• 제목/요약/키워드: submergence

검색결과 187건 처리시간 0.029초

펌프장에서 Sump내 흡입구 주위의 유동해석 (Flow Analyses around Intake within Sump in a Pump Station)

  • 노형운;김재수;서상호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.597-600
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    • 2002
  • In general, the function of intake structure, whether it be a open channel, a fully wetted tunnel, a sump or a tank, is to supply an evenly distributed flow to a pump station. An even distribution of flow, characterized by strong local flow, can result in formation of surface or submerged vortices, and with certain low values of submergence, may introduce air into pump, causing a reduction of capacity and efficiency, an increase in vibration and additional noise. Uneven flow distribution can also increase or decrease the power consumption with a change in total developed head. To avoid these sump problems pump station designers are considered intake structure dimensions, such as approaching upstream, baffle size, sump width, width of pump cell and so on. From this background, flow characteristics of intake within sump are Investigated numerically to obtain the optimal sump design data. The sump model is designed in accordance with HI code.

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폴리머 콘크리트를 이용한 조명등 디자인에 관한 연구 (A Study Lighting Design Using Polymer Concrete)

  • 한기웅
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2000년도 학술대회논문집
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    • pp.25-29
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    • 2000
  • Nowadays, natural resource are running out and the level of the environment contamination is getting serious. To solve these problems, each country and institute tend to need many-sided researchs and developments. At this point, especially, there are many coal-mines in Jung-sun and Tae-back where are located in Kangwon province. By the way the abandoned mines cause not only local economy collapse but also environment contamination by submergence of stony mountains. The counterplan is positively inquired further examination by the government. Consequently, we hope that the recycle of polymer concrete can reduce the environment contamination, suggest the new direction of Green Design and can be switched over high added value goods. In conclusion, the recycle of polymer concrete will be valuable.

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펌프장내 흡수정 설계 기준 (The Standard of Sump Design in Pump Station)

  • 노형운;오상현;이영호
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2005년도 연구개발 발표회 논문집
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    • pp.589-592
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    • 2005
  • In general, the function of intake structure, whether it be a open channel, a fully wetted tunnel, a sump or a tank, is to supply an evenly distributed flow to a pump station. An even distribution of flow, characterized by strong local flow, can result in formation of surface or submerged vortices, and with certain low values of submergence, may introduce air into pump, causing a reduction of capacity and efficiency, an increase in vibration and additional noise. Unfortunately in order to design the sump station, the reasonable code or the standards weren't presented yet in Korea. Thus, some researchers had often referred the HI code, JSME code or CEN code to design the sump station. This study aims to prescribe the standard of sump design which were matched well the Korean pump station. Thus, the HI code and TSJ code would be interpreted fully to Korean language, the part of interpreted clauses of the western codes would be selected to compose the standard.

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벼의 관수시 Peroxidase 활성도 및 Banding Pattern의 품종간 차이 (Varietal Differences of Peroxidase Activites and Banding Pattern of Rice Plants under Flooding)

  • 강양순;남민희
    • 한국작물학회지
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    • 제34권3호
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    • pp.270-273
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    • 1989
  • 벼 품종의 관수저항성 관련 특성을 검토코자 24일묘를 3일간 관수처리하여 뿌리와 엽신의 POD 비활성도 및 POD 동위효소들을 PAGIF법으로 전기영동하여 본 결과 관수저항성이 상대적으로 약한 일본형품종들은 통일형이나 인도형품종들보다 POD 비활성도가 높았으며 또한 관수처리로 일본형품종들의 엽신부에서는 무관수시 어느 부위에서도 나타나지 않았던 POD 동위효소의 특이 band가 등전점 9부근에서 출현하였다.

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심해 잠수정용 테더 케이블에 관한 연구 (A Study on Tether Cables Used for Deep Submergence Vehicles)

  • 신현경;김덕수
    • 대한조선학회논문집
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    • 제32권2호
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    • pp.56-67
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    • 1995
  • 본 연구에서는 케이블 비선형 정역학 방정식의 해로서 선박-케이블-잠수체 시스템의 정적모양이 보여지고, 선형 운동 방정식의 진동수영역해석에 의해 고유진동수가 구해진다. 또한 긴 연직케이블의 스내핑 현상을 클리핑 오프(clipping-off) 수치모형으로 이상화하여 극단장력을 계산한다.

