• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.89-92
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• 2001

This study was to analyse the correlations between pumping rate to irrigated area and rainfall amount in the Geum river basins. A total of 84 pumping stations and field data from the paddy of 28,772 ha were introduced to the analysis. The results showed that the pumping volume was highly correlated to the rainfall during the irrigation period and irrigated area. But, it was difficult to determine the exact correlation factors, because of the lack of data like the efficiency of water in the paddy field.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.13-16
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• 2002

The analysis of characteristics of pumping in the small tube well for agriculture were surveyed. Study area was located at the Galsinri in Yesangun near the yedang reservoir. Agricultural electricity using rates for pumping, ground water level and volume of pumping was monitored every week. Pump working ratio and pump efficiency during period of transplanting of rice showed 48.9%, 62.7% respectively.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권3호
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• pp.111-119
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• 2005

In the magnetic fluid linear pump, the pumping forces and pumping speed mainly depend on the current patterns. In this research, a new design to reduce the discontinuities of the pumping forces of the MFLP was studied. Continuous pumping of the newly designed MFLP by using AC current increases pumping efficiency and reduces the pumping force. Forming shapes of the magnetic fluid at the intermediate state were computed and compared to measurement. Since the back flow of the fluid is reduced remarkably, 4 yoke's AC driving is more efficient than 7 yoke's DC driving. The size, weight and pumping discontinuity are also reduced.

• 대한기계학회논문집A
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• 제28권4호
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• pp.378-385
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• 2004

Viscous-driven pumping is a very promising type in microscale applications. However, there exist a few disadvantages such as low efficiency and small volume flow rate. In the present study, a pump with tandem rotating cylinders and its optimum synthesis are proposed fur enhancing pumping performance. First, using an unstructured grid CFD method, we investigate the effects of geometrical parameters and then the performance of the pump with tandem cylinders is evaluated. Next, an optimum design synthesis tool is constructed by combining the aforementioned CFD analysis model with the mathematical optimization model, namely, Modified Method of Feasible Directions (MMFD). This technique is used to optimize the geometrical parameters of the pump, fur maximizing pumping efficiency. From the optimization results, it is believed that the present optimum synthesis is robust and has a potential fur other microfluidic device design.

• 지질공학
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• 제20권2호
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• pp.127-136
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• 2010

본 연구에서는 현장에서 수행한 단계양수시험을 이용하여 최적 양수량, 우물효율 및 양수 영향반경을 산정하였다. 시험결과 최적 양수량은 KDPW 1, KDPW 2에서 수위강하가 0.5, 1.0 m 일어났을 때 각각 9.37, 16.20 $m^3/day$과 8.11, 14.10 $m^3/day$으로 계산되었다. 또 우물효율은 KDPW 1에 대하여 72.02~90.73%의 효율을 그리고 KDPW 2에 대하여 70.62~88.52%의 효율을 보였다. 한편 정류상태 해석으로 영향반경은 KDPW 1에서 양수하였을 경우 관측정에서 3.50~31.92 m로 계산되었다. 또 KDPW 2에서 양수하였을 경우 관측정에서 영향반경이 0.14~37.43 m로 산정되었다. 부정류 해석결과에 따르면 KDPW 1에서 양수하였을 경우 관측정에서 영향반경이 0.02~8.34 m로 계산되었다. 그리고 KDPW 2에서 양수하였을 경우 관측정에서 영향반경이 0.24~9.68 m로 계산되었다. 본 연구에서 적용한 방법론은 오염지하수 양수처리법의 설계에 실용적으로 활용될 수 있을 것으로 사료된다.

