• 제목/요약/키워드: Water's view

검색결과 378건 처리시간 0.036초

시간의존 완경사방정식의 이론적 비교 (Analytical Comparison of Time-Dependent Mild-Slope Equations)

  • Lee, Chang-Hoon;James T. Kirby
    • 한국해안해양공학회지
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    • 제6권4호
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    • pp.389-396
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    • 1994
  • 현존하는 시간의존 완경사방정식으로 Smith와 Sprinks(1975)가 개발한 식(이와 대등한 정확도로 Radder와 Dingemans(1985)가 개발한 식)과 Kubo 등 (1992)이 개발한 식이 있다. 분산관계식과 에너지 전송의 관점에서 시간의존 완경사방정식을 분석하였다. 수평방향으로 1차원적으로 시간의존 완경사방정식의 진폭변조현상을 선형 Scrodinger식과 대비하여 비교하였다. 분산관계식과의 관점에서 보면, Smith와 Sprinks의 모형이 보다 얕은 수심(kh$\leq$0.2$\pi$)에서 더 정확하고 아주 얕은 수심(kh=0)에서는 선형 Scrodinger식을 만족시키는 반면 Kubo 등의 모형은 보다 깊은 수심(kh>0.2$\pi$)에서 더 정확하고 천이영역의 한 지점(kh=0.3$\pi$)에서 선형 Scrodinger식을 만족시킨다. 에너지 전송의 관점에서 보면 Kubo 등의 모형이 더 정확하지만 높은 주파수 영역에서 해가 발산하는 단점이 있다.

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Modeling of decision-makers negotiations in reservoir operation with respect to water quality and environmental issues

  • Mojarabi-Kermani, A.R.;Shirangi, Ehsan;Bordbar, Amin;Bedast, A.A. Kaman;Masjedi, A.R.
    • Membrane and Water Treatment
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    • 제9권6호
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    • pp.421-434
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    • 2018
  • Decision-makers have different and sometimes conflicting goals with utilities in operating dam reservoirs. As repeated interactions exist between decision-makers in the long-term, and the utility of each decision-making organization is affected not only by its selected strategy, but also by other rivals' strategies; selecting and prioritizing optimum strategies from a decision maker's point of view are of great importance while interacting with others. In this paper, a model based on a fuzzy set theory, for determining the priority of decision-makers' strategies in optimal qualitative-quantitative operation management of dam reservoir is presented. The fuzzy priority matrix is developed via defining membership functions of a fuzzy set for each decision maker's strategies, so that all uncertainties are taken into account. This matrix includes priorities assigned to possible combination for other decision makers' strategies in bargaining with each player's viewpoint. Here, the 15-Khordad Dam located in the central part of Iran, suffering from low water quality, was studied in order to evaluate the effectiveness of the model. Then, the range of quality of water withdrawal agreed by all decision-makers was determined using the prioritization matrix based on fuzzy logic. The results showed that the model proposed in the study had high effectiveness model.

한강수질의 관리방안 (Han River Management Policy)

  • 심영섭
    • 환경위생공학
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    • 제7권2호
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    • pp.29-36
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    • 1992
  • Among the rivers in Korea, the Han River is the largest, most important one, which runs through the Seoul metropolitan region in the west toward the yellow sea. In the Han River basin there live as many as 17.1 mil. people including appr, 11 mil, citizens in Seoul. The Seoul Metropolitan region, already containing appr. 40% of the nation's total populating, expectedly poses an ever-growing polluting burden to the Han River. Due to Korea's vigorous industrialization and heavy urbanization in the past quarter century, water pollution was observed to be increasing in the Han River until the mid-1980's, but thereafter the Han River began to improve little by little by virtue of the government's massive investment and all-out efforts in water preservation. Public awareness on the importance of environmental protection is increasing unprecedentedly. With a view to meeting people's growing demand for clean water and pleasant environment, the government established the "Comprehensive Mid-Term Environmental Conservation Plan" (1992∼1993) in 1991. According to the plan, 1,315 bil.won(1.7 bil.us$ ) is to be poured into the Han River Basin to install 113 water pollutant abatement plants including 43 treatment facilities. To successfully cope with the future's challenging need for the environmentally sound sustainable development, a variety of measures and an array of policies are going to be incorporated with emphasis on, -redistributing such polluting sources as population and industries -tightening control of the water pollutant discharge -restricting the pollution-accompanying land use -enhancing the assimilation capacity of the river -stirring up the public awareness and participation in the environment protection We hopefully anticipate that with those e(forts the Han River will improve as drawn in the attached "1996's Envisioned Han River Quality".

