• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.114-116
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• 2001

This paper deals with the design and fabrication of loop superconducting Persistent Current Switch(PCS) circuit. The self and mutual inductances of the circuits are calculated and compared to the measured values. The size of loop circuits was determined using the calculated inductances, and the fabrication processes of the superconducting persistent current switch are described.

• 한국통신학회논문지
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• 제28권11A호
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• pp.912-920
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• 2003

본 논문에서는 UWB용 소형 안테나를 설계하기 위해 폭이 넓은 안테나의 슬롯면내에 구형 루프를 추가하고 이중급전 방법을 사용한 슬롯루프 안테나를 제안하였다. 이 안테나는 3개의 기하학적인 공진 구조에 의해 다중 공진 모드를 발생시키는 새로운 구조이며, 각각의 공진 주파수에 따른 임피던스 정합은 이중 급진점의 오프셋 길이를 변화하여 얻을 수 있다. 제작된 안테나는 중심 주파수가 6.755 ㎓이며, 슬롯의 크기는 12.5mm${\times}$50mm이고 슬롯 내의 구형 루프의 크기는 10.5mm${\times}$27.5mm이다. 실험 결과 슬롯루프 안테나의 비대역폭은 VSWR 2:1 기준으로 63.21 %로 측정되었으며 이는 이론 값과 5% 범위 이내에서 일치하였다. 또한 안테나의 최대 이득은 7.42 ㏈i로 측정되었다.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1134-1145
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• 2021

A design parameter study is presented for the closed-loop type passive containment cooling system (PCCS) which is equipped with two heat exchangers: one installed at the inside of the containment and the other submerged in the water pool at the outside of the containment. A GOTHIC code model for PCCS performance analyses was set up and the design parameters such as the heat exchanger sizes, locations, and water pool tank volumes were analyzed to investigate the feasibility of installing this type of PCCS in PWRs like OPR-1000 being operated in Korea. We identified the size of the circulation loop and heat exchangers as major design parameters affecting the performance of PCCS. The analyses showed that the heat exchangers in the inside of the containment would be more influential on the heat removal capability of PCCS than that installed in the water pool at the outside of the containment. Hence, it was recommended to down-size the heat exchangers in the water pool to optimize PCCS without compromising its performance. Based on the parametric study, it was demonstrated that a closed-loop type PCCS could be designed sufficiently compact for installation in the available space within the containment of PWRs like OPR-1000.

• Korean Chemical Engineering Research
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• 제55권3호
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• pp.279-286
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• 2017

This review paper evaluates different kinds of synthesis methods for calcite precipitated calcium carbonates by using different materials. The various processing routes of calcite with different compositions are reported and the possible optimum conditions required to synthesize a desired particle sizes of calcite are predicted. This paper mainly focuses on that the calcite morphology and size of the particles by carbonation process using loop reactors. In this regard, we have investigated various parameters such as $CO_2$ flow rate, Ca $(OH)_2$ concentration, temperature, pH effect, reaction time and loop reactor mechanism with orifice diameter. The research results illustrate the formation of well-defined and pure calcite crystals with controlled crystal growth and particle size, without additives or organic solvents. The crystal growth and particle size can be controlled, and smaller sizes are obtained by decreasing the Ca $(OH)_2$ concentration and increasing the $CO_2$ flow rate at lower temperatures with suitable pH. The crystal structure of obtained calcite was characterized by using X-ray diffraction method and the morphology by scanning electron microscope (SEM). The result of x-ray diffraction recognized that the calcite phase of calcium carbonate was the dominating crystalline structure.

• 한국정보통신학회논문지
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• 제21권2호
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• pp.339-344
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• 2017

본 논문에서는 Early-late detector, Duty-rate modulator, 그리고 LSI(Lock Status Indicator)를 사용하여 작은 크기와 빠른 위상고정 시간을 갖는 위상고정루프를 제안하였다. 제안된 위상고정루프는 작은 용량을 가진 하나의 커패시터를 사용하게 됨으로써 칩의 크기를 결정하는 루프필터의 크기가 작아지게 되어 크기를 최소화 하였다. 기존의 전하펌프와 달리 2개의 전하펌프를 사용하여 하나의 커패시터를 사용하더라도 2차 루프필터를 사용 한 것과 같은 전압파형을 만들어 줌으로써 위상을 고정시킬 수 있다. 2개의 전하펌프는 UP, DN신호 위상의 빠르기를 감지해주는 Early-late detector와 일정한 비율의 파형을 만들어주는 Duty-rate modulator에 의해 제어된다. LSI회로를 사용함으로써 빠른 위상고정시간을 얻을 수 있다. 제안된 위상고정루프는 1.8V $0.18{\mu}m$ CMOS 공정을 사용하여 설계하였고, Hspice 시뮬레이션을 통해 회로의 동작을 검증하였다.

