bluuebunny/crossref_metadata_2025_split huggingface dataset:
Block placement method based on evaluation of idle area using simulated annealing
Authors: Koakutsu Seiichi , Sugai Yasuo , Hirata Hironori 
Published: July 2007

AbstractThe simulated annealing method is concerned with the large‐scale combinational optimization problem such as VLSI layout design. It aims at arriving at the global optimum without being captured by the local minimum, by the probabilistic optimization based on the stochastic process. This paper considers the idle area between blocks and proposes a method of handling the block placement problem, where the simulated annealing is applied to the optimization. The result of the proposed method is compared with the result obtained by the constant‐ pressure Monte Carlo method, which is one of the block placement methods with simulated annealing. It is seen that the proposed method can arrive at an almost equivalent result, even though the number of parameters is less and the determination of the parameters requires less time.
Transposition operations in permutation networks
Authors: Wu Dun , Kurihara Masahito , Kaji Ikuo 
Published: July 2007

AbstractNumerous routing algorithms have been proposed for the overall network on the traditional Benes permutation networks. to achieve efficient system communication, a study of routing through a small number of information paths is needed from a practical viewpoint. In other words, it is desired that the requirement of permutation by a system should be realized so that for networks currently used, only a small part of the switch settings is affected. In this paper in the forementioned principle, a dynamic routing algorithm (basic design) based on permutation is proposed. Given a permutation t as a control input, a new permutation P̄ = P · t can be realized through currently realized permutation by resetting only a part of the information paths in a network, which does not affect any other information path. Moreover, as an element of a permutation network, we propose a d‐transposition block which performs a transposition operation efficiently, and show examples of d‐transposition blocks for d = 3, 4.
Two conjectures concerning nonlinear circuit problems
Authors: Itoh Makoto , Tomiyasu Ryuichi 
Published: July 2007

AbstractSeveral basic results on nonlinear circuit problems are presented from the topological viewpoint. There have been numerous papers which studied the relations between the boundedness of the solutions and the characteristics of the nonlinear resistors. an interesting question related to this was raised by Smale and Matsumoto. Smale assumed that there exists a compact set of attraction if the power of the resistors satisfy the eventual passivities. In addition, Matsumoto conjectured that the total number of singular points is odd if eventually the circuit is passive. This paper shows that the two fore‐mentioned conjectures are true under some additional conditions concerning the singular points of the circuits. For the proof of those conjectures, we used the Morse‐Smale inequalities and the technique of the Gnomon projection (Poincaré compactification) which projects the n‐dimensional Euclidean space onto the n‐dimensional compact sphere Sn.
Circuit module placement method based on physical model
Authors: Yamada Shoichiro , Fukunaga Kunio , Kasai Tamotsu 
Published: July 2007

AbstractThis paper proposes an efficient circuit module placement based on a force model. It is known that the module placement based on the force model arrives at a placement relatively close to the optimum. However, in the traditional method, a repulsive force is employed. As a result, the equation be comes nonlinear with a large number of variables, which is not easy to handle. First, this paper shows a simplification by replacing the forementioned problem by a nonlinear equation with a single variable. Then the module placement based on the foregoing formulation is proposed. Discussions are made on the size of the module, the case of multi‐terminal nets and the optimality of the obtained placement. Finally, a result of application to the placement design of the gate array is presented, indicating the use fulness of the proposed method. the features of the method are that the solution of the nonlinear equation can easily be determined, and the sparse matrix technique can be applied. Consequently, it is applicable to the placement design of a large‐scale circuit with more than 1000 modules.
An analysis of electrical equivalent circuit constants for a GT cut quartz crystal resonator with supporting portions at both ends
Authors: Kawashima Hirofumi , Matsuyama Masaru 
Published: July 2007

AbstractA GT cut quartz crystal resonator with supporting portions at both ends has superior frequency‐temperature characteristics similar to the conventional rectangular GT plate. It was reported that it is a high‐Q resonator with a small equivalent series resistance from experiments [1, 2]. In this paper, the electrical equivalent circuit constants of the GT cut quartz crystal resonator with supporting portions at both ends is described. First, the equivalent circuit of the GT cut quartz crystal resonator is studied. It is found that the main vibration and the subvibration can be treated approximately as a single‐mode resonator since the coupling coefficient is only about 3 percent. Next, the relationship of the motional inductance L1, motional capacitance C1, parallel capacitance CO, capacitance ratio r1, and electromechanical coupling coefficient Kvl of the main vibration to the plate thickness electrode area and cut angle ϕ is found theoretically. Also found is the relationship of the motional inductance L2 of the subvibration and the plate thickness. These relationships are compared with the experiments. Calculated and measured results agreed well. Hence, the present analytical results are useful for design of a resonator with a new frequency.
Propagation characteristics of plate waves in a Z‐cut X‐propagation LiTaO3 thin plate
Authors: Toda Kohji , Mizutani Koichi 
Published: July 2007