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집중호우 시 도시 소유역 배수펌프장 운영을 위한 강우유출모의 (Runoff simulation for operation of small urban storm water pumping station under heavy storm rainfall conditions)

  • 길경익;한종옥;김성근;이창노;김구현
    • 한국습지학회지
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    • 제8권2호
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    • pp.75-81
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    • 2006
  • 본 연구에서는 도시 소유역에 위치한 배수펌프장의 집중호우 시 운영 개선방안을 도출하기 위한 기초연구로서 강우유출을 모의하고자 하였다. 이를 위해 GIS근간의 강우유출 모의 모델인 HEC-HMS를 활용하였으며, 2001년 7월 구리시에 발생한 집중호우에 대한 홍수유출수문곡선을 모의 할 수 있었다. 이때 강우유출모의에 필요한 유역의 토지이용현황, 토양형 및 유출곡선지수 등의 모델 입력자료는 ArcView GIS 툴과 수치지도 자료를 활용하여 산정할 수 있었다.

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GIS 기반의 HEC-HMS를 이용한 정자천 유역의 연속 강우.유출 분석 (Continuous Rainfall-Runpff Simulation Analysis of Jeongjacheon watershed using GIS-based HEC-HMS Model)

  • 김용국;노재경
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2009년도 학술발표회 초록집
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    • pp.997-1001
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    • 2009
  • GIS 기반의 HEC-HMS를 이용하여 유량자료가 있는 소하천인 정자천 유역을 대상으로 장기 강우 유출 분석을 하였다. 일반적으로 홍수량 산정은 단기해석으로 분석하나 평 갈수기와 홍수기 때의 하천 유황이 다르기 때문에 매개변수가 불일치할 것이라 생각되고, 이에 대한 보정이 필요한지 판단이 필요하다. 이를 위해 장기 연속모의를 통하여 매개변수의 보정 필요성을 검토하였다. 연구는 수치지도를 조합하여 ARC-VIEW로부터 Map파일 및 Basin파일을 생성하였고, 토지이용도와 토양도를 ARC-VIEW를 이용하여 CN value를 추출하였다. 계산조건중 손실량 산정방법은 SCS Curve Number법으로 하였고, 단위도 방법은 Clark UH법, 하도추적방법은 Muskingum방법, 기저유량산정방법은 Constant monthly로 설정하였다. 유역면적, 도달시간자료, 저류상수 값 등의 추출은 GIS기법을 이용하여 추출하였다. HEC-HMS의 장기 연속모의(Continuous Simulation)로 얻어진 Element Graph를 보면 대략적인 형태가 일치하나 2006년도에 대한 모의에서는 홍수기의 결과만 일치하는 것으로 보이고, 2007년도에 대한 모의에서는 평 갈수기와 홍수기의 그래프 형태가 유사하게 나타났다. 실측 유량보다 유량 값이 약간 크게 산출되어 홍수량 산정에서 볼 때 안정성에 무리가 없다고 판단되지만, 평 갈수기 기간에서 볼 때 연마다 하천의 매개변수가 일치하지 않는다고 생각되며, 홍수 후 유역의 변화로 매개변수가 변화한 것이라 생각된다. 향후 정자천유역의 보다 많은 강우사상과 실측유량을 통해 HEC-HMS의 유출량을 비교 분석하면 보다 더 정확한 해석이 가능할 것이며, 홍수가 빈번한 지역의 경우 유수지의 검토와 저수지의 시간당 방류량을 알 수 있다면 오차의 범위를 줄일 수 있다고 생각된다. 더 나아가 우리나라에 적합한 매개변수와 GIS 프로그램이 개발된다면 보다 쉽고 정확한 해석이 가능할 것이라고 생각된다.

