bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scattering of Hermite‐Gaussian beams by parallel conducting cylinders
Authors: Yokota Mitsuhiro , Takenaka Takashi , Fukumitsus Otozo 
Published: July 2007

AbstractThe problem of a Gaussian beam with the spatial energy concentrated along the propagation axis is important in engineering applications. This paper studies scattering of two‐dimensional Hermite‐Gaussian beams by several parallel conducting cylinders located arbitrarily. First, the relation between the conventional beam modes and the complex beam modes proposed by Siegman is used for expression of a Hermite‐Gaussian beam in terms of multipoles with complex points. Next, the scattered field of each multipole field by cylinders is derived. The scattered fields of a conventional beam mode are represented in terms of those of complex‐source‐point multipole fields. As a numerical example, the effect of the spot size and that of the displacement of the propagation axis are studied in the case where a Gaussian beam is incident with the Bragg angle on the array of eight cylinders. It is found that the directivity of the diffraction of the order ‐1 is increased with the spot size and the maximum can be found in the direction almost equal to that for a plane wave incidence.
Inversion for 2‐D systems
Authors: Shimonishi Jiro , Hinamoto Takao , Maekawas Sadao 
Published: July 2007

AbstractThis paper describes a method for constructing an inverse system with inherent delay for causal two‐dimensional (2‐D) systems described by the Roesser state‐space model. In other words, the weakly causal 2‐D systems proposed by Eising are considered as 1‐D dynamic systems such that each element of the coefficient matrix is a rational function of one variable. It is shown also that an inversion with inherent delay for causal 2‐D systems can be discussed in general from a viewpoint of 1‐D dynamic systems. The features of the method are as follows: (i) the theory in 1‐D dynamic systems can be applied to the construction of 2‐D inverse systems; and (ii) a weakly causal inverse system can be obtained more easily from the viewpoint of a local state‐space model.
Scheduling of extended marked graphs
Authors: Onaga Kenji 
Published: July 2007

AbstractThe extended marked graph EMG = (V, E, c, d, p±, τ) is an excellent analytical tool for systems such as multi‐PERT and flow‐shop, where nondestructive resources are cyclically shared. This paper present a quantitative analysis for EMG scheduling (f, s) and describes the method of computation. fx (t) represents the number of firings of node x until time t and sx (t) is the kth firing time of node x. There are two kinds of rules, free and conservative types. The computation algorithm for scheduling and the method of determining the executability of the schedule are derived for each type.
Statistical design method of loss budget for the optical subscriber transmission system
Authors: Yamashita Ichiro , Kikushimas Koji 
Published: July 2007

AbstractIn the transmission system for the trunk lines, where a high reliability, i.e., a severe loss requirement is imposed, the worst condition is usually assumed in the design for the individual gain and loss of the transmission devices and media. In this paper this method is called the worst‐case transmission loss budget method or the worst‐case design. Although this method is reliable, it often contradicts the economical requirement in the subscriber transmission system. This paper proposes a design method for the transmission system, called the statistical loss budget method or statistical design method. Here, the transmission characteristics of the devices and media are assumed to follow statistical distributions with certain ensembles, and assuming that included statistical phenomena are always independent, the transmission performance is secured at a certain level with the specified danger level (significance level). By the proposed statistical design method, the economical requirement can be satisfied while maintaining the overall transmission performance of the system. In the optical transmission system, where the transmission loss is less compared with the metallic system, it is a great advantage of the statistical design method that the transmission length can be increased. In the design example where the statistical method is applied to the design of an optical subscriber transmission system, the transmission length is increased to approximately 1.8 times compared with the worst‐case design.
Development of several ohp equipment of physics using moiré patterns
Authors: Kitagaki Ikuo 
Published: July 2007

AbstractThis paper reports on several simple OHP equipments for education using Moiré patterns. The first equipment is concerned with centrifugal waves. The Moiré pattern is produced by superposing two specified patterns composed of straight lines and curves. The two patterns are determined as functions of the wave propagation velocity. The second is the fluid model used in demonstrating such notions in vector analysis as divergence. The spiral travelling wave is simulated using the reverse Moiré, which is a counterpart of the Moiré technique. The third is the equipment to simulate the electric lines of force produced by a pair of point charges and is used in teaching electromagnetics. The patterns are designed also for easy understanding of Moiré phenomena. This paper describes the design procedures for the patterns, indicating several points to be noted in the actual application of the equipments.
Design of digital nyquist filters based on the measure of squared errors at sampling points
Authors: Kida Takuro , Fukuda Yutaka 
Published: July 2007

