• 한국농공학회논문집
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• 제65권2호
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• pp.59-71
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• 2023

As the frequency of drought increases due to climate change, water scarcity in agriculture would be a main issue. However, it seems difficult to solve the water scarcity by securing alternative water sources. The aim of this study is to analyze optimal water supply capacity of agricultural reservoir for emergency operation connecting reservoirs and dams. First, we simulated the water storage of agricultural reservoir playing the role emergency water supplier to other water facility such as dams and other reservoirs. In particular, the results of simulation of water storage through K-HAS model was calibrated using the optimization process based on ratio correction factors of outflow and inflow. Finally, the optimal amount of water supply securing water supply reliability in emergency interconnection operation was analyzed. The results of this study showed that Janchi reservoir could supply 12.8 thousand m³/day maintaining 90 % water supply reliability. The result of this study could suggest the standard for connecting water facilities as emergency water supply.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권8호
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• pp.551-556
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• 2000

A zero-voltage-switching(ZVS) programmable power supply employing the ZVS active clamp forward converter is suggested. Through the analysis on operation region of the supply, the constant power region and the maximum current limit region are clearly identified. Furthermore, the duty ratio range corresponding to the variation range of the output voltages and the control scheme at the minimum duty ration region are presented. Finally, in order to vefity the validity of the operation for the proposed power supply, experimental evaluation results obtained on an 1kW prototype power supply for the 198~242VAC input voltage range(220VAC$\pm$10%), the 0~25V output voltage range, and the 100kHz switching frequency are presented.

• 한국농공학회지
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• 제40권4호
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• pp.58-66
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• 1998

Irrigation Reservoir Water Supply Index(IRWSI), which can be applied to the effective supply and management of the irrigation water resources, was developed. IRWSI was formulated as resealed nonexceedance probabilities of two hydrologic components : reservoir storage ratio and precipitation. To generate nonexceedance probability of hydrologic component, it was important to define the optimal one among the various probability distribution function in the state of nature. To define an optimal probability distribution, in this study, four types of probability distribution function were tested by the K-S fitting, and for the calculation of IRWSI, reservoir storage ratio(%) and precipitation used Normal distribution & Gamma distribution, respectively. In this study, the weight coefficients of a and b for each hydrologic component, which is precipitation and reservoir storage ratio, was decided as 0.8 and 0.2, respectively. While some studies changed weight coefficients according to the size of basin area, this study used same values without considering that. From the analysis of drought characteristics, it was found that the IRWSI was sensitive to the size of irrigation area rather than the size of basin area, and the south-eastern region of Korea had been suffered from severe drought damage.

• 한국수소및신에너지학회논문집
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• 제18권3호
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• pp.348-355
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• 2007

To grasp a feasibility of back fire control by valve overlap period, back fire limit equivalence ratio was estimated with valve overlap period which has the same supply energy and positive intake pressure as valve overlap period $300^{\circ}\;CA$. As the result, it was shown that the smaller valve overlap period has the higher back fire limit equivalence ratio under valve overlap period $300^{\circ}\;CA$ as well as VOP $0^{\circ}\;CA$. This result means that expansion of back fire equivalence ratio by decreasing valve overlap period was caused by decrease of back flow duration of flame from in-cylinder to intake port than decrease of lower supply energy.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.95-97
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• 2000

With the increasing demands for clean environment development of air cleaning systems has been received increasing attention. Pulse power systems are widely used for air cleaning in the industrial applications. High voltage pulse power supply affects the performance of the overall environmental system. In this study high voltage micro pulse power supply for removing NOx in diesel engines is developed. The ratings of the pulse voltage is 20kV. The pulse width is 10usec and max. pulse repetition ratio is 1kHz.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권5호
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• pp.193-200
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• 2004

In this study, we propose a small high voltage power supply, which uses a half-bridge ZCS resonant and Cockroft-Walton circuit as its ESP (Electrostatic Precipitator). This power supply transfers energy from the ZCS resonant inverter to the step-up transformer. The transformer secondary is then applied to the Cockroft-Walton circuit for generating high voltage as a discharging source of electrodes. It is highly efficient because its amount of switching losses are reduced by virtue of the current resonant half-bridge inverter, and also due to the small size, low parasitic capacitance in the transformer stage owing to the low number of winding turns of the step up transformer secondary combined with the Cockroft-Walton circuit. Using this power supply, experiments have been carried out as a function of the switching frequency and duty ratio in order to investigate the smoke removal characteristics. From these results, the best operational condition is obtained at the switching frequency of 9 kHz and the duty ratio of 50% in this ESP.

