bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two‐dimensional arrays and finite‐dimensional commutative linear representation systems
Authors: Matsuo Tsuyoshi , Hasegawa Yasumichi 
Published: July 2007

AbstractAs an application of realization theory for nonlinear systems, the authors have proposed a realization problem for arrays leading to the following realization theorem. “For a given arbitrary array, there always exists a canonical commutative linear representation system that realizes (computes) the array and is unique except for isomorphisms.” This paper discusses a finite‐dimensional commutative linear representation system that is manageable in practice. The notion of the pseudo‐realizable canonical form is introduced and the principal findings are as follows. (1) Among the isomorphism classes of finite‐dimensional canonical commutative linear representation systems, there always exists only one pseudo‐realizable canonical system. (2) Two necessary and sufficient conditions are derived for the array to be a behavior of a finite‐dimensional commutative linear representation system. (3) A realization procedure is described for deriving the pseudo‐realizable canonical form from the given array. The proposed theory of the finite‐dimensional commutative linear representation system is an extension of the theory of the finite‐dimensional constant‐coefficient linear system. The theory is also adapted for handling arrays on a digital computer.
LPC peak weighted spectral matching measures
Authors: Sugiyama Masahide , Shikano Kiyohiro 
Published: July 2007

AbstractThis report proposed an LPC peak weighted spectral matching measure, a voice recognition method with weighted global spectral peaks (formants), and demonstrates its usefulness by comparing it with the conventional LPC matching measure. The “peak weighted measure” is defined by the integral of the product Kw, where K is a function representing spectral differences between the standard pattern and input voice and w is a weighted function representing peaks. It is shown that the integral value can be computed simply by LPC analysis parameters. Analysis of the weighted spectral difference Kw shows some variation in effectiveness of peak weighting.Experiments on vowel discrimination to evaluate the measure conclude that the discrimination error rate of 11.7% in the conventional LPC matching measure can be reduced to 9.3% by using the peak weighted measure and, especially, it is remarkably improved for the vowels /a/, /u/, /o/. Further, the variance of the discrimination error rates by speakers is smaller than that of the conventional LPC matching measure.
Linear and nonlinear analysis of electromyography time series
Authors: Ishii Naohiro , Iwata Akira , Suzumura Nobuo , Yamazaki Yoshiki 
Published: July 2007

AbstractThe purpose of this paper is to extract the information of the posture control of an experimenter standing on a plate. In the experiment, the object is vibrated sinusoidally in the vertical direction on the plate and the electromyography (EMG) and force on the plate are measured. A method of estimating the delay time of the system, the system response of the position component and the velocity component of the input is developed. The pseudo‐white noise is constructed by changing the angular frequency of the input. It is shown that the EMG and the force are well represented by a nonlinear input‐output relation.
A novel radar reflector with variable RCS
Authors: Kotajima Hiroshi , Fujita Hirotoshi 
Published: July 2007

AbstractIt is convenient to have a standard radar reflector with a variable radar cross section when the reflection characteristics of radar reflectors and various objects are measured or when performance tests of radar systems are carried out. There have been several proposals for such radar reflectors in the past. However, since all of them make use of reflection of the conductor surface, their reflection efficiency is too low to be practical. The principle of the radar reflector reported in this paper is completely different from that of conventional ones and makes use of focusing and spherical symmetry of the Luneburg lens. The reflection efficiency is quite high and the radar cross section can be varied in response to the rotating angle of the lens. First a method is proposed to obtain a desired radar reflector and the design and fabrication method are described. Further, by means of a prototype development and subsequent measurement is is shown that the proposed method is realizable. As an example, the prototype reflector for a horizontally polarized wave of 9375 MHz is made using a Luneburg lens with diameter of 30.5 cm. The radar cross section can be varied from 43.28 m2 to 0.42 m2 as designed.
Separation of kernel in the hexagonal discrete fourier transform
Authors: Morikawa Yoshitaka , Hamada Hiroshi , Yamane Nobumoto 
Published: July 2007

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 hexagonal DFT.
Theoretical study on cantor function‐like response characteristics of neuron model
Authors: Osada Hiroyasu , Yoshizawa Shuji , Nagumo Jin‐Ichi 
Published: July 2007