AbstractThis paper describes the numerical analysis and experimental verification of the behavior of plate waves in a Z‐cut X‐propagation LiTaO3 thin plate. With the product of the frequency and the substrate thickness as a parameter, the phase velocity, mechanical displacement and electromechanical coupling coefficient are obtained. the Lamb waves of zeroth‐order antisymmetric mode (AO) and symmetric mode (SO) are coupled more tightly than the Rayleigh mode. the SO mode SH wave is a tightly coupled mode comparable to the piezoelectric plate, and is of low dispersion. the results of an experimental verification in an LiTaO3 of 100 μ thick agreed well with the theoretical data in the frequency range below 50 MHz. These results are effective in designing the plate wave devices.
Convergence properties of waveform relaxation‐newton method
Authors: Urahama Kiichi 
Published: July 2007

AbstractThis paper shows the following properties for the waveform relaxation‐Newton method: (1) the iterative solution converges uniformly and globally under the same condition as the convergence condition for the waveform relaxation method; (2) the waveform Newton method used in the inner loop of the iteration converges locally with the second‐order; (3) the waveform relaxation‐Newton method is slower in the convergence both globally and locally than the waveform relaxation method; (4) the time interval where the error monotone decreases is shorter in the waveform relaxation‐Newton method than in the waveform relaxation method; and (5) the convergence speed asymptotically approaches that of the waveform relaxation method.
Transient analysis of anisotropic elastic media by Bergeron's method
Authors: Sato Masahiro , Yoshida Norinobu , Fukai Ichiro 
Published: July 2007

AbstractWe have proposed a transient response analysis method for isotropic elastic media. In this method, the transient response analysis formulation by Bergeron's method is applied to the equivalent circuit of isotropic media made of multiple spatial combinations of local distributed equivalent circuits. This paper describes the basic treatment using equivalent circuit elements and their characteristics when the previous method is extended to the analysis of anisotropic elastic media. Since the equivalent circuits are used for analysis in this method, correlation with the electrical treatment of electron device design is excellent. By applying Bergeron's method, the transient response can be calculated successively at each discretization point similarly to the finite difference method. These characteristics are attractive from engineering viewpoints. the local distributed equivalent circuit representation of anisotropic elastic media and the formulation of the transient responses using Bergeron's method are also described. the results of the application of the present method to fundamental anisotropic problems are presented.
Energy trapping of higher‐harmonic width vibrations in piezoelectric strips and its application to filters
Authors: Watanabe Hiroshi , Shimizu Hiroshi 
Published: July 2007

AbstractThe energy trapping of the higher‐harmonic width‐extensional and width‐shear vibrations in a piezoelectric ceramic strip is studied based on the dispersion characteristics of these modes. By the use of energy trapping of the higher‐harmonic width vibrations, new small‐sized trapped‐energy resonators and filters that can be used at the high‐frequency range beyond several megahertz are developed. In the resonator and filter using a higher‐harmonic width vibration, it is necessary to excite strongly the width vibration of a specific order and to suppress all other vibrations. In this paper, a new electrode configuration is proposed for this purpose by taking into account the stress distribution of the mode. In addition, this method is used for fabrication of 4.5 and 10.7 MHz trapped‐energy filters using the 3rd‐harmonic width‐extensional vibration and the trapped‐energy resonators using the 2nd, 3rd‐ and 4th‐harmonic width‐extensional vibrations.
Super‐resolution NMR spectrum estimation method
Authors: Nishiyama Kiyoshi , Mita Tutomu 
Published: July 2007

AbstractSeveral methods have been proposed to determine a high‐resolution NMR spectrum from limited data. This paper attempts to improve and extend the NMR spectrum estimation method using a complex Kalman filter, which was proposed previously by Nishiyama and Mita. In the proposed NMR spectrum estimation using the Kalman filter, extra data were required in addition to that to be used in the spectrum estimation, in the approximate determination of the spin‐spin relaxation time. Hence, the previously reported NMR spectrum estimation is not based strictly on the same condition as that of the discrete Fourier transform. This paper improves this point, and the extra data are obtained by extrapolation by the AR model. This makes it possible to compare the method with the discrete Fourier transform based on the same number of data. It is shown that when the spectrum is limited to a certain frequency band, the proposed method gives an NMR spectrum with twice higher frequency resolution by reducing the effect of the spin‐spin relaxation time and the effect of discrete approximation. In the proposed method, the spin‐spin relaxation time of the nucleus, corresponding to the frequency resolution that is twice higher than usual, is determined by a linear interpolation of the spin‐spin (relaxation time which is obtained approximately by discrete Fourier transform.
A synthesis of RC active filters simulating uniformly dissipative LC filters
Authors: Ishibashi Yukio , Nakahigashi Hideto 
Published: July 2007

