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, 11 号
選択された号の論文の23件中1~23を表示しています
特集:電気関係学会関西支部連合大会
特集論文
<電子材料>
  • 小松 直佳, 杉野 隆, 木村 千春, 青木 秀充, 栗本 裕史, 近松 健太郎
    2007 年 127 巻 11 号 p. 1822-1825
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    An attractive gate insulator film with a wide bandgap and a high dielectric constant is required to achieve high performance power field-effect transistor (FET) using wide bandgap semiconductors such as SiC and diamond. An Al2O3 film is one of the candidates for this purpose. The AlO film was produced by means of RF sputtering on Si and SiC substrates, and I-V and C-V characteristics of the AlO film were measured. However, the AlO film was not stoichiometric and it has large gate leakage current and large charge shifts. So we added Si in AlO (AlSiO).
    We have succeeded in suppressing the gate leakage current and the charge shifts by using the AlSiO film. The optimized AlSiO film was applied to SiC-MIS structure. It was also observed that the leakage current level was suppressed.
<電子・集積回路>
  • 加藤 利次, 井上 馨, 神田 義教
    2007 年 127 巻 11 号 p. 1826-1831
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    The envelope following(EF) method is an approximate transient simulation technique which considers switching dynamics. It skips analysis of several switching cycles and considers the cycles by using, for example, the backward Euler or the trapezoidal type algorithm. It is more accurate than the averaging method because it considers switching ripples and it is still efficient. However it has been proposed only for non-autonomous systems. This paper proposes a new extended EF method which can also analyze autonomous systems which are typical in the power electronics field. It is extended by introducing a switching condition to the original one and the two conditions are solved simultaneously. In the numerical process, a Jacobian matrix is evaluated where switch timing sensitivities are considered. A hysteresis controlled buck and a C´uk converter examples are investigated and validated.
<医用電子・生体工学>
  • Hiroshi Matsumoto, Hiroki Ishida, Satoshi Nakamoto, Hiromasa Takeno, Y ...
    2007 年 127 巻 11 号 p. 1832-1838
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    For the treatment of cancer using hyperthermia, high frequency electromagnetic fields are used to heat the cancer cells. These electromagnetic fields fall into two general frequency ranges, one relatively low, and the other in the microwave range. Both produce some side effects such as the heating of healthy cells or the impact on the body of invasive surgery required to expose deep-lying cells. To reduce these side reactions, the use of lower microwave frequencies with phase control was proposed. In this paper, we present a very basic study to prove the viability of the proposed scheme. This includes the selection of a suitable frequency, demonstration of localized heating using the selected frequency, and a three-dimensional numerical analysis of the electromagnetic fields involved. In the heating demonstration, a tissue-equivalent phantom made from agar was irradiated by phase-controlled electromagnetic waves from a pair of circular patch antennas operating at 430MHz. This produced localized heating. The numerical analysis produced a field distribution that corresponded closely to the results from the heating experiment. It confirmed that the phase control technique for long-wavelength microwaves was effective in producing localized heating.
  • 今井 晴香, 楠 正暢, 橋本 典也, 西川 博昭, 本津 茂樹
    2007 年 127 巻 11 号 p. 1839-1842
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    Biological molecular adsorption on crystal hydroxyapatite (HAp) and amorphous Ca10(PO4)6(OH)2 was investigated using quartz crystal microbalance (QCM) method. The pulsed laser ablation (PLA) was applied to coat both kind films for QCM sensors. A crystal HAp sensor was prepared with thermal treatment during the fabrication process. An amorphous Ca10(PO4)6(OH)2 sensor was prepared without any thermal treatment. Not only crystal HAp but amorphous Ca10(PO4)6(OH)2 showed good adsorptive feature compared with conventional QCM on the market. The result showed that a low temperature deposition of HAp is adaptable to polymer-based materials for medical purposes.
