• 대한지하수환경학회지
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• 제7권1호
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• pp.20-23
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• 2000

양수시험시 획득되는 회복자료만을 이용하여 저유계수를 추정하는 일반해를 제시하였다. Banton and Bangoy(1996)가 제시한 단 단계(single-step) 양수시험에서 얻는 회복자료를 이용한 저유계수 추정해를 일반적인 다단계 (multi-step)시험 회복자료에도 적용 가능하게 확장한 것이다. 본 연구에서 구한 일반 해를 이용하여 저유계수와 투수계수를 구한 결과 다른 방법으로 구한 결과 값과 잘 일치하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.66-81
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• 2014

A Fortran program was developed to determine the optimal locations of an artificial recharge well. Three objective functions were considered: (1) maximizing the recovery rates, (2) maximizing the injection rates, and (3) minimizing the coefficient of variation of the increased pumping rates. We also suggested a new aggregate objective function which combined the first and the third objective functions. The model results showed that locating the injection well inside the cluster of pumping wells was desirable if either the recovery or the injection rate was taken into account. However, the injection well located outside the cluster evenly increased the pumping rates in existing pumping wells. Therefore, for clustered pumping wells, installing an injection well at the center or the upstream of the pumping wells seems beneficial. For linear arrangement of pumping wells parallel to the constant head boundary, locating the injection well in the upstream was recommended. On the contrary, in case of the linear arrangement perpendicular to the constant head boundary, the injection well installed on both sides of the central part of the pumping wells was preferable.

• 한국유체기계학회 논문집
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• 제6권3호
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• pp.58-63
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• 2003

The performance of turbo pump drops rapidly and it gets into break-down when the void fraction reaches above the threshold value because the impeller flow passage is choked up with air bubbles. Phenomenological understanding of break-down and pumping recovery mechanisms under air-water two-phase flow conditions are therefore important for pump designers and essential assignment for researchers. In this paper, we investigated the characteristics of break-down and pumping recovery due to entrained air occurring inside a screw-type centrifugal pump which has a wide flow passage mainly through the findings of suction and discharge pressures, rotational speed, flow rate measurements and visualization.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.184-187
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• 2001

This study presents procedure and analysis method for not well known slug interference tests. Results of the slug interference tests were compared with those of pumping and recovery tests and conventional slug tests.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.201.2-201.2
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• 2011

A water-source heat pump system has been developed for cooling and heating of a green house on the waterfront in Jinju. In order to supply a heat source/sink of water in alluvium aquifer to the heat pump system, the riverbank filtration facility (two pumping wells and one recharge well) for water intake and injection has been constructed. To pump and recharge water sufficiently, the geometric design such as depth and diameter for the wells have been completed, and details of the well such as slot size and length of the screen and filter pack size have been designed based on the practical and theoretical design method including D30 technique. For the investigation of the hydrogeological characteristics, step-drawdown test, long-term pumping test, and recovery test have been carried out for two developed pumping wells. Step-drawdown test has been performed on 4 step flowrates of 150, 300, 450, $600m^3$/day for 1 hour, and long-term pumping test on flowrate of $500m^3$/day for 24 hours, and recovery test for 6 hours. Since the underground water filtrated by riverbank is flowing smoothly into the well, the water level goes down slightly for the long-term test. Consequently, the stable pumping flowrate for two pumping well has been predicted at least over $1,647m^3$/day which is larger than the flowrate of $1,000m^3$/day for a 60 RT heat pump system.

• 한국기계가공학회지
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• 제12권4호
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• pp.22-28
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• 2013

It is important to begin left ventricular assist device (LVAD) treatment at appropriate time for heart failure patients who expect cardiac recovery after the therapy. In order to predict the optimal timing of LVAD implantation, we predicted pumping efficacy of LVAD according to the severity of heart failure theoretically. We used LVAD-implanted cardiovascular system model which consist of 8 Windkessel compartments for the simulation study. The time-varying compliance theory was used to simulate ventricular pumping function in the model. The ventricular systolic dysfunction was implemented by increasing the end-systolic ventricular compliance. Using the mathematical model, we predicted cardiac responses such as left ventricular peak pressure, cardiac output, ejection fraction, and stroke work according to the severity of ventricular systolic dysfunction under the treatments of continuous and pulsatile LVAD. Left ventricular peak pressure, which indicates the ventricular loading condition, decreased maximally at the 1st level heart-failure under pulsatile LVAD therapy and 2nd level heart-failure under continuous LVAD therapy. We conclude that optimal timing for pulsatile LVAD treatment is 1st level heart-failure and for continuous LVAD treatment is 2nd level heart-failure when considering LVAD treatment as "bridge to recovery".

