著者

尾ノ井 正裕 山渕 正彦 八束 充保

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.123, no.1, pp.12-19, 2003 (Released:2003-04-01)

参考文献数

11

被引用文献数

1 1

---

A virtual cathode oscillator with a stainless-steel mesh anode of various transparencies and wire diameters was studied experimentally for improvement of microwave power and its repetitive operations. The maximum microwave power was observed to be about 20 MW at 12 GHz for the diode voltage of 250 kV and the electron beam current of 39 kA using the anode mesh with the wire diameter of 0.22 mm and the transparency of 67 %. The microwave emission enhanced with decreasing the wire diameter as the mean beam scattering angle decreased with the smaller wire diameter. Also the increased transparency of fine mesh caused an enhancement of microwave emission. Use of mesh anode allowed us a few repetitive operations.

著者

鈴木 良博 清家 捷二 今井 修 内藤 克彦

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.118, no.10, pp.1158-1165, 1998-10-01 (Released:2008-07-15)

参考文献数

5

---

The semiconducting glaze insulators show excellent electrical performance under contaminated condition. In order to make mass production of such type of insulators, it is first necessary to determine the kind of the materials to develop such a semiconducting property and to decide an optimum resistivity of the semiconducting glaze from practical manufacturing technology point of view.This paper describes the results of a series of investigation into the macroscopic surface resistivity to develop the expected superior electrical characteristics of insulators, the optimization of the volume resistivity of glaze itself, the optimum distribution of volume resistivity of the glaze over the actual insulator surface, etc. The chemical composition of the glaze ingredients and the manufacturing conditions are essential for the resultant glaze characteristics.

著者

野澤 昭雄

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.141, no.9, pp.NL9_3, 2021-09-01 (Released:2021-09-01)

著者

秋山 秀典 寺本 明美 小薗 和剛

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.126, no.8, pp.782-788, 2006 (Released:2006-11-01)

参考文献数

11

被引用文献数

2 3

---

A conventional lecture on Laser Engineering had been done in a lecture room till 1999. A content using on-demand streaming method was made for an online lecture of Laser Engineering in 2000. The figures and equations used on the conventional lecture and the voice recorded for the online lecture were converted to the real media. Then an online lecture has been provided to students by using a Helix Universal Server. The trial of the online lecture was done only for the students who wanted to take the online lecture course in 2000. The online lectures have been recognized as the credits for graduation by the change of a law since 2001. About 100 students have registered the online lecture of Laser Engineering every year since 2001. Here, three years' questionnaire surveys of the online lecture are summarized, and results of examinations on the conventional lecture for two years and on the online lecture for three years are compared. It is recognized for the lecture of Laser Engineering that the educational effect of the online lecture is comparable to or better than that of the conventional lecture.

著者

遠藤 守信 加藤 厚志 上野 秀樹 白石 稔

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌. A (ISSN:03854205)

巻号頁・発行日

vol.108, no.7, pp.279-286, 1988-07-20 (Released:2008-06-30)

参考文献数

13

被引用文献数

1 1

著者

徳山 貢 太田垣 博一

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. A, 基礎・材料・共通部門誌 = The transactions of the Institute of Electrical Engineers of Japan. A, A publication of Fundamentals and Materials Society (ISSN:03854205)

巻号頁・発行日

vol.126, no.7, pp.584-590, 2006-07-01

参考文献数

5

被引用文献数

1 1

---

In this paper, a method is proposed to education of starting characteristics and stationary characteristics of three phase induction motors based on a direct numerical analysis. At first, a mathematical model is presented to three phase induction motors. Secondly, program codes in C language are shown to simulation studies with results obtained by the program codes. Finally, the results obtained in this paper are shown to the effectiveness of the proposed method to education of starting characteristics and stationary characteristics of various three phase induction motors.

著者

廣岡 伸治 服部 克巳 西橋 政秀 紺 晋平 竹田 辰興

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌. A, 基礎・材料・共通部門誌 = The transactions of the Institute of Electrical Engineers of Japan. A, A publication of Fundamentals and Materials Society (ISSN:03854205)

巻号頁・発行日

vol.131, no.9, pp.691-697, 2011-09-01

---

The ionospheric anomaly prior to the 2007 SouthernSumatra earthquake (M8.5) was observed by GPS receivers around Sumatra islands. In this paper, to investigate the three-dimensional structure of electron density in Ionosphere, a tomographic approach (Residual Minimization Training Neural Network; RMTNN) has been performed. The results of the tomographic approach are consistent with those of total electron content (TEC) approaches. We found that the significant decreases take place in the heights of 250-400 km, especially at 330 km height. But the height which gives the maximum electron density is not changed. The obtained structure is that the decreased region exists in the southwest side of Integrated Electron Content (IEC) (400-550 km altitudes) and in the northern side of IEC (250-400 km altitudes). Global tendency of the decreases area is expanded to the east with an altitude and it is concentrated in the southern hemisphere of over the epicenter. These resultsshow that the high capability of RMTNN method for the estimation of the ionospheric electron density distribution possibly associated with earthquake.

