著者
防災科学技術研究所長岡雪氷防災実験研究所
出版者
独立行政法人防災科学技術研究所
雑誌
防災科学技術研究所研究資料 (ISSN:0917057X)
巻号頁・発行日
vol.195, pp.1-14, 1999-10-16

本報告は, 1998年から1999年にかけての冬の積雪観測結果をまとめたものである. 観測項目は天気, 積雪深, 積雪相当水量, 新積雪深, 新積雪の相当水量および新積雪の密度の6項目である. 今冬は12月31日に根雪となり, その後は順調に降雪が見られ, 3月26日に根雪は消雪した. 今冬の最大積雪深は2月15日に観測された135cmである. また, 新積雪深の最大値は2月2日に観測された52cmで, 積算新積雪深は621cmとなった.
著者
三友 信夫 松倉 洋史 松岡 猛 Nobuo MITOMO Hiroshi MATSUKURA Takeshi MATSUOKA 運輸省船舶技術研究所システム技術部 運輸省船舶技術研究所システム技術部 運輸省船舶技術研究所システム技術部
出版者
運輸省船舶技術研究所
雑誌
船舶技術研究所報告 (ISSN:0495775X)
巻号頁・発行日
vol.37, no.3, pp.77-141, 2000

For large and complex systems, full and enough investigation is required not to damage the public or operators, before design, construction and operation. Especially chemical plant, nuclear power plant and ships etc. must not cause any large accidents because of the safety of the public or lots of people working there. So, the new assessment, PSA (Probabilistic Safety Assessment), becomes popular in addition to deterministic safety assessment for these complex systems. In this paper, as an example of an application of PSA for the marine field, the event tree analysis method was applied to the Titanic accident. Factors which related to the Titanic accident were all selected under the those day's surrounding condition. The occurrence probabilities of the factors have been estimated from various data. The probability that the Titanic encounters the sever accidents, and number of fatality have been calculated. This report has shown the detailed procedure of event tree analysis for a marine accident. It has also shown the effectiveness of event tree analysis for the analysis of accident causes and for the improvement of the safety for various large complex systems.
著者
二村 正 石田 茂資 渡辺 巌 Tadashi NIMURA Shigesuke ISHIDA Iwao WATANABE 船舶技術研究所運動性能部 船舶技術研究所運動性能部 船舶技術研究所運動性能部
出版者
運輸省船舶技術研究所
雑誌
船舶技術研究所報告 (ISSN:0495775X)
巻号頁・発行日
vol.32, no.5, pp.233-264, 1996-02

Capsizing and re-righting performance of three types of sailing yachts, IOR racer type, conventional type and intermediate type, was experimentally investigated in beam transient waves with various wave heights. The effect of CG height, existence of mast and flooded water volume on the critical wave height for capsizing and for re-righting was examined. It was characteristic in the capsizing motion of the models with mast that the rolling motion almost stopped just after the mast plunged into the water because of the hydrodynamic impulsive force on the mast. The stopping heel angle was almost independent of hull forms and model conditions. As a result the static stability vanishing angle, θv, was crucial for capsizing even in flooded conditions. As for re-righting motion θv was also crucial. It was clarified that the IOR racer type yacht is easier to capsize and harder to re-right because of its small θv value even if it has large GM. The way of improving the capsizing resistance was discussed. Lowering the center of gravity or attaching a small float on top of the mast could be an easy and effective way to prevent capsizing disaster because that leads to a large θv value. The flooded water, in general, enlarged θv, that made the models capsize-resistant. But for re-righting motion the relation between the critical wave height for re-righting and θv was complicated, because the water prevents the motion of the models at the same time. The probability of capsizing and re-righting in a sea state with ISSC spectrum was examined. Moreover the capsizing duration time was calculated as a safety index. It was reconfirmed again by the probabilistic approach that θv is very important for the safety of sailing yachts. θv of 120 degrees was proposed as an safety criteria.
著者
諏訪 晴香 木村 悟朗 篠原 正典 Haruka SUWA Goro KIMURA Masanori SHINOHARA 帝京科学大学理工学研究科環境マテリアル専攻 イカリ消毒株式会社技術研究所 帝京科学大学生命環境学部自然環境学科
雑誌
帝京科学大学紀要 = Bulletin of Teikyo University of Science
巻号頁・発行日
vol.9, pp.147-149, 2013-03-31

Larvaes of varied carpet beetle (Anthrenus verbasci ) are well known as insects injurious to clothes and crops, and theirfood preference have been researched well and known to inclinable toward animal fiber. Here, we widely invested theirpreference to six clothes including wool, silk, cotton, hemp, rayon and polyester from their gathering behavior. As the results,they gathered on wool most and their preferences to plant fiber were intermediate between those to animal and artificial fiber.
著者
花岡 達郎 Tatsuro Hanaoka 運輸省船舶技術研究所運動性能部
出版者
運輸省船舶技術研究所
雑誌
船舶技術研究所報告 (ISSN:0495775X)
巻号頁・発行日
vol.5, no.6, pp.217-257, 1969-01
被引用文献数
3

The purpose of the present paper is to give a fundamental theory of hydrodynamics concerning a screw propeller on the status of both potential and vortex theory.Chapter 1 is a brief description regarding historical aspect of the recent development in propeller theory.Chapter2 is devoted to the theory of a wing with finite span. We have been made familiar with propeller theory through wing theory. The description will be useful for us to understand the remainder of this paper.In this paper the propeller theory consists of three parts. The first deals with the fundamentals of the theory in the frame of linearized theory in Chapter 3.In Chapter 4 and 5, the theory previously discussed is developed to nonlinear theory and theory of wake-adapted propellers.
著者
防災科学技術研究所長岡雪氷防災実験研究所
出版者
独立行政法人防災科学技術研究所
雑誌
防災科学技術研究所研究資料 (ISSN:0917057X)
巻号頁・発行日
vol.206, pp.1-14, 2000-08-31

本報告は, 1999年から2000年にかけての冬の長岡における積雪観測結果をまとめたものである. 観測項目は天気, 積雪深, 積雪相当水量, 新積雪深, 新積雪の相当水量および新積雪の密度の6項目である. 今冬は1月21日に根雪となり, その後は順調に降雪が見られ, 4月2日に根雪は消雪した. 今冬の最大積雪深は3月10日に観測された109cmである. また, 新積雪深の最大値は3月8日に観測された43cmで, 積算新積雪深は602cmとなった.