bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reorganization of node connection in chordal‐ring networks with variation of the number of nodes
Authors: Masuyama Hiroshi , Miki Tadayuki 
Published: July 2007

AbstractIn a network operated under a certain system management to make the topological structure invariant for insertion of a newly arising node, accompanied by the increase of the number of users or extension of the system scale, some modifications of the node connection must be required. In a fourth‐degree chordal‐ring network which is known to have a disadvantage with respect to diameter minimization although management software is easy, the forementioned system modification is expected to be required relatively less frequently. This paper presents a new measure for system modification for a chordalring network by formulating modifications of node connection required for the change of the number of nodes.
A realization scheme for the identity‐based cryptosystem
Authors: Tanaka Hatsukazu 
Published: July 2007

AbstractAt Crypto ′84, A. Shamir [1] presented the new concept of identity‐based cryptosystems. Yet no realization scheme has yet been proposed. This paper proposes a scheme for realizing an identity‐based cryptosystem which modifies Shamir's original concept without losing its essential characteristics. The fundamental idea of this realization scheme is based on the well‐known one‐way functions, “the difficulty of calculating a discrete logarithm” and “the difficulty of factoring the composite of two large primes.” As long as all the users in the system keep their own secret keys secure, this cryptosystem is perfectly secure. Even if there is a conspiracy among users in the system, this system remains secure when the number of conspirators is less than a certain number which has been determined during the design phase. In this way, a threshold scheme for a secret information sharing system is realized. This paper presents a detailed analysis of this threshold scheme and shows how to evaluate the secret key of the center when the number of conspiring users is over the threshold. In addition, a scheme which facilitates a reduction in the amount of computation needed to generate a common key is also presented.
Preservation of liveness in hierarchical petri nets
Authors: Kumagai Sadatoshi , Kodama Shinzo , Tsuji Kohkichi , Nakamura Youichi 
Published: July 2007

AbstractFor large‐scale systems for discrete events such as FA, OA and sequence control systems, it is desirable to establish a systematic design methodology. It is expected that a systematic design methodology for systems can be obtained using a Petri net model (a powerful model for discrete event systems) for system specification, analysis and verification. Generally, in the top‐down design of a large‐scale system, we begin with a rough design for the system and apply successive refinements. In the Petri net model, a hierarchical representation is considered such that in a refinement step, one of the elements in the net is replaced by a subnet which represents its behavior in more detail. This paper considers some questions regarding this hierarchical representation of Petri nets, such as whether properties such as liveness and safeness of nets are preserved by the refinement. In particular, we consider simultaneous refinement of parallel transitions to derive several sufficient conditions concerning preservation of properties of the net, and represent these as conditions on subnets which are to replace blocks in the parent net.
A synthesis of low‐sensitivity digital filters using T‐cascade connections. Extraction of wave digital lattice filter sections
Authors: Watanabe Eiji , Minagawa Kenji , Nishihara Akinori 
Published: July 2007

AbstractDigital filter response is degraded from that desired when the filter is implemented using finite wordlength multipliers. To avoid such degradation, low‐sensitivity filter structures such as wave digital filters (WDF's) often are used. On the other hand, the pipeline processing would be preferable for the high‐speed applications of filters. In general, the pipeline approach is not applicable to WDF's.This paper proposes new low‐sensitivity filter structures which are also suited for the pipeline processing. The fundamental idea to obtain low‐sensitivity structures is to synthesize digital 2‐port circuits with “structurally induced losslessness,” as done by Vaidyanathan and Mitra. The losslessness of a digital 2‐port circuit is characterized by a para‐unitary scattering matrix. WDF's also have this losslessness when they are modeled after reactance filters.The proposed structures are synthesized by factoring such scattering matrices, and constructed using T‐cascade connection of new basic sections, in contrast with the II‐cas‐cade connection used in WDF's and Vaidyana‐than‐Mitra structures. Each section, which is also characterized by a paraunitary scattering matrix, is realized as a lattice WDF. The proposed structures can realize any given transfer function, and if the function has a certain symmetry, they reduce to lattice WDF's.
A general method of deriving a discrete normalized system of orthogonal functions and its application to adaptive digital filters
Authors: Kobayashi Shoji , Takahara Mikio , Kubota Hajime 
Published: July 2007

