電気学会論文誌C(電子・情報・システム部門誌)
Online ISSN : 1348-8155
Print ISSN : 0385-4221
ISSN-L : 0385-4221
120 巻, 2 号
選択された号の論文の19件中1~19を表示しています
  • 王 〓, 須貝 康雄
    2000 年 120 巻 2 号 p. 185-193
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    Wavelet transformation has the ability of representing a function and revealing the properties of the func-tion in both the localized time domain and frequency domain. Wavelet neural networks employing the wavelet function as the activation function of the units of the neural networks have been proposed as an alternative approach to nonlinear mapping problems. In this paper, we propose a novel wavelet neural network which can be employed as a useful tool for learning a mapping between an input and an output space. The activa-tion function of the units of the proposed network is compact supported non-orthogonal function which has been described by Yamakawa et al. as convex wavelet in their paper. We present the theoretical proof about the function approximation ability of the proposed network. The experimential results of solving function approximation problems and the two-spirals classification problem indicate the better performance of the proposed network.
  • Jaka Sembiring, Kageo Akizuki
    2000 年 120 巻 2 号 p. 194-200
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    This paper will describe a theoretical background and a possible application on the problem of realization of a certain class of stochastic multi-scale process. The realization problem of interest in this paper is to construct a multi-scale stochastic model to realize some pre-specified finest-scale covariance. Here, instead of focusing on a simple Haar system, a more general approach will be derived by introducing the so called Multiple Tree (MT). The main drawback in a plain Haar system, despite its successful applications, is the apparent blocky nature. This is due to a rather rough interpolator being used. It will be shown in this work that by a multiple tree it is possible to overcome such weakness. This characteristic will be apparent in the application part of this paper, in which a sample generation problem will be considered.
  • 中村 眞, 佐藤 康二, 江指 正洋, 宇野 裕史, 藤井 章博, 根元 義章
    2000 年 120 巻 2 号 p. 201-207
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    An optical wireless communication system may be disturbed by the interference caused by the signal trans-mitted from the other communication system, when several optical wireless communication systems exist in the same physical space. In this treatise, a framework that avoids communication disturbance of the optical signal interference, achieved by having each communication system to adjustively change the communication initiation timing, is proposed. This mechanism will then implement a medium access control scheme that allows several communication systems to co-exist in the same physical space.
  • 古田 貴之, 大和 秀彰, 永野 雅邦, 富山 健
    2000 年 120 巻 2 号 p. 208-214
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    The purpose of this study is to realize 3D biped walking in a humanoid robot. A robot that has 12 degrees of freedom with two legs was designed and constructed as an experimental platform. A new walking control method that is a model reference type with a virtual inverted pendulum model is proposed. The proposed method was implemented on the constructed robot and its successfully realized various walking.
  • 荒木 肇, 加地 太一, 山本 雅人, 鈴木 恵二, 大内 東
    2000 年 120 巻 2 号 p. 215-221
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    The optimal sequential partitioning problem is defined as the problem to find the minimum cost partition of the nodes of a directed acyclic graph into subsets of a given size, subject to the constraint that the prece-dence relationships among the elements are satisfied. The heuristic algorithm based on a tabu search for this problem has been proposed(2). However, there is a tendency for the solutions obtained using the tabu search approach to be trapped in bad local optima in the parallel graphs with random costs of edges
    In this paper we present the genetic algorithm for the optimal sequential partitioning problem. We developeffective two point partial order crossover satisfying sequential conditions, which preserve better block that has the larger sum of edge costs of block. In this crossover we introduce roulette selection method to escape local optima. We also assess the effectiveness of the developed algorithm. The results show that this proposed algorithm outperforms, in terms of solution quality, any other algorithm using tabu search.
  • 浴 百合雄, 村田 純一, 平澤 宏太郎
    2000 年 120 巻 2 号 p. 222-228
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    This paper is focused on the model-based control system by neural networks. There are two types of neural network-based models for dynamical systems, i.e., one is the series parallel model, and the other is the parallel model (external recurrent model). The former is generally used in predictive control. But it is not appropriate for the long-range (multiple-step) prediction because of its error accumulation through iterative application of the model. The latter is complex in terms of learning and control calculation, but it is favorable for the multi-ple-step predictive control. Many learning methods of parallel models were developed, but any control algo-rithm for this model has not been found yet. We developed the control algorithm by minimizing the multiple-step cost function based on multiple-step prediction. The iterative inverse method was used in the calculation of control. To illustrate the usefulness of the techniques presented in this paper, the comparison of the conven-tional (1step series parallel model) prediction/control and multiple step prediction/control are presented.