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From Emerging to Submerging Economies: New Policy Challenges for Research and Innovation

  • Soete, Luc
    • STI Policy Review
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    • 제4권1호
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    • pp.1-13
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    • 2013
  • The Schumpeterian process of "creative destruction", associated with the emergence and diffusion of new radical, so-called "general purpose" technologies, has throughout history impacted wealth and income, jobs creation, jobs displacement, and the emergence and submergence of new hotspots of innovation. Emerging countries have benefited most from such a renewing of those societies' dynamics, leading them to higher levels of economic development and welfare. Doing so they have shown a remarkable capacity in moving upstream in the value chain, from outsourcing of manufacturing activities to autonomous process technology development, product development, design, and applied research. At the same time however, such Schumpeterian processes have now and then turned into exactly opposite processes of "destructive creation." Such processes seem to have become common among what could be called "submerging" economies: innovation only benefitting a few at the expense of many with as a result an opposite pattern of a long term reduction in overall welfare, productivity, and employment growth.

신뢰성 해석에 의한 제방의 월류 위험도 산정 (Evaluation of Overtopping Risks of Levee by using Reliability Analysis)

  • 이철응;박동헌;심재욱
    • 산업기술연구
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    • 제29권A호
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    • pp.101-110
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    • 2009
  • Due to frequent occurrence of a localized torrential downpour caused by global warming and change of outflow tendency caused by rapid urbanization and industrialization, risk analysis must be carried out in levee design with uncertainty. In this study, reliability analysis was introduced to quantitatively evaluate the overtopping risk of levee by the uncertainty. First of all, breaking function was established as a function of flood stage and height of levee. All variables of breaking function were considered as random variables following any distribution functions, and the risk was defined as the possibility that the flood stage is formed higher than height of levee. The risk evaluation model was developed with AFDA (Approximate Full Distribution Approach). The flood stage computed by 2-D numerical model FESWMS-2DH was used as input data for the model of levee risk evaluation. Risk for levee submergence were quantitatively presented for levee of Wol-Song-Cheon.

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염해와 동해를 받는 콘크리트의 내구성 평가실험 (The Experimental Study on the Durability of Concrete under Freezing & Thawing Action and Salt attack)

  • 이준구;박광수;조영권;김명원;김관호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.213-216
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    • 2005
  • Salt attack and freezing & thawing test, one of the combined deterioration tests was performed to explore the mechanism of concrete structure deterioration under marine environment. Simple submerging test was proceeded to draw out its diffusion factor with salt water at the same time. Some of the mechanisms were driven with using three types of cements and four kinds of salt water concentrations. $\circ$ TBC was more durable than OPC or SRC for freezing and thawing action $\circ$ The higher chloride concentration of salt water was, the faster relative dynamic elastic modulus decreased and the higher the loss of weight was. $\circ$ The diffusion factor of TBC was smaller than those of TBC or SRC at simple submergence of concrete specimens into salt water.

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자유표면시뮬레이션의 TOUD 연구 (Study on the Third-Order-Upwind-Difference(TOUD) for the Free-Surface Simulation)

  • 곽승현
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.154-159
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    • 2004
  • A new finite difference scheme is studied fur the simulation of free surface, surface the third derivative tenn for the wave elevation is artificially added in the the free-surface boundary condition. This study presents a comparative analysis with simulations performed by using the classical MAC method. More systematic computations are carried out by changing the submergence depth and angle of attack. Through the numerical simulation, it is found that a new numerical method becomes more efficient for the reason that the free surface elevation is reasonably developed at tire rear of trailing edge.

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해양 자켓구조물 진수 영향인자에 대한 고찰 (Influential Parameters on Offshore Jacket Structure Launching)

  • 조철희;김경수;김재환;이수훈
    • 한국해양공학회지
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    • 제15권2호
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    • pp.141-147
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    • 2001
  • The launching process is one of the most critical operations for large structure in offshore installation. Since as the size increases it limits the availability of offshore crane facilities, the large jacket structures are often installed by launching. As the structure approaches to tilt beam, it reaches critical load, and there are parameters to affect on launching procedure. The major influential parameters are trim, draft of barge, center of gravity, center of buoyancy and reserved buoyancy of jacket. As increasing of trim and draft, structural loads tend to decrease. The trim is found to be more contributing than draft on structural loads. Therefore the trim should be increased so as to decrease structural loads and to avoid stalling of structure and submergence of stern. During the launching process, the distance between jacket and seabed should be investigated which differs from the amount of reserved buoyancy and launching condition of barge. In this paper the effects of parameters on launching process are numerically investigated.

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