AbstractIt is known that the active RC filter simulating the ladder LC filter has a lower sensitivity than the cascade active RC filter. A number of construction methods for filters of this king have recently been proposed. This paper considers the simulation type active RC filter. First, an LC filter is proposed as the prototype, which is obtained by adding losses to L and C in the conventional ladder LC filter. A method is described which realizes the relation between the node voltages and the loop currents of the circuit by an active RC filter. By the proposed method, the inverting integrator section in the traditional leapfrog structure can be realized by an active RC circuit with an operational amplifier, and the noninverting integrator section is realized by a voltage‐follower and a first‐order RC low‐pass circuit. It is shown that the number of operational amplifiers in the proposed circuit are approximately half the conventional leapfrog construction. Then the element sensitivity analysis is made, and the magnitude of the element sensitivity is discussed. Finally, a 5th‐order Chebyshev low‐pass filter is constructed and an experiment is made. the element sensitivity is calculated by a computer. It is shown that the element sensitivity in the proposed circuit is lower by 10 to 20 percent than the circuit with the conventional leapfrog structure.
Secret sharing scheme realizing general access structure
Authors: Ito Mitsuru , Saito Akira , Nishizeki Takao 
Published: July 2007

AbstractAs a method of sharing a secret, e.g., a secret key, Shamir's (k, n) threshold method is well known. However, Shamir's method has a problem in that general access structures cannot be realized. This paper shows that by providing the trustees with several information data concerning the distributed information of the (k, n) threshold method, any access structure can be realized. the update with the change of the secret trustees and the relation to the threshold graph are also discussed.
A parallel processing architecture for parameter estimation with recursive least squares
Authors: Ohkama Hiroshi , Miki Nobuhiro , Nagai Nobuo , Miyanaga Yoshikazu 
Published: July 2007

AbstractThe recursive least‐squares method (RLS) is often employed in the identification of the linear discrete‐time system, in which the parameters are time‐varying. This paper aims at producing the output which is an estimation of the system parameters, and derives a new algorithm which minimizes the RLS criterion with (time‐variable) forgetting factor. A parallel architecture is proposed which executes the algorithm. the derived algorithm is composed of two‐step processes, which are the Agee‐Turner PD factorization update theorem and the forward‐substitution for solving linear triangular systems. the proposed parallel architecture is composed of a large number of processing elements (PE) connected in a regular way. the communication is performed only between adjacent PE, and the architecture can easily be implemented by VLSI. It can be considered as a systolic array composed of PE with a queue (FIFO memory). By introducing PE with a queue, the two‐step processes can be executed in parallel for the first time. It is shown that by employing the proposed parallel architecture composed of (N2 + 5N − 2)/2 PE in the real‐time processing, the estimated parameters for any time can be produced as the output, in a processing time independent of the number of parameters of the estimation, even though the computational complexity is of the order of square of the number of estimated parameters.
Design of FIR partial response filters with equiripple stopband attenuation (class II, V)
Authors: Takebe Tsuyoshi , Matsumoto Toyoji , Chaisawadi Ake 
Published: July 2007

AbstractThis paper considers the design of transmitter and receiver FIR digital filters with partial response of class II and V for data transmission. the filters are required to band‐limit the transmitting and receiving signal, while maintaining the overall impulse response with zero intersymbol interference (ISI). Two cases are considered: 1) the case where the transmitter itself has the zero ISI impulse response; and 2) the case where the transmitter and receiver filters are matched. In the former, the length of the filter is set to be equal to the number of samples between two zero‐cross points, which are at a certain symmetrical distance from the center of the ideal impulse response. Then a linear‐phase transfer function is derived with an equiripple approximation to the ideal amplitude frequency response. In the approxiamtion, the weight in the stopband is set as less than 1, and ISI of less than 1. percent is obtained. In the design of the matched filter pair, the overall order is set in the same way as in the former. Applying the Herrman‐Schuessler design method for the minimum phase‐shift filter in the frequency domain, the transfer function is derived.To realize ISI of less than 1 percent, it suffices to set the weight in the stopband less than 5 times in the passband. Although an effort was made to decrease ISI by successive approximation with the mirror zeros as the parameters, only a slight improvement was obtained. In either case, class V requires approximately a twice higher order than class II to realize the same attenuation and ISI.
Realizing an arbitrary conductance matrix via operational amplifier and its applications
Authors: Imai Yukio 
Published: July 2007