AbstractThe system of orthogonal functions is very useful in science and engineering, and the theory on the orthogonal function system in the continuous time domain has been established. On the other hand, with the advance in digital signal processing, a need for processing the signal in the discrete time domain is acute. With this background, a general derivation of the orthogonal function system in the discrete time domain is desired. This paper proposes a general method for deriving the orthogonal function system in the discrete time domain from the already established orthogonal function system in the continuous time domain. First, the orthogonal function system in the continuous time domain is presented. Next, by the bilinear information of its transfer function, the system is transferred to the discrete time domain. However, in general, the orthogonality in the discrete time domain is destroyed by the bilinear transformation. It is shown that the orthogonality can be maintained in the discrete time domain and the orthonormal function system can be constructed by an appropriate processing. Further, the digital filter using this orthonormal function system is applied to the adaptive digital filter and the number of adaptive parameters is reduced. Finally, by computer simulation, the effectiveness of the adaptive filter configuration by means of the orthonormal function system is proven.
Generalized Minkowski metrics for mixed features
Authors: Ichino Manabu , Yaguchi Hiroyuki 
Published: July 2007

AbstractThis paper presents simple and convenient generalized Minkowski metrics on multidimensional feature space in which each coordinate axis is associated not only with a quantitative feature, but also a qualitative feature. The metrics are defined on a new mathematical model (U(d), +, × constructed by the authors called simply the Cartesian space model. In this model, U(d) is the feature space, + is the Cartesian join operator which abstracts a generalized description from two given descriptions on U(d), and × is the Cartesian meet which extracts a common description from two given descriptions on U(d). In our approach, intervals and finite sets are also permitted as possible feature values. Two simple numerical examples are presented to illustrate the usefulness of our metrics.
Orthonormal discriminant vectors of pattern recognition
Authors: Hamamoto Yoshihiko , Kanaoka Taiho , Tomita Shingo 
Published: July 2007

AbstractRecently, concerning statistical feature extraction, Okada and Tomita presented an orthonormal discriminant vector method based on the Fisher criterion. The advantage of their method has been discussed experimentally. However, it has not been discussed theoretically in comparison with a well‐known discriminant analysis. For a two‐class problem, it is shown that the method is more powerful than discriminant analysis from the viewpoint of the discriminatory ability between classes. Numerical examples are presented to illustrate the results obtained in this paper.
Image reconstruction from erroneous projections—radon transform as an analog coding
Authors: Kumazawa Itsuo , Ogawa Hidemitsu , Tajima Hiroshi 
Published: July 2007

AbstractIn the image reconstruction problem, projections obtained by scanning X‐rays from many directions around an object are shown to have redundant information for reconstructing a section image of the object. This redundancy means that some relationship or dependency exists among the projections. This paper formalizes the dependency using some linear equations and regards these equations as parity check equations of the analog coding theory. In addition, after an appropriate transformation of the variables, it is shown these equations become equivalent to the parity check equations of the DFT codes, which are well understood and are the most established analog codes. It is shown experimentally that errors or impulsive noises included in about 10 percent of the projections can be detected and corrected automatically by applying the error correcting schema developed from the DFT codes. Also proposed is an error correcting algorithm for the DFT codes, which gives stable results even in the high‐dimensional case similar to those in the practical applications of Computerized Tomography (CT).
Multichannel linear prediction models and their convergence property
Authors: Cheng Fulin , Koga Tosiro 
Published: July 2007

AbstractThis paper considers theoretically the relation between the convergence problem of various algorithms and statistical properties of a signal appearing during construction of a linear prediction system of signals when the time series of the signal is a multiple Gaussian process. Specifically, we consider first the convergence problem of the covariance matrix of a predicted error arising as a linear prediction algorithm applied to the solution of a Yule‐Walker equation.Next, in comparison with the convergence speed of the correlation coefficient matrix of a multiple signal time series, we obtain an evaluation formula for the convergence speed of a covariance matrix of a linear prediction error. Furthermore, we discuss the convergence of an algorithm for constructing an orthonormalized polynomial matrix which corresponds to a transfer function matrix of a whitening filter from a solution of the Yule‐Walker equation. We present a concrete evaluation formula for the convergence speed of the algorithm.
Overlap resolution problem for block placement in VLSI layout
Authors: Ohmura Michiroh , Miyao Jun'Ichi , Yoshida Noriyoshi , Kikuno Tohru 
Published: July 2007

