摘要:

AbstractThe author has recently proposed a method which, given information concerning the relation between the difference of states and the means to be adopted, constructs the quotient problem based on that information and decomposes the given problem into a sequence of subproblems using the solution of the quotient problem. This paper proposes a successive problem decomposition method which, by repeating the decomposition procedures, decomposes the given problem into a sequence of subproblems that is the simplest in the sense that there exists only one difference between the initial state and the goal. A sufficient condition is presented for such a decomposition to be executed. Given a sequence of differences D, the decomposition procedure is represented by an AND/OR sub‐problem tree T(D) and a sufficient condition is sought for T(D) to contain a solvable tree. When T(D) contains a solvable tree, it is possible for the proposed successive problem decomposition to decompose the given problem into a sequence of simplest subproblem

ISSN:8756-6621    

DOI:10.1002/ecja.4410640702

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

年代:1981

数据来源: WILEY

摘要:

AbstractThis paper discusses simultaneous realization of some system matrices Fidefined by x‐y =f1 x‐y where × is an n‐dimensional state vector, by a network composed of resistors, capacitors, amplifiers and switches. Based on a weak assumption, we obtain the following results: (1) The minimum number of switches required for realization of F1and F2(or F1, F2and F3) equals r(F1− F2) (the minimum value of r(H1) + r(H2) + r(H3) where r(A) denotes the rank of a matrix A and Hi(i = 1, 2, 3) satisfies F1− F2= H1+ H2and F1− F3= H1+ H3; (2) At most (n + 1) amplifiers are required; (3) There is an example in which (n + 1) amplifiers

ISSN:8756-6621    

DOI:10.1002/ecja.4410640703

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

年代:1981

数据来源: WILEY

摘要:

AbstractFor the two‐dimensional signal with circular band‐limiting in frequency space, a square arrangement of sampling points in the real space is usually used. Assuming, however, that the signal is band‐limited in a hexagonal region, being regarded as periodic and adopting the triangular sampling point arrangmeent in real space, the number of sampling points can be reduced by 13.4% that in the usual method. Mersereau has derived a discrete Fourier transform (DFT) for a two‐dimensional signal hexagonal band‐limited both in real and frequency spaces. In his method, however, separation of the Fourier kernel is impossible and Rivard's FFT algorithm is not applicable to the computation of hexagonal DFT. The authors introduce a periodic extension vector system and sampling point generating vector system. By a generalized method, the two‐dimensional DFT is reformulated. It is shown that the kernel can be given a separable expression by suitable choice of coordinates as in the square DFT, actually presenting the method of determining the coordinate. When the kernel of a hexagonal DFT is separable, the computation reduces to that of the one‐dimensional DFT. This permits the application of already developed FFT algorithms, enlarging the range of utilization of the

ISSN:8756-6621    

DOI:10.1002/ecja.4410640704

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

年代:1981

数据来源: WILEY

摘要:

AbstractIn the layout design of building block LSI's wires are placed in the region between a pair of columns of cells. Usually, lines parallel to columns of cells (trunk) and lines perpendicular to them (branch) are placed in different layers and they are connected by throughholes. In the channel routing method we note first that the ordering of trunks is restricted if branches of different nets should not intersect each other. Then we represent this restriction with a digraph called a constraint graph. Using this graph we determine the order of placements of trunks. When there are directed circuits in a constraint graph we must destroy them by partitioning trunks.In this paper we modify the definition of constraint graph so that transformations on a constraint graph due to a partition of trunks become easy. To be more specific, information on terminals also will be incorporated in a constraint graph thereby limiting the extent of a transformation due to a partition of trunks. In addition, the trunk division method proposed earlier is redefined considering multiple divisions; conditions for each partition method to be effective in removing conflicting constraints are examined.

ISSN:8756-6621    

DOI:10.1002/ecja.4410640705

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

年代:1981

数据来源: WILEY

摘要:

AbstractWhen a pulse series with fixed frequency is applied to a neuron model employing tunnel diodes, the firing frequency of the model increases with increasing pulsewidth. The relation between these two quantities can be described by an extended Cantor function. This is identical to the abnormal phenomenon which Harmon discovered experimentally with a neuron model using transistors. One of the authors derived the same result for Caianiello's neuron model which was given by nonlinear difference equations. The neuron model discussed in this paper is described by the first‐order nonlinear differential equation and two jump conditions. The authors predict that the Cantor characteristics can be found experimentally in actual nerve cell

ISSN:8756-6621    

DOI:10.1002/ecja.4410640706

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

年代:1981

数据来源: WILEY

摘要:

