• 제목/요약/키워드: Resources circulation

검색결과 408건 처리시간 0.028초

흐름에 의한 만내의 순환의 수학적 모의모형 (MATHEMATICAL SIMULATION MODEL OF FLOW INDUCED CIRCULATION IN A HARBOR)

  • 윤태훈;윤성범
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 1982년도 제24회 수공학 연구발표회 논문초록집
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    • pp.91-98
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    • 1982
  • The formulation of depth-averaged two-dimensional mathematical model for the analysis of tide induced circulation in a harbor by the Galerkin finite element techique is presented. In integration of the Galerkin approach in time both explicit and implicit method have been tested for one and two dimentional water bodies, and the two step Lax-Wendroff explicit method is found to be effective than the implicit in reducing computing time. The essential characteristics of the tide induced flow in Busan Harbor with two open boundaries has been foccud to be reproduceable in the numerical model and the simulated results encourage that the model can be used as a predictive tool.

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식생의 영향을 고려한 울산지역의 중규모 지역기상장에 관한 연구 (Numerical Analysis of Meso-Scale Circulation with Inclusion of a Layer of Vegetation over Ulsan Area)

  • 이성대
    • 한국수자원학회논문집
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    • 제30권2호
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    • pp.119-129
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    • 1997
  • 울산지역의 해륙풍장을 해석하기 위해 3차원 중규모 지역기상 수치모형을 개발하여 흐름장의 변동을 수치해석하였다. 식생의 영향을 고려한 지표면 열수지모형을 이용하여 지표면의 온도 및 습도를 결정하도록 하였다. 그리고 접지층에서의 연직방향 확산계수는 Businger의 모형을, Eckman층에서는 Yamada의 난류 closure모형을 사용하여 계산하였다. 그 결과 울산지역의 해륙풍장의 거동특성을 해석하는데 있어서 본 모형은 효과적임을 알 수 있었다.

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산업기술정보원(産業技術情報院)의 자료관리(資料管理) 시스템(I) -시스템 구성(構成)과 운영- (KINITI LIS : Library Information System(I) - System Structure and Operation -)

  • 최원태
    • 정보관리연구
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    • 제23권2호
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    • pp.73-89
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    • 1992
  • 산업기술정보원(産業技術情報院)은 산업(産業) 및 과학기술 분야의 도서, 연속간행물(連續刊行物), 해외공관자료, 특허 등의 다양한 정보자료(情報資料)를 수집하고 있다. 본 논문은 산업기술정보원(産業技術情報院)에서 자체 개발(開發)한 자료관리시스템의 구성과 운영에 관하여 기술하였다. 본 시스템은 IBM 3090/150 E를 이용하여 개발(開發)되었으며, 수서, 목록, 검색, 대출, 연속간행물(連續刊行物) 관리의 하부 시스템으로 구성(構成)된다.

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The effect of error sources on the results of one-way nested ocean regional circulation model

  • Sy, Pham-Van;Hwang, Jin Hwan;Nguyen, Thi Hoang Thao;Kim, Bo-ram
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2015년도 학술발표회
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    • pp.253-253
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    • 2015
  • This research evaluated the effect of two main sources on the results of the ocean regional circulation model (ORCMs) during downscaling and nesting the results from the coarse data. The two sources should be the domain size, and temporal and spatial resolution different between driving and driven data. The Big-Brother Experiment is applied to examine the impact of them on the results of the ORCMs separately. Within resolution of 3km grid point ORCMs applying in the Big-Brother Experiment framework, it showed that the simulation results of the ORCMs depend on the domain size and specially the spatial and temporal resolution of lateral boundary conditions (LBCs). The domain size can be selected at 9.5 times larger than the interest area, and the spatial resolution between driving data and driven model can be up to 3 of ratio resolution and updating frequency of the LBCs can be up to every 6 hours per day.

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하수처리수의 하천유지용수 활용을 위한 역순환시스템의 비교 (The Inverse Circulation System for Using Treated Waste Water as Instream Flow)

  • 김기형;최계운;안태진;김진홍;심명필
    • 한국수자원학회논문집
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    • 제36권5호
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    • pp.863-878
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    • 2003
  • 본 연구에서는 하천의 유지용수를 확보하기 위하여 하수처리장에서 처리하여 방류하는 하수처리수를 활용하기 위한 방안을 검토하고 이를 하천유지용수로 직접 활용하기 위하여 역순환시스템의 활용을 검토하였다. 역순환시스템은 하천 하류에 위치한 하수처리장으로부터 방류되는 하수처리수를 펌핑하여 하천상류부로 이송함으로써 하천에 부족한 유지유량을 확보하는 방법으로 여러 가지 형태의 이송방안을 조합하여 하천의 특성에 맞는 최적의 시스템을 구성하고 간단한 수처리를 적용함으로서 하수처리수의 수질을 추가적으로 개선할 수 있는 특징이 있다. 또한 이송된 하수처리수를 하천에 유입시키는 방안들은 시각적으로 친수적인 경관을 제공하고 폭기 등에 의한 수질개선효과를 얻을 수 있다. 이러한 하수처리수를 활용한 역순환시스템을 하천유지용수확보에 적용하기 위하여 국내 하수처리장의 처리수 활용실태 및 수질 상태 등을 검토하였고, 국내의 하수처리수 활용 사례를 조사하였으며 외국의 유사사례 조사를 통해 국내에 적용하기 위한 방안을 마련하고 실제 하천을 대상으로 역순환시스템의 적용방안을 제시하였다.

