• Title/Summary/Keyword: cone-bearing behaviour

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Basic studies on pine cone harvest (I) (잣송이의 채취(採取)를 기계화(機械化)하기 위한 기초연구(基礎硏究) (I))

  • Kang, Whoa Seug;Yi, Jae-Seon;Kim, Sang Hun;Choi, Jong-Cheon
    • Journal of Forest and Environmental Science
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    • v.9 no.1
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    • pp.1-9
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    • 1993
  • In the fall of 1992, growth characteristics and cone-bearing behaviour of crown top shoots were investigated on Pin us koraiensis trees, belonging to age class VII and IV, in the School Forests, College of Forestry, Kangwon National University to obtain basic information for the design of Korean pine cone harvesting machine. The results were summarized as follows. 1. The length of terminal main shoots and lateral shoots of the trees in age class IV was 27~56cm and 18~47cm, respectively, both of which were significantly higher than those of the trees in age class VII. 2. There was no significant difference between two age classes in the branching angle ($24{\sim}89^{\circ}$) of lateral shoots and in the diameter (10~30mm) of two-year-old main shoots. However, one-year-old terminal main shoots of age class IV showed the higher diameter (9~18mm) than those of age class VII. 3. Mean cone number per tree was 5, and mean fresh weight of cone was 272g. No significant difference was found in these traits between both age classes. 4. Cones, on an average, hung on the two-year-old main shoots 15cm above the basal ends in age class VII and 33cm above in age class IV. Both lengths are equivalent to one half and four fifths of the shoots, respectively. 5. The fresh weight range of crown-top shoots containing cones was 1.0~7.4kg.

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Bearing Capacity of a Monopod Bucket Foundation for Offshore Wind Towers - Centrifuge and Numerical Modeling (해상풍력 모노포드 버켓기초의 지지력 거동 - 원심모형실험 및 수치해석)

  • Kim, Dong-Joon;Choo, Yun Wook;Kim, Surin;Kim, Jae-Hyun;Choi, Ho-Young;Kim, Dong-Soo;Lee, Man-Soo;Park, Yung-Ho
    • Journal of the Korean Geotechnical Society
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    • v.29 no.4
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    • pp.23-32
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    • 2013
  • In order to evaluate the bearing capacity behaviour of a monopod suction bucket foundation for an offshore wind tower at the western sea of Korea, a centrifuge load test and numerical analyses were performed. The monopod bucket foundation was designed to be installed in a silty sand layer. The model soil was prepared to simulate a target site by using soil samples having similar properties and controlling relative density. In-flight miniature cone penetration test and bender element array were used to confirm that the model soil had represented the target site conditions. The load - rotation curve of the centrifuge load test was analysed. A series of numerical analyses were performed to validate the experimental conditions. Self-weight of the model, distance to the boundary and elastic modulus of the soil layer were varied to study their effects on the load - rotation curves.