著者

寺口 直希 南 政孝

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.139, no.5, pp.259-263, 2019-05-01 (Released:2019-05-01)

参考文献数

25

---

A Tesla coil is a resonant transformer circuit that generates very high voltages which are made to arc through the air. Recently, a solid state Tesla coil was produced according to developing the semiconductor. In addition, the solid state Tesla coil makes sound by the air discharge. Hence, the sound is used as musical devices. In the past, the musical solid state Tesla coils are generated by PWM (Pulse Width Modulation) method. However, it is difficult to use the high pitch sound and the tone color. This paper investigates the musical solid state Tesla coil by using not PWM method but PRF (Pulse Repetition Frequency) method. As the result, the proposed musical solid state Tesla coil provides good sound.

著者

堤 泰行 草野 善照 小野 訓 藤井 寛一 檜垣 勝

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.111, no.11, pp.979-987, 1991-11-20 (Released:2008-07-15)

参考文献数

9

被引用文献数

4 4

---

Effect of discharge inception voltage on electromagnetic noise spectra in VHF and UHF region from spark discharge at hemisphere-plane electrodes in atmosphere is studied. The discharge inception voltages are changed by several means, such as increasing gap length from 2mm to 6mm, or UV-ray irradiation, or increasing stress concentration at the electrode tip, or spreading dust such as cotton cloths, acylic resin particles, copper particles, or alminum particles on the plane electrode.When the discharge inception voltage is increased, macroscopic slope of noise spectra from 100MHz to 1 GHz decreases generally, that is, high frequency components of noise increase with thevoltages.These phenomena can be explaned by theoretical analysis based onToepler's Law of spakdischarge and Hertz's dipole EM radiation law. As the exceptional cases, low dicharge inception voltages by metal particles or by positive stress concentration at the electrode tip do not contribute much to suppression of high frequency components of the noise.

著者

木部 道也 長嶋 満宏 土志田 実 釜 啓輔 大中道 崇浩

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.129, no.11, pp.746-750, 2009-11-01 (Released:2009-11-01)

参考文献数

7

被引用文献数

3 3

---

This paper describes an uncooled infrared (IR) camera especially optimized for small size & weight, less power consumption without degrading noise equivalent temperature difference (NETD). This camera has two features, including a wafer-level chip scale vacuum package with 160x120 SOI-diode array and germanium lid for good IR transmission, and also a real-time signal correction capability with respect to ambient temperature. These features enabled the considerable size/power consumption reduction and the operation without thermoelectric cooler (TEC) which usual IR cameras require for temperature stabilization. As a result, we realized compact infrared camera (less than 71grams) with low-power consumption and excellent NETD of 22 mK (F/0.8 optics).

著者

横田 晴光 永見 剛一

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌. A (ISSN:03854205)

巻号頁・発行日

vol.98, no.9, pp.489-493, 1978-09-20 (Released:2008-06-30)

参考文献数

10

著者

田村 哲志 瀬戸本 龍海 田口 常正

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.120, no.2, pp.244-249, 2000-02-01 (Released:2008-07-15)

参考文献数

13

被引用文献数

3 7

---

We describe for the first time the basic illumination characteristics of lighting source using 10cd-class InGaN-based LEDs (an efficacy of 151m/W) under a driving condition of AC 100V at 60Hz. Several hundred white LEDs with series connections were arrayed on a glass epoxy substrate and were driven by adjusting a current of less than 20mA under the AC 100V. The dependence of temperature and injection current on both the emission spectra and intensity were measured. The white LED array indicates distinct two electroluminescence peaks at 460 and 555nm at room temperature, which are related to the recombination emissions from the InGaN MQW blue LED and from the YAG: Ce phosphor, respectively. We have obtained a maximum luminous intensity of about 10000lx at a distance of 30cm from the LED array, which is sufficient for the practical application. After operating for 1 hr, a temperature of the LED array increased up to about 65°C without a cooling system.