  • 永田 武, 金 釣, 畠山 秀一, 佐々木 博司
    2000 年 120 巻 2 号 p. 229-235
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    This paper aims to develop a suitable distribution system restoration method by using a Mathematical Programming(MP). Generally, the problem of determining the target configuration can be formulated as a Mixed Integer Programming(MIP) problem. Whether or not each branch is included in a target system is expressed by a 0-1 variable, whereas other constraints such as the demand and supply balance conditions are formulated in terms of continuous variables. Although an MP based method can obtain an optimal solution under specified operational constraints, solution time often exceeds practically allocated computation time for a large scale problem due to combinatorial explosion. The object of this paper is to develop an efficient solution algorithm for service restoration for distribution systems. To solve the problem, a two-step algorithm is developed using mathematical programming methods. First, a MIP problem is solved to determine the sound network configuration to maximize the available power to the out of service area, then a MIP problem is used to solve the target configuration for the out of service network. The proposed method has been applied to distribution system restoration problems, and simulation results demonstrate its effectiveness.
  • 斉藤 文彦
    2000 年 120 巻 2 号 p. 236-243
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    This paper describes a method to search a similar image area with arbitrary location, angle and size to a template image using a genetic algorithm. The positioning parameters for an objective image area are represented as an individual chromosome. The normalized correlation degree between the objective image area and the template image is defined as the individual fitness. Through experiments to evaluate the efficacy of image pre-processing, the most reliable result was obtained in the case of matching between original gray scaled images without image pre-processing.And through experiments to evaluate crossover methods, the two-point crossover by each positioning parameter recorded the best score. Experimental results show that the normalized correlation image search by the genetic algorithm with the proper crossover method is useful compared with the sequential search and the random search.
  • 斉藤 文彦
    2000 年 120 巻 2 号 p. 244-251
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    In the magnification process of a digital gray-leveled image, the image quality often becomes inferior because of dull edges or block noises. This paper proposes a method to determine appropriate gray levels of all pixels in a magnified image using a genetic algorithm in order to obtain the magnified image with sharp edges. The gray level of each pixel that is estimated by the nearest neighbor interpolation is changed dynamically in the range of gray levels included in the neighbor pixels. The fitness of an individual is evaluated by the spatial differential values included in the magnified image Experimental results show that the magnified images by the proposed method have sharpness compared with the conventional magnification method. Also, the higher SN ratios between the magnified images and the original images were obtained.
  • 高橋 正弘, 大倉 敬規, 浜田 卓志
    2000 年 120 巻 2 号 p. 252-257
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    In a network for an information and control systems, real time communication of large volume data and transsmitting multimedia information such as video and voice has been required. In response to realize these requirements, a loop-type ATM (Asynchronous Transfer Mock)-LAN have been investigated to realize low-cost, high-reliability and a communication function such as cyclic communication for control use keeping simplicity of loop configuration. This paper describes performance evaluation of cyclic communication for control use in a loop-type ATM-LAN. Relationship of cyclic-data traffic and arrival interval of cell to a station and loop round-trip delay of cells is obtained by simulation using GPSS.
  • 鶴岡 信治, 荒川 忠洋, 吉川 大弘, 陳 新開, 石田 宗秋
    2000 年 120 巻 2 号 p. 258-264
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    The purpose of the automatic fire alarm facilities is to detect the fire earlier which occurs under the various facility environment and to provide a judgment result with high reliability. The facilities protect a human life and a fortune from the fire and they become indispensable equipments. On the other hand, however, the lack of the reliability of the facilities, accompanying the occurrence of the false alarm, is pointed out. We propose a new fire judgment system using the time series of smoke density in early stage in order to improve the reliability. We think that the different causes of smoke arise different statistical properties on the time series. We employ the statistical model which uses a 36-dimensional histogram as the feature vector and a statistical distance as the discriminant function. We evaluated experimentally an efficiency of our method for actual 171 unknown time series. The average judgment rate was 84%, and this rate was higher than the rate of the former method (60%).
  • 大内 隆夫, 桑原 弘晃, 金子 正人
    2000 年 120 巻 2 号 p. 265-272
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    There is not a limit to that the states of systems on the sampling point of time take always on the switching surface in discrete sliding mode control. The chattering is easy to induce when those states go away from this surface. New determination method of control input to prevent a chattering to the discrete sliding mode control with element of uncertainty satisfying the matching condition has been proposed by Mr.Miguchi, et al. But the chattering is induced to reach the switching surface. Therefor, the control input conditions approach-ing exponentially to switching surface are discovered by defining and introducing a new nonlinear control input to solve this problem. The methods which expand the fuzzy logic systems using Back-Propagation al-gorithm to multiinput-multioutput types and infer the element of uncertainty by this algorithm are described in this paper. And the designing methods approaching exponentially to the switching surface and detering the chattering front and on the switching surface are proposed, when the control input searched in such a way is applyed to linear systems with element of uncertainty satisfying matching condition.
