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
141 巻 , 12 号
選択された号の論文の7件中1~7を表示しています
論文
  • 佐山 周次
    2021 年 141 巻 12 号 p. 642-649
    発行日: 2021/12/01
    公開日: 2021/12/01
    ジャーナル 認証あり

    To detect a target (light buoy) and suppress Weibull distributed clutter, I have introduced CFAR (Constant False Alarm Rate) circuit by normalization of standard deviation. The false alarm probability does not depend on the parameters of the Weibull distribution in this CFAR circuit. To examine the effect of this CFAR circuit, I have observed sea clutter containing a light buoy using an S-band radar with a frequency of 3.05GHz, a beamwidth of 1.8°, a pulsewidth of 0.5µs, and a pulse-repetition frequency of 1,600Hz. To investigate the sea clutter amplitude statistics, I have used partial Q-Q plot, which is more rigorous fit of the distribution to the data than conventional Q-Q plot. It has been found that the sea clutter amplitudes obey the Weibull distribution with the shape parameter of c=3.50 for entire data and the Weibull and log-Weibull distributions with the shape parameters of c=2.97 to 3.77 and c=11.31 to 12.93, respectively, for data within the beam width of an antenna. The number of the best model of the Weibull and log-Weibull distributions to data is 8 and 3, respectively, from 11 small data. I have applied CFAR circuit by normalization of standard deviation to the observed data. I have succeeded in detecting light buoy and suppressed sea clutter with improvement 32.22dB by CFAR processing.

  • 雑賀 友, 水野 統太, 松本 悠佑, 水戸 和幸, 板倉 直明
    2021 年 141 巻 12 号 p. 650-656
    発行日: 2021/12/01
    公開日: 2021/12/01
    ジャーナル 認証あり

    The purpose of this study is to develop a line-of-sight input interface using the eye-glance input method, which uses a glance eye movement and method of estimating the eye-control movement by analyzing the image of the area near the eye-ball. The motion was discriminated by taking an image using the built-in camera of a smartphone to rapidly look at the four corners of the smartphone and calculate the moving distance of the eyeball, which was divided into horizontal and vertical components using the optical flow function in Open CV library. In the experiment, we obtained data by asking the subjects to look at the reciprocate of quick gaze movements at each of the four corners and the center of the screen. As a result of data analysis, characteristics of waveforms were obtained for the movements looking at the four corners, and we could determine which of the four corners the users were looking at. Furthermore, by distinguishing between camera shake and line-of-sight movement using the variance value, the discrimination rate was 90% or more even when held in the hand. It was shown that the Eye Glance movement can be measured with a smartphone as well as a PC.

  • 榎本 壮一郎, 小西 大輔, 宇都 義浩, 下村 直行
    2021 年 141 巻 12 号 p. 657-664
    発行日: 2021/12/01
    公開日: 2021/12/01
    ジャーナル 認証あり

    With the goal of establishing a new cancer treatment method using nanosecond pulsed electric fields (nsPEFs), we investigated the effect of applying nsPEFs and anticancer drugs (adriamycin, ADM) to cancer cells. The surviving fraction of cancer cells was significantly reduced by nsPEFs application compared to the control. Compared to nsPEFs alone and ADM administration alone, a significant decrease of the surviving fraction was observed in combination of nsPEFs application and ADM administration. In addition, multiplying value of surviving fractions of nsPEFs application and ADM administration was calculated as a pseudo-combination effect. The surviving fractions of the experimental combinational results of nsPEFs and ADM were lower than the pseudo-combination results. Therefore, the synergistic effect of combination of nsPEFs and ADM was confirmed. Furthermore, the surviving fraction of ADM administration after nsPEFs application was significantly lower than that of ADM administration on 24 hours before nsPEFs application. ADM action on cells would be effective owing to nanopores were formed by applying nsPEFs. It was confirmed that ADM and nsPEF induced apoptosis of cells from apoptosis and necrosis test using FACS.

  • Kaisei Enoki, Kazuki Endo, Hiroaki Miyake, Yasuhiro Tanaka
    2021 年 141 巻 12 号 p. 665-671
    発行日: 2021/12/01
    公開日: 2021/12/01
    ジャーナル 認証あり

    Spacecraft are exposed by radioactive rays, such as highly energetic electrons, protons, and plasma. The surface insulating materials of spacecraft are charged because of being exposed by such high energy charged particles. This charging phenomenon is one of the origins of an electrostatic discharge and may lead to a fatal error during those operations of spacecraft. For the improvement of the reliability of spacecraft operation, we should understand charge accumulation phenomena based on the actual surface conditions. Therefore, our group and other researchers have tried to develop systems to measure the surface and bulk charges of some seat specimens modeling surface insulators. As the results, we developed new space charge measurement equipment based on the pulsed electroacoustic (PEA) method. That system can apply the pulsed electric filed to the sample through the vacuum gap using a grid electrode located 125 µm above the sample. Electrons through the grid electrode to the sample. Therefore, this electrode can be applied to measurement of the surface and internal charge accumulation in the bulk of sheet specimens. While our past study had described only internal charge accumulation by the conventional PEA method, this paper presents a seamless charge profile from the surface to internal of the sample by such newly developed method. In this paper, we measured space charge distributions caused by electron irradiations to fluorinated materials were studied by using above developed method. The negative charge accumulation distributed the surface and penetrated the bulk up to approximately 32 µm depth from the surface. The amount of irradiated electrons accumulation was more than 30 times as much as the results obtained by a conventional measurement system. From those results, the space charge distribution can be measured under vacuum conditions close to actual situations.

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