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지역의 경관을 고려한 도막방수재의 색채별 사계절 차열 및 축열 성능에 관한 연구 (A Study on the Four-Season Cooling Performance by Color of Water Proofing Membrane Materials Considering the View of Area)

  • 고진수;김병윤
    • 한국농촌건축학회논문집
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    • 제17권2호
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    • pp.9-16
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    • 2015
  • This study comparatively analyzed thermal characteristics of the green color, which is currently used the most, and other various colors of a rooftop urethane water proofing sheet. This study also analyzed the cooling performance by color of the water proofing sheet that fused cooling paints, and presented the effective water proofing sheet color for building energy savings. The experimental results are as follows: (1) The value of L (brightness) diminished, and brilliance also became lower from the white color to the black color, and thus, it was confirmed that relatively more heat was absorbed. In a and b chromaticity, which is the color attribute that ignores brightness, no special relationship was identified. (2) Considering that the cooling performance effect is bigger in summer than winter, due to heat reflection, the white water proofing sheet is more effective in building energy savings than the green water proofing sheet that is currently used the most. (3) The water proofing sheet's color has an impact more on cooling performance than the color of the background side of a structure on which water proofing sheet is installed. The experiment object of gray, of which background side is similar to cement mortar, was lower by $5.7^{\circ}C$ than the white background side.

Dynamic risk assessment of water inrush in tunnelling and software development

  • Li, L.P.;Lei, T.;Li, S.C.;Xu, Z.H.;Xue, Y.G.;Shi, S.S.
    • Geomechanics and Engineering
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    • 제9권1호
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    • pp.57-81
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    • 2015
  • Water inrush and mud outburst always restricts the tunnel constructions in mountain area, which becomes a major geological barrier against the development of underground engineering. In view of the complex disaster-causing mechanism and difficult quantitative predictions of water inrush and mud outburst, several theoretical methods are adopted to realize dynamic assessment of water inrush in the progressive process of tunnel construction. Concerning both the geological condition and construction situation, eleven risk factors are quantitatively described and an assessment system is developed to evaluate the water inrush risk. In the static assessment, the weights of eight risk factors about the geological condition are determined using Analytic Hierarchy Process (AHP). Each factor is scored by experts and the synthesis scores are weighted. The risk level is ultimately determined based on the scoring outcome which is derived from the sum of products of weights and comprehensive scores. In the secondary assessment, the eight risk factors in static assessment and three factors about construction situation are quantitatively analyzed using fuzzy evaluation method. Subordinate levels and weight of factors are prepared and then used to calculate the comprehensive subordinate degree and risk level. In the dynamic assessment, the classical field of the eleven risk factors is normalized by using the extension evaluation method. From the input of the matter-element, weights of risk factors are determined and correlation analysis is carried out to determine the risk level. This system has been applied to the dynamic assessment of water inrush during construction of the Yuanliangshan tunnel of Yuhuai Railway. The assessment results are consistent with the actual excavation, which verifies the rationality and feasibility of the software. The developed system is believed capable to be back-up and applied for risk assessment of water inrush in the underground engineering construction.

