電気学会論文誌A(基礎・材料・共通部門誌)
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
132 巻, 10 号
選択された号の論文の24件中1~24を表示しています
特集(I):新機能性ナノスケール磁性材料の作製・評価
特集(II):イノベーションを支える最新の計測技術2012
特集論文(I)
特集論文(II)
  • 佐山 周次, 石井 誠四郎
    2012 年 132 巻 10 号 p. 849-856
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    We have observed weather clutter including targets (ships) using an S-band radar with a frequency of 3.05GHz, a beamwidth of 1.8°, and a pulsewidth of 0.5μs. To investigate the weather clutter amplitude statistics, we introduce the Akaike Information Criterion (AIC). We have found that the weather clutter amplitudes obey the log-normal, Weibull, and log-Weibull distributions with the shape parameters of 0.329 to 0.477, 4.40 to 4.55, and 11.93 to 16.44, respectively, for data within the beam width of an antenna. We have proposed the log-normal/CFAR circuit which is modified a Cell-Averaging (CA) LOG/CFAR circuit. It is found that weather clutter is suppressed with improvement of 51.58dB by log-normal/CFAR.
  • Xiaofeng Lu, Takashi Izumi, Lin Teng, Tadahiro Horie, Lei Wang
    2012 年 132 巻 10 号 p. 857-863
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    Background subtraction is a method typically used to segment moving vehicles in image sequences taken from a static camera by comparing each new frame with a model of the background scene. This paper presents a robust background subtraction algorithm which reduces the influence of illumination changes and shadows and adapts to rapid changes in the traffic scene. A statistical background modeling method is presented, which is based on a histogram at the pixel level and produces a color model from a series of frames. For foreground detection, we propose the Choquet integral to fuse the three color-component similarity measures and a texture similarity measure based on a uniform local binary pattern. Finally, we propose a new adaptive background maintenance method. The experimental results for several dataset videos show that the proposed method is more efficient, robust, and accurate than classical approaches.
  • 福地 哲生, 布施 則一, 岡田 満利, 藤井 智晴, 水野 麻弥, 福永 香
    2012 年 132 巻 10 号 p. 864-870
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    The spatial resolution of THz imaging in nondestructive testing of thermal barrier coating was evaluated. The instrumental resolution was evaluated using a test pattern and was found to be about 0.6mm. The test pattern under a YSZ sample of thickness 1.25mm could be identified from the spatial distribution of the wave reflected from the back side of the YSZ sample, with a planar spatial resolution of about 1mm. THz imaging successfully detected an artificial defect of 1mm×1mm under the topcoat in a TBC sample. The results showed the possibility of detection of surface defects under the topcoat by THz imaging.
  • 作田 幸憲, 渡邉 充紘, 今池 健, 関根 好文
    2012 年 132 巻 10 号 p. 871-877
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    The progress of the fabrication technology of the crystal resonators became to expand to VHF and UHF band beyond a traditional HF band. Along with this fact, the characteristic of the crystal resonators is demanded to be measured in these frequency bands. An international standardized measurement method, however, do not exist now. In these frequency range, all of devices and circuits work as distributed constant circuit. When we measure the characteristic of the crystal resonator, it is necessary to consider the setting portion of the crystal resonator on circuit as the distributed constant circuit. We have examined the use of the microstrip line to measure the characteristic of the crystal resonator.
  • 内田 雅文, 松谷 麻美, 野澤 昭雄
    2012 年 132 巻 10 号 p. 878-885
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    Today is the information society and handwriting is reconsidered and adopted for various systems, for example, authentication systems and input systems. In this paper, MWL (Mental Work Load) and iterative process of stroke based on the characteristics of human rhythm perception and the relationship between them was examined. Specifically, the period of ISI draw stroke and some continuous synchronous repetitive auditory stimuli (complex tasks such as synchronous tapping and drawing and stroke) in a process set out by using various and repetitive stroke times such as SE, IWI, IE, WE and SWE was examined. In addition, in order to propose a new experimental system, the parameters that reflect the structure of the process related to the stroke mechanism during the repetitive SWE process were identified. Finally in order to pay a further attention to the consumed resources, the dynamics of SWE, MWL and the related physiological, psychological and performance indicators were compared.
  • 佐山 周次, 石井 誠四郎
    2012 年 132 巻 10 号 p. 886-892
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    We have observed sea clutter using an X-band radar with a frequency of 9.41GHz, a beamwidth of 1.0°, and a pulsewidth of 0.5μs. To investigate sea clutter amplitude statistics, we introduce four probability distribution models and the Minimum Description Length (MDL) principle, which is more rigorous comparison between the distributions than the Akaike Information Criterion (AIC). We have found that the sea clutter amplitude obey the generalized gamma distribution with the shape parameter of α=3.54 for entire data and the log-normal, Weibull, log-Weibull, and generalized gamma distributions with the shape parameters of σ=0.467, c=2.86 to 3.39, c=9.37 to 10.76, and α = 2.52 to 4.18, respectively, for data within the beam width of an antenna. The number of best fit of the log-normal, Weibull, log-Weibull, and generalized gamma distributions to data are 1, 2, 2, and 18, respectively.