• 설비공학논문집
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• 제16권10호
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• pp.932-941
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• 2004

The objective of this study is to detect the multi-fault of HVAC system using a new pattern classification technique. To classify the effect of single-fault in determining the pattern, supply air temperature, OA-damper, supply fan, and air flowrate were chosen as experimental parameters. The combination of supply temperature, flow rate, supply fan and OA-damper were chosen as multi-fault conditions. Three kinds of patterns were introduced in the analysis of multi-fault problem. To solve multi-fault problem, the new pattern classification technique using residual ratio analysis was introduced to detect the multi-fault as well as single-fault. The residual ratio could diagnose single-fault or multi-fault into several patterns.

• 한국동물학회지
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• 제11권3호
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• pp.99-102
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• 1968

햄스터에 대하여 水蔘을 1日 1g 씩 25日간 給與하였던 바, 다음과 같은 實驗結果를 얻었다. 1) Hb 量은 人蔘投與 10日부터 급격한 有意性 增加를 보여준다. 2) 人蔘을 給與한 뒤 15日부터 血淸總蛋白의 含量은 有意性 증가를 나타낸다. 3) 人蔘을 給與한 뒤, 10日부터 A/G率은 차차로 增加 되는 것 같이 보이지만 有意性 增加는 25日부터 나타나고 있다. 이는 globulin 보다 albumin의 含量이 더욱 增加됨을 의미한다. 요컨데 햄스터에 대하여 人蔘을 給與한 뒤, 25日간의 결과를 보명 Hb, 血淸總蛋白量 및 A/G率이 增加됨을 알게된 것이다.

• KDI Journal of Economic Policy
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• 제14권1호
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• pp.89-119
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• 1992

본고(本稿)는 최근 논란이 되고 있는 금융기관(金融機關)들의 꺾기관행의 의의와 꺾기의 통화량효과(通貨量效果)를 분석함으로써 예대상계(預貸相計)를 통한 정부(政府)의 꺾기규제정책의 효과를 규명해 보고자 하는 데 그 목적이 있다. 꺾기란 여신(與信)(대출(貸出))에 대응해서 일정한 금액의 수신(受信)(예금(預金))을 요구하는 금융관행을 통칭하는데, 기존 문헌에 의하면 이윤극대화(利潤極大化)를 추구하는 금융기관이 정보(情報)의 비대칭성이나 예금(預金) 및 대출금리규제(貸出金利規制)와 같은 금융규제(金融規制) 등에 따른 금융시장의 불완전성을 극복하기 위해 도입하는 관행으로서 궁극적으로는 금융자원배분(金融資源配分)의 왜곡을 시정하는 데 기여하게 된다. 한편 꺾기의 통화량효과(通貨量效果)는 꺾기가 일국(一國)의 통화승수(通貨乘數)에 미치는 효과에 의존하게 되는데, 꺾기의 통화승수효과(通貨乘數效果)는 총대출 중 예금으로 회귀하는 적정예금회귀율(滴定預金回歸率)과 은행(銀行)들의 적정예금지급준비율(滴定預金支給準備率)에 미치는 꺾기의 효과에 의존하게 된다. 이론적으로 이들 효과의 방향은 불분명한데 실증분석결과에 의하면 우리나라의 경우 꺾기의 통화량효과(通貨量效果)는 유의성(有意性)이 없는 것으로 나타나고 있다. 따라서 이에 의하면 꺾기가 인위적으로 통화량(通貨量)을 증가시킬 것이라는 통념은 지지되지 않고 있을 뿐만 아니라, 예대상계정책(預貸相計政策)을 통해 통화량(通貨量)을 감소시킴으로써 여유대출자금(餘裕貸出資金)을 창출할 수 있을 것이라는 기대가 실현되기도 어렵다 할 것이다. 이에 따라 앞으로 예대상계(預貸相計)를 통화량관리(通貨量管理)의 방편으로 이용하고자 하거나 이를 통해 대출여유자금(貸出餘裕資金)을 창출하고자 하는 정책의 추진은 대단히 신중을 기하는 것이 바람직하다 할 것이다.

• 환경위생공학
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• 제7권1호
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• pp.45-56
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• 1992

The Anaerbic Anoxic/oxic process is one of the biological treatment methods to remove nitrogen and phosphorus effectively which are nutritional elements for eutrophication. Supernatant of primary sediment of Anaerobic digester is used as a carbon source instead of methanol methanol supply in usual A$_{2}$/O process. The efficiency of the following treatment processes are as follow : 1) Changing recycle ratio in the usual A$_{2}$/O process without the stage of Anaerobic digester. 2) Changing recycle ratio in the usual A$_{2}$/O process with the supernatant supply of the Anaerobic digester. In the result of comparison, changing recycle ratio is almost no effect in the removal of phosphorus, however the effect of removal in nitrogenous substance are remarkable, and the effect of Anaerobic digester is not as effective as expected because the BOD removed in the digester partly, the rate of phosphorus to the BOD exceed pertinent range.