• 대한전자공학회논문지SD
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• 제40권11호
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• pp.45-53
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• 2003

DRAM에서 사용되는 내부 승압 전원 전압과 기판인가 전원 전압 발생기를 공유함으로써 단일 Charge Pump에서 승압 전원과 기판 전원을 동시에 발생시키는 회로를 설계하였다. 이 회로는 0.14um의 DRAM 공정을 사용하여 기존 보다 전력 소모를 30%, 전체 면적을 40% 그리고 Pumping capacitor 면적을 29.6% 각각 감소하였으며 또한 전류 공급 효율을 13.2% 향상 시켰다. Charge Recycling 기법을 적용하여 Pumping capacitor의 Precharge 구간 동안 소모되는 전류를 75% 감소하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권4호
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• pp.257-263
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• 2006

New charge pump circuits with low area and high power efficiency are proposed and verified in this paper. These pump circuits do not suffer the voltage stress higher than $V_{DD}$ across their pumping capacitors. Thus they can use the thin-oxide MOSFETs as the pumping capacitors. Using the thin-oxide capacitors can reduce the area of charge pumps greatly while keeping their driving capability. Comparing the new pump (NCP-2) with the conventional pump circuit using the thick-oxide capacitors shows that the power efficiency of NCP-2 is the same with the conventional one but the area efficiency of NCP-2 is improved as much as 71.8% over the conventional one, when the $V_{PP}/V_{DD}$ ratio is 3.5 and $V_{DD}$=1.8V.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.111-122
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• 2014

Partitioning interwell tracer test (PITT) is a method to quantify and qualify a site contaminated with NAPLs (Non-Aqueous Phase Liquids). Analytical description of PITT assumes that the injection-pumping well pair is on the line of the ambient groundwater flow direction, but the test-well pair could frequently be off the line in a real field site, which could be an erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair on the ambient groundwater flow direction based on the result from PITT. From the experiments, it was found that the obliqueness of the test-well pair to the ambient groundwater flow direction could affect the tracer test resulting in a decreased NAPL estimation efficiency. In case of an oblique arrangement of the test-well pair to the ambient flow direction, it was found that the injection of a chase fluid could enhance the estimation efficiency. An increase of the pumping rate could enhance the recovery rate but it cannot be said that a high pumping rate can increase the test efficiency because a high pumping rate cannot give partitioning tracers enough time to partition into NAPLs. The results have a implication that because the arrangement of the test-well pair is a controlling factor in performing and interpreting PITT in the field in addition to the known factors such as heterogeneity and the source zone architecture, flow direction should be seriously considered in arranging test-well pair.

• 전기학회논문지P
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• 제50권3호
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• pp.109-116
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• 2001

In this paper, we adapted BLDC motor to PV water pumping systems to maintain high efficiency in the wide speed area. Also, to design confidence we adapted the vector control that drive the maximum torque at each speed limit. We designed optimal gain value of current, speed and pressure PI controller. Inverter gate pulse used Space Vector PWM to reduce torque pulsation of BLDC motor. According to, it was improve general matters of high water storage tank method by direct water supply pumping method.

• 펄프종이기술
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• 제48권3호
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• pp.14-22
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• 2016

Pulping is a stage that can change fibrous raw materials into pumpable slurry. Recovered paper can be defibrated to individual fibers by shear stress generated by rotation of a rotor and water. Disintegration of recovered paper is more complicated than that of chemical pulp. When disintegration of recovered paper is poor, screening and cleaning efficiency will be worse and properties of paper will also be deteriorated. Therefore, pulping is an important treatment for improvement of availability of recovered paper and process runnability. In this study, degrees of disintegration of KOCC obtained from a linerboard mill was analyzed with a pilot-scale screen. Flake removal of KOCC slurry was performed by a pilot screen. Simple pumping action gave a positive effect on disintegration of KOCC. After pumping for 10 minutes, paper strength increased without the change of water retention value and fibrillation of KOCC slurry. This phenomena can be explained by modification of hornified surface of KOCC fibers by shear stress generated by pumping. Consequently, disintegration efficiency of KOCC can be enhanced by control of retention time at pulper or an agitation power at chests of papermaking process.