AbstractThis paper describes design methods of the digital Nyquist filters based on the squared errors of the impulse response at equally spaced sampling points except one. First of all, for a specified pole of a transfer function, we consider the pole location which causes a problem when we use the residue formula proposed by Kida and Ohsumi to minimize the above mentioned squared errors. Then, assuming about 6 to 8 degrees for the orders for transfer functions, we consider a method which gives a favorable pole arrangement. We make an examination about a simple method of determining a pole arrangement which provides a favorable characteristic such that the squared errors at equally spaced sampling points except one point are about 10−5 and that the stopband attenuation is about 50 dB. Furthermore, in order to realize a large stopband attenuation which is required in the design of digital Nyquist filters, propose a design method of a transfer function based on a quadratic programming specifying the attenuation at a point in the frequency domain specified in advance. We show its effectiveness by examples. Finally, for the design of digital Nyquist filters using an interpolation method based on the sampling theorem of non‐equal space derived by Kida and Fukuda, we consider an example which indicates that transfer functions obtained by the above two design methods are appropriate.
A class of nonuniform coupled transmission lines and their equivalent circuits
Authors: Kobayashi Kunikatsu , Saito Nobuji 
Published: July 2007

AbstractY‐type and Z‐type parabolic‐taper single‐mode transmission lines and their equivalent circuits are first discussed. Then, by superposition of two of the above single modes, the TEM mode along a parabolic‐taper coupled transmission line (PTCTL) is analyzed. According to the choice of Y‐type or Z‐type for tapered single modes and the choice of combinations of balanced‐unbalanced modes or open‐short line modes as two independent superposed modes, there can be six types of PTCTL. Their equivalent circuits are also easily shown. Through the superposition of the voltages and currents of two Y‐type single‐mode parabolic‐taper lines, a Y‐type parabolic‐taper coupled two‐wire line is obtained. Similarly, from two Z‐type single‐mode parabolic‐taper lines, a Z‐type parabolic‐taper coupled two‐wire line is obtained. Furthermore, from a Y‐type parabolic‐taper line and a Z‐type parabolic‐taper line, we derive a mixed type of parabolic‐taper coupled two‐wire line. In any case there are two forms of combination, balanced‐unbalanced modes and short‐open line modes as superposition of two independent modes. An obtained nonuniform coupled two‐wire line does not always have the same taper. A special case of interest is that in which one of the two wires of a coupled line has decreasing taper and the other has increasing taper. Finally, a low‐pass filter is designed by the use of nonuniform coupled transmission lines and it is shown that the line length along the axis can be reduced.
Numerical analysis of diffraction from a sinusoidal metal grating
Authors: Yasuura Kamenosuke , Murayama Masanao 
Published: July 2007

AbstractDiffraction of plane waves by a metal grating of a sinusoidal cross section is investigated theoretically by considering a finite conductivity of the material. The analysis is based on the mode‐matching method with a smoothing operation. The numerical results of the diffracted power from a sinusoidal gold grating are presented with sufficient accuracy for both P‐polarization and S‐polarization. The results have been compared with those for perfectly conducting gratings. It is found that: (i) the reflected power is reduced due to loss compared to the perfectly conducting case, and the acuteness of the anomalous diffraction phenomenon called Wood's anomaly is decreased; and (ii) another anomaly called plasmon anomaly is observed in the case of P‐polarization. The latter cannot be observed in a perfect conductor.
Multiport power combining transmitter for multibeam satellite communications
Authors: Egami Shunichiro , Kawai Makoto 
Published: July 2007

AbstractA multiple beam power combining transmitter which has the flexibility to adapt beam power to varying beam traffic is proposed. The new multiport power combining network consists of a power‐dividing multiport directional coupler, multiple amplifiers and a power‐combining multiport directional coupler. The multiport directional coupler consists of multiple quadrature hybrids. Since each amplifier commonly amplifies signals to each beam, the power allotment to each beam can be changed with flexibility. The concept and configuration of the multiport directional coupler which divides and combines input signals are described. Also, the effects of uneven gain and phase distribution or failure of amplifiers are represented theoretically. Implementation to 8‐or 10‐beam systems is shown. Finally, the characteristics of the 8‐port experimental transmitter utilizing 1.5W FET amplifiers and branch line type hybrids are shown.
Vowel recognition using an LPC deviation model
Authors: Kumazawa Itsuo , Iijimas Taizo 
Published: July 2007

