• Title/Summary/Keyword: Damaged areas

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Analysis of Importance of Damaged Area Assessment Indices using Analytic Hierarchy Process (AHP 기법을 활용한 훼손지 평가항목의 중요도 분석)

  • Song, Ki-Hwan;Choi, Yun-Eui;Seok, Young-Sun;Jeon, Seong-Woo;Sung, Hyun-Chan;Seo, Jung-Young;Chon, Jin-Hyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.6
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    • pp.15-28
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    • 2020
  • Urbanization and industrialization have caused increasing damage to national lands, and ecological restoration has proceeded without any specific assessment of this damage. The purpose of this study is to select indices to assess damaged areas through literature review and panel discussions, and to derive the importance of damaged area assessment indices by analyzing them through the Analytic Hierarchy Process (AHP). This study has derived, via literature review, six types of damage and a total of 18 related assessment indices. A total of 51 responses were collected from surveys and given to experts, and an AHP analysis conducted. As a result of the analysis, "Landform change (0.268)" was of the highest importance, with associated damage types as follows: "Soil contamination (0.193)", "Vegetation damaged (0.149)", "Surface soil loss (0.143)", "Change in soil physiochemical property (0.125)", and "Vegetation decline (0.122)". The analysis determined that the item of the highest importance in the overall assessment of damage was "Slope occurred area (0.100)", and that "Conductivity (0.022)" was of the lowest importance. This study can be presented as a criterion in determining the type and degree of damage in setting priorities for future ecological restoration projects.

Infection Properties of Oak Wilt Disease in Bukhansan National Park Adjacent to Metropolitan Areas in Korea

  • Choi, Jin-Woo;Yeum, Jung-Hun
    • Journal of Environmental Science International
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    • v.26 no.7
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    • pp.803-815
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    • 2017
  • In this study of the oak wilt disease that has occurred in a large scale in a protected area located near South Korea's metropolitan region, a detailed analysis has been conducted on the terrain, species and Diameters at Breast Height (DBH) of infected trees to identify the distribution of infection properties in the affected area. Taking into consideration the distribution of oak tree vegetation, a total of 4,640 quadrats in a size of 10 m by 10 m, have been set; and oak tree species, the DBH and infection damage per quadrat have been investigated. Geological properties have been analyzed according to elevation, slope, aspect and micro topography while a weighted value has been given according to the degree of infection in order to calculate an infection index. Through correlation analysis, the infection ratio of seriously-damaged and withered trees and the infection index have been analyzed with regards to the geological properties, tree species and DBH. The analysis shows that the disease tends to affect an area with medium elevation rather than those in the highest or lowest areas and that serious damage has been observed at rugged spots with a steep gradient (more than $30^{\circ}$). Although there has been no distinct tendency with regards to aspect, the infection ratio is relatively high in areas facing the north while the seriously-damaged and withered ratio are high in areas facing the south. In terms of micro topography, more damage has been spotted in valley terrain. Quercus mongolica has sustained more damage than other species. When it comes to the DBH, as seen in previous studies, large trees have suffered severe damage, but the analysis has also revealed conspicuous damage to medium trees with a DBH of 15-20 cm, which had not previously been considered at high risk.

Effects on Response of Nervous Tissue to Samuljetong-tang after Damaged by Taxol Treatment or Sciatic Nerve Injury (사물제통탕(四物除痛湯)이 Taxol 처리 및 좌골신경 압좌 손상 후 신경조직 변화에 미치는 영향)

