著者

持永 芳文

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.121, no.9, pp.629-632, 2001-09-01 (Released:2008-04-17)

参考文献数

1

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.129, no.2, pp.85, 2009-02-01 (Released:2009-02-01)

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本記事に「抄録」はありません。

著者

鳳 誠三郎

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.61, no.631, pp.61, 1941

著者

坂井 俊文 國廣 直希 大塚 邦晃 篠宮 健志

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌D(産業応用部門誌) (ISSN:09136339)

巻号頁・発行日

vol.141, no.7, pp.552-560, 2021-07-01 (Released:2021-07-01)

参考文献数

24

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This study presents a magnetic polarity detection method of an initial rotor position estimation for permanent magnet synchronous motor drives without a position sensor. The magnetic polarity detection method utilizes stator core magnetic saturation caused by the rotor magnet and uses current responses when a high frequency or impulse voltage is applied to the motor. Recently, capacity enlargement, miniaturization, and cost reduction of the motor have been steadily progressing and motors with complicated magnetic saturation characteristics are available. The authors have developed a new magnetic polarity detection method for initial rotor position estimation that is suitable for many motors having common or complicated magnetic saturation characteristics. In the proposed method, high-frequency voltage waves with different amplitudes are applied to the motor. The proposed method measures the motor current ripple components and can estimate the magnetic polarity by using the amount of d-axis inductance variation caused by magnetic saturation. The basic idea, computer simulation, and experimental results are discussed in this paper.

著者

小島 友和 横井 貴樹 豊田 陽平 脇田 紘一

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. C (ISSN:03854221)

巻号頁・発行日

vol.121, no.12, pp.1796-1800, 2001

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A new electroabsorption modulator operating at a parallel electric-field to the quantum wells is proposed and its modulation characteristics have been calculated. Transverse p-i-n structure on semi-insulating substrate enables us to apply a parallel field for MQW layers and results in low device capacitance and high-speed operation. The exciton resonance can easily broaden and disappear at field-intensity of 10⁴ V/cm, one tenth of the perpendicular field previously used. A 3-dB bandwidth and operation voltage required for 20 dB extinction ratio are estimated to be over 250 GHz and less than 1 V, respectively, with transmission loss of less than 3 dB. High allowability of high incidental optical power and negative chirp operation are also discussed for this structure.

著者

沼辺 健史 西川 一弘

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌D(産業応用部門誌) (ISSN:09136339)

巻号頁・発行日

vol.141, no.7, pp.513-519, 2021-07-01 (Released:2021-07-01)

参考文献数

10

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In the future, a tsunami may occur in Japan due to a large earthquake. Railway companies must take measures for tsunami evacuation. In order to protect the lives of many people, we must ensure quick evacuation. However, train announcement for tsunami evacuation has become a major issue and currently takes too long. This study proposes train announcement for quick evacuation.

著者

久保 理 小林 康弘

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. C, 電子・情報・システム部門誌 = The transactions of the Institute of Electrical Engineers of Japan. C, A publication of Electronics, Information and System Society (ISSN:03854221)

巻号頁・発行日

vol.124, no.9, pp.1834-1840, 2004-09-01

参考文献数

9

被引用文献数

1 1

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Weather derivatives are getting to be powerful tools for weather risk hedging. A popular method which draws out valid prices of weather derivatives is a stochastic modeling approach. In the method, expected payoffs of weather derivatives based on stochastic weather models are regarded as their valid prices. Although useful stochastic models of temperature have been shown, stochastic models of daily rainfall are still being developed. Therefore, it is considered that pricing of daily rainfall derivatives is difficult. This paper shows a new stochastic daily rainfall model for pricing daily rainfall options. The new model in which a modified geometric distribution model is applied can express stochastic features of daily rainfall. Furthermore, this paper also shows that the combination model of the Markov chain rainy day model and the new model can express stochastic features and risks of daily rainfall option payoffs.

著者

松本 涼佑 奥田 大樹 深澤 紀子

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌D(産業応用部門誌) (ISSN:09136339)

巻号頁・発行日

vol.140, no.10, pp.769-781, 2020

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<p>A train schedule in Japan includes regular trains which is fixed on annual basis and pre-planned extra trains whose operation dates are not predetermined. Accordingly, in order to provide efficient transport services, a plan for the daily operation of extra trains must be established based on accurate passenger demand fluctuations forecasts by day/time. Therefore, we developed a method to forecast for the demand fluctuation by day/time on a certain day in the future. The method was developed by combining several fundamental waves, which are extracted by applying independent component analysis to actual ridership records with calendar information, and information on events which was held in target areas. We confirmed that the method has high accuracy by verifying its reproducibility and forecasting accuracy. In addition, the extra trains' operation planning system, which implements the forecasting method, can estimate the load factor of all trains between stations on the planning schedule based on the forecasted demand fluctuations. Then, the system can suggest an optimal extra trains' operation plan based on these values. We estimated the load factor based on forecasted demand fluctuations with the system, and we verified its accuracy. As a result, we confirmed that we can estimate the load factor with high accuracy.</p>

著者

平野 克己

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.101, no.6, pp.534-537, 1981-06-20 (Released:2008-04-17)