AbstractWhen the linear prediction coefficients (LPC) are used as a feature parameter of speech, a problem in speech recognition is the variation of LPC due to the difference of the speaker and the effect of the preceding or succeeding utterances. Because of this variation, LPC is distributed in a certain region in the LPC space. This paper proposes a method which approximates the region of distribution by a linear manifold model described in [1], and recognizes the category permitting the variation of LPC. The method is applied to the vowel recognition of CV syllable, and its usefulness is verified experimentally. It is shown first by spectrum analysis experiment that the linear manifold model is useful in the approximation of the variation of the vowel spectrum due to the preceding consonant. Second, a recognition experiment is carried out based on the model, and it is shown that the recognition rate can be improved by a simple model of linear manifold which is suited to computation.
A rearrangement algorithm for three‐stage switching networks
Authors: Ohta Satoru , Ueda Hiromi 
Published: July 2007

AbstractIn the three‐stage rearrangeable switch‐ing network, an internal blocking can occur. However, such a blocking can be eliminated by rearranging the already set‐up paths, and thus the network can satisfy any connection requirement. To eliminate this internal blocking, a successive rearrangement of more than one already set‐up path is required. The sequence of the paths to be rearranged can clearly be represented by extending the notion of the connection chain introduced by Gotoh. This paper presents a sufficient condition for the Internal blocking to be eliminated by the rearrangement in the extended connection chain, which is a basis for the rearrangement algorithm. It is also verified that the rearrangement algorithm proposed by Gotoh satisfies the sufficient condition. Based on these results, a connection chain is shown in which the internal blocking can be eliminated by the rearrangement. The algorithm to search for the connection chain and to perform the rearrangement is presented. Compared with past methods, in the proposed method, a fewer number of paths is distorted. The usefulness of the method is examined by a simulation.
σ gi/m/s/k queues with mixed batch renewal inputs
Authors: Machihara Fumiaki 
Published: July 2007

AbstractThis paper presents the analysis for the finite capacity queueing model with two independent mixed batch renewal inputs. The analysis is presented for the steady‐state distribution at an arbitrary time and the steady‐state distribution immediately before the arrival for each type of customers. The results can be applied to the models of various kinds of strategies such as delay‐delay, delay‐loss and loss‐loss. The structure of this paper is as follows. First, a simple numerical calculation procedures is proposed for the distribution at an arbitrary time which, compared with past methods, drastically reduces the computational complexity. Then the relationship is established between the distribution at an arbitrary time and the distribution immediately before the arrival, using the rate conservation principle in the theory of piecewise Markov process. Using this relationship, one distribution can easily be derived from the other. The individual blocking probabilities, which are the most important performance measures, are derived from the distribution immediately before the arrival. Finally, several examples are presented in order to discuss the effects of the interarrival distribution and the batch‐size distribution on the individual blocking probabilities.
A multiplexing system for digital transmission and process in vehicles
Authors: He Aiguo , Kawamatas Akira 
Published: July 2007

AbstractAt present, the vehicular electronic system is composed of several independent subsystems. By contrast, this paper proposes an integrated system where the same functions are realized in a more reasonable and economical way, utilizing the digital multiplex communication and distributed control. The system aims at optimization of the connections and control of the components, considering only the distances among the subsystems and components, independently of their kinds and functions. To improve the economy, reliability and flexibility, the system is composed of a ring transmission system and a distributed processing system using the microprocessors and optical fibers. This paper discusses the functions and structures of the transmission and processing devices composing the system. The optimum number of transmission and processing devices as well as the processing ability of the system are examined.
Transmission characteristics of PSK signals in satellite communication with nonlinearity and bandwidth limitation
Authors: Katayama Masaaki , Morinaga Norihiko , Namekawa Toshihiko 
Published: July 2007

AbstractThis paper reports on the results of analysis of the error‐rate performance when a PSK signal is transmitted through a satellite transponder. A waveform analysis is performed for the in‐phase and orthogonal components of the output from the nonlinear satellite transponder. The nonlinearity of the satellite transponder is represented by a bandpass hard limiter. In the analysis, the effect of both the ground transmitting and receiving filters are considered. As a result, the effect of the receiving filter on the signal is indicated clearly, which heretofore has been difficult in theoretical analysis. The reason for the degradation of the error‐rate performance in the bandpass hard limiter system is also clarified by the theoretical analysis, which has been pointed out by experiment and simulation.
Numerical method for analyzing transient and steady states of sine wave oscillator circuit with stiffness
Authors: Okumura Kohshi , Kishima Akira , Yasuda Hisashi 
Published: July 2007

