bluuebunny/crossref_metadata_2025_split huggingface dataset:
A method of two‐dimensional spectral analysis using the wigner distribution
Authors: Suzuki Hiroshi , Kobayashi Fuminori 
Published: July 2007

AbstractWigner distribution (WD) has recently attracted attention as a powerful tool for time‐varying signals analysis and several applications have been proposed. WD is calculated as the Fourier spectra of a signal with special preprocessing. The preprocessing allows the frequency resolution to be better than that of Fourier transform (FT). However, this preprocessing causes WD to generate interference terms and more complicated aliasing compared to FT. To cope with these problems, WD is usually calculated using analytic signals. In one‐dimension, the method of deriving analytic signal is unique. However, in two‐dimensions (2‐D), several methods have been proposed.This paper presents the reason for 2D‐WD to generate aliasing and interference for negative frequency components and its solution. Based on the discussion, a new analytic signal for 2D‐WD is proposed together with a method of new spectral analysis using the signal. The proposed method offers higher frequency resolution and no interference term for negative frequency components, as well as no aliasing, providing characteristics similar to WD. By using this method, spectral analysis for low frequencies can be realized with small‐sized windows.
A method for selecting the most suitable pitch from some candidates utilizing its time continuation
Authors: Ogihara Akio , Yoneda Shojiro 
Published: July 2007

AbstractPitch frequency is a basic characteristic of the human voice, and pitch extraction is one of the most important studies for speech recognition. This paper describes a method for selecting the most suitable candidate from candidates (pitch candidates) obtained by the short‐range autocorrelation function. The selection is done utilizing the time continuation which is realized by that history of pitch candidates at previous frames referred to with a referential matrix. In addition, an improved result of pitch extraction is obtained by introducing restraints of double‐pitch and half‐pitch. The pitch extraction was performed for three males and three females. The proposed method improves the percentage of correct pitch from 64.86 to 91.06 percent.
Effects of aluminum thickness on temperature characteristics of surface acoustic wave devices on the quartz LST‐cut
Authors: Murota Masao , Hirano Tetsuya , Shimizu Yasutaka , Lam C. S. , Holt D. E. 
Published: July 2007

AbstractOne of the highly stable quartz substrates for surface acoustic devices is the LST‐cut using the leaky surface acoustic waves. It has been reported that the temperature dependences of the center frequency and the insertion loss are affected by the thickness of the electrode film.In this paper, with a view to finding the relationship between the optimum cut angle and the thickness of the electrode film, the temperature dependences of the center frequency and the insertion loss have been studied theoretically and experimentally in the case where the cut angle and the thickness of the electrode film are varied. Good agreement has been found between the theoretical and experimental results if the thickness of the electrode film is taken into account.The relationship between the cut angle and the thickness of the electrode film for the temperature dependences of the center frequency and the insertion loss has been found theoretically and presented in the form of contour plots. It has been demonstrated that devices with superior performance can be obtained by controlling the cut angle and the thickness of the electrode film.
A method of hazard detection by five‐valued logic simulation based on the TRF delay model
Authors: Kang Min Sup , Deguchi Hiroshi , Shirakawa Isao 
Published: July 2007

AbstractThis paper proposes an efficient method to detect the hazard existing in the logic circuit using the five‐valued logic simulator. The proposed method is effective in logic verification for the combinational and asynchronous and sequential logic circuits as well as the verification for the hazard (race).Using the proposed method, the timing of the logic circuit is analyzed, including the rise/fall delay considering the signal transition time. The hazard is detected based on the output of the gate and the scheduled time. Also discussion is a method of event cancellation, which is a problem in the delayed simulation. Through the results of experiments using several circuits, the proposed algorithm is shown to be useful.
Coefficient sensitivity analysis for block‐state realization of state‐space digital filters
Authors: Tsunekawa Yoshitaka , Shida Junichi , Kawamata Masayuki , Higuchi Tatsuo 
Published: July 2007

AbstractThis paper presents an analysis of the frequency characteristics of the coefficient sensitivity in the block‐state realization. The expression for the coefficient sensitivity is derived first, and the following properties are shown. In contrast to the usual state‐space realization, the coefficient sensitivity in the block‐state realization has the periodicity with period (2π/L), where L is the block length. There is also a symmetry for the response in a period. Then the following property is shown in the coefficient quantization in the block‐state realization. The peaks of the coefficient sensitivity, which usually appear only at the end of the passband, appear many times iteratively in other frequency ranges, resulting in a particular coefficient quantization error. This point must be considered in the design of the filter by block‐state.A measure for the coefficient sensitivity is defined anew to evaluate the coefficient sensitivity over the whole frequency range. It is shown that this measure of the coefficient sensitivity is an extension of the ordinary state‐space realization. The expression of the measure is given by the state covariance matrix of the subfilters for the elements of transfer function in the block‐state realization, i.e., the L‐input/L‐output system, together with the noise matrix. Finally, a computation example is shown.
A design method of LQ regulator by fuzzy set theory
Authors: Hagino Kojiro , Ohbayashi Tokuji 
Published: July 2007