AbstractIn VLSI layout design by the building block approach, a hierarchical floorplanning method is proposed in which the floorplan and global routing are determined simultaneously to realize low‐congestion switchboxes. In this method, overlap resolution, which preserves relative position and minimizes the obtained chip area, is needed to prevent the increase in the wire length of each net.In this paper, a fundamental study of this overlap resolution is made, and the following are described.(1) The formulation of the overlap resolution problem RI is given. In the formulation, (a) preservation of relative position among blocks, and (b) the minimization of obtained chip area are considered; (2) the computational complexity of the problem is analyzed, and then NP‐completeness of the problem RI is proved; and (3) a polynomial heuristic algorithm R for the problem RI is given. In addition, the result of simulation experiments to verify the efficiency of the heuristic algorithm R is also described.
Scheduling methods for a low‐bit‐rate speech coding algorithm (ATC‐VQ) on a multicomputer‐type DSP system
Authors: Sawabe Tomoko , Suzuki Junji , Ohta Naohisa , Ono Sadayasu 
Published: July 2007

AbstractFor parallel implementation of a digital signal processing algorithm, the solution of scheduling problems that consist of task partitioning and task allocation are important. This paper considers an ATC‐VQ (Adaptive Transform Coding using Vector Quantization) algorithm because it is a typically used complex algorithm, and describes the basic study of the scheduling techniques used for implementation of this algorithm on a multicomputer‐type DSP system.With the ATC‐VQ algorithm the scheduling methods for the LPC residual signal coding has a large effect on the overall performance, because this coding occupies more than 85 percent of the processing time. The LPC residual signals are divided first into multiple vectors and then vector quantized. Three scheduling methods are shown whose partition units quantize the LPC residual signal vectors, and the performance of each method is evaluated. Appropriate scheduling methods suitable to the ATC‐VQ algorithm are discussed.
A bayesian reliability analysis model by two debuggers for discrete‐type software and its applications
Authors: Sandoh Hiroaki , Fujii Susumu , Yamawaki Tatsuya 
Published: July 2007

AbstractThis paper considers the software which is used discretely with regard to time, such as the usual software for numerical computation, and proposes a model for the reliability analysis in the development stage. Also, the case of the software test is considered in which two debuggers attempt to detect the bugs in the software. A discussion is made from the viewpoint of Bayes' theory. The case of two debuggers is as follows. Two software engineers execute the test independently for the same software. The detected bugs are compared later, including their overlaps, to acquire a larger amount of information. Based on the model for analysis proposed in this paper, a formulation is presented for the determination of the release of the software, i.e., the time to terminate the test. Numerical examples are presented, providing discussions on the features of the model considered in this study as well as on its usefulness.
Optimization of system reliability using bicriteria 0‐1 linear programming with GUB constraints
Authors: Ida Kenichi , Sasaki Masato , Gen Mitsuo 
Published: July 2007

AbstractGenerally, problems in the optimization of system reliability such as unit selection and allocation have been formulated as single‐objective nonlinear integer problems and solved by various optimization techniques. The method for solving such problems was based on an implicit enumeration method, which transformed them into 0‐1 linear programming problems. These methods have not considered the GUB constraint, which arises when transforming to 0‐1 linear programming problem, but recently, an efficient method which considers this GUB structure and introduces the AHP (Analytic Hierarchy Process) into the system constraints has been proposed. However, in such system optimization problems, there are many problems that cannot be solved by formulating them as single‐objective programming which optimizes only a single reliability or cost function. Instead, they must be solved by applying MODM methods, which handle multiple objectives that conflict with each other.In this paper, we propose an efficient algorithm that makes use of the 0‐1 LP (GUB) package, written to solve single‐objective 0‐1 linear‐programming problems, in order to solve large scale 0‐1 linear programming problems that have two conflicting objectives and GUB constraints. To illustrate the effectiveness of the method proposed here, we present two numerical examples, optimal unit selection and optimal redundancy, and compare the results with those of previous methods.
Model reference adaptive control of nonminimum‐phase discrete‐time systems using approximate inverse systems
Authors: Yahagi Takashi , Yokomori Masao 
Published: July 2007

AbstractThe model reference adaptive control is well known in the deterministic system, as a method of adaptive control for the linear discrete‐time system. In the model reference adaptive control, the plant is controlled to follow the output of the given reference model while estimating the unknown parameters of the plant. One of the important problems in this system is the control of the nonminimum‐phase system. Often even if the plant as the continuous‐time system is minimum‐phase, the representation of the plant as the discrete‐time system is nonminimum‐phase.From such a viewpoint, the control of the nonminimum‐phase system is very important from the practical standpoint. This paper proposes a new method of model reference adaptive control which can effectively control the nonminimum‐phase discrete‐time system using the approximate inverse system by division method. In this method, the approximate inverse system with any accuracy can be constructed by appropriately defining the threshold. The method is very useful in practice since the approximate inverse system of the nonminimum‐phase system can be determined only by iterating simple divisions.To examine in detail the result of application of the proposed method, various computer simulations were made and the results are discussed.
A theory of estimating the whole from the partial information on the probability distribution of amplitude fluctuation and its application to noise environment
Authors: Ohta Mitsuo , Xiao Yegui , Ikuta Akira 
Published: July 2007