  • Youn, Sung-Sik;Kim, Chul-Jung;Cho, Chung-Sik
    • The Journal of Internal Korean Medicine
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    • v.33 no.2
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    • pp.126-144
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    • 2012
  • Background : Peripheral nerves more rapidly recover than central nerves. However, it has been known that the degree of reaction of axons of peripheral nerves is affected by distinctive characteristics of axons and environmental factors near the axons. Taxol is a widely used medicine as for ovarian, breast, lung and gastric cancer. However it causes patients difficulties under treatment due to its toxic and side effects, which include persistent pain. Objectives : This study reviewed how SJT extract in vitro and in vivo affects nerve tissues of a sciatic nerve damaged by Taxol. It also studied how SJT extract in vivo affects axons of the sciatic nerve after the sciatic nerve was damaged by pressing. Methods : After vehicle, Taxol, and Taxol plus SJT were treated respectively for tissue of the sciatic nerve in vitro and then tissues were observed using Neurofilament 200, Hoechst, ${\beta}$-tubulin, $S100{\beta}$, caspase-3 and anti-cdc2. SJT was also oral medicated by injecting Taxol into the sciatic nerve of in vivo rats. Tissues of the sciatic nerve and axons of DRG sensory nerves were then observed using Neurofilament 200, Hoechst, ${\beta}$-tubulin, $S100{\beta}$, caspase-3 and p-Erk1/2. After inflicting pressing damage to the sciatic nerve of in vivo rats, tissues of the sciatic nerve and DRG sensory nerve were observed using Neurofilament 200, Hoechst, $S100{\beta}$, caspase-3, anti-cdc2, phospho-vimentin, ${\beta}1$-integrin, Dil reverse tracking and p-Erk1/2. Results : The group of in vitro Taxol plus SJT treatment had meaningful effects after sciatic nerve tissue was damaged by Taxol. The group of in vivo SJT treatment had effects of regenerating Schwann cells and axons which were damaged by Taxol treatment. The group of in vivo SJT had effects of regenerating axons in damaged areas after the sciatic nerve was damaged by pressing, and also had variations of distribution in Schwann cells at DRG sensory nerves and axons. Conclusions : This study confirmed that SJT treatment is effective for growth of axons in the sciatic nerve tissues and improvement of Schwann cells after axons of the sciatic nerve tissues was damaged. After tissues of sciatic nerve was damaged by pressing in vivo, SJT treatment had effects on promoting regeneration of axon in the damaged area and reactional capabilities in axons of DRG sensory nerves.

Regional Distribution of Peach Freezing Damage and Chilling Days in 2010 in Gangwon Province (강원지역의 2010년 복숭아 동해)

  • Seo, Young-Ho;Park, Young-Sik;Cho, Byoung-Ouk;Kang, An-Seok;Jeong, Byeong-Chan;Jung, Yeong-Sang
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.12 no.4
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    • pp.225-231
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    • 2010
  • Extremely low values of the daily minimum temperature occurred in January 2010, ranging from -18 to $-29^{\circ}C$ at various locations growing peach trees in the Gangwon province. Due to the extreme cold temperature during the winter dormancy period of peach trees, the growth of the peach trees was damaged and the damaged areas increased as the extent of 17 to 144 ha. In order to provide information on mitigation measure of the cold temperature on the peach trees in the Gangwon province, we assessed the distribution of the damaged areas of growing the peach trees in 2010 and compared it with freezing risk estimated from the dormancy depth of the peach trees and the daily minimum temperature. The dormancy depth of 'Changhowon Hwando (Prunus persica (L.) Batsch)' ranged from -62 to -90 and the freezing risk was greater than 51%. The relationship between the freezing risk and the actual damaged area ratio showed reasonable agreement ($r^2$ of 0.5 with p < 0.01). The results imply that the estimates of the freezing risk based on the dormancy depth can be used as a mitigation measure to identify susceptible peach growing areas to freezing damage injury.

A Study on Risk of Electric Shock from Damaged Grid Connection Cable in Floating Photovoltaic System (수상 태양광 발전설비 계통 연계 케이블 손상시 감전 위험에 관한 연구)

  • Song, Young-Sang;Jeon, Taehyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.9
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    • pp.14-19
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    • 2014
  • Recently, many renewable energy generating businesses are ongoing progress due to the introduction of the RPS(Renewable Portfolio Standards) as well as the needs of environmentally friendly energy resources. Researches on photovoltaic system are actively being processed since the photovoltaic system is relatively easy to install and becomes commercialized in many domestic application areas. Furthermore, the floating photovoltaic system is likely to be installed more actively since the conventional photovoltaic system requires relatively large areas of land. Also, the floating photovoltaic system is more efficient than photovoltaic system installed in land due to the operation in lower temperature. However, safety problems such as electric shock could arise since the cable should be installed in the water. In this paper, the leakage current and the voltage rising are measured and analyzed for the case when the cables are damaged connecting the floating photovoltaic system to the grid.