<電子応用>
<センシング>
論文
<光・量子エレクトロニクス>
<医用電子・生体工学>
  • 吉田 豊, 横山 清子, 石井 直宏
    2007 年 127 巻 11 号 p. 1859-1864
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    In this study, it aimed at the proposal of real time and continuous estimating method of physiological states using biological signals. The proposal method will be one of the basic technology to develop physiological state monitor. The proposal index is defined in the ratio of the number of extreme points of the heart rate time series and the number of heart rate. This index is called NEP. The characteristic of the NEP was shown by simulation analysis. The NEP was compared with classical indices of heart rate variability by the analysis of measured heart rate time series. NEP decreased significantly (p<0.05) when posture changed from supine to standing. In this case, the autonomic nervous activity balance changes from the parasympathetic to the sympathetic nerve. Moreover, the NEP was correlated with the respiratory frequency in supine position (p<0.01). It is not necessary to consider individual variation of NEP in the physiological state evaluation. Standardization process or relative value is not necessary to compare individual persons. This parameter is applicable to evaluate physiological state at real time and continuously.
  • —電子的コミュニケーションにおける顔の効果—
    湯浅 将英, 斎藤 恵一, 武川 直樹
    2007 年 127 巻 11 号 p. 1865-1870
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    In this paper, we describe that brain activities associated with emoticons by using fMRI. In communication over a computer network, we use abstract faces such as computer graphics (CG) avatars and emoticons. These faces convey users' emotions and enrich their communications. However, the manner in which these faces influence the mental process is as yet unknown. The human brain may perceive the abstract face in an entirely different manner, depending on its level of reality. We conducted an experiment using fMRI in order to investigate the effects of emoticons. The results show that right inferior frontal gyrus, which associated with nonverbal communication, is activated by emoticons. Since the emoticons were created to reflect the real human facial expressions as accurately as possible, we believed that they would activate the right fusiform gyrus. However, this region was not found to be activated during the experiment. This finding is useful in understanding how abstract faces affect our behaviors and decision-making in communication over a computer network.
<音声画像処理・認識>
  • 寺田 賢治, 鴨頭 大輔
    2007 年 127 巻 11 号 p. 1871-1879
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    Recently, many brutal crimes have shocked us. Therefore, the importance of security and self-defense have increased more and more. It is necessary to develop an automatic method of detecting suspicious persons. In this paper, we propose a method of detecting suspicious persons using the internet camera. An image sequence is obtained by the internet camera. By using these images, the recognition of suspicious persons is carried out. Our method classifies the condition of the target person into 3 postures: walking, staying and sitting. The system employs the subspace method which uses three features: the value of movement, the number of looking around restlessly, and the rate of stopping and going. Some experimental results using a simple experimental system are also reported, which indicate effectiveness of the proposed method. In most scenes, the suspicious persons are able to be detected by the proposed method.
  • 多々良 友英, 大橋 剛介
    2007 年 127 巻 11 号 p. 1880-1887
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    In this paper, edge detection for the sketch image retrieval system is proposed. An effective edge detection is required for the edge-based sketch image retrieval system, because the retrieval results depend on edge images. Canny edge detection is known as one of effective edge detections, but Canny edge detection is difficult to apply to various images since it is needed to optimize three parameters. In this method, edges are, therefore, detected with Canny edge detection from multiple-resolution images of database images, and desired images are retrieved by extracting features from detected edge images. Experimental results of applying this method to 6,500 images in Corel photo gallery showed a good performance of this method.
  • 松永 聖平, 大松 繁, 小坂 利壽
    2007 年 127 巻 11 号 p. 1888-1893
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    The purpose of this paper is to classify bank notes into “true” or “counterfeit” ones faster and more precisely compared with a conventional method. We note that thin lines are represented by direct lines in the images of true notes while they are represented in the counterfeit notes by dotted lines. This is due to properties of dot printers or scanner levels. To use the properties, we propose two method to classify a note into true or counterfeited one by checking whether there exist thin lines or dotted lines of the note. First, we use Fourier transform of the note to find quantity of features for classification and we classify a note into true or counterfeit one by using the features by Fourier transform. Then we propose a classification method by using wavelet transform in place of Fourier transform. Finally, some classification results are illustrated to show the effectiveness of the proposed methods.
  • 劉 飛, 大山 航, 若林 哲史, 木村 文隆
    2007 年 127 巻 11 号 p. 1894-1901
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    There are numerous cadastral maps generated by the past land surveying. The raster digitization of these paper maps is in progress. For effective and efficient use of these maps, we have to assemble the set of maps to make them superimposable on other geographic information in a GIS. The problem can be seen as a complex jigsaw puzzle where the pieces are the cadastral sections extracted from the map. We present an automatic solution to this geographic jigsaw puzzle, based on the generalized Hough transformation that detects the longest common boundary between every piece and its neighbors. The experiments have been conducted using the map of Mie Prefecture, Japan and the French cadastral map. The results of the experiments with the French cadastral maps showed that the proposed method, which consists of a flood filling procedure of internal area and detection and normalization of the north arrow direction, is suitable for assembling the cadastral map. The final goal of the process is to integrate every piece of the puzzle into a national geographic reference frame and database.