AbstractThe most important problem in the design of control systems by the LQ regulator theory is the absence of guidelines to determine the weighting coefficient matrices Q and R in the quadratic objective function. In practice, a designer determines Q and R by trial‐and‐error while observing the step response waveform. A designer modifies Q and R and observes the obtained response waveforms. While making a compromise with design specifications for a considered system, a designer tacitly sets the tolerance for response waveform in the sense that he can tolerate the deviation from the design specification.In contrast to the traditional method of design, this paper formulates the tolerance for a response waveform conceived by a designer for design specifications as a fuzzy constraint using fuzzy set theory. A method of design is proposed in which the fuzzy representation for the weighting coefficient matrices is constructed for given design specifications, and the satisfactory solution (Q*, R*) to satisfy the designer's standard is determined. An application for the aircraft is shown.
Software reliability growth model with continuous error domain—application of a linear stochastic differential equation
Authors: Tanaka Hiroaki , Yamada Shigeru , Osaki Shunji , Kawakami Shin‐Ichi 
Published: July 2007

AbstractThis paper considers the software error detection process in the testing phase, which is the final stage of the software development. The process is modeled by a stochastic process with a continuous changing variable. Employing a new mathematical technique based on the stochastic differential equation, a new software reliability growth model is constructed.First, the traditional basic differential equation, which describes the average behavior in time of the number of errors, is extended to the Itǒ‐type stochastic differential equation, and the probability distribution of the solution process is investigated. Then, using the derived distribution, several reliability assessment measures are derived.Finally, the unknown parameters of the model are estimated based on the actual test data, and the stochastic property of the temporal variation of the errors remaining in the software is examined numerically. Using MTBF (mean‐time between failure), which is the important reliability assessment measure, the problem to determine the release time of the software is discussed.
A synthesis of switched capacitor inductance simulation circuit using voltage followers
Authors: Ono Toshio 
Published: July 2007

AbstractVoltage followers are used for the switched capacitor (SC) circuit simulating the ungrounded inductance based on the bilinears‐Ztransform. The operation is confirmed by experiments. In the circuit configuration, it is pointed out that the block diagram often used in the derivation of the SC inductor complicates the circuit and the control clock and a new block diagram is proposed. The circuit derived by this method is simple since the control clock has two phases and the spreading of the capacitance value is only 2. Further, the circuit is not affected by the parasitic capacitance caused by the substrate‐side electrode of the integrated capacitor which typically affects the characteristics significantly.Although two voltage followers are needed for realization of one inductor, it can be considered that effectively one inductor is constructed with one voltage follower if the adjacent SC resistance and SC inductor are shared with a voltage follower. It is described that the spread of the capacitance value in the entire filter can be made smaller than other SC inductors when this SC inductor is used in the SC filter. Simplification of the circuit with this filter is investigated.
Application of modified off‐axis spectrum to speech recognition under noisy conditions
Authors: Nakagaki Atsushi , Miyanaga Yoshikazu , Tochinai Koji 
Published: July 2007

AbstractThis paper introduces a peak enhancement method using an off‐axis spectrum which is used in peak picking. It also considers its advantages and problems for the application of speech recognition. An off‐axis model modified to be suitable for speech recognition is proposed. The modified off‐axis model is realized by combining a peak emphasis model and a peak repressed model. The modified off‐axis model can control the peak bandwidths and the slope of its spectrum by operating two parameters. The values of the parameters are determined adaptively to each sample by a stability test. In addition, some results of experimental speech recognition under noisy conditions are described and the efficiency of the method is discussed.
VLSI‐oriented design method of asynchronous sequential circuits based on one‐hot code and two‐transistor and logic
Authors: Cho Kyong‐Rok , Asada Kunihiro 
Published: July 2007

AbstractThis paper proposes a new method of synthesis for a CMOS LSI‐oriented asynchronous sequential circuit with the two‐transistor AND logic structure, using the one‐hot code for the internal state assignment. The assignment of the state by the one‐hot code is executed uniquely, independently of the properties of the state‐transition table. The CPU time for state assignment, which has been a problem, can be ignored.The critical race‐free property, which is then a problem, is solved by a 4‐FET set/reset flip‐flop which stores the state variable and the drive circuit for the flip flop, not the internal code assignment. The set and the reset driving circuits have the AND logic circuit structure, where two transistors are placed (with the state variable and the external input as the gate inputs) on each conduction path. The synthesized circuit is hazard‐free. It realizes a pseudo‐CMOS operation without static power consumption.Comparing the method proposed in this paper with other methods of synthesis, it is compact and especially suited to the large‐size asynchronous sequential machine (with 40 or more cells in the row‐column product of the state transition table).
A parameter optimization method for electronic circuit design using stochastic model function
Authors: Lu Jin‐Qin , Adachi Takehiko 
Published: July 2007

