• 한국수자원학회논문집
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• 제34권5호
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• pp.487-497
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• 2001

옥정호에 대한 수질변화 조사 자료를 토대로 수질모의를 실시하였으며, 그 결과 바탕으로 효율적인 댐저수지 수질관리 방안을 제시하였다. 옥정호의 수질은 계절에 다라 중영양상태와 부영양상태를 나타내는 것으로 평가되었으며 이러한 수질상태는 외부로부터 유입되는 오염원에 많은 영향을 받게 되므로 우선 유역으로부터 유입되는 오염부하의 정확한 산정이 필요한 것으로 평가되었다. 1999년에 조사한 7차례의 강우기간 중 총 부하와 일년간 발생한 총 부하를 비교하면 강우량은 17.5%인데 비해 SS는 72.8%, TN과 TP는 약 50%가 강우기에 유입되는 것으로 조상되었다. 또한 퇴적물의 용출율은 TP의 경우 가두리 양식장이 운영되던 지점에서는 11.92 mg/L, 정기수질 조사지점에서 0.2∼1.9 mg/L로 국내·외 자료와 비교하여 용출율이 작은 것으로 나타났다. 댐저수지 수질관리 방안 수립을 위하여 WASP5 모형을 적용하였으며 검증된 결과를 이용하여 각 소유역에서 오염부하 삭감에 따른 6가지 방안에 대한 수질모의를 실시하였고 각각에 대한 수질개선 효과를 제시하였다. 가장 효율적인 방안은 임실천 유역과 관촌교 유역의 오염부하를 제어하는 방안으로 평가되었으며, 가장 수질개선효과가 좋은 것은 대표 세유역의 오염부하를 제어하는 것으로 나타났다. 이를 바탕으로 수질개선을 위한 하·폐수처리장의 건설 적지를 제시하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.111-112
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• 2013

• 한국해양공학회지
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• 제25권2호
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• pp.79-84
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• 2011

The purpose of this study was to investigate the buckling load of filament-wound composite towers for large scale wind-turbines using the finite element method (FEM). To define the material properties, we used both the effective property method and stacking properties method. The effective properties method assumes that a composite consists of one ply. The stacking properties method assumes that a composite consists of several stacked plies. First, a linear buckling analysis of the tower, filament-wound with angles of $[{\pm}60]$, was carried out using the two methods for composite material properties: the stacking method and effective method. An FE analysis was also performed for the composite towers using the filament winding angles of $[{\pm}30]$, $[{\pm}45]$, and $[{\pm}60]$. The FE analysis results using the stacking properties of the composite were in good agreement with the results from the effective properties method. The difference between the FEM results and material properties method was approximately 0~2.3%. Above the angle of $[{\pm}60]$, there was little change in the buckling load.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.413-416
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• 2007

Motion-estimation/motion-compensation (ME/MC) provides superior motion picture quality but its huge computation load results in high cost. Impulsive driving is a cost-effective solution but it suffers from large flicker and brightness loss. Motion compensated impulsive driving technology has been developed to achieve high motion picture quality in a cost-effective implementation by combining ME/MC and impulsive driving. The key idea is to apply ME/MC or impulsive driving selectively according to the motion vector distribution of the incoming image sequence. In this paper, the description of the algorithm and the experimental results are provided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.226-228
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• 2006

This paper presents the two lossless auxiliary inducors-assisted voltage source type half bridge(single ended push pull:SEPP) series resonant high frequency inverter for induction heated fixing roller in copy and printing machines. The simple high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation forwide its output power regulation ranges and load variations under constant high frequency pulse density modulation (PDM) scheme. Its transient and steady state operatprinciple is originally described and discussed for a constant high-frequency PDM control strategy under a stable ZCS operation commutation, together with its output effective power regulation charactertics-based on the high frequency PDM strategy. The experimenoperating performances of this voltage source SEPP ZCS-PDM series resonant high frequency inverter using IGBTs are illustrated as compared with computer simulation results and experimenones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The feasible effectiveness of this high frequency inverter appliimplemented here is proved from the practical point of view.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권3호
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• pp.201-213
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• 2012