  • 菰口 直之, 山根 健治, 田中 正吾
    2007 年 127 巻 11 号 p. 1902-1908
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    Developing a monitoring system for a bathroom is important to prevent aged persons from accidents. The authors previously developed a bathroom monitoring system using an acoustic sensor which measured the water level of a bathtub and the temperature and also recognized the sound environment. The sound environment was however occasionally mis-recognized with the system. The present paper proposes a new method which recognizes the sound environment in the bathroom more accurately. Experiments demonstrate the effectiveness of the method.
<制御・計測>
  • 久保 和良
    2007 年 127 巻 11 号 p. 1909-1917
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    In this paper, instantaneous frequency expressions are mathematically derived, where each of the expressions is a function of sine-wave samples in time-differential domain space. At first, we introduce differential operator, divided finite difference operator, shifting operator, and mean operator. Then, we derive a strict expression of instantaneous frequency by applying the operators to the governing equation, which generates sine-wave. It is shown that the derived expression is identical to the Prony's method. Next, the other five expressions of instantaneous frequency are derived by the operator-applying method. Numerical results show that precise instantaneous frequencies are calculated by using the expressions. All the expressions are not under constraint of the uncertainty principle, and one of them is not under constraint of the sampling theorem.
  • 不破 勝彦, 成清 辰生, 神藤 久
    2007 年 127 巻 11 号 p. 1918-1927
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    A disturbance observer is well known as a control system which can reduce the adverse effect of disturbances. In order to synthesize the disturbance observer, the exact dynamical model of disturbance is required. However, in general, it is difficult to obtain the exact disturbance model. On the other hand, an observer with a function of estimating unmeasurable inputs has been already proposed. By using this observer, unmeasurable disturbances can be estimated without the exact disturbance model. However, disturbance attenuation problem based on the observer still remains as an open issue. In this paper, a synthesis method of the control system for disturbance attenuation based on an observer with a function of estimating unmeasurable inputs is proposed and the class of compensators which guarantee the internal stability of the closed loop system is clarified.
<システム>
  • 嶋吉 隆夫, 堀 謙太, 陸 建銀, 天野 晃, 松田 哲也, 野間 昭典
    2007 年 127 巻 11 号 p. 1928-1936
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    Biological simulation has become an important technology for biological research. Though multi-domain simulation technique is required for analysis of complicated biological activities, multi-domain biosimuator system tends to be very complicated and so requires a high developing cost. To improve this situation, we propose a biosimulator development platform, DynaBioS, which can handle complex interactions between phenomena in different domains, such as electrophysiology and mechanics. A biosimulator system is composed of components, each of which is a sub-simulator of a phenomenon, and exchanges event messages to each others as the interaction of the phenomena. This design allows easy replacement of a model for a phenomena by interchanging a corresponding component. This platform reduces costs to develop simulators, by implementation of components by wrapping existing software products, and by reuse of components. Examples of developed simulators are given to show that this platform facilitates the development of biosimulators.
  • 南保 英孝, 岡峰 正, 木村 春彦, 中沢 実, 服部 進実
    2007 年 127 巻 11 号 p. 1937-1946
    発行日: 2007/11/01
    公開日: 2007/11/01
    ジャーナル フリー
    When we examine goods with their pictures at online shops, regarding flowers and drawings, it is difficult to give proper keywords for retrieving goods' pictures. To refer their pictures efficiently, image retrieval systems using adjectives called as Kansei words, which represent human feelings, impressions, etc., are proposed. However, since the current systems retrieve pictures without customers' preferences, outputs disagree with the preferences. To cope with the problem, we propose an image retrieval system with Kansei words according to users' preferences. Experimental results have shown the efficiencies of the proposed system comparing with performances of a conventional system.
研究開発レター
<電子・集積回路>
<医用電子・生体工学>
<センシング>
<マルチメディア>
<制御・計測>
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