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.32-35
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• 2006

The validation of a groundwater source heat pump system installation site is estimated by bydrogeothermic model ing. The hydraulic characteristics of the aquifer system is evaluated from pumping and recovery tests. In addition, the temperature distribution by the pumping and the injection of groundwater, and water level fluctuations are simulated by numerical modeling. The total cooling and heating load for the building is designed as 120RT(refrigeration ton) and the ground water source heat pump system covers 50RT as a subsidiary system The scenario of heat pump operation is organized as pumping and inject ion of groundwater that is performed for 8 hours per day in cooling mode for 90 days during the summer season The heat transfer by the injected warm water is limited near the inject ion wells in the simulated temperature distribution. The reason is that the given operation time is too short to expect broad thermal diffusion in large volume of the aquifer in the simulation time The simulated groundwater level and temperature distribution can be used as important data to develope an energy effective pumping and injection well system. Also it will be very useful to evaluate the hydraulic capacity of a target groundwater reservoir.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.487-491
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• 2004

For tile hydrogeological data of the National Groundwater Monitoring Wells(NGMW), a statistical analysis is made to reveal aquifer characteristics of the country. Results of the pumping and recovery test are classified into 4～5 types by the pattern of drawdown and residual drawdown curves. The analysis of aquifer characteristics shows that the hydraulic conductivity of alluvial aquifers is greater than that of fractured-rock aquifers. The hydraulic conductivity of alluvial aquifers slightly increases as the distance to the discharge area decreases. 77.5% of the NGMWs, where the distance to the discharge area is more than 100m, shows the constant head boundary. This result suggests that the fractured and the alluvial aquifers are fairly interconnected, and water can be supplied from one aquifer to tile other where pumping tests are performed. It is analyzed that the wells showing the impermeable boundary are influenced by small scale of aquifers, poor aquifer transmissivities, and impermeable layers.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권6호
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• pp.32-44
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• 2005

국가지하수 관측망의 314개 관정에 대한 양수시험 자료를 분석하여 국내 암반 및 충적대수층이 나타내는 수리전도도 분포, 투수량계수와 비양수량과의 관계, 양수 및 회복시험 유형에 관한 통계 자료를 제시하였다. 충적대수층의 평균 수리전도도는 1.26m/day로 암반대수층(0.076 In/day)보다 약 17배 크게 나타났다. 암반대수층 수리전도도의 평균과 분산도는 국외의 결정질 균열 암반과 거의 일치하였으며, 암종별 평균값은 퇴적암, 화성암, 변성암 순으로 뚜렷한 차이를 보였다. 투수량계수 분석 결과 국가지하수 관측망의 지하수는 암반을 통하여 $32\%$, 충적층을 통하여 $68\%$ 정도가 흐르는 것으로 나타났다. 회귀분석을 통하여 국가지하수 관측망의 대수층이 나타내는 비양수량과 투수량계수의 관계식을 제시하였다 양수 및 회복시험의 수위강하 양상에 따라 대수층의 유형을 $4\~5$개로 분류하여 각 유형이 나타내는 대수층의 특성을 분석하였다 국가지하수 관측망 대수층의 대부분$(83.7\%)$은 함양경계형을 보였으며, 관측소 인근의 하천, 암반 및 충적대수층의 수리적 연결에 의한 두 대수층간의 수직적인 지하수의 흐름, 자유면대수층에서 중력배수에 의해 발생하는 지연산출 등 다양한 공급원에 의하여 함양경계형이 나타난 것으로 분석되었다.

• 지질공학
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• 제29권3호
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• pp.329-337
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• 2019

샘물개발허가의 유효기간은 5년이며, 연장허가를 위하여 만료 6개월 전까지 샘물환경영향조사 보고서를 첨부하여 기간 연장을 신청하여야 한다. 제출된 보고서의 심사과정에서 가장 큰 관심은 샘물 취수에 따른 지하수위 강하, 원수 수질분석 및 감시정의 모니터링 결과에 집중된다. 중생대 백악기 지역과 선캠브리아기 변성암 지역에 각각 위치하는 먹는샘물 제조업체의 취수정에 대하여 수중모터펌프의 양수능력과 양수시간을 조절하는 방법으로 수위강하량과의 상관성을 조사하였다. 양수능력을 감소시키는 방법이 매시간 동일하게 양수시간과 회복시간을 조정하는 방법보다 수위강하량을 줄이는데 효과적이었다. 또한 변성암 지역에 설치한 감시정에 대하여 pH센서의 계측자료를 분석한 결과, 설치 후 경과시간에 따라 계속 증가하여 일정한 값에 수렴하는 것으로 조사되어 관리가 어려운 pH항목을 감시정에서 제외하거나 사용자 친화적인 계측방법으로 보완이 필요할 것으로 판단된다.