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
127 巻 , 12 号
選択された号の論文の30件中1~30を表示しています
特集:電気関係学会東海支部連合大会
特集論文
<電子材料>
  • 加藤 弘晃, 蟹江 知彦, 安達 雅人, 野呂 雄一, 竹尾 隆
    2007 年 127 巻 12 号 p. 1960-1966
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    This paper describes a method for measuring magnetic permeability dispersion of ferrite cores widely used in RF devices such as splitters in CATV systems. The present method has a step of measuring reflection coefficients for three kinds of microstrip line circuits, one having a test sample (ferrite core) mounted on it, one with a non-magnetic core instead of the ferrite, and one with an impedance matching resistor only. From the three reflection coefficients derived, the impedances of the coils with the ferrite and non-magnetic cores, respectively, are calculated and the complex permeability is determined by dividing the impedance of the ferrite core coil by the reactance component of the non-magnetic core coil. In this paper, the accuracy of the proposed method is discussed through a electromagnetic simulation and then the calculated results are compared with the experiments, indicating the validity of the method.
<光・量子エレクトロニクス>
  • Kayastha Madhusudan, Koichi Wakita, Kiyohide Baba
    2007 年 127 巻 12 号 p. 1967-1972
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    The wavelength red-shifting of integrated DFB (Distributed feedback) laser and EA (Electro-absorption) modulator with applied modulator bias voltage has been investigated and this phenomenon is estimated to be due to non-uniform temperature distribution in the device and caused by thermal crosstalk. From the experimental data and thermal analysis, increased absorbed photocurrents associated with EA modulator bias and dissipated power in the EA modulator lead to the temperature increase in continuously operating DFB laser, resulting wavelength red-shifting.
  • 高橋 港一, 宮崎 保光, 後藤 信夫
    2007 年 127 巻 12 号 p. 1973-1981
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    X-ray diagnosis depends on the intensity of transmitted and scattered waves in X-ray propagation in biomedical media. X-ray is scattered and absorbed by tissues, such as fat, bone and internal organs. However, image processing for medical diagnosis, based on the scattering and absorption characteristics of these tissues in X-ray spectrum is not so much studied. To obtain precise information of tissues in a living body, the accurate characteristics of scattering and absorption are required. In this paper, X-ray scattering and absorption in biomedical media are studied using 2-dimensional FDTD method. In FDTD method, the size of analysis space is very limited by the performance of available computers. To overcome this limitation, parallel and successive FDTD method is introduced. As a result of computer simulation, the amplitude of transmitted and scattered waves are presented numerically. The fundamental filtering characteristics of grid-type filter are also shown numerically.
<医用電子・生体工学>
  • 吉田 豊, 横山 清子, 石井 直宏
    2007 年 127 巻 12 号 p. 1982-1987
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    It is reported that frequency component of approximately 0.25Hz of heart rate time series (RSA) is corresponding to the respiratory frequency. In this paper, we proposed that continuous estimation method of respiratory fequency during sleep using the number of extreme points of heart rate time series in real time. Equation for calculation of the method is very simple and the method can continuously calculate frequency by window width of about 18 beats. To evaluate accuracy of proposal method, RSA frequency was calculated using proposal method from the heart rate time series during supine rest. Result, minimum error rate was observed when RSA had time lag for about 11s and error rate was about 13.8%. Result of estimating RSA frequency time series during sleep, it varied regularly during non-REM and varied irregularly during REM. This result is similar as report of previous study about respiratory variability during sleep. Therefore, it is considered that proposal method possible to apply respiratory monitoring system during sleep.
<通信・ネットワーク>
<音声画像処理・認識>
  • 矢崎 俊平, 山本 修身
    2007 年 127 巻 12 号 p. 2005-2010
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    Recently, we can easily obtain a fast computer and a digital video camera as their prices go down. In this paper, we describe a method and a system for analyzing performance of tennis players of a given singles tennis game. We assume that a movie of the game has been shot by a digital video camera which is fixed at a place such that the camera could film whole area of the tennis court and the two players, and that we have the sequence of the images in the computer. Using the positions of the players and the ball detected by techniques of image processing and partially by human assistance, we analyzed the game by defining an evaluation function. We made a prototype of a tennis-player-evaluation system by implementing the method. The system appropriately evaluated performances of players of some sample tennis games, although the evaluation function cannot analyze the player's tactics enough.
  • 宮 立文, 山本 和彦, 加藤 邦人
    2007 年 127 巻 12 号 p. 2011-2017
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    In this paper, we described various properties of a Generalized Horizon View Camera (GHVC). Original Horizon View Camera (HVC) is a optical system composed of a camera and a mirror. HVC put a single camera on the ground, and the optical axis of the camera is set on the horizon by a mirror. HVC can obtain two kinds of images. One is the image including only objects on the ground in front of the HVC. The other image is including just in front of the HVC. Therefore, it is possible to detect object easily. The GHVC is able to improve a degree of freedom of HVC. In this experiment, we measured a distance to an object by the GHVC. We confirmed that detecting object using the GHVC was effective.
