著者

小田 仁

出版者

公益社団法人 日本地震学会

雑誌

地震 第2輯 (ISSN:00371114)

巻号頁・発行日

vol.42, no.3, pp.333-339, 1989-09-24 (Released:2010-03-11)

参考文献数

21

---

We have reexamined whether the velocity decrease of the seismic waves due to dilatancy can be detected or not. A numerical investigation was made to see the change of travel times by using synthetic seismograms of P-waves traveling through a dilatant region. In synthesizing the seismograms, the Brune's source model was used, and the P-wave velocity was assumed to increase with increasing frequency and to approach asymptotically an intrinsic velocity. This relation between P-wave velocity and frequency is based on the experimental result obtained by uniaxial compression test of a granitic rock sample; the velocity decrease is larger at low frequencies than at high frequencies. The dispersion curve is characterized by crack density ε, crack width 2a and intrinsic velocity α. A characteristic frequency fM=5α/πa, above which no velocity decrease is found, is defined. We investigated the change of the P-arrival times in the synthetic seismograms, changing both crack density and crack width. When the P-wave forms of earthquakes with the same magnitudes are recorded without off scale, the travel time anomaly can be detected in the case of fc<<fM, where fc is the corner frequency of seismic source spectrum. Therefore, for detecting the travel time anomaly, it is necessary to observe earthquakes in low frequency range of f<<fM, where the significant velocity decrease is expected. For this purpose, group arrival times of the P-wave at low frequencies may also be useful.

著者

思想問題研究所 編

出版者

東山書房

巻号頁・発行日

1937

著者

梅本 洋

出版者

早稲田大学大学院文学研究科

雑誌

早稲田大学大学院文学研究科紀要. 第1分冊, 哲学 東洋哲学 心理学 社会学 教育学 (ISSN:13417517)

巻号頁・発行日

vol.60, pp.六九-八三, 2015-02-26

出版者

滋賀県彦根市立図書館

巻号頁・発行日

1941

著者

広重

出版者

喜鶴堂

雑誌

東都名所

著者

星崎広助 著

出版者

星崎広助

巻号頁・発行日

1893

著者

長尾豊 著

出版者

厚生閣書店

巻号頁・発行日

vol.尋常 5年生, 1930

著者

押川春浪 著

出版者

大学館

巻号頁・発行日

1903

著者

磯ケ谷紫江 著

出版者

墓碑史蹟研究発行所

巻号頁・発行日

1924

著者

夏目氐月 編

出版者

湖岸探勝刊行会

巻号頁・発行日

1923

著者

的場麗水 著

出版者

吉野屋

巻号頁・発行日

1895

著者

木村 学

出版者

一般社団法人 日本地質学会

雑誌

日本地質学会学術大会講演要旨 日本地質学会第118年学術大会・日本鉱物科学会2011年年会合同学術大会(水戸大会) (ISSN:13483935)

巻号頁・発行日

pp.105, 2011 (Released:2012-03-27)

著者

高瀬羽皐 著

出版者

東亜堂書房

巻号頁・発行日

1914

著者

木村三樹 編

出版者

帝国講学会

巻号頁・発行日

1926

著者

小田省吾 等著

出版者

朝鮮史学会

巻号頁・発行日

vol.中世史, 1927

著者

森安 孝夫 モリヤス タカオ Moriyasu Takao

出版者

大阪大学大学院文学研究科

雑誌

待兼山論叢. 史学篇 (ISSN:03874818)

巻号頁・発行日

vol.32, pp.1-24, 1998

著者

中山 雅雄 浅井 武

出版者

一般社団法人 日本体育学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

vol.54, no.2, pp.343-353, 2009-12-10 (Released:2010-02-13)

参考文献数

22

被引用文献数

3

---

The purpose of this study was to investigate the elements that constitute an effective environment for passing practice in soccer by analyzing the relationship between player age range as an organism constraint and the width of the area in which the ball is possessed in a three vs. one (3 vs. 1) task constraint. The task consisted of passing the ball employing one or two touches to maintain possession in a 3 vs. 1 formation in three different square-shaped areas measuring 8m×8m, 10m×10m and 12m×12m. The participants were divided according to age, and categorized as under (U)-10 (fourth grade elementary school), U-12 (sixth grade elementary school), U-14 (second grade junior school) and U-16 (first grade high school). The following criteria were then investigated: passing performance (passing success rate and the number of passing sequences), speed of the passing movement, support available to the player, and decision-making about the passing direction.It was found that U-10 players performed worse in the task than players in the other age groups. Moreover, passing speed was affected by the width of the play area for the U-10 and U-12 players, but not for the U-14 and U-16 players. The distance between the support players was the same for all age groups; however, for the U-10 players, the support angles were more acute than those for the other age groups, thus preventing the U-10 players from adopting useful supporting positions. Furthermore, it was found that the width of the play area did not affect passing performance, but did affect the speed of the passing movement in the 3 vs. 1 task. The distance and the angle of support differed among the players in the different age groups.It is concluded that a wider area in the 3 vs.1 possession task creates easier choices for U-10 and U-12 players, leading to easy understanding of the passing motions. For the U-14 and U-16 players, making the area narrower is effective for maintaining a higher 3 vs.1 possession level. From these perspectives, considering the width of the area for 3 vs.1 possession is important in relation to the developmental stage of soccer players.

著者

森三渓 編

出版者

民友社

巻号頁・発行日

1898

著者

井原西鶴 [著]

出版者

大倉広文堂

巻号頁・発行日

1934

出版者

日本旅行協会

巻号頁・発行日

1940