AbstractActual environmental noise and vibration exhibit arbitrary probability distribution forms due to the diversified causes of the fluctuation. Furthermore, the objective signal usually is contaminated by background noise or vibration, and often is effected by the dynamical range of the measuring meter. Therefore, it happens that the reliable observation data are only the partial information confined to a finite amplitude interval.This paper proposes a practical test to estimate the whole probability distribution (connected with the evaluation quantities: Leq and Lx) of the objective signal by using only the partial stochastic information with the influence of the background noise or vibration and of the forementioned dynamical range.More explicitly, the probability distribution of the objective signal is given first in a generalized series expansion form of probability expression. Next, we estimate the expansion coefficients in this expression by using four methods from different viewpoints. Finally, the effectiveness of the proposed theory is confirmed by applying it to the observed data of actual road traffic noise.
Analysis of frequency characteristics for flexural‐mode tuning‐fork type quartz crystal resonator, taking into account thickness, rotary inertia and shear force
Authors: Kawashima Hirofumi , Sunaga Kenji 
Published: July 2007

AbstractA study was conducted with a view to finding theoretically and experimentally the relationship between the resonant frequency and its temperature dependence of the thickness of the resonator. As the analytical means, the energy method was used for deriving the equation of motion in which the thickness and rotary inertia and shear force were taken into account.Since a tuning‐fork type flexural‐mode quartz crystal resonator is considered to have two cantilevers, the equation of motion was solved under the boundary condition of a clamped‐free end. The frequency equation was derived as a function of the thicknesszO' widthxOand lenghtyO.Next, from this equation, the following relationships are derived: the frequency constant (f·yO) versus the dimensional ratioRxy=xO/yO, the resonant frequency versus the dimensional ratioRzy=zO/yO, the turnover temperature pointTpversus the dimensional ratioRxyand the relationship between the first‐ and second‐order frequency temperature coefficients andTpversus the dimensional ratioRzy. It is shown that the apex temperatureTpchanges significantly for the thickness. Further, these results were compared with the experimental data and good agreement between them is shown. Hence, it is concluded that the present analysis results are useful for the design of new frequency resonators.
Unified analysis of the waves in fluids and solids in time domain by spatial network method
Authors: Sato Masahiro , Yoshida Norinobu , Fukai Ichiro 
Published: July 2007

AbstractWhen a fluid and a solid are in contact, complex and characteristic wave propagation phenomena emerge and their engineering applications are being planned in various areas. This paper presents a method which systematically treats the wave propagation in a fluid and a solid by means of the spatial network method which is a numerical time domain analysis of the wave. In the spatial network method (SNM), the wave field is expressed in terms of an equivalent circuit with one‐dimensional transmission lines. Bergeron's method and the circuit theory are applied to the equivalent circuit so that the time domain response is obtained. Here, the flow and viscosity are neglected in the fluid and lossless isotropic solids are treated. Since the waves in a fluid are scalar and those in a solid are vector, their equivalent circuits are different. Their coupling section becomes important. In order that the waves in a solid and a fluid can be treated systematically, a new equivalent circuit for the waves in a fluid is proposed in which particle velocity nodes are added. (SNM) is applied to basic problems so that its characteristics and validity are determined.
A placement method for size‐restricted blocks in VLSI layout design
Authors: Izumoto Hiroshi , Wakabayashi Shin'Ichi , Miyao Jun'Ichi , Yoshida Noriyoshi 
Published: July 2007

AbstractIn VLSI layout design, the placement problem of functional blocks with different sizes and shapes include two NP‐hard problems, that is, the problem of minimizing the chip size and the problem of minimizing the total virtual wire length. Therefore, in general, it is considered that any efficient placement method is very hard to develop.As a fundamental consideration of the placement problem, this paper discusses a placement problem in which the size of each block to be placed is restricted. First, the placement problem MSL in which the size of each block is restricted to be either 2 × 2, 2 × 1, or 1 × 1 is formulated. Next, a heuristic algorithm for the problem MSL is presented and some theoretical consideration on the proposed algorithm is given.In the theoretical consideration, the following two results are shown: 1) that the algorithm can find an initial placement with minimum chip area within a linear time on the number of blocks; and 2) that a set of placement change operations used to improve the total virtual wire length is a sufficient set of operations in a sense that any placement can always be transformed into another arbitrary placement by using the set of operations.Finally, the results of simulation experiment which was performed to evaluate empirically the proposed algorithm are described.