AbstractAlthough a number of components for millimeter‐wave integrated circuits based on an open dielectric waveguide have been proposed, little has been reported on nonreciprocal devices and no significant results have been obtained. In this paper we discuss experimental verification of nonreciprocal propagation phenomena in an open ferrite waveguide and their application to open nonreciprocal devices. Based on the results, we propose a circulator of directional coupler type which makes use of nonreciprocal propagation phenomena in an open ferrite waveguide. We also propose a pillbox resonator type circulator and a junction type circulator using the nonreciprocal resonance of an open cylindrical ferrite. Circulators of the directional coupler type and the pillbox type do not need any conductor in principle. The radiation loss can be reduced without significant increase of the conductor loss if a conductor shield is used in the E‐plane of the junction circulator. A junction circulator with practical characteristics is developed for millimeter‐wave integrated cir

ISSN:8756-6621    

DOI:10.1002/ecja.4410640707

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

年代:1981

数据来源: WILEY

摘要:

AbstractA one‐point back‐feed type circularly polarized microstrip disk antenna is investigated. To establish a design procedure, (1) the operating condition for circular polarization is studied and design formulas and data are presented and (2) the fabrication and radiation characteristics of arrays consisting of the present circularly polarized disk antenna element are discussed. It is demonstrated that this class of antennas can serve as a useful form of circularly polarized array element. Further, in order to analyze the mutual coupling of such antenna elements, the resonance and inter‐element mutual admittance of an array consisting of two disk antennas located on the same plane are determined. The fundamental information on the mutual coupling thus obtained is presented for a design aid. Using these results, a circularly polarized array is realized with good axial ratio and boresight ratio less than 0

ISSN:8756-6621    

DOI:10.1002/ecja.4410640708

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

年代:1981

数据来源: WILEY

摘要:

AbstractSpace‐division electronic switching systems require the use of a swtiching network with the fewest possible crosspoints, since switching elements are expensive. Therefore, the switching capacity must be limited to the extent that a switching network should be structured in a multistaged manner if the switching network itself must be large. However, switching networks with multistaged provisions generally need complex control. Accordingly, complex studies must be devoted to the amount of control, as well as to the switching efficiency, of networks in designing multistaged switching networks. These considerations herein lead to an evaluation study on the amount of control for path hunting and clarification of the relationship between switching network types and the amount of control for path hunting. Initially, the space‐division multistage switching network is described and then path hunting methods which are used for evaluation are examined. The results of evaluating the amount of control for path hunting are described and consideration is given to switching networks which are most favorable with respect to the amount of control for path hunt

ISSN:8756-6621    

DOI:10.1002/ecja.4410640709

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

年代:1981

数据来源: WILEY

摘要:

AbstractThis paper proposes and analyzes a new waveguide resonator filter for comparatively low microwave frequency use. It describes a practical example for its application. The new waveguide structure consists of thin center conductors embedded in cylindrical dielectric rods in contact with conducting parallel plates. This structure can be viewed as a dielectric‐filled coaxial cable provided its external cylindrical conductor extends to a parallel plate. By using the relaxation method calculations are conducted under the assumption of pure TEM fields. The calculated impedance, line coupling, effective dielectric constant and circuit Q are found to be in good agreement with experiment.In order to investigate the higher‐order mode of the filter using this guided structure, the lowest higher‐order is assumed to be the TM01mode and the effect of the conducting plate is excluded; the wave‐numbers are calculated and compared with experiment. The Q of the 1/4‐wavelength resonator using this guide is higher than that of the dielectric‐filled coaxial line resonator and, without using the interdigital arrangement, couplings between resonators can nonetheless be realized. In the example of the 850‐MHz band filter, it is clear that this waveguide can be used to realize miniaturized, light‐weight, inexpensive and high‐pe

ISSN:8756-6621    

DOI:10.1002/ecja.4410640710

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe propagation characteristics of the TM mode wave in a two‐dimensional dielectric slab with a sinusoidal corrugation are theoretically analyzed. A coupled‐mode equation is derived for describing the coupling between the forward and backward waves near Bragg frequency caused by the corrugation and the Brillouin diagram is clarified. The theoretical characteristics of the reflection filter made of a dielectric slab with a finitely long corrugation are investigated. Using a Teflon slab loaded with a rectangular corrugation, experiments are conducted on the reflection filter in the 40‐GHz band and the results are compared with theoretical values. It is found that such filter characteristics as the Bragg frequency, return loss and stopband half‐width agree well with theoretical pred

ISSN:8756-6621    

DOI:10.1002/ecja.4410640711

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

年代:1981

数据来源: WILEY