• Title/Summary/Keyword: 분포확산

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격자형 공간 모델링을 이용한 해양 오염원 확산 예측 시스템

  • 이종근;이장세;지승도
    • Proceedings of the Korea Society for Simulation Conference
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    • 1997.04a
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    • pp.115-119
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    • 1997
  • 본 논문은 해상에서 발생될 수 있는 기름 유출 사고시 효과적 방제의 지원을 위한 오염원 확산 예측 시스템의 개발을 주목적으로 한다. 이를 위하여, 격자형 공간 DEVS 모델 링 방법론을 이용한 SOS(Save Our Sea) 시스템을 개발하였다. 기존의 해양오염 예측 시스 템들이 대부분 해석적 기법에 의존하는데 비해 제안된 시스템은 격자형 공간 모델링을 이용 한 시뮬레이션 기법으로서 전체 해양을 Cell 단위의 공간으로 분할하고, Cellrks의 결합관계 는 Name-Directed Coupling을 적용함으로서 시스템 설계상의 효율성과 유연성을 제공한 다. 제안된 시스템은 기름유출사고의 발생시 오염원 확산에 영향을 주는 각종 벡터 변수값 들에 따른 해양 오염 물질의 확산 분포를 예측함과 동시에 확산에 영향을 주는 많은 벡터 값들이 모니터링 정보를 함께 제공함으로서 해양 오염 방제 및 환경 보존에 효과적으로 적 용될 수 있을 것으로 기대된다.

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Factors Affecting Longshore Current Profile (연안유속분포 형상에 미치는 제인자)

  • 김경호;윤영호;조재희
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.3 no.2
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    • pp.108-115
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    • 1991
  • This paper aims at the elucidation of the characteristics of longshore current profile after wave breaking. Wave breakers are always accompanied by complex turbulent process, wave energy losess occur and the mean water level also varies due to the gradient of radiation stress. These with other factors result in the development of longshore currents. Longshore currents have relations to the alongshore sand transport and to the diffusion of contaminants in nearshore region, thus the understanding and elucidation of them are very important from the engineering point of view. Using the calculated results, the factors such as lateral mixing cofficients, bed shear stress. wave angle. wave steepness and bottom slope. which are influencing the longshore current profile. are examined. Also, by comparing the results of longshore currents with the experimental data obtained by other investigators, the procedure proposed in the present study is shown to be valid.

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Analyzing Spread Rate of Samcheok Forest Fire Broken out in 2000 Using GIS (GIS 응용(應用)에 의한 2000년(年) 삼척(三陟) 산불의 확산속도(擴散速度) 분석(分析))

  • Lee, Byung-Doo;Chung, Joo-Sang;Kim, Hyung-Ho;Lee, Si-Young
    • Journal of Korean Society of Forest Science
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    • v.90 no.6
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    • pp.781-787
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    • 2001
  • The spread rate of forest fire was analyzed on Samcheok forest fire that broke out on April 7, 2000 in Kunduck-Myun, Samcheok-City, Kangwon-Province and lasted for about 9 days. The spatial database including topography, overstory species distribution, micro-climate, daily fire front lines for the area was built using GIS and the daily spread pattern was investigated to determine a multiple regression equation to estimate forest fire spread rate. The results of the investigation showed that, on the first day, the forest fire spreaded out extremely fast up to 12.3m/min at about 10 a.m. until noon. After that, the forest fire spread rate fluctuated and slowed down as low as below 1m/min and quenched on April 15. The daily area-based spread rate along the fire spread line got to the peak of about 5,700ha on April 11, of which spread rates were recorded as 2.84m/min in the first half and 1.10m/min in the second half. Also, it was found that slope aspect, wind velocity and % area distribution of Pinus densiflora are the major factors affecting the spread rate of forest fire in this area.

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Slope and Forest Fuel Effect on Spreading of Forest Fire (산불 확산에 영향을 미치는 임지내 산림연료와 경사도에 관한 연구)

  • 채희문;이찬용
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.5 no.3
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    • pp.179-184
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    • 2003
  • This study investigated the relationship of fuel weight and depth together with slope on the spread of forest fire. Fire spread was faster on the greater slope in forested land. Fire had a greater spread rate with lighter fuel weight. The thickness of the fuel bed and forest fire spread rate were not related. The fire spread rate was closely related to the slope and weight of the fuel bed (significant at 0.01, 0.05, respectively). The thickness of the fuel bed was not significant (0.05).

Influence of Reinforcements on the Chloride Diffusion Analysis of Concrete Structures (철근의 영향을 고려한 콘크리트 구조물의 염소이온 확산해석)

  • 오병환;장봉석;이명규
    • Journal of the Korea Concrete Institute
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    • v.14 no.6
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    • pp.883-891
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    • 2002
  • The chloride penetration in concrete structures is influenced by many factors such as types of cement and admixture proportion. Therefore, the effects of these factors on chloride diffusion must be correctly considered. The conventional diffusion analysis also neglected the existence of reinforcing bar in concrete structures. The purpose of the present paper is therefore to investigate the effect of reinforcing bar on the chloride diffusion in concrete structures. For this purpose, a comprehensive finite element analyses have been conducted to obtain chloride penetration profile. The results indicate that the chlorides are accumulated in front of a reinforcing bar and that the accumulation is much larger for the case of large diameter bars. The higher accumulation of chloride at bar location causes much faster corrosion of reinforcing steel. It can be concluded from the present study that the effects of reinforcing bars must be considered in chloride diffusion analysis for more realistic prediction of durable life of concrete structures.

마산만의 해저퇴적물 입자 분포의 통계학적 특성

  • 염말구;권영택;정태성
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2002.10a
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    • pp.164-165
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    • 2002
  • 내만의 해저퇴적물은 하천이나 외해로부터 유입되어 침강, 응집, 확산, 이동, 재용출 등의 과정에서 수질변화와 저서생물의 서식에 많은 영향을 주는 것으로 알려져 있다(조 등,1982; ASCE, 1992; Kwon and Lee, 1998). 그러므로 해저퇴적물의 변화과정을 이해하기 위해서는 먼저 그 입자 분포의 특성을 파악할 필요가 있다고 생각한다. 이 논문은 오염이 비교적 심한 것으로 알려져 있는 마산만의 여러 정점에서 채취한 해저퇴적물의 입자크기를 측정하고 그 분포의 통계학적 특성을 조사한 것이다. (중략)

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