  • —三線式交差誘導線を用いた列車位置検知方式—
    松村 太陽, 小野 隆
    2012 年 132 巻 10 号 p. 893-900
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    At present, there are a variety of measures that are being taken in the face of the lengthening of level crossing closure times, but since these all rely on the intermittent detection of the location and speed of the train, they have not yet shown sufficient effectiveness. Against this backdrop, we will show in our simulation and experimental result the use of inductive wires to continuously detect the location of the train, while also outlining the crossing warning time control system, and how the application of this system. In this paper, warning time optimum control for level crossing with a continuous type train location detector using crossed inductive wires will be proposed and its effect to shorten crossing warning times will be discussed. And we have also confirmed the feasibility of the bidirectional information flow method. As a result, we have demonstrated that the proposed method is effective in delaying the timing of the initiation of warning and it is applicable to a high speed train.
  • 新井 茂雄, 大谷 昭仁, 野中 弘二
    2012 年 132 巻 10 号 p. 901-906
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    An optical performance monitor (Q-monitor) based on all-optical sampling technology has been reported as an optical signal quality monitor for photonic networks. The Q-monitor measures the eye pattern of the optical transmission signal, and the signal quality is assessed by calculating the Q factor from the measured eye patterns. Here, we propose a short optical pulse generator with low time jitter as an optical sampling pulse source for the Q-monitor. It consists of an optical pulse source, a pulse compressor, and a waveform shaper. We confirmed that the pedestal-suppressed pulse was obtained using the pulse shaper, and that optimizing the pulse generator operating conditions produced a pulse width of 7.0 ps when the RMS time jitter was less than 0.5 ps. The eye pattern is clear for a 10-Gb/s NRZ signal using a Q-monitor with the short optical pulse generator. This paper explains the pulse generator principle and performance. Furthermore, we report evaluation results for the Q-monitor with pulse generator.
  • 門馬 英一郎, 高木 銀次, 胡桃 聡, 鈴木 薫, 小野 隆
    2012 年 132 巻 10 号 p. 907-912
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    This study aims to establish a method of an automatic nondestructive evaluation of a pearl nucleus. In this paper, we examined a distinction of a material of the pearl nucleus using optical properties and an evaluation of quality using image processing about the pearl nucleus made of mussel shell. As a result, it is clarified that the nondestructive evaluation of the pearl nucleus was possible by our method.
  • 小平 和明
    2012 年 132 巻 10 号 p. 913-919
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    An evaluation method of platinum resistance thermometers (PRTs) used in the stationary air was considered. A comparison measurement apparatus to evaluate PRTs was developed by using a commercially available temperature bath and the performance of the apparatus was evaluated. The apparatus has high temperature stability and good temperature distribution although the thermal medium is the air. The uncertainty of the apparatus is less than 1mK. A PRT was evaluated for a trial with this apparatus at 23°C. First, a PRT that was set in the water was measured with a Standard Platinum Resistance Thermometer (SPRT) in the temperature bath. Next, the identical PRT was set in the air chamber of the developed apparatus and measured with the SPRT. And, each result was compared. As a result, it was possible to distinguish the difference of behavior of the PRT at different environment by a proposed method in this study. And, it was confirmed that the cause of different behavior was the self-heating of the PRT.
  • Hiroshi Sakuma, Tomoyasu Taniyama, Kiyoshi Ishii
    2012 年 132 巻 10 号 p. 920-923
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    Fe/Fe-O granular thin films were fabricated by gas flow sputtering. Transmission electron microscopy analysis reveals that α-Fe granules are surrounded by a matrix consisting of tiny crystallites of Fe3O4 and/or γ-Fe2O3. The matrix acts as a tunnel barrier for electrical conductance. The Fe/Fe-O granular thin film exhibits an anomalous response to magnetic fields at low temperatures. When a magnetic field is applied, the resistance decreases. After the field is settled, the resistance increases for more than 1800s. A possible mechanism for the anomalous relaxation is the relaxation of the spins in the spin-glass-like Fe-O matrix.
  • 堤 晋太郎
    2012 年 132 巻 10 号 p. 924-929
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    Inductive voltage dividers (IVDs) are widely used in the field of AC measurements, such as impedance measurements at audio frequencies. Two-stage guarded IVD has been developed by D N. Homan and T L. Zapf about forty years ago. However, it is not easy to construct the two-stage guarded IVD. Therefore, we have developed a two-stage IVD using special winding method without guard by magnetic and electrical shield. To reduce admittances of each winding wires, corrugated cardboard of polypropylene is used for new two-stage IVD. In addition, ratio winding and excitation winding were wound toroidally around two FINEMET ring cores using PEW flat cable 0.7 mm in diameter. As a result, the in-phase ratio errors are within ±6.1×10-8 of the input at frequency 1kHz or less. In this report, the winding methods and measurement results of new two-stage IVD are described.
  • 甲斐 祐一郎, 槌田 雄二, 戸高 孝, 榎園 正人
    2012 年 132 巻 10 号 p. 930-935
    発行日: 2012/10/01
    公開日: 2012/10/01
    ジャーナル フリー
    It is needed to know magnetic properties under various stress and magnetic flux conditions in order to utilize electrical steel sheets effectively. In this paper, we examine a measurement method of the vector magnetic properties of a non-oriented electrical steel sheet under stress conditions. At first, an evaluation method of the stress is examined in order to control the amplitude and direction of principal stress in the plane of the non-oriented electrical steel sheet. In addition, the vector magnetic properties of the non-oriented electrical steel sheet are measured by applying the stress along the arbitrary direction. As these results, the difference of the magnetic anisotropy of the non-oriented electrical steel sheet is obtained due to the stress.
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