AbstractThis paper proposes a method for analyzing the transient and steady states of a sine wave oscillator circuit with reactive elements which have large differences in their values. These reactive elements can be divided broadly into three categories: elements for determining the frequency of the oscillation; very small elements such as stray capacitors in the transistor; and very large elements such as by‐pass capacitors. The circuit equation is represented by an autonomous nonlinear differential equation with the values of these elements. There are remarkable differences in magnitude between the eigenvalues of the linear parts of the equation. In this paper, first, we describe the method for solving numerically the differential equation regardless of the stiffness by the asymptotic method developed by Krylov, Bogolyubov and Mitropolskiy. Second, we present the method for obtaining solutions of the differential equation with regard to the stiffness by combining the asymptotic method with numerical integration. Especially, when we obtain the transient solution, we demonstrate that the application of the interpolation method to the asymptotic method reduces the computing time considerably. As examples, we consider the CR sine wave oscillator circuit using the Ebers–Moll model of transistors.
Design of IIR nyquist filter pairs with equi–ripple stopband attenuation
Authors: Takebe Tsuyoshi , Matsumoto Toyoji 
Published: July 2007

AbstractThis paper deals with a design of digital transmitter and receiver IIR Nyquist low‐pass filter pairs for data transmission. The transmitter and receiver filters are required to limit the spectrum bandwidth of a transmitting signal and a received signal, respectively, and to have zero intersymbol interference when the filters operate in a cascade. Due to the bandlimiting requirements, the sampling frequency Fs = 1/Ts for the filters must be larger than twice the data transmission rate 1/T. This paper supposes the receiver filter followed by the time domain equalizer. The filter design proceeds as follows: first, the transmitter and receiver filters are designed to have the same transfer function with a stopband equiripple attenuation, considering the amplitude characteristics only. The filter transfer function is designed by using s – z transformation of the known analog elliptic filter, realizing the transition band characteristics with the preassigned roll‐off factor. The method does not require any iterative approximation. Secondly, the output of the receiver filter is decimated to the data symbol repetition rate T, then equalized in the time domain. The time domain equalizer consists of a linear or a decision feedback circuit, using an MS adaptive algorithm. The amount of delay given to the training signal supplied to the equalizer affects the residual errors. Let the order of the equalizer (numerator and denominator has the same order) denoted by n. Then an optimum delay is found to be equal to nT for the linear feedback circuit and (n/2)T for the decision feedback circuit.
Minimum confluent cut of a directed graph and its application to the block replacement problem in VLSI design
Authors: Kajitani Yoji , Tsuji Katsufumi , Chen Ray R. 
Published: July 2007

AbstractAssume a situation in which a block is required to change its relative position at the step where placement and routing in the VLSI layout design has been completed. We formulate a problem of minimizing the number of steps for modification, assuming that we need a step of one unit for rerouting one channel. Then we obtain a solution. For routing, we assume a channel routing style performed channel by channel on the grid determined by a design rule, and that a block movement is required by such slight increase of the width that a new wiring requirement is generated between blocks. The problem is reduced to that of finding an A‐confluent cut with total minimum weights for an arbitrarily specified edge set A in a directed graph with weighted edges. By an A‐confluent cut we mean a cut such that the orientation of each constituent edge is the same with respect to edges in A. Although it is a fundamental notion in graph theory, it appears to have been given little consideration.
Analysis of mobile antenna in UHF band
Authors: Nishikawa Kunitoshi , Asano Yoshikazu 
Published: July 2007

AbstractTheoretical and experimental studies are made on an antenna mounted on the roof of an automobile. The theoretical model of an automobile body and a calculation technique based on GTD are developed to calculate the input impedance and vertical plane patterns of a quarter‐wavelength monopole in the 300–900 MHz band. The theoretical model consists of three perfectly conducting plates. From a comparison of calculated and measured results it is seen that the effect of the body and the earth can be examined well with the theoretical model. The results of the pattern calculation show that the radiation patterns depend largely on the configuration of the automobile body.
Non–preemptive priority queue with server's walking process
Authors: Fukagawa Yukinori , Yanaru Torao , Yoshida Sho 
Published: July 2007

AbstractThis paper considers the non‐preemptive priority queue problem, where the server in a station participates in a walking process. When the server arrives at the station, he/she processes the job with the highest priority at that time and begins the walking process. The jobs arrive with the external priority r and with Poisson distribution. If two or more jobs have the same priority, they are processed on a first‐come first‐served basis. The processing time and the walking time of the server follow general distributions. Starting from the generating function and the normalizing condition for the number of jobs at the arrival of the server, the state probability for the number of jobs at that moment is derived. Next, the jobs are considered and partitioned into two classes (priority jobs and ordinary jobs), and the following functions are derived: (i) generating function for the number of priority jobs at the arrival of the server; (ii) generating function for the number of priority jobs at the end of service by the server; and (iii) generating function for the number of priority jobs at the completion of the priority job. From these generating functions, the waiting time distribution and the mean waiting time are derived for each class of priority. Numerical examples are shown.