著者

坂井 純子 加藤 達郎 平岡 秀雄 斉藤 勝

出版者

東海大学体育学部

雑誌

東海大学紀要 体育学部 (ISSN:03892026)

巻号頁・発行日

no.11, pp.p61-70, 1981

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The purpose of this study was to investigate if a volleyball player could change the course of the spike by a signal given at various stage in spiking motion, and to find the differences of the spike form on these conditions. Conditions were to make a full swing spike toward a cross course and to change the spike course toward a straight course when signal was shown. All of spike motions were filmed and analyzed. Points of view for analyzing are following : a) Initial velocity of the ball. b) Maximum velocity of the finger. c) Body angle to the direction of running. d) Direction of spiking hand after striking the ball. Results of these experiments indicates that : 1) If the signal was switched on just before the beginning of the forward swing in spiking, all subjects could change the spike course on most occasions. On this study, "just before the beginning of the forward swing" meant about 0.30 to 0.35 seconds before the beginning of the forward swing. 2) Initial velocity of the ball, on the case when the signal was given just before the beginning of the forward swing, was later than ones on the another cases. 3) However, the finger velocity of this case was faster just before meeting to the ball. 4) There were no significant differences on the body angle to the direction of running jump at the various spike motions. 5) Directions of the arm after spiking the ball was decided depending on the course of the spike.

著者

坂井 純一 西河 謙一

出版者

富山大学

雑誌

富山大学工学部紀要 (ISSN:03871339)

巻号頁・発行日

vol.34, pp.80-91, 1983-03

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A model of 'disparitions brusques' (sudden disappearance of eruptive prominences) is discussed based on the Kippenhahn and Schluter configuration. It is shown that Kippenhahn and Schluter's current sheet is very weakly unstable against magnetic reconnecting modes during the lifetime of quiescent prominences. Disturbances in the form of fast magnetosonic waves originating from nearby active regions or the changes of whole magnetic configuration due to newly emerged magnetic flux may trigger a rapidly growing instability associated with magnetic field reconnection.This instability gives rise to disruptions of quiescent prominences and also generates high energy particles.

著者

井上 英二 鹿島 潤 坂井 純 井手 治

出版者

農業食料工学会

雑誌

農業機械学会誌 (ISSN:02852543)

巻号頁・発行日

vol.55, no.5, pp.3-10,27, 1993 (Released:2010-04-30)

参考文献数

11

被引用文献数

1

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ゴム履帯走行部を有する農業機械では, 路面の凹凸や作業機の他に, 転輪配置の良否更には左右履帯の位相などによって振動が生じる。機体の振動特性を把握するには, 機体重心位置での並進加速度成分計測法の精度向上のため, 12個の加速度変換器を用いた計測理論の拡張を行い, この計測法の利点について報告する。さらに, 本計測法を用いてゴム履帯車両の振動加速度の6自由度成分計測を行い, 転輪配置と左右履帯ラグの位相の影響による履帯車両の並進・回転成分の振動特性を明らかにした。

著者

坂井 純一 鷲見 治一

出版者

富山大学

雑誌

富山大学工学部紀要 (ISSN:03871339)

巻号頁・発行日

vol.36, pp.47-52, 1985-03

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Recent observations of solar prominences show that slow upward motions ( ≌ 1 kms^<-1> ) occur through quiescent prominences and a fast input of material with horizontal motions ( ≌ 5 kms^<-1> ) occurs at both edges of prominences. A time-dependent dynamical model of solar prominences with current sheet is investigated. It is natural extension of the magnetostatic models proposed by Kippenhahn and Schluter (KS) and Kuperus and Raadu (KR). It is shown that horizontal nonlinear oscillations can exist in the prominences. The global structure of current sheet including solar wind plasmas is also simulated by means of full MHD equations.