An Analysis on Economic Effectiveness of Environment Improvement Project in Oil Spill Damaged Fishing Grounds (유류피해지역 어장환경 개선사업의 경제적 효과 분석)

  • KIM, Hong-Sik;JEON, Hyoung-Joo;KIM, Do-Hoon
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.6
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    • pp.1781-1791
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    • 2016
  • This study aimed to analyze the economic effectiveness on environment improvement project that has been implemented in five fishing grounds of Taean-gun which had been damaged by the Hebei Spirit oil spill accident. In the analysis, first, this study performed the survey on residents perceptions about the environment improvement project. Second, the cost-benefit analysis was carried out to evaluate the economic effectiveness of the project. The survey results of residents perceptions indicated that the damage of oil spill was considerable in the target areas. It also showed that residents wanted to continue the environment improvement project and the levels of project satisfaction were quitely high. The economic results showed that 3 areas(Woong-do, Wang-san, and Dang-mi) would have positive values of NPV and B/C ratio, but the other(Nu-dong) would have negative values. The findings of this analysis could be used as the base data for increasing operational efficiency of future environment improvement projects.

A Study for the Characteristic Changes under the Repeated Thermal Exposure in the Process of Repairing Aircraft Sandwich Structures (항공기용 복합재 샌드위치부품의 수리시 열간노출에 따른 물성변화에 관한 연구)

  • 최병근;김돈원;김윤해
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.105-110
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    • 2001
  • Autoclave curing using the vacuum bagging method is widely used for the manufacture of advanced composite prepreg airframe structures. Due to increasing use of advanced composites, specific techniques have been developed to repair damaged composite structures. In order to repair the damaged part, it is required that the damaged areas be removed, such as skin and/or honeycomb core, by utilizing the proper method and then repairing the area by laying up prepreg (and core) then curing under vacuum using the vacuum bagging materials. It shall be cured either in an oven or autoclave per the original specification requirements. Delamination can be observed in the sound areas during and/or after a couple times exposure to the elevated curing temperature due to the repeated repair condition. This study was conducted for checking the degree of degradation of properties of the cured parts and delamination between skin prepreg and honeycomb core. Specimens with glass honeycomb sandwich construction and glass/epoxy prepreg were prepared. The specimens were cured 1 to 5 times at $260^{circ}F$ in an autoclave and each additionally exposed 50, 100 and 150 hours in the $260^{circ}F$ oven. Each specimen was tested for tensile strength, compressive strength, flatwise tensile strength and interlaminar shear strength. To monitor the characteristics of the resin itself, the cured resin was tested using DMA and DSC. As a results, the decrease of Tg value were observed in the specific specimen which is exposed over 50 hrs at $260^{circ}F$. This means the change or degradative of resin properties is also related to the decrease of flatwise tensile properties. Accordingly, minimal exposure on the curing temperature is recommended for parts in order to prevent the delation and maintain the better condition.

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Wood Anatomical Characteristics of Pine Tree (Pinus densiflora S. et Z.) Damaged by Air Pollution (대기오염(大氣汚染) 피해(被害) 소나무의 목재(木材) 해부학적(解剖學的) 특성(特性))

  • Kim, Yoon-Soo;Park, Byung-Dae;Shim, Keun
    • Journal of the Korean Wood Science and Technology
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    • v.15 no.2
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    • pp.105-112
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    • 1987
  • Some anatomical characterisitcs of Japanese red pine (Pinus densiflora S. et Z.) collected from pollution-exposed areas in Korea were investigated. These sites were reportedly the most severe air polluted areas in Korean peninsular. A decline in overall growth rate was apparent since the late 10-year period of growth. P. densiflora in Onsan and in Yeochon recorded in the radial growth reduction of approximately 70 and 60% respectively. The formation of earlywood in the period of air pollution was restricted, whereas the percentage of latewood increased. The maximum wood density was lower in xylem rings formed during a period of air-pollution than in rings found without pollution. Most of pine trees damaged by air pollution showed the classical type of length-on-age curve for tracheids. However, reduction in cell wall-thickness and diameter was revealed in the wood exposed to air pollutants. Nor anomalies in microstructures nor microorganisms in wood structures were found in the damaged trees.

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