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 cells.
Trunk reservation for two‐way trunk group with overflow input
Authors: Machihara Fumiaki 
Published: July 2007

AbstractThe total blocking probability for three types of calls and the individual blocking probabilities for each type of call are analyzed for the case where the trunk reservation system is applied to a two‐way trunk group and priority is assigned to the downward first‐routed traffic, the upward first‐routed traffic and the alternate‐routed traffic in that order. The analysis is outlined below.First, we analyze the transition proabbility of simultaneous circuit connections in the circuit holding model M1, M2/M/n(n2) with due regard to the downward first‐routed traffic and upward first‐routed traffic only, which have Poisson distribution. This analysis involves difficulty in numerical computation because the occurrence rate depends on the number of simultaneous circuit connections and hence it has not been solved yet. We solve it here by introducing the characteristic eigenvalues of system generation operators. Then we mark the instants at which overflow calls of the alternate‐routed traffic arrive at the two‐way final trunk group. Accordingly, this model can be considered as applying regenerative inputs to the above‐described M1, M2/M/n(n2). Therefore, the individual blocking probability for each type of call is introduced by using the piecewise Markov process. The total blocking probability can simply be given through the individual blocking probabilities. Numerical computations are performed and reservation effects are quantitatively shown.
Multiple communication bus network
Authors: Kajiwara Masaichi , Hishinuma Chiaki , Itoh Masaki 
Published: July 2007

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 thousands.
An analysis of coplanar waveguides with finite conductor thickness‐computation and measurement of characteristic impedance
Authors: Koshiji Kohji , Shu Eimei , Miki Shichiro 
Published: July 2007

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 shortened.
A stable narrow band‐pass quartz crystal filter at 150‐MHz region
Authors: Sawamoto Kenichi , Kojima Hiroshi , Hirama Koichi , Kameyama Korenori 
Published: July 2007

AbstractResearch on a stable narrowband quartz crystal filter at 150‐MHz band is presented. The design is based on the operational parameter method for low device sensitivity. The three‐section Wagner type circuit is realized by a symmetric lattice circuit and imaginary gyrator and in the present treatment the circuit elements of the series‐parallel branches of the symmetric lattice circuit replace the corresponding crystal resonators. The crystal resonators are AT cut and operate in the 5‐th overtone mode with thickness above 50 μm. A thin‐wafer polishing technique and adjustment method is employed. The resonator has a resonance frequency temperature coefficient of 0.2 ppm/°C, aging coefficient about −6 ppm/decade (days) and its equivalent resistance change with respect to temperature and aging is small.The passband attenuation (finite loss) change with respect to temperature depends on the temperature characteristics of circuit components other than the resonators. By suitable selection of these components, the attenuation variation is about 0.1 dB in the temperature range of 0 to 50°C. The passband width is about 10 KHz and, as calculations show, depends on the resonator characteristics. The stopband attenuation is above 60 dB in the band of f0 ± 100 kHz, where f0 is the center frequency of the pass‐band and no spurious mode is observed. As the crystal resonators have stable temperature‐aging characteristics, long‐term stable operation is anticipated.
Heterodyne detection of partially coherent optical signal
Authors: Takenaka Takashi , Saga Nobuhiro , Fukumitsu Otozo 
Published: July 2007

AbstractThe SN ratio is studied for heterodyne detection of partially coherent plane wave optical signals when they are focused by a lens after passing through a circular aperture and are added to a coherent Gaussian beam local oscillator signal. We treat the case in which the intensity distribution of the signal over the aperture is uniform and the natural logarithm of its spatial coherence is expressed as the vth power of the distance between two arbitrary points on the aperture. Using a two‐dimensional Fourier transform, we express the mutual coherence function of the signal on the detector surface in a series form. The results are used to present an expression for the SN ratio suitable for numerical calculations. The SN ratio is investigated numerically with the correlation length on the aperture and the detector radius as parameters. It is found that, regardless of the correlation length, the detector radius of the order of the Airy disk is sufficient for obtaining an SN ratio almost equal to the maximum value determined for each correlation length. We also find that the maximum SN ratio is approached in the case of partially coherent signals if we use the optimum beam parameter of local oscillator signals, which has already been determined.
Chaos in a manifold piecewise linear system
Authors: Saito Toshimichi , Fujita Hiroichi 
Published: July 2007