AbstractThis paper presents a realization of an arbitrary conductance matrix using operational amplifiers, together with some applications. It is shown first that any conductance matrix can be realized using operational amplifiers, and the design algorithm which is convenient in the realization is given in the form of a flowchart. Then as an application, a construction of a practical matched bilateral amplifier is presented, together with its application. the realization of a gyrator is also shown. the method presented in this paper is a new and simple way to realize an arbitrary conductance matrix. the matched bilateral amplifier obtained by the proposed method is simple and better than the traditional circuit in terms of the number of circuit elements, element sensitivity, adjustment of the matching impedance, dynamic range and stability. As a practical example of application, the circuit is applied to the four‐line carrier telephone link.
An algorithm for finding a forest in a planar graph‐case in which a net may have terminals on the two specified face boundaries
Authors: Suzuki Hitoshi , Akama Takehiro , Nishizeki Takao 
Published: July 2007

AbstractRiver routing in VLSI and the one‐layer wire routing problem for printed circuit boards can be formulated as a problem of finding a forest in a planar (grid) graph. Given a planar graph G representing a wiring region and sets of terminals to be equipotential (that is, nets), we want to find vertex‐disjoint trees (i.e., a forest), each of which interconnects terminals of each net. This paper presents an algorithm for solving the forementioned problem in O (MIN {kn, n log n}) time when terminals of nets are placed on the two faces of a planar graph G, where n is the number of vertices of G, and k, that of nets.
System design of the figure operation hardware engine used for LSI layout design rule checking
Authors: Sakamoto Mamoru , Onodera Hidetoshi , Tamaru Keikichi , Nomura Toshihiro 
Published: July 2007

AbstractOne of the methods to perform the high‐performance LSI design rule check (DRC) on an engineering work station (EWS), is to employ the dedicated hardware engine. This paper considers the figure operation, which is the fundamental function of DRC, and describes the hardware‐oriented algorithm and the design of the hardware system for its implemen tation. the algorithm is obtained by improving the slit method and the vector method used in the usual software system so that they fit the hardware implementation. the hardware is composed of five functional blocks (VS, OP1‐OP‐3 and WL), and is implemented on four of 16‐bit microprocessors with 1 MByte main memory, together with FIFO memory. the blocks operate in parallel, realizing a high‐speed operation based on the three‐stage pipeline. It was verified by a software simulation that the hardware configuration is adequate.
Two‐dimensional filter banks containing prefilter
Authors: Ikehara Masaaki , Takahashi Shin‐Ichi 
Published: July 2007

AbstractTwo‐dimensional (2D) filter banks are used in subband coding of images, and are systems which split a signal into the narrow bands and/or resynthesize it. This paper presents a method of constructing 2D filter banks using 2D prefilter and 2D polyphase filter banks. First, the input signal is divided into four kinds of band on the 2D plane by 2D prefilter with IFIR (Interpolated FIR) transfer function. Then the 2D prefilter is designed so that the four kinds of band become 1. These resulting output signals are band‐split separately and synthesized by 2D DFT polyphase filter banks. Hence, its design method becomes very simple and both the required order and the number of multiplications can be reduced.
Sampling theorems for multidimensional waves with casual interpolation functions
Authors: Kida Takuro 
Published: July 2007

AbstractThis paper considers approximation formulas of the n‐dimensional wave f(X) expressed by the sum of sampled values of f(X) multiplied by certain n‐dimensional waves called interpolation functions. A systematic discussion is made to determine whether or not the approximate function converges to the original wave f(X). In this paper it is assumed that the interpolation functions satisfy the causality in regard to a certain axis in the n‐dimensional space Rn. Usually, that axis is considered to be the time axis. These discussions are important from the theoretical viewpoint, since it is closely related to the problem as to whether or not interpolation functions can be realized as impulse responses of physically realizable time‐invariant linear circuits. the set of sampling points is defined as a set of vertices obtained by sampling periodically all the vertices of the n‐dimensional parallel polyhedra periodically arranged in the space Rn. This definition of the set of sampling points includes most of the important arrangements of the sampling points, such as the hexagon and octagon lattices in the two‐dimensional plane. In this paper, it is assumed that the interpolation functions have supports, which are parallel translations of each other. the functional forms of the interpolation functions may be different. the set of f(X) considered in this paper is defined as the set of n‐dimensional waves whose Fourier spectra have the weighted power‐of‐p norm (p > 1) smaller than the specified positive value. It is shown first that, under the condition that the squared‐sum of the interpolation functions is bounded, the considered approximate expression does not in general converge to the original wave. It is shown that if the foregoing condition is relaxed, an approximate expression can be found with the impulse response of a causal time‐invariant linear network as the interpolation function, which converges to the original wave.