• Title/Summary/Keyword: dispersal simulation

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Approach to the Location of Wildlife Corridors on Highways - Between Yang-jae and Pan-gyo ICs of Seoul-Busan Highway, Korea - (고속도로 생태통로 위치 선정 방법에 관한 연구 - 경부 고속도로 양재-판교 구간을 중심으로 -)

  • Shin, Su An;Ahn, Tong Mahn
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.2
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    • pp.19-27
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    • 2008
  • Ecosystem fragmentation by human intervention breaks down the biosphere habitat. Wildlife corridors connect biosphere habitats to maintain ecosystem continuity and provide animals with connecting routes. In Korea, there are 17 existing wildlife corridors on highways (as of December, 2006. Korea Freeway Corporation). There are 24 highway routes, 2,923km of highway(as of December, 2004. Korea Freeway Corporation). However, wildlife corridors are not enough and roadkill increases every year, so we need to construct additional wildlife corridors on highways. This study proposes a new approach to the location of wildlife corridors on highways, using a comprehensive analysis method for main location elements, and applies it to a study area. First, it examines traditional approaches to location of wildlife corridors through literature review and field study to analyze the present conditions of existing wildlife corridors. Then, it developes a comprehensive analysis method for the location of wildlife corridors. (1) Field investigation : investigate planting, water bodies and so on. (2) Roadkill analysis : roadkill counts, locations, time, and so on. (3) Monitoring : animal traces were surveyed and sensor cameras were installed to determine target species. (4) Simulation for animal movement : most probable wildlife dispersal was simulated by a computer software. (5) A new comprehensive approach overlays all analysis on a map and determines the location of proposed new wildlife corridors. In conclusion, it proposes an over-bridge type wildlife corridor in Dalnaenae Hill (413-414km from Busan) and an underpass type near the entrance to Gwanhyun temple way (415-416km from Busan). This new approach based on roadkill data, computer simulation of wildlife dispersal, monitoring of animals, and site analysis, may contribute to better location of wildlife corridors on highways.

A Study on the Analysis of Connectivity for Green Space Planning in Daejeon Metropolitan City (대전시 녹지계획을 위한 연결성 분석에 대한 연구)

  • Cheong, Yong-Moon;Kim, Sun-Tae;Kim, Myoung-Soo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.6
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    • pp.14-23
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    • 2002
  • Daejeon is a large city in Korea and very high-speedly developing city. Recently urban area is expanding and large forest patch is fragmenting into small habitats because of urban sprawl. The fragmentation of large forest patch decreases the size of habitats and increases the loss of biodiversity in urban area. This study is to analysis the connectivity of green space of Daejeon metropolitan city, and suggest the optimum location of greening site and corridor in order to increase the connectivity of green space of Daejeon metropolitan city. The findings of this study are as follows; (1) The result of this study showed that ${\alpha}$ and ${\gamma}$ index are -0.24 and 0.20. A ${\alpha}$ index is very low and a ${\gamma}$ index is relatively low. (2) The dispersion was very high, for urban forest patches were isolated through fragmentation. Therefore, it needed ecological corridors in order to connect the patches. (3) A urban streams were very important in connectivity of urban green space. Urban riparian corridor must be preserved and restored. (4) A urban green space policy and planning must be prepared to increase the connectivity and assessment of alternatives must be accomplished from perspective of connectivity. The results of this study show the practical implications in perspective of green space planning and policy in Daejeon metropolitan city. The suggestions by findings of this study are to connect green space between large forest patch in urban fringe and island green space in inner city. Also, It is required that urban stream is restored to natural feature for use of corridor by wildlife.

Aerodynamic Features of Maple Seeds in the Autorotative Flight (자동회전 비행을 하는 단풍나무 씨앗의 항공역학적 특성)

  • Sohn, Myong Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.10
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    • pp.843-852
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    • 2016
  • The autorotative flight of maple seeds(Acer palmatum) is numerically simulated based on the 3D geometry and the motion parameters of real seeds. The nominal values of the motion parameters are 1.26 m/s for descent velocity, 133.6 rad/s (1,276 rpm) for spinning rate, $19.4^{\circ}$ for coning angle, and $-1.5^{\circ}$ for pitch angle. A compact leading-edge vortex (LEV) positioned at the inner span of the seed blade causes a large suction pressure on its leeward surface. The suction pressure peaks occur near the leading region of inner span sections. The flow pattern characterized by the prominent LEV and the values of aerodynamic force coefficients obtained in the present study are in good agreement with experimental data measured for a dynamically-scaled robot maple seeds. A spiraling vortex developed in the leeward region advances toward the seed tip and merges with the tip-passing flow, which is considered to be a mechanism of maintaining stable and attached LEV for the autorotating maple seeds.

Study on Influence Analysis of Radioactive Terror Scenarios by Weather Conditions (기상조건에 따른 방사능테러 시나리오 영향 분석)

  • Kim, Tae Woo;Jeon, Yeo Ryeong;Chang, Sunyoung;Kim, Yongmin
    • Journal of the Korean Society of Radiology
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    • v.12 no.6
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    • pp.719-725
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    • 2018
  • After 9/11 attacks in the U.S, Terrorism has increased the number of unspecified casualties through multi-use facility terror attacks compared to the past. The subsequent London bombings and the self-destruction of Pakistan increased people's fear and social anxiety. As international events have been held in Korea recently, awareness and concern over radioactive terrorism and security management of radioactive materials are increasing. In this paper, we compared the results of different meteorological conditions using HotSpot Code. After creating a possible terror scenario in Korea, sources likely to be use in RDD and Dirty bomb were investigated. The meteorological condition was selected by comparing the Pasquill-Gifford stability class with the most stable condition F and the most unstable condition A. The result value of the A and F condition through simulation were shown not to cause citizens to die from acute effects due to radiological effects. The range of radioactivity is different according to the wind speed and the meteorological stability, and the degree of radioactivity dilution is different according to meteorological conditions. Analysis results are expected to be used for initial response in the event of a radioactive terrorist attack.