AbstractThis paper describes the irregular behavior of solutions to certain differential equations. This phenomenon is called chaos and in ordinary automomous differential equations it occurs beyond three dimensions when represented by normal type. The authors propose here a new differential equation, called the manifold piecewise linear system, in dealing with this phenomenon. The equation is described by special coupling of the linear system and, from the local solution rigorously obtained, a Poincaré map for investigation of the solution behaviors is calculated rigorously. Thus, an analytical approach to the chaos of differential equations which cannot be dealt with at the present becomes possible. The differential equation solution is shown in a certain parameter region to become aperiodic and is neither convergent nor divergent. This equation can be analyzed as a whole by the Poincaré map in terms of the different parameters with the same form. This is desirable for sensitivity analysis. Also, for a given parameter and region of definition, Poincaré maps are expressed in terms of different forms and an example corresponding to previous research is presented.
Bending loss formulas for step‐index optical fiber and their applicable regions
Authors: Kusano Kiyonobu , Nishida Shigeo 
Published: July 2007

AbstractThis paper presents a method for analyzing bending loss formula for the hybrid mode propagating in a uniform bend. As a hybrid mode, we chose the LP mode and found dependency of the bending loss formula on the directional angle, propagation constant and the amplitude ratio and phase difference of the constituent mode. The results contain those previously obtained and are applicable to more cases. We found that the bending loss of a general LP mode depends on the amplitude ratio and phase difference of the constituent mode, the directional angle, and the propagation constant. A linearly polarized LP mode has its bending loss dependent on the directional angle but not on the polarization angle. The bending loss of the HE and EH modes does not depend on the directional angle. Based on the condition for which the deviation of the field distribution due to the bend is negligible, we found the applicable range of the bending loss formula.
Micro fresnel lenses fabricated by electron‐beam lithography
Authors: Fujita Teruo , Nishihara Hiroshi , Koyama Jiro 
Published: July 2007

AbstractMicrolenses constitute an area of very important components in microoptics. This paper proposes the use of electron‐beam lithography for making micro Fresnel lenses. An electron‐bean machine developed for this purpose offers great flexibility in their design and fabrication. Micro Fresnel lenses for visible and infrared were made using PMMA as an electron‐beam resist. Fabricated lenses with F‐numbers above 1 can focus incident plane waves into a nearly ideal diffraction‐limited spot with an efficiency of 30%, while theory predicts 40%. A minimum spot size, or intensity half‐width, of 0.7 μm was obtained at wavelength of 0.6328 μm using an electron‐beam fabricated lens with a very small F‐number of 0.65.
A composite gate structure for enhanced‐performance power MOS FET'S
Authors: Yoshida Isao , Okabe Takeaki , Hashimoto Norikazu , Nagata Minoru , Ochi Shikayuki 
Published: July 2007

AbstractA new composite gate structure is proposed to reduce the power MOS FET ON‐resistance (loss). This gate structure consists of inhomogeneous gate oxides in an E/D gate, with a thin oxide in the enhancement gate region and a thick oxide in the depletion gate region. The structure is optimized by a 2‐dimension computer analysis. The optimum composite gate is realized with two silicon‐gate layers.The performance of the fabricated composite‐gate power MOS FET is better than that of the conventional device for the same breakdown voltage (250 V); the ON‐resistance is only one‐half and the transcon‐ductance is four times that of the conventional device.The proposed composite‐gate techniques are important for short‐channeling and relaxation in MOS FET and they can be applied not only to power MOS FET, but also to all MOS FET to yield higher performance.
Stability theory and existence of periodic solutions of time delayed compartmental systems
Authors: Maeda Hajime , Kodama Shinzo , Konishi Tomohisa 
Published: July 2007