Re-development of Waterway system in Nihombashi River

  • Ito, Kazumasa
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2009년도 학술발표회 초록집
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    • pp.2190-2199
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    • 2009
  • Nihombashi is located in the central area of Tokyo, Japan. Tokyo has been the capital in Japan since the Edo period, which started approximately 400 years ago, and has accepted a variety of cultures, human resources, businesses for the last 400 years. This has resulted in building up the present prosperity. The Sumida River, one of the symbols of Tokyo and its tributaries including the Kanda River and the Nihombashi River, flows through the Nihombashi district. The river and tributaries used to benefit to the City of Edo. Due to the economic development and the industrial growth in Tokyo, however, they were polluted and lost their functions. In 1960s, approximately 40 years ago, the Sumida River became so dirty that local citizens kept away from it. The Nihombashi River was covered with an expressway, which was obscuring the river view. Since 1970s, local communities have proposed to rehabilitate rivers in Tokyo successively, and have proceeded with measures for river floods, improvement of sewage systems and construction of water purification facilities. Consequently, the quality of the river water was considerably improved in 1990. The stagnant rivers were turned into ones that local citizens were physically able to come close by. Today, restoring of the environment and the appearance of the city in the old days, Nihombashi district has been proposed as a model city of the future, which is alive with history and culture and harmonizing with rivers. The concept is "To Create, To Reserve, To Restore." This paper introduces a case study of the urban development, in which the local communities and public authorities collaborated with and proposed a brand-new style of the urban city harmonizing with the environment.

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집적암거에 의한 대류수개발에 관한 연구 (A study on the Development of Ground water by the Infiltration Gallery)

  • 한욱동
    • 한국농공학회지
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    • 제15권3호
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    • pp.3096-3106
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    • 1973
  • As a link in the chain of antidrought measure, our attempt is made to obtain basic informations on the construction of an infiltration gallary which can be supplied with irrigation water by catching of underground water in small river beds, which is economical, permanent and efficient. The experiment was made, concerning the structure of catchment conduits, by constructing a model sand tank $1.5m{\times}5m{\times}1.5m$ in dimension made of reinforced concrete. Various kinds of measuring equipment were attached to the model tank which contains a set of catchment conduits, each of them was made 30cm in diameter and 60cm in length with the ratio of sectional area to total area of influx holes 10:1, 20:1, 30:1. The average size of influx holes was fixed from 0mm to 10mm, 20mm and 30mm in diameter respectively. Obtained results are as follow; (a) In view of the water catchment capacity, manufacturing cost and the antipressure strength of the catchment conduits, it is the best method to decide the total number of influx holes 20 per sq. meter of each tile surface, and the size of influx holes 20mm in diameter, when the conduits have diameter less than 1m. (b) The greatest factor of safety against external load is to arrange the influx holes in a zigzag manner on the tile surface. The most effective formula of arrangement is $S{\geqq}\sqrt{2gd}$ where: s : spacing of opening row. g : spacing of opening line. d : diameter of influs hole.

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LOSS-OF-POOL-WATER 사고시 연구용 원자로 MAPLE-X10 시설에서의 감마 방사선장 해석 (Analysis of Gamma Radiation Fields in the MAPLE-X10 Facility Associated with Loss-of-Pool-Water Accident Conditions)

  • Kim, Kyo-Youn;Ha, Chung-Woo;I.C. Gauld
    • Nuclear Engineering and Technology
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    • 제21권2호
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    • pp.63-72
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    • 1989
  • 연구용 원자로 MAPLE-X10 시설의 안전성을 평가하기 위하여 원자로 pool 및 보조 pool로부터 물의 상실이 가정되었을 때 시설에 대한 감마 방사선장을 해석하였다. 차폐 해석에 고려된 4개의 photon 선원항은 ORIGEN-S코드를 이용하여 계산하였다. 또한, pool물 상실 사고 조건하에서 원자로 pool 및 보조 pool에서의 감마 선량율은 QAD-CG코드를, 그리고 pool외부의 방사선장은 입체각 외부에서의 산란 photon 선량율 계산에도 적합한 MCNP 코드를 이용하여 평가하였다.

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