현재와 미래의 북반구 눈피복 변화와 대기순환과의 잠재적인 상관성 (Current and Future Changes in Northern Hemisphere Snow Extent and Their Potential Linkages with Atmospheric Circulation)

  • 최광용;김준수;데이비드라빈슨
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2008년도 학술발표회 논문집
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    • pp.294-298
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    • 2008
  • Snow cover is a potential water resource for later spring and summer seasons as well as a thermal mirror with high reflectivity causing decreases of surface air temperature during cold winter seasons. In this study, current and future changes in Northern Hemisphere snow extent and their potential linkages with atmospheric circulation are examined. The NOAA AVHRR visible snow extent (1967-2006) data as well as observational (NCEP-DOE 1979-2006) and modeled (GFDL 2.1 2081-2100) pressure and surface air temperature data are used. Analyses of observational data demonstrate that the snow extent in meteorological spring (March to April) and summer (June to August) has significantly decreased since the late 1980s. The offset of snow seasons (the timing of snow melt in spring) have also significantly advanced particularly in Europe, East Asia, and northwestern North America. Analyses of pressure fields reveal that the spatial patterns of the earlier snow melt are associated with changes in atmospheric circulation such as the Arctic Oscillation (AO). In the positive winter AO years, multiple positive pressure departure cores in the upper troposphere (200hPa) are observed over the mid-latitude regions from March to mid-April, while a negative pressure departure core (70hPa) prevails over the Arctic Ocean. The reversed anomaly patterns related to later snow melt occur in negative winter AO years. The comparison between current and future thermal spring onsets suggest that snow melt patterns will intensify with larger greenhouse gas emissions, indicating earlier hydrological spring onset.

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자연순환식 유회수선박에서의 부유식 기름유도장치에 관한 연구 (A Study on the Buoy type Oil Guiding System for the Active Circulation type Oil Recovery Vessel)

  • 이귀주;김경화
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 추계학술대회 논문집
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    • pp.185-189
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    • 2001
  • A study on the new active circulation type oil-water separation system including buoyancy type guidance system was carried out in this paper. Oil-water separation system is composed of several oil separation steps. Buoy type oil guiding system was developed based on the difference of buoyance of water and oil. The design speed of this vessel is 25 knots.

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MGIS 기반 섬진강 하구역 3차원 해수유동 (Three-dimension리 Circulation of MGIS based Seomjin River Estuary)

  • 박상우;김종규;이문옥
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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    • pp.431-434
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    • 2006
  • This study reviews the properties of coastal ocean and Seomjin River estuary spaces then define some MGIS(Marine Geographic Information System) related terminologies for clarifying the scope of MGIS boundaries. Therefore, we show the three-dimensional circulation of MGIS-based Seomjin River Estuary integrating three-dimensional POM model and observed data.

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LOCALLY ENRICHED QUADTREE GRID NUMERICAL MODEL FOR NEARSHORE CIRCULATION IN THE SURF ZONE

  • Park, Koo-Yong
    • Water Engineering Research
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    • 제1권3호
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    • pp.187-197
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    • 2000
  • This paper describes an adaptive quadtree-based 2DH wave-current interaction model which is able to predict wave breaking, shoaling, refraction, diffraction, wave-current interaction, set-up and set-down, mixing processes (turbulent diffusion), bottom frictional effects, and movement of the land-water interface at the shoreline. The wave period-and depth-averaged governing equations are discretised explictly by means of an Adams-Bashforth second-order finite difference technaique on adaptive hierarchical staggered quadtree grids. Grid adaptation is achieved through seeding points distributed according to flow criteria(e.g. local current gradients). Results are presented for nearshore circulation at a sinusoidal beach. Enrichment permits refined modelling of important localised flow features.

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Design and Performance Verification of Compound CVTs with 2K-H I type Differential Gear

  • Kim Yeon-Su;Park Jae-Min;Choi Sang-Hoon
    • Journal of Mechanical Science and Technology
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    • 제20권6호
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    • pp.770-781
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    • 2006
  • This paper defined design constraints for the compound CVTs (continuously variable trans-missions) by combining power-circulation-mode CVTs and power-split-mode CVTs, which were proposed for connecting 2K-H I-type differential gear to V-belt-type CVU (Continuously Variable Unit). The design constraints are the necessary and sufficient conditions to avoid geometrical interferences among elements in the compound CVTs, and to guarantee smooth assembly between the power-circulation-mode CVT and power-split-mode CVT Two com-pound CVTs were designed and manufactured in accordance with the design constraints. With these compound CVTs, theoretical analysis and performance experiments were conducted. The results showed that the design constraints were valid and effective design method, and that the designed compound CVTs had the improved performance.