著者

園田 潤 八巻 宏太

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.130, no.1, pp.74-80, 2010-01-01 (Released:2010-01-01)

参考文献数

29

---

We develop an automatic Live Linux rebuilding system for science and engineering education, such as information processing education, numerical analysis and so on. Our system is enable to easily and automatically rebuild a customized Live Linux from a ISO image of Ubuntu, which is one of the Linux distribution. Also, it is easily possible to install/uninstall packages and to enable/disable init daemons. When we rebuild a Live Linux CD using our system, we show number of the operations is 8, and the rebuilding time is about 33 minutes on CD version and about 50 minutes on DVD version. Moreover, we have applied the rebuilded Live Linux CD in a class of information processing education in our college. As the results of a questionnaires survey from our 43 students who used the Live Linux CD, we obtain that the our Live Linux is useful for about 80 percents of students. From these results, we conclude that our system is able to easily and automatically rebuild a useful Live Linux in short time.

著者

寺口 直希 南 政孝

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. A (ISSN:03854205)

巻号頁・発行日

vol.139, no.5, pp.259-263, 2019

---

<p>A Tesla coil is a resonant transformer circuit that generates very high voltages which are made to arc through the air. Recently, a solid state Tesla coil was produced according to developing the semiconductor. In addition, the solid state Tesla coil makes sound by the air discharge. Hence, the sound is used as musical devices. In the past, the musical solid state Tesla coils are generated by PWM (Pulse Width Modulation) method. However, it is difficult to use the high pitch sound and the tone color. This paper investigates the musical solid state Tesla coil by using not PWM method but PRF (Pulse Repetition Frequency) method. As the result, the proposed musical solid state Tesla coil provides good sound.</p>

著者

脇坂 俊幸 松嶋 徹 古賀 久雄 奥村 浩幸 桑原 伸夫 福本 幸弘

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. A (ISSN:03854205)

巻号頁・発行日

vol.140, no.12, pp.557-564, 2020

---

<p>In this paper, the influence to electromagnetic environment was evaluated on the outside of buildings where power line communication (PLC) systems were installed to a three-wire three-phase power distribution line. The electric field strength was measured at 140 points in five factories, in two office buildings, and in one stadium. Since many radio waves existed in the environment, the electric field strength when PLC system was operated and was not operated was measured. The influence was evaluated by the cumulated occurrence probability because the frequency characteristics of the electric filed strength changed by the measurement points. The results showed that the occurrence probability was not changed when the PLC system was operated and was not operated. The electric field strength was calculated by the common mode current obtained from the test result, and this indicated that the occurrence probability was lower than the measured occurrence probability of electric field strength.</p>

著者

吉満 哲夫 三井 久安 見城 享

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌. A (ISSN:03854205)

巻号頁・発行日

vol.102, no.9, pp.515-522, 1982-09-20 (Released:2008-06-30)

参考文献数

23

著者

山田 忠比古 後田 澄夫 近藤 芳孝

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.114, no.6, pp.459-466, 1994

被引用文献数

1

---

Luminosity of wire corona has been observed by the technique of the computed tomography. The light output from wirecorona has been compared with the calculated result. Spatial distributions of space-charge and current density of each type ofcharges carrier in a corona field has been also determined by computing the ionization and attachment process under the Deutschassumption and compared with experimental results.<br>The calculated results along the symmetry axis of the electrodes show very good agreement with measurements.Unfortunately, there is a slight difference between the experimental results and those of the calculation under the Deutschassumption in the distribution of luminosity.

著者

鶴田 浩一 江原 玄

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.111, no.10, pp.939-940, 1991

著者

東山 禎夫 武藤 三郎 堀井 憲爾

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌. A (ISSN:03854205)

巻号頁・発行日

vol.99, no.9, pp.411-418, 1979-09-20 (Released:2008-06-30)

参考文献数

15

著者

赤崎 勇

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.124, no.2, pp.107-113, 2004 (Released:2004-05-01)

参考文献数

37

---

Breakthroughs in crystal growth and conductivity control of nitride semiconductors during last two decades have led to such developments as high-brightness blue, green and white light-emitting diodes and long-lived violet laser diode and so forth. The high electron saturation velocity in GaN is also suitable for application in high-speed/high power electronic devices. All of these nitride-based devices are the most environmentally-friendly ones available. They are tough and should enable a tremendous saving in energy. Further progress in the area of crystal growth and device engineering is necessary for the development of new frontier devices based on nitride semiconductors.