著者

大石 博之 松隈 明彦 相原 安津夫

出版者

九州大学理学部

雑誌

九州大学理学部研究報告 地球惑星科学 (ISSN:09167315)

巻号頁・発行日

vol.18, no.1, pp.p73-84, 1993-12

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The Oligocene Yoshinotani Formation of Takeo, Saga Prefecture, Japan, yielded several distinct footprints without any track maker at the end of its trail. The most well-preserved trackway, consisting of eight left footprints and seven right ones, is described in this paper. Each footprint has four'fingers'and a bifurcate'heel'. The right and left footprints are arranged symmetrically. An average stride length, 25.8 cm, is nearly equal to an average track breadth, 24.6 cm. All left footprints are nearly equal in form and size, averaging 6.2 cm long and 3.4 cm wide. All right ones, 5.4 cm in length and 3.7 cm in width, are also identical with each other. This evidence suggests that the trackway was made by a pair of left and right legs of the track maker, which moved both left and right legs simultaneously. These footprints have been compared with the trails of bipedal vertebrates, including birds and turtles, but the manner of occurrence and the morphology of footprints suggest that they are probably undertracks formed by the pushing appendages of a limulid, i.e. the paired sixth cephalothracical appendage with four blades. Although no fossil limulid has been reported from Japan, the trackway of the Yo shinotani Formation, i. e. Kouphichnium sp., suggests that Japanese limulids should go back to the Oligocene age. It is predicted that limulid body fossils will be found from the Yoshinotani Formatiom, which is important in considering the origin of the living Japanese limulid, Tachypleus tridentatus

著者

古川 浩平 松本 幸太郎 大石 博之 円田 竜太 井上 佳子

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.61, no.3, pp.15-26, 2008-09-15 (Released:2013-09-02)

参考文献数

12

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In erosion control engineering field, various kinds of new techniques have been developed and briskly put into practical uses. Among these techniques, it is said that non-structural measures have been in demand lately. These measures contain many kinds of techniques and the terminology “non-structural measures" that are still not clear. Therefore, in this study, various kinds of non-structural measures which have been developed so far are reviewed, and the present technological development measures are analyzed in relation to social demands. As a result, practical needs on these measures, today and in the future, will be clarified. This paper's distinctive feature is its analysis based on the quantity of patent right registration, while in many preceding papers, major analyses used to be conducted based on the quantity of academic papers. Additionally, the questionnaire survey or the hearing investigation was executed to extract the problem that the erosion and torrent control field had, and it listened to engineer's opinion and manager's opinion at the technology development. From the result of this investigation, it turned out to be felt that the entrepreneurial strategy and the advantage of making to the patent are different.

著者

大石 博之 小林 央宜 尹 禮分 田中 浩一 中山 弘隆 古川 浩平

出版者

公益社団法人 土木学会

雑誌

土木学会論文集F (ISSN:18806074)

巻号頁・発行日

vol.63, no.1, pp.107-118, 2007 (Released:2007-03-20)

参考文献数

3

被引用文献数

1

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斜面の災害危険度を評価することは,効率的に防災事業を進めるための重要な課題である.これについては詳細な調査や安定解析に基づいた評価を個別に行うことが望ましいが,対象数が膨大であるため困難となることが多い.そこで,本研究では数理的手法のひとつであるサポートベクターマシンを活用し,各斜面の諸元データと災害履歴を学習することで災害危険度を評価することを試みた.道路沿線斜面のデータを例とした分析では,従来法以上の高い精度で危険度が評価できることが判明した.また,既に対策済みの斜面については,無対策斜面データのみの学習結果に基づく評価と対策済み斜面のみでのそれとを比較することで,対策工効果の指標値を得ることを発案した.これらの成果は,防災事業を進めていく上で大変有効なものと考えられる.