<制御・計測>
  • 成清 辰生, 若松 康介, 不破 勝彦, 神藤 久
    2007 年 127 巻 12 号 p. 2018-2026
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    In this study control system of two-degree-of-freedom (2 DOF) robust servo system combined with repetitive controller is proposed for the control of a disk file head-positioning system. For the control of the disk file system both the tracking performance and robust stability are mainly required. In addition the periodic disturbance produced by disk rotation should be considered. The excellent tracking performance and robust stability can be attained by the 2 DOF robust servo system and the adverse effect of the periodic disturbance can be reduced by the repetitive controller. In order to reduce the adverse effects of the periodic disturbance while keeping the excellent closed loop performance the 2 DOF is combined with the repetitive control. Proposed control system is applied to the forcussing control system of the CD-R experimental system. Experimental results show the usefulness and effectiveness of the proposed control system.
  • 林 知秀, 矢野 良和, 津田 紀生, 山田 諄
    2007 年 127 巻 12 号 p. 2027-2032
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    In recent years, as a result of a large amount of greenhouse gas emission, atmosphere temperature at ground level gradually rises. Therefore the Kyoto Protocol was adopted to solve the matter in 1997. By the energy-saving law amended in 1999, it is advisable that an escalator is controlled to pause during no user. Now a photo-electric sensor is used to control escalator, but a pole to install the sensor is needed. Then, a new type of approach detection sensor using laser diode, CCD camera and CPLD, which can be built-in escalator, has been studied. This sensor can derive the irradiated area of laser beam by simple processing in which the laser beam is irradiated in only the odd field of the interlace video signal. By second order derivative of laser irradiated area, this sensor can detect only the approaching target but can not detect the target which crosses and stands in the sensing area.
  • 不破 勝彦, 成清 辰生, 神藤 久
    2007 年 127 巻 12 号 p. 2033-2041
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    In a state feedback control, all state variables should be detected accurately and these informations should be utilized without time delay. Then if some of state variables cannot be detected directly, these have to be estimated from output signals and input signals by observers. For the synthesis of Luenberger type observer, plant parameters must be exactly known. Therefore, when some of plant parameters are varied or unknown, Luenberger type observer cannot be utilized. In this paper, a new observer synthesis method with insensitivity (zero sensitivity) to parameter variations of the plant is discussed. On the basis of the zeroing concept and the quadratic stabilization method via linear control strategy, the existence condition of the observer which is related to a class of variations of the plant parameters is given.
  • 深川 雄司, 後藤 優一, 野呂 雄一, 竹尾 隆, 久野 和宏
    2007 年 127 巻 12 号 p. 2042-2049
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    In this paper, use of portable music players with recording function to measure the environmental noise for long hours is proposed, and the method of specific operation and measurement accuracy are discussed. Specifically, players are used to record the sound, and the recorded sound is analyzed on personal computer to calculate the noise evaluation function, such as A-weighted sound pressure level or equivalent continuous level. To check the accuracy, continuous recording for 24 hours at 20 sites, targeting at the sounds received in general residence, was carried out and equivalent continuous levels over a fixed period of ten minutes were calculated. As a result, difference to the measured value by the sound level meter turned out to be less than 0.5 dB (0.26 dB with rms) when built-in microphone of sound level meter was used to record (the AC output). For this reason, when used in combination with sound level meter, back-up usage with actual sound recording is expected. Also, difference to the measured value by the sound level meter was less than 2.0 dB (1.24 dB with rms), and it is considered fully usable when portable players are used alone for such as preliminary survey.
  • 鳥井 昭宏, 永田 千咲子, 道木 加絵, 植田 明照
    2007 年 127 巻 12 号 p. 2050-2056
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    This paper describes a position measurement system for a mobile microrobot used in a desktop manufacturing system. Three line laser projectors are carried by linear stages, which are placed above the microrobot. The mobile microrobot carries three optical devices which receive laser beams. The position and orientation of the microrobot is determined by the position of the linear stages. The measurement accuracy in 8 mm × 8 mm area was about 5 μm, and that in 50 mm × 50 mm area was about 50 μm.
  • 森 貴彦, 不破 勝彦, 神藤 久
    2007 年 127 巻 12 号 p. 2057-2063
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    In this paper, we propose a new design method of frequency dependent optimal servo system for the positioning of flexible structures. In order to reduce the sensor costs and to suppress spillover phenomena which are caused by ignored elastic modes of the plant, we introduce a pre-filter into an input, which possesses low pass characteristics. The proposed method enables to design specified characteristics of the pre-filter and to assign poles to desirable locations of a closed loop system exactly while keeping optimality. Some results of experiments are given in order to verify the usefulness of our method.
