was relatively large in the case of impedance mismatching. The far end crosstalk noise, previously neglected in most cases, becomes especially larg

ISSN:8756-6621    

DOI:10.1002/ecja.4410700407

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

年代:1987

数据来源: WILEY

摘要:

AbstractData transmission between a satellite and an aircraft is investigated in the case of a multiphase DPSK system operating in the L‐band. The error rate characteristics of matched filter detection are analyzed exactly on the basis of a multipath model consisting of a direct path wave and a relatively delayed, high‐speed, diffuse‐path Rayleigh wave due to reflection at the Earth's surface. On the basis of this model, concrete error rate (Pe) computations are performed in the case of 4‐phase DPSK (symbol rate 1/Ts) as a function of the Doppler spread (BD) and average relative delay (T) of the reflected wave. Considering the influence of varying duration of the reflected wave, the results show that the error rate Peis maximum (worst case) for BDTs≒ 0.40 independently of the powers of the direct wave, reflected wave and noise. Furthermore, in the range BDTs⩽ 0.17 the diffusion wave can be treated as an AC vector. Next considering the influence of the relative delay of the reflected wave, the value of Peis given for the 16 cases of phase difference in the delay range 0 ≦ T ≦ Tsand it is shown that the effect of relative delay is negligible for T/Ts⩽ 1/40 and that the minimum average error rate (best case) is obtai

ISSN:8756-6621    

DOI:10.1002/ecja.4410700408

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

年代:1987

数据来源: WILEY

摘要:

AbstractScattering of Hermite‐Gaussian beams by two‐parallel conducting cylinders is considered in this paper. Hermite‐Gaussian beams of arbitrary order incident on the cylinders, are expanded in a Fourier‐series with respect to each cylindrical coordinate system, and multiply scattered fields by both cylinders are derived rigorously. Since the analysis for the fundamental beam incidence already has been done, this paper carries out the theoretical analysis for the first‐ or second‐order beam incidence. Several numerical examples of the far‐zone scattering pattern and the equi‐amplitude and phase distribution of the near field are shown. When the configuration of the twocylinder scattering system is symmetric with respect to the beam axis of the first‐order beam, the scattering pattern becomes symmetric with respect to the beam axis and deep dips are produced in the directions of forward and backward scattering. Moreover, it is shown that both deep dips and the symmetry of the scattering pattern disappear even if an imperceptible asymmetry of the configuration of the scattering system occurs. The distribution of the equi‐phase planes near the cylinders, which have not yet appeared in problems of this kind, is depicted and the interference of the multiply scattered fields and the incident

ISSN:8756-6621    

DOI:10.1002/ecja.4410700409

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

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper describes a new automatic equalizer for digital subscriber loops. The new equalizer is composed of a √f equalizer and a BT equalizer. The √f equalizer is a new type of linear equalizer which is based on the approximate theory of exponential orthogonal functions. The BT equalizer is a decision‐feedback equalizer. Subscriber loops can be closely approximated to RC‐dis‐tributed constant circuits. Since the new √f equalizer is composed of a linear combination of RC low‐pass circuits, the required hardware is small in scale. By adjusting the multiplication weights for both the √f equalizer and the BT equalizer, the equalizing characteristics can be controlled continuously. Moreover, since the multiplication weights of the √f equalizer are performed digitally by C‐2C ladder circuits and the main part of the BT equalizer is composed of digital circuits, the equalizing characteristics can be controlled by a digital controller and neither analog multiplication circuits nor analog delay circuits are required. As a result of our trial manufacture and performance tests that were conducted in a 320 Kb/s time‐division burstmode transmission system, it has been verified that this automatic equalizer has sufficient eq

ISSN:8756-6621    

DOI:10.1002/ecja.4410700410

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

年代:1987

数据来源: WILEY