A gear type lubrication pump is an essential component of the powertrain and has a major role for supplying oil to the gears and bearings in automatic transmission with a hydraulic clutch. Therefore, the durability test code design of lubrication pump is very important to ensure the reliability of the entire transmission and the vehicle. In this study, the design process for the life testing of lubrication pump has been generalized by four steps. The four design steps of the life testing of lubrication pump consist of the configuration of load spectrum, rain flow counting and analysis of load level, the equivalent damage assessment and test code generation. In fact, the load spectrum should be obtained from the field operating condition but that kind of data is the top secret of manufacturers. This is not open to the public in general. So we could use the artificially simulated load spectrum instead of field obtained one and focused on the development of the general process for designing the life test of a gear type lubrication pump. Reliability goals for lubrication pump, pressure, torque, temperature and load spectrum, if present, as appropriate for the given test conditions, accelerated life testing for the lubrication pump can be designed by the developed design steps.

• 한국주거학회논문집
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• 제12권4호
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• pp.227-230
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• 2001

The Sri Autobindo Learning Center(SALC) is sponsoring the development of a passive solar village in Creston, Colorado, Situated near the Sangre de Cristo mountains, Savitri Village will be one of several religious communities in the area. This village will incorporate 12 permanent residences and teaching and guest facilities for fifty to one hundred people. The purpose of this study is to evaluate the passive solar elements and performance of guest house at the Sri Autobindo Learning Center(SALC). To do this evaluation, the following tasks needed to be addressed. 1. the guest house design 2. the location of weather data 3. The determination of the building heating load As part of the evaluation process, guest house design will be modified and the building load and solar saving recalculated. This process will be completed until the building performance is deemed satisfactory. The conclusion is as follows; The high solar savings fraction predicted by SUNCODE should taken as an indication that further design changes would probably not be cost effective. But adding removal overhangs or other low costs measures to increase comfort in the summer appear to be appropriate.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.816-818
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• 2005

In this paper, we have developed an hourly operating strategy for Direct load control (DLC) considering the efficiency of DLC program and increasing the utility of DLC resource. According to the operating code for DLC, the DLC center should curtail the load for 4 hours when the control notification has been enforced. Since the above strategy may limit the participation of entities, who intend to take part in the DLC program, the new strategy to mitigate the above limitation is required. In this paper, we have developed the operating strategy of DLC program and the mechanism to apply the proposed strategy in the DLC center. The proposed strategy makes the important role from the view of guaranteing the effective alternative raising the participation and avoiding the penalty of the entities.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1114-1119
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• 2010

Pile foundations have been used for upholding superstructure's loads. The researches on pile foundations subjected to compressive forces or horizontal loads have been actively carried out. However, recently, pile foundations, which are subjected to pull-out forces, are getting increased. The study on the pull-out resistance of piles becomes to be important. In addition, it is expected that belled piles will be used more and more, since the belled piles are effective to resist the pull-out forces. But there is still a lack of research on pull-out resistance of belled piles. Therefore, in order to investigate the resisting effect against pull-out of belled piles which is embedded in cohesionless soil. a series of pull-out test is performed on belled piles in field. Especially, the relation between load and displacement is analyzed through the pull-out test.

• ETRI Journal
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• 제43권1호
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• pp.53-63
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• 2021

Cloud computing has drastically reduced the price of computing resources through the use of virtualized resources that are shared among users. However, the established large cloud data centers have a large carbon footprint owing to their excessive power consumption. Inefficiency in resource utilization and power consumption results in the low fiscal gain of service providers. Therefore, data centers should adopt an effective resource-management approach. In this paper, we present a novel load-balancing framework with the objective of minimizing the operational cost of data centers through improved resource utilization. The framework utilizes a modified genetic algorithm for realizing the optimal allocation of virtual machines (VMs) over physical machines. The experimental results demonstrate that the proposed framework improves the resource utilization by up to 45.21%, 84.49%, 119.93%, and 113.96% over a recent and three other standard heuristics-based VM placement approaches.