AbstractThis paper presents an optimization procedure using the stochastic model function, aiming at the application to the optimization of the circuit constant in the integrated circuit. The optimization of the circuit constant is formulated as a minimization problem for the objective function derived from the circuit response under the specified condition.In the method presented in this paper, the model function is constructed which approximates well the objective function, and the objective function is minimized by minimizing the model function. The features of the method are that the algorithm is simple, the number of evaluations of the objective function is small, the result depends less on the initial value, and the minimum of the objective function can be determined with a high accuracy. The method is evaluated using the standard test function, and it is verified that all minimum values of the objective function can be determined with a high accuracy with fewer number of calculations of the objective function. The optimization procedure is applied to two circuit examples: the analog control circuit and the inverter chain. The result is satisfactory and the usefulness of the presented optimization procedure in the circuit design is demonstrated.
Construction of codes on arbitrary plane curves
Authors: Kamiya Norifumi , Miura Shinji , Imai Hideki 
Published: July 2007

AbstractIn 1981, Goppa established an epoch‐making method for constructing a code utilizing the theory of algebraic curves [1]. This is called the algebraic curve code. This paper develops the theory on an arbitrary curve, which may contain singular points and discusses the method of constructing the code.The method employed in this paper is to eliminate the singular point by applying the transformation called blowing‐up and to construct the code on the nonsingular model. The number of genes of curves can be derived simultaneously. It is made easy to derive the bases of the linear spaces L(G) and Ω(G‐D), as in the case of the nonsingular curve.The algebraic curve C considered in this paper is the irreducible projected plane curve or the algebraic curve which is obtained by gluing irreducible affine plane curves. In this case, the nonsingular model of C can also be represented as a gluing of irreducible affine plane curves. Then the method is applied to the hyperelliptic plane curve on which the number of rational points achieves the Hasse‐Weil bound or certain hypernonelliptic plane curves. It is shown that the precise structure of the code can be examined.
Switched network analysis based on final value theorem of Laplace transform
Authors: Suetsugu Tadashi , Mori Shinsaku , Mizutani Hikaru , Tanaka Mamoru 
Published: July 2007

AbstractThis paper proposes a new method of analysis in the modified nodal analysis of the switched network. In the proposed method, the limit of the switching resistancerfor 1/∞ or ∞ is replaced by the limit of the variable “s” of Laplace transform fors→ 0. Then by applying the final value theorem of the Laplace transform, the solution of the network equation immediately after switching is derived as the limit fort→ ∞ of the virtual state equation.By this transformation based on the final value theorem of the Laplace transform, the limiting operation of the switching resistance can be transformed into the iterative calculation of the product of the nonsingular matrix, which does not depend on the switching resistance, and a vector.In this new method, the coefficient matrix of the backward Euler method in the numerical integration of the virtual state equation is always nonsingular. This makes it possible to designate the next switching pattern without a particular algorithm, even in the singular problem where the network equation becomes singular for a certain switching pattern.When the state before the switching is the actual solution, as in the SC network, this method can derive the discontinuous solution which jumps from one state to the next state. Since the coefficient matrix of the backward Euler method is always nonsingular, the inverse matrix lemma can be applied to the calculation of the inverse matrix, which can be executed by lowering the order of the matrix from the given matrix to the actual order of the switched pattern.
Integration environment to invoke CAD tools efficiently
Authors: Miyazaki Toshiaki , Hoshino Tamio , Endo Makoto 
Published: July 2007

AbstractThis paper describes an integration system for VLSI design tools and their interface builder. The main advantage of this system is its unique process control mechanism. Once VLSI designers specify their tasks by using a flowchart‐based graphic editor, the system could handle the design process and maintain the design data produced by each tool. In addition, the system features several interface building tools and subroutine packages that readily integrate new design tools into the system environment. The system was conceived to provide a unified interface for designers and to manage CAD tool invocation to improve design turnaround time.
Evaluation and analysis of coded speech quality
Authors: Nakayama Takeshi , Futagami Tohru , Takida Keiji , Kodama Kazuyuki , Kawasaki Zenshiro 
Published: July 2007