  • 三村 淳, 萩原 将文
    2000 年 120 巻 2 号 p. 273-278
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    In this paper, we propose an understanding presumption system from facial images using a three-layered neural network. It can presume a degree of understanding from facial expressions; it can recognize whether a person understands a question or not. Feature points are located on each facial image and are used to extract expression information. The expression information is given as an input and the system presumes the degree of understanding based on the facial images into 5 levels, from NOT UNDERSTAND to WELL UNDERSTAND. The network is learned using Back Propagation algorithm. The average presumption rates of the proposed system was over 70%.
  • Kouki Shimizu, Manabu Taniwaki, Shunichi Sato
    2000 年 120 巻 2 号 p. 279-284
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    The performance characteristics of a fast-axial-flow, rf-discharge-excited CO laser have been investigated in the operating temperature range of 240-290 K. The laser gas is cooled with a water cooler and/or with a commercial available refrigerator. Eight discharge tubes are optically connected in series, each of which is composed of a 19-mm inner-diameter quartz pipe and a pair of 300-mm-long outer metallic electrodes. They are geometrically optimized to obtain uniform excitation over the whole discharge volume. At room temperature, the influence of the operating gas conditions, the additives, and the impurities on the laser performance are examined. It is shown that the addition of Ar, instead of Xe. to the working mixtures (CO/N2/He/O2) drastically improves the laser performance. Finally, it is demonstrated that 40-50% higher outputs than that at room-temperature are obtained at temperature of 240 K, and the output reaches over 1 kW with the Xe-free, Ar-added mixture. The output spectrum and the beam characteristics are reported.
  • 茂出木 敏雄
    2000 年 120 巻 2 号 p. 285-291
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    Monitoring operations are required in various kinds of industries including printing processes and medical cares, and most of them are dependent on operators' visual tracking of sensor signals. In medical cares, pulse sounds synchronized with ECG signals or alarm sounds indicating emergent events are currently used for bedside monitors. These simple audio signals are helpful for medical staff and give great advantage to quality of cares.
    We propose extending this idea to general monitoring operations utilizing MIDI technology so that we should monitor sensor signals through their synchronized MIDI sounds by the following two methods. The first one called Direct Real-time Playback is converting the source signals to MIDI notes, and the second one called Indirect Stored Playback is modulating a given MIDI music notes by the source. In this paper, we describe our proposed concept of playback control system including these two MIDI playback methods and a networked remote playback method, and present two software implemented prototypes based on these proposed structures for a printing application and a medical application.
  • Hirohumi Hirayama, Toshihiro Nishimura, Toshimitsu Okita, Tcruhisa Kaz ...
    2000 年 120 巻 2 号 p. 292-299
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    We proposed a mathematical method for the optimal control in the carrier mediated transport across the biological membrane. This paper refers to the condition when the rate constant is a function of concentration of the spccics. Based on the optimal control principle, optimized six non linear differential equations of the four step transport across the membrane wcrc obtained. These equations wcrc restricted by the rigorous boundary conditions. Increases in weighting coefficients by the factor of ten significantly influenced the optimized time courses of the concentrations of the species and the optimized control inputs. The coordinated temporal changes in the species and control inputs could be explaincd by the compensatory rcaction of the system so as to minimize the disturbances of the mcmbranc transport. The present work will be available for evaluating the biological membrane functions.
  • 瀧 森徹, 高橋 秋典
    2000 年 120 巻 2 号 p. 300-301
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    Approximations of continuous many-valued functions were tried using sand glass type neural network of 5 layers. In the examples of success in identity mapping learning to sample points on the curve, the output value of the third layer unit changed with a specific value to a sample point and did not overlap in the whole range although there were cases that it changed discon-tinuously. Approximation of several many-valued functions were realized by propagating the third layer unit value along the behavior to the second half part of the network except narrow areas between sample points correspondent to the discontinuous areas of third layer unit values.
  • 横山 和哉, 貝津 弘幸
    2000 年 120 巻 2 号 p. 302-303
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    We propose a sliding mode control of high speed phase shifters to improve the transient stability of power systems. This note presents a sliding mode control with time delays in phase shifters. The occurrence condition is given and the validity is numerically tested on a single machine infinite bus power system.
  • 横山 清子, 青野 祐美, 小関 修, 高田 和之
    2000 年 120 巻 2 号 p. 304-305
    発行日: 2000/02/01
    公開日: 2008/12/19
    ジャーナル フリー
    Bio-medical signal analysis is applied to many fields. We propose a consultation system for the analysis of bio-medical signals. Our system has three features in addition to those of past expert systems: 1)acquisition of the expert knowledge, 2)consultation, and 3)user friendly interface. This paper describes the design of the system and examples of the human interface.
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