著者

木下 篤彦 坂井 佑介 大野 亮一 田畑 三郎 川島 正照 山崎 孝成

出版者

公益社団法人 砂防学会

雑誌

砂防学会誌 (ISSN:02868385)

巻号頁・発行日

vol.65, no.5, pp.11-20, 2013-01-15 (Released:2015-08-03)

参考文献数

11

被引用文献数

8

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Tree roots with an underground lateral network play a very important role in slope stability. In studies such as those by Tsukamoto(1987)and Abe(1997), the authors focused on roots that have a vertical connection between the surface soil layer and below, but they did not place much emphasis on the lateral spread of roots. Because slope failures occur in three dimensions, horizontal roots fully demonstrate their resistance against the failure. This paper aims to describe the resistance force Δ C that lateral roots provide. Two types of field investigations were made. One was the root pulling test to monitor the strength of a root pulled by a clamp. The other surveyed the lateral root distribution exposed in vertical sections excavated in the plots of Japanese cypress and cedar forests. The observed root distribution was used to calculate the resistance force Δ C. The field data show that as the distance between two trees increases, the Δ C value gets smaller. Their relationship can be described by a negative power function. It has also been proven that as the age of a tree increases so does the Δ C, but its increment gets smaller in the later stages of the tree's lifecycle. Intensive work with the field data has shown that forest thinning operations might decrease the root volume after felling and bring about an increase of Δ C that lasts for several decades. Moreover, thinning operations produce good results in slope stability when lateral roots are effectively increased. However, if the increase is insufficient, it might not contribute to slope stability.

著者

大野 亮

出版者

The Society of Fiber Science and Technology, Japan

雑誌

繊維学会誌 (ISSN:00379875)

巻号頁・発行日

vol.49, no.12, pp.654-657, 1993

被引用文献数

1

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The temperature rise of high density polyethylene films during necking was measured with a thermocouple and the generated heat was estimated. The fractions of mechanical work converted into heat were estimated to be 60-86% from the temperatures immediately after necking, and to be 67-90% from the maximum temperatures. Real films showed the fractions lower than 75% because of heat loss and of the formation of new surfaces like cracks. The fraction of heat conversion depended on film thickness, and thin films showed the higher values because of those larger neck propagation speeds.

著者

大野 亮一 鈴木 雅一 太田 猛彦

出版者

公益社団法人 砂防学会

雑誌

砂防学会誌 (ISSN:02868385)

巻号頁・発行日

vol.51, no.4, pp.3-10, 1998-11-15 (Released:2010-04-30)

参考文献数

18

被引用文献数

3

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Prediction of ground water movement is very important and critical to forecasting slope failure because many slope failures are triggered by the surcharge of water weight and drop of suction when precipitation infiltrates into soils. It is necessary to consider both saturated and unsaturated flow phases, particularly for sequentially estimating ground water flow to specify the time and location of the failure.Richards' equation has strong nonlinearity of coefficients. As a result, its numerical analysis tends to be much more difficult than that under moderate conditions, especially with very dry soils or a perched water table. Recently, new methods to solve Richards' equation that focused on diminishing water balance errors and less limitation of time step size were presented (Celia 1990, Pan 1995). In this paper, those new methods are first introduced with explanation of their algorithms specified for balance errors or time step size. Second, based on the fact that both steady and unsteady phases are combined in Richards' equation, the consequent oscillation problem is demonstrated and examined. The algorithm of the oscillation is explained with the analytic method presented in this paper.

著者

松村 和樹 藤田 正治 山田 孝 権田 豊 沼本 晋也 堤 大三 中谷 加奈 今泉 文寿 島田 徹 海堀 正博 鈴木 浩二 徳永 博 柏原 佳明 長野 英次 横山 修 鈴木 拓郎 武澤 永純 大野 亮一 長山 孝彦 池島 剛 土屋 智

出版者

公益社団法人 砂防学会

雑誌

砂防学会誌 (ISSN:02868385)

巻号頁・発行日

vol.64, no.5, pp.43-53, 2012-01-15 (Released:2015-02-02)

参考文献数

8

被引用文献数

4

著者

大野 亮司

出版者

立教大学

雑誌

立教大学日本文学 (ISSN:0546031X)

巻号頁・発行日

vol.97, pp.119-127, 2006-12-25

著者

大野 亮仁 藤 博幸 山名 早人

雑誌

研究報告バイオ情報学(BIO)

巻号頁・発行日

vol.2013-BIO-34, no.11, pp.1-7, 2013-06-20

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G タンパク共役受容体 (G-protein-coupled receptor,以下 GPCR) は,内在性リガンドと結合することで細胞外からの様々なシグナルを細胞内に伝達しており,新薬開発の重要なターゲットとして注目されている.しかし,GPCR と化合物の組合せは膨大であるため,計算機による正確な結合予測手法が求められている.先行研究として,GPCR を構成するアミノ酸配列全長が持つ化学的性質と化合物の化学的性質を用いて結合を予測する手法がある.しかし,GPCR には立体構造が既知のものがあり,その細胞外側の領域にリガンド結合部位が決まっている.よって,リガンド結合部位のアミノ酸が結合に強く影響を与えると考えたため,リガンド結合部位のアミノ酸に注目すべきと考えた.本研究では,全長配列を使用する代わりに,リガンド結合部位のアミノ酸のみを利用することで予測の改善を試みた.特徴量として結合部分のアミノ酸と化合物の化学記述子を用い,SVM により GPCR と化合物の結合を予測したところ,アミノ酸配列全長を用いた時に比べ Accuracy が 3.6%,F 値は 0.038,AUC は 0.002 向上した.