• Title/Summary/Keyword: Life distribution

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Changes in Potential Distribution of Pinus rigida Caused by Climate Changes in Korea (기후변화에 따른 리기다소나무림의 잠재 생육적지 분포 변화 예측)

  • Kim, Yong-Kyung;Lee, Woo-Kyun;Kim, Young-Hwan;Oh, Suhyun;Heo, Jun-Hyeok
    • Journal of Korean Society of Forest Science
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    • v.101 no.3
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    • pp.509-516
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    • 2012
  • In this research, it was intended to examine the vulnerability of Pinus rigida to climate changes, a major planting species in Korea. For this purpose, the distribution of Pinus rigida and its changes caused by climate changes were estimated based on the 'A1B' climate change scenario suggested by IPCC. Current distribution of Pinus rigida was analyzed by using the $4^{th}$Forest Type Map and its potential distribution in the recent year (2000), the near future (2050) and the further future (2100) were estimated by analyzing the optimized ranges of three climate indices - warmth index(WI), minimum temperature index of the coldest month (MTCI) and precipitation effectiveness index(PEI). The results showed that the estimated potential distribution of Pinus rigida declines to 56% in the near future(2050) and 15% in the further future (2100). This significant decline was found in most provinces in Korea. However, in Kangwon province where the average elevation is higher than other provinces, the area of potential distribution of Pinus rigida increases in the near future and the further future. Also the result indicated that the potential distribution of Pinus rigida migrates to higher elevation. The potential distributions estimated in this research have relatively high accuracy with consideration of classification accuracy (44.75%) and prediction probability (62.56%).

Environmental Monitoring of Heavy Metals and Arsenic in Soils Adjacent to CCA-Treated Wood Structures in Gangwon Province, South Korea

  • Abdelhafez, Ahmed A.;Awad, Yasser M.;Kim, Min-Su;Ham, Kwang-Joon;Lim, Kyoung-Jae;Joo, Jin-Ho;Yang, Jae-E.;Ok, Yong-Sik
    • Korean Journal of Environmental Agriculture
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    • v.28 no.4
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    • pp.340-346
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    • 2009
  • Chromated copper arsenate (CCA) is a chemical wood preservative that has been intensively used to protect wood from decay during the last few decades. CCA is widely used to build structures such as decks, fences, playgrounds and boardwalks. However, structures constructed of CCA-treated wood have caused adverse environmental effects due to leaching of Cr, Cu and As into surrounding soils. This research was conducted to monitor the vertical and horizontal distribution of Cr, Cu and As in soils adjacent to CCA-treated wood structures in Korea. Two structures constructed with CCA-treated wood were selected at Hongcheon and Chuncheon in Gangwon Province, South Korea. Eleven soil profile samples were collected at depths of 0 to 80 cm at each site, while 12 surface soil samples were collected at distances of 0 to 200 cm from each structure. The soil chemical properties, soil particle size distribution and total metal concentrations were then determined. The results revealed that soils near CCA-treated wood structures were generally contaminated with Cr, Cu and As when compared to the background concentration of each metal. In addition, the concentrations of Cr, Cu and As in soils decreased as the vertical and horizontal distance from the structure increased. Further studies should be conducted to evaluate the mobility and distribution of these metals in the environment as well as to develop novel technologies for remediation of CCA contaminated soils.

Statistical Analysis for Fatigue Life Evaluation of Vehicle Muffler (자동차용 머플러의 피로수명평가를 위한 통계적 분석)

  • Choi, Ji-Hun;Lee, Yong-Jun;Yoon, Jin-Ho;Kang, Sung-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.3
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    • pp.365-372
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    • 2013
  • In this study, a statistical method for evaluating the fatigue life of a vehicle muffler was used to obtain reliable fatigue data using a limited number of specimens. Cyclic bending tests were conducted using specimens manufactured to be exactly the same as the mufflers installed in cars that are currently in use. To estimate the fatigue life by comparing the data obtained during the fatigue tests, the most suitable probability density function for the normal, lognormal, and Weibull distributions was selected. A goodness-of-fit test was performed on the probability distributions, and then a Weibull distribution using the least square method was selected. By using the selected Weibull distribution, the probability-moment-life curves (P-M-N curve) reflecting the fatigue characteristics were suggested as the data for the reliable design of a muffler.