• 한국신뢰성학회지:신뢰성응용연구
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• 제14권4호
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• pp.230-235
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• 2014

The failure modes of pneumatic directional control valves include leakage, wear of the spool seal, and sticking of the spool. Among them, the main failure mode of the valve is leakage. The leakage is caused by the wear of the spool seal. However, due to the characteristics of the seal material, the leakage rate is fluctuated a lot rather than constantly increased over time. If life analysis is performed using the first time data of leakage failure, predicted life cycles can be different from the real life cycles. This paper predicts life cycles of the pilot pneumatic directional control valve based on the three point moving average which considers the average of the fluctuating leakage rate.

• 상하수도학회지
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• 제20권2호
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• pp.197-206
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• 2006

The leakage in the water distribution system means both the loss of money and water resource. To minimize the leakage, we introduced the pressure control method using the pressure reducing valve and pump schedule. For the pressure control, the total leakage is needed to divide into each node. In this study, EPANET 2.0 was used to simulate the water networks in two selected blocks after the total leakage was distributed with each node by four ways. The leakage was allocated into each node as water measured by meter, water pressure, water faucets and Lpcd and simulated by EPANET 2.0. Regardless of the leakage distribution ways, there was no significant difference between the measured water and the estimated water pressure. Thus, the leakage distribution way using water pressures estimated by simulation could be recommended. The scenarios controlling the pressure reducing valve and pump were made in two blocks(A and B). $86,713m^3/year$ leakage in the A block and $11,442m^3/year$ in the B block could be reduced as controlling the pressure reducing valve and pump schedule. It was shown that the fifty million won a year can be saved in the A block and 6.8 million won in the B block.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.725-728
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• 2000

Air hoist system has been using in the industry. In gradually, the system of function was developing, but system was not enough compensation for leakage. In this paper, developed the anti-leakage system with stability and convenience of operate.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.655-658
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• 2005

Due to reduced device sizes and threshold voltages, leakage current becomes an important issue in CMOS design. In a CMOS combinational logic circuit, the leakage current in the standby state depends on the state of the inputs and thus can be minimized by applying an optimal input when the circuit is idling. In this paper, we present a New Input Vector Control algorithm, called Leakage Minimization by Input vector Control (LMIC) for minimal leakage power. This algorithm finds the minimal leakage vector and reduces leakage current up to 22.% on the average, for TSMC 0.18um process parameters. Minimal leakage vectors are very useful in reducing leakage currents in standby mode of operation.

• Journal of Power Electronics
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• 제16권1호
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• pp.66-73
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• 2016

The quantity of alternating current (AC) leakage and the value of distortion factor in capacitor currents are discussed with regard to a new power component called variable capacitance device (VCD). This component has terminals for controlling its capacitance. Nonlinear dielectric characteristics are utilized in this device to vary the capacitance. When VCD operates in an AC circuit, the AC leakage from this device through direct current (DC) control voltage source increases according to the conditions of DC control voltage and so on. To solve this problem, we propose techniques for suppressing AC leakage. Although VCD has strong nonlinear characteristics, the current through the capacitor is not distorted significantly. The relations between AC leakage and the distortion in current waveforms are investigated. An application example for an AC power regulator is also introduced to evaluate the distortion in waveforms.

• 전력전자학회논문지
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• 제19권2호
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• pp.164-172
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• 2014

This paper presents an analysis of a leakage inductance for a toroidal type flyback transformer. The equation to calculate the leakage inductance is derived using the MMF diagram of the transformer. The analysis for the different types of the cores and winding structures is also provided using the FEM simulation. The winding structures minimizing the leakage inductance are finally discussed from the simulation and experimental results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.488-491
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• 1997

In this paper, a ncw control 'ialvc which can misc air-iraksge pneumatically and compensate pressure drop for an alrho~ st system uas proposed A new control valve called "Pneuniatic C70ntro1 Valve (PCV)" functions as a control valve to compcns;ltc prcssure in thc casc of air-leakage. by using the pure pneummatic control ofpilot pressure. Based on the sirnulation of the proposed PCY, thc experimental system was fabricaied su as to illustrate the efficient pcrformance of the proposed PCV with anti-leakage. Such good perfo~manccs of PCV in the air-hoist system are shown by the simulation. In addition, the simulation bascd design approach presented in this paper can be applied to any hydraulic or pneumatic-hydraulic system.

• 전자공학회논문지 IE
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• 제49권2호
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• pp.52-57
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• 2012

사회발전과 더불어 가전기기의 발전은 누전으로 인한 감전, 화재 등 여러 가지 누전전류의 위험성에 노출되어 있다. 가정 내 배전함에 누전차단기가 설치되어 있지만, 기존의 누전차단기는 배전함에 설치되어 누전시 전원을 차단해주는 기능만을 갖는다. 또한 집안 벽마다 설치된 콘센트에 연결된 가전기기들을 개별적으로 점검하는 일은 쉬운 일이 아니다. 따라서 본 논문에서는 누전차단기회로의 성능 및 회로를 분석하고, ZigBee기반의 센서를 이용하여 가정 내 가전기기들의 누전상태를 모니터링 할 수 있는 방법에 대해 제시하였다. 성능분석 결과, 제안된 ELB 누전전류 제어시스템은 가전기기에 내장된 누전차단기 회로를 응용했기 때문에 각각의 가전기기들의 누전상태를 확인할 수 있어 기존 시스템 보다 누전을 쉽고 편리하게 모니터링 할 수 있을 것이라 기대한다.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.131-138
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• 1981

The purpose of this study was to evaluate the marginal leakage of composite resin. Preparing 144 class V cavities on freshly extracted noncarious teeth, composite resins were prepared and inserted by one dentist according to the manufacturer's instructions. The experiments were performed in two different groups; In group I; Class V cavities with $90^{\circ}$ cavosurface angle, In group II; Class V cavities with $135^{\circ}$ cavosurface angle. And each group was divided 2 subgroups; In control group; composite resin restoraions without acid etch technique. In experimental group; composite resin restorations with acid etch technique. All specimens were immersed in 0.05% crystal violet solution. Before examination, the restored teeth were subjected to thermal stress. The specimens were sectioned occlusogingivally through the center of the restorations with a diamond disk. The sections were examined under a reflected light microscope at 1 day, 7 days and 30 days after immersing the specimens in dye solution. The results were as follows; 1. Control group of group I and group II showed marginal leakage. 2. The degree of marginal leakage in experimental group was greater reduced than control group. 3. In control group, the degree of marginal leakage in group I was greater than group II. 4. In experimental group, there is not statistical differences of the degree of marginal leakage between group I & group II.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.61-62
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• 2018

On this Study, it conducts the Standards investigation about air leakage of Buildings for performance improvement of Smoke control in Fire. In domestic standards, it is incomplete the Criteria standards of air leakage. Therefore it is considered that won't limit the smoke spread due to stack effect. But in the case of the United States, it conducts the Hot smoke air-Leakage test and it consider that can prevent the Smoke Spread in Compartment.