AbstractThis paper discusses the global asymptotic stability and existence of periodic solutions of periodically varying nonlinear compartmental systems with time delay. We exploit the inherent property that any bounded solution approaches a periodic solution. Based on this result, we derive a necessary and sufficient condition for a homogeneous (zero‐input) system to be globally asymptotically stable and derive a necessary and sufficient condition for the system forced by a periodic input to admit a periodic solution. These conditions do not include time delay and are stated in terms of the interconnections among compartments. This amounts to showing that such qualitative properties of solutions are preserved irrespective of the introduction of arbitrary time delay.
Reduction method of calculating high‐order volterra functionals
Authors: Ichikawa Satoshi , Tokoro Setsuo , Kawasaki Shuji , Hagihara Satoshi , Higawara Tetsuya 
Published: July 2007

AbstractA well‐known analytical method for linear systems is that which employs the Laplace transformation. Such method is applicable to analytical nonlinear systems in various ways, as has already been reported [1, 2]. A problem in this method is calculation of the multidimensional inverse transformation, which is normally performed after reduction to one dimension. However, if higher‐order terms have to be taken into account, the amount of calculation for the reduction becomes excessive, so that manual calculation is impossible. Thus, in this report we propose to achieve the reduction operation by computer. Algorithms derived are practical for application to systems that consist of the sum and product of linear subsystems, cascade connection, and feedback. These are quite efficient algorithms, fully utilizing the system characteristics. We show that the advantage of the algorithm is to have the output in the form of frequency components.
Surface acoustic wave parametric oscillation in Si/LiNbo3 substrate
Authors: Nakagawa Yasuhiko , Wakuda Mutsuo , Kobayashi Kenichi 
Published: July 2007

AbstractSurface acoustic wave parametric oscillation due to the backward nonlinear process in a surface acoustic wave convolver is an interesting phenomenon and various applications have been considered. This paper discusses the theory and experimental results with a SAW reflector design with a low oscillation threshold, using a Si/LiNbO3 substrate, which yields the highest convolution efficiency. The results show that the oscillation threshold power can be greatly reduced by using reflectors (threshold power is reduced to 1/30 for a reflection coefficient of 0.75, as compared with the reflectionless case). In the experiment oscillation could be achieved with such low input power that the oscillation threshold was only 14.4 dBm, and thus SAW parametric oscillation is possible. Also, the experimental oscillation characteristics agree well with theory.
Adjoint network approach to sensitivity calculation for switched‐capacitor networks
Authors: Kunieda Hiroaki , Kaneko Mineo , Onoda Mahoki 
Published: July 2007

AbstractThis paper introduces a computer analytical technique for obtaining the element sensitivities of switched‐capacitor networks (SC networks) with good efficiency by using adjoint networks similar to those for conventional linear networks. The SC networks treated here consist of capacitors, ideal two‐mode switches and operational amplifiers represented by nullator‐norator models. The network equations for the SC networks with amount of charge movement and voltage as variables are so formulated that the network equations of the adjoint networks can be obtained by a simple transformation such as the transpose of their coefficient matrices and with minimum order in many cases. It is also shown that by using Tellegen's theorem in the SC networks, the element sensitivities for capacitors can be obtained as the product of the amount of charge movement in the original SC networks and the voltages in their adjoint networks. Therefore, the element sensitivities can be determined by network analysis of the SC networks and their adjoint networks and the analysis can be performed efficiently with the abovementioned formulation of network equations. Finally, an example of sensitivity analysis by implementing a computer program is shown and its effectiveness is confirmed.
Analysis and applications of new I2L multivalued logic circuits
Authors: Taniguchi Kazutaka , Inoue Takahiro , Ueno Fumio 
Published: July 2007

AbstractMIN/MAX and Literal/Successor circuits are proposed which can perform two different operations at the same time. Furthermore, these circuits have fewer elements than conventional circuits. Therefore, they contribute to increasing the applicability of I2L logic circuits. New multivalued I2L D latches are also proposed, which reduce the number of elements. Their sensitivities are estimated and the relative errors in output and effective threshold are evaluated in the presence of errors in the current mirror gain and in the designed current threshold values. Operation and experimental results are described for a 3‐valued full adder and a 4‐valued D flipflop circuit.