AbstractRating scale data for evaluating coded speech quality by the mean opinion score (MOS) are factor‐analyzed to show the possibility of extracting rich information from them. Two factors, softness‐shrillness and clearness‐noisiness, are extracted. Factor scores expressing a kind of multidimensional scale of speech quality are related to several physical parameters of speech samples, e.g., differential spectral distortion, phase distortion, and dissonance. Individual subject differences in evaluating speech quality are extracted as the factor loadings. It is found also that speech specialists and nonspecialists place different weights on different factor axes.
Analysis of quantization errors in digital control systems using floating‐point arithmetic—considering computational order in controller
Authors: Okada Kazuho , Kuroe Yasuaki 
Published: July 2007

AbstractThe floating‐point representation is employed widely in the digital control system due to its features of large dynamic range and high accuracy. However, a sufficient study has not been made on the quantitative evaluation of the quantization error because of the difficulty of the analysis.From such a viewpoint, this paper considers the general digital control system and discusses the evaluation method for the control error and the performance deterioration of the control system due to the quantization in the A‐D and D‐A converters, as well as the arithmetic operations in the controller. The difference equation for the error of the state of the digital control system is derived, and the quantitative evaluation of the error (i.e., the mean and the variance) is proposed based on the equation.It is noted that there is a freedom in the order of computation in the control operation in the digital controller, and the computation error depends on the order of computation. Consequently, a matrix is newly defined to specify the order of computation, and a method is proposed for the analysis of the control error considering the order of computation.In the proposed method, the error can be evaluated for the general digital control system without specifying the object of analysis. The usefulness is demonstrated by a numerical example.
An analysis for steady‐state response of nonlinear systems with sinusoidal inputs
Authors: Ichikawa Satoshi , Goto Tsutomu 
Published: July 2007

AbstractNumerous studies have been made to analyze the input/output relation of the weakly nonlinear system by applying the theory of Volterra series. When this theory is applied directly to the analysis, a complex multiple integration must be calculated. On the other hand, it is shown in this paper that the solution can be derived by a systematic calculation using multiplications and additions if the input is restricted to the sum of sinusoidal waves and only the steady‐state output is considered for the system represented by a nonlinear equation or a circuit equation. A detailed algorithm is presented, which is called the “nonlinear steady‐state method”.The purpose of this paper is to demonstrate the usefulness as well as the problems of the nonlinear steady‐state method through examples. The first step is to derive the algorithm for the analysis, which can produce a result equivalent to that of the theory of Volterra series. The Duffing equation is used as an example of the system represented by a nonlinear differential equation. Then, as an example of the system represented by a circuit equation, the method is applied to the analysis of the linear antenna with a nonlinear load. The application of the method is inevitably limited due to the condition that the system is weakly nonlinear and the input is the sum of a finite number of sinusoids. However, the result seems to indicate that the method is very useful when those conditions are satisfied.
A synthesis of pipelineable wave digital filters by scattering matrix factorization
Authors: Watanabe Eiji , Mogi Yoshiaki , Nishihara Akinori 
Published: July 2007

AbstractThis paper proposes a synthesis of low‐sensitivity digital filters which are pipelineable and have simple structures. Their sensitivity characteristics are similar to those of wave digital filters. The synthesis of these filters is attained by factorizing paraunitary scattering matrices derived from given z‐domain transfer functions without referring to analog filters. The synthesized structures are the T‐cascade connection of fundamental sections which are constructed by using series and parallel sections of wave digital filters.The proposed synthesis method can realize any given IIR transfer function, while previous methods which synthesize T‐cascaded structures can realize only the amplitude response of any given transfer function. In addition, the method can realize the transfer functions of which the order of their denominator is higher than that of their numerator including FIR transfer functions.
An algorithm for generating finite two‐dimensional real number sequences with low autocorrelation sidelobes
Authors: Ohue Kenji , Aibara Tsunehiro 
Published: July 2007

AbstractWhen the spread‐spectrum technique or smear technique is applied to the two‐dimensional data such as the image data, which have the two‐dimensional array structure, it is important to apply the two‐dimensional numerical sequence that minimizes the sidelobe component of the autocorrelation function.This paper proposes a new method of generation, where the two‐dimensional complex exponential function is used as the generating function and a finite two‐dimensional real‐number sequence with a sharp autocorrelation function is derived from the two‐dimensional Fourier expansion coefficients.As the first step, the phase condition is derived for the Fourier expansion coefficients of the generating function to be real. It is shown that the infinite two‐dimensional real‐number sequence constructed by the forementioned infinite number of Fourier expansion coefficients is an uncorrelated sequence. Then it is shown that by using the proportional constant of the phase function as the parameter, a finite two‐dimensional real‐number sequence with the autocorrelation function with arbitrary evaluation function value can be derived.Finally, a generation example of the finite two‐dimensional real‐number sequence is shown, demonstrating that the finite two‐dimensional real‐number sequence with a very sharp autocorrelation can be generated by the proposed method.