参考文献数

27

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

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<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

太田 正哉 花光 敦 山下 勝己 小南 昌信

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌. C, 電子・情報・システム部門誌 = The transactions of the Institute of Electrical Engineers of Japan. C, A publication of Electronics, Information and System Society (ISSN:03854221)

巻号頁・発行日

vol.123, no.11, pp.1951-1957, 2003-11-01

参考文献数

12

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In cellular mobile communication systems, a channel assignment problem has been extensively studied. In order to avoid exhaustive search, the number of reallocatable channel is limited only one in TPB method which is one of dynamic channel assignment proposed by Chang. In this paper, a dynamic channel assignment by using the maximum neural network with reinforced self-feedback (MNN-RS) is proposed. From numerical experiments, it is confirmed that the proposal improves blocking probability and reduces the probability that blocking probability exceeds arrowable rate. Lastly the proposed model is implemented on Xilinx FPGA XCV300E and scalability is discussed.

著者

榎 敏明

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.114, no.1, pp.13-17, 1993-12-20 (Released:2008-04-17)

参考文献数

5

著者

綿谷 吉松

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.47, no.463, pp.139-145, 1927 (Released:2008-11-20)

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一、 我國有鐵道、地方鐵道等の産業鐵道は電化によりて鐵道經營の改善が得らるゝを實例を擧げて詳細に説明し二、 電氣運轉軌道が從來の蒸汽運轉軌道と異れる諸點を建設、改良の兩方面より説明し結局電化軌道たるべきを力説し三、 電化費額と電化營業收支の一般を述べ尚最も經濟的なる費額と營業收支の實例を擧げ四、 最後に鐵道電化は我國電氣事業の健全なる發達と送電網の完成を促し、旦つ地方産業の發展に資すること多大にして一般社會に及ぼす影響の重大なるを述べたり。

著者

飯島 泰蔵

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.83, no.898, pp.1073-1078, 1963-07-01 (Released:2008-11-20)

著者

国松 賢四郎

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.81, no.879, pp.2061-2064, 1961

著者

芝間 祐介 土屋 勝彦

出版者

一般社団法人 電気学会

雑誌

電気学会誌 (ISSN:13405551)

巻号頁・発行日

vol.139, no.12, pp.806-809, 2019

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<p>1.はじめに</p><p>JT-60SAトカマク装置において,プラズマの不安定性を抑える観点から,誤差磁界(コイルの寸法や据付の精度で生じる磁界の非軸対称成分)をトロイダル磁界の10⁻⁴倍以下に抑えることが要求されている。直径が10 m,高さ7 mを超える超電導トカマク本体の主要機器では,運</p>

著者

旭 健作 小川 明

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.126, no.12, pp.1483-1489, 2006 (Released:2007-03-01)

参考文献数

17

被引用文献数

1

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Speech recognition systems have come to be used widely. When any speech recognition system is disturbed by surrounding noises, considerable reduction in the recognition rate is inevitable. It is much desired to develop noise reduction methods so that any speech recognition system can be used in realistic environments. We propose a novel scheme especially effective for reducing the noise generated in the vehicles. The reduction is achieved through image processing techniques applied to the corresponding spectrograms. Experiments have been conducted on speech sounds in the vehicles. The performances have been evaluated in terms of the output signal-to-noise ratio (SNR). The proposed scheme has been compared with the conventional spectral subtraction method, and found to be promising especially for speeches corrupted with great amount of car noises.

著者

弦田 幸憲 河村 篤男

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌D(産業応用部門誌) (ISSN:09136339)

巻号頁・発行日

vol.125, no.11, pp.977-987, 2005 (Released:2006-02-01)

参考文献数

16

被引用文献数

4 9

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We have proposed a high efficiency and high power chopper based on new soft switching scheme QRAS (Quasi-resonant Regenerating Active Snubber) and we studied the practical effectiveness and the novelty of the QRAS by the simulation and by the experiment. This time we made one-tenth prototype model actually and tested it by rating test, light load test, current discontinuous mode test and test out of resonance stable operation. We report the general evaluation of these test results and the possibility of the realization on the 80kW practical model is demonstrated by these successful test results. In addition, as an approach of the next study the feasibility test of 8kW SiC-QRAS is followed and the preliminary evaluation of efficiency rise using “Silicon Carbide (SiC)" power devices is given with the successful experimental results.

著者

田中 一男 松永 和之 堀 滋樹

出版者

一般社団法人 電気学会

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.124, no.3, pp.890-896, 2004 (Released:2004-06-01)

参考文献数

23

被引用文献数

1

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This paper presents electroencephalogram-based control of a mobile robot. The control purpose is to achieve direction control of a mobile robot only by electroencephalogram. We develop an algorithm for detecting direction thinking (‘going left’ or ‘going right’) and apply it to direction control of a mobile robot. The detecting algorithm is based on time-frequency domain analysis using continuous wavelet transformation. Our experimental results demonstrate the possibility of achieving direction control of a mobile robot only by electroencephalogram.

著者

大槻 義彦

出版者

一般社団法人 電気学会

雑誌

電氣學會雜誌 (ISSN:00202878)

巻号頁・発行日

vol.109, no.5, pp.367-370, 1989