<ロボティクス>
<ソフトウェア・情報処理>
  • 池崎 正和, 渡邉 豊英, 牛尼 剛聡
    2007 年 127 巻 12 号 p. 2071-2076
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    Recently, a lot of researches on geographic information models for handling events have been proposed. However, many of researches are application-oriented. Namely, they are not suitable to represent a phenomenon spreading broadly in the geographic space such as earthquakes, typhoons, and so on. In this paper, we propose a new model for handling events in a distributed geographic information system. In our model, event information and geographic information are represented independently, and they are associated dynamically according to the viewpoint of users for an event.
  • 山田 貴大, 石井 直宏, 中島 豊四郎
    2007 年 127 巻 12 号 p. 2077-2085
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    The text classification is an important subject in the data mining. For the text classification, several methods have been developed up to now, as the nearest neighbor analysis, the latent semantic analysis, etc. The k-nearest neighbor (kNN) classification is a well-known simple and effective method for the classification of data in many domains. In the use of the kNN, the distance function is important to measure the distance and the similarity between data. To improve the performance of the classifier by the kNN, a new approach to combine multiple distance functions is proposed here. The weighting factors of elements in the distance function, are computed by GA for the effectiveness of the measurement. Further, an ensemble processing was developed for the improvement of the classification accuracy. Finally, it is shown by experiments that the methods, developed here, are effective in the text classification.
特集研究開発レター
<センシング>
論文
<センシング>
  • 加藤 英志, 吉田 永, 林 伸一郎, 小川 雄一, 水津 光司, 川瀬 晃道
    2007 年 127 巻 12 号 p. 2088-2092
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    We report on a novel sensing method in the terahertz region using metallic mesh. Conventionally, the band-pass filter property of a metallic mesh can be adjusted by changing the mesh geometrical parameters. However, the band-pass filter parameters also depend on the refractive index of the medium in the vicinity of the mesh openings. To inspect this effect as a potential measurement principle, we calculated the electric field distribution around the metallic mesh and analyzed the frequency characteristics due to a sample attached to the metallic mesh using the Finite Difference Time Domain method. For bio-molecular sensing, the Electrospray Deposition method was applied in order to spray a uniform layer of protein over a metallic mesh. We observed a correlation between the quantity of protein and the transmission characteristics of the metallic mesh.
<音声画像処理・認識>
  • 吉森 聖貴, 満倉 靖恵, 福見 稔, 赤松 則男
    2007 年 127 巻 12 号 p. 2093-2100
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    Previous studies of image restoration for noise images were based on a mask processing. These conventional noise removal methods based on the mask processing have an issue of defining degradation to accompany a spacial processing. In this paper, we propose a graininess suppression method based on edge shape. In this method, we detect edges from an noise image and perform graininess suppression for this image based on edge information. On the edge detection, we execute an image transformation for an image that enables us to extract edge by making principal component images. Moreover, we use the canny edge detection operator with can detect a weak edge that relates to a real edge, and do not detect a lie edge. In the suppression process, we use Wiener filter that can restore an noise image without making a complete edge map and the original signal map. We demonstrated the effectiveness of the present method for the noise added images and confirmed it by means of computer simulation.
<制御・計測>
<ソフトウェア・情報処理>
資料
<医用電子・生体工学>
  • 石原 美弥, 佐藤 正人, 三谷 玄弥, 長井 敏洋, 沓名 寿治, 持田 讓治, 菊地 眞
    2007 年 127 巻 12 号 p. 2166-2170
    発行日: 2007/12/01
    公開日: 2007/12/01
    ジャーナル フリー
    There is a new demand in the field of tissue engineering for evaluation technology of extracellular matrix because the extracellular matrix plays an important role in the function of skeletal tissue such as articular cartilage. We previously proposed a noninvasive method of viscoelastic characterization of tissue phantom, based on the photoacoustic measurement. The purpose of this study was to verify the applicability of the photoacoustic measurement method for monitoring of the development of extracellular matrix using tissue engineering technology. The decay times measured by the photoacoustic method were varied with culture periods when tissue-engineered articular cartilages with various culture periods (-12 weeks) were used as samples. Tissue-engineered cartilage cultured for a long period showed shorter decay times, indicating that the samples approached an elastic solid from a rheological viewpoint. By comparison between biochemical analyses and biomechanical studies, we proved that the photoacoustic signal was a good indicator for evaluating extracellular matrix formation because the change of the photoacoustic decay times would reflect the production of an extracellular matrix.
<センシング>
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