• Archives of Pharmacal Research
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• 제19권4호
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• pp.275-279
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• 1996

To study the functional roles of dopamine receptors, we decided to raise antibodies against these proteins. To make antigen, we expressed the whole 3rd cytoplasmic loop of dopamine receptors in a fusion protein with glutathione-S-transferase (GST). $For D_2\; and\; D_3$ receptors, it was successful to express and purify fusion proteins for the whole 3rd cytoplasmic loops. However, we could not express the fusion protein for the whole 3rd cytoplasmic loop of $D_4$ dopamine receptor in the bacteria. To study the causes that prevent the bacterial expression of the GST-fusion protein of the 3rd cytoplasmic loop of $D_4$ dopamine receptor, we conducted more detailed studies on $D_4$ dopamine receptor. To locate the region which prevents bacterial expression, we made sequential constructs in the 3rd cytoplasmic loop decreasing the size step by step, and confirmed their expressions in the SDS PAGE. It was found that certain regions of 3rd cytoplasmic loop of $D_4$ dopamine receptor, located in N-terminal side of the 3rd cytoplasmic loop of $D_4$ dopamine receptor suppress the bacterial expression of fusion protein.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.58-63
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• 2009

A ground-loop heat exchanger for the ground source heat pump system is the core equipment determining the thermal performance and initial cost of the system. The size and performance of the heat exchanger is highly dependent on the ground thermal properties - the ground effective thermal conductivity, the borehole thermal resistance and the undisturbed ground temperature. Nowadays, precast concrete piles using steel reinforced precast concrete piles - energy piles - are used to reduce the installing cost of the ground-loop heat exchanger. We were carried out some tests to investigate the effects of some parameters such as borehole length, grouting materials and U-tube configuration of the energy piles. 4 concrete piles, each measuring $250mm{\sim}400mm$ in diameter and approx. 10m in length, and rigged with single spiral and 3 U-tube loop of $16mm{\times}2.3mm$ PB piping. The thermal response tests were conducted using a testing device for 4-different ground-loop heat exchangers. During the heating period, the energy piles absorb the heat of 0.89kW to 1.37kW.

• 한국세라믹학회지
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• 제32권4호
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• pp.436-440
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• 1995

Effects of microstructure of two Mg-ferrite specimens with the same starting composition and relative density but with different grain size on B-H hysteresis loop, natural resonance frequency, and ferromagnetic resonance line width are reported. Such properties as B-H hysteresis loop, saturation magnetization, natural resonance frequency, and ferromagnetic resonance line width were influenced by the microstructure development during sintering. Large grain size specimen showed high saturation magnetization, low coercive force, low natural resonance frequency, and low ferromagnetic resonance line width compared with the specimen of small grain size. The main reason for the changes in properties can be explained by the variation in anisotropic characteristics due to Fe+2 content generated during sintering process.

• 산업경영시스템학회지
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• 제28권1호
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• pp.55-63
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• 2005

This paper is to analyze the travel distance and the transport size of the vehicle when the AGV carries multiple-load in the tandem automated guided vehicle systems. The size of multiple-load represents the number of load that the AGV can carry simultaneously. The AGV can carry simultaneously multiple-load that load types are different. The transport system of the manufacturing system is a tandem configuration automated guided vehicle system, which is based on the partitioning of all the stations into several non-overlapping single closed loops. Each loop divided has only one vehicle traveling unidirectionally around it. The AGV of each loop has to have sufficient transport capacity that can carry all loads for given unit time. In this paper, the average loaded travel distance and the size of feasible multiple-load of the vehicle are analyzed. A numerical example is shown.

• 한국정보통신학회논문지
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• 제5권5호
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• pp.1011-1016
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• 2001

본 논문에서는 교차 및 결합 선로를 갖는 마이크로스트립 개방루프 공진기를 이용한 협대역 대역통과 여파기를 설계.제작하였다. 이 여파기는 크기가 작고 경량이며, 협대역 타원함수 대역통과 특성과 같은 우수한 특성을 가지고 있다. 여파기는 두 개의 동일한 마이크로스트립 개방루프 공진기와 교차 및 결합선로로 구성되어 있다. 개방루프 공진기를 사용함으로서 여파기 크기는 링 공진기와 비교하여 50% 정도가 축소된다. 교차선로는 억제대역에서 두 개의 노치를 제공하므로, 통과대역에서 예리한 선택도를 가진다. 중심주파수 2.455GHz로 설계된 마이크로스트립 대역통과 여파기는 1.22%의 대역폭을 가지며, 이는 무선LAN의 응용에 매우 적합하다. 여파기는 포토 에칭법으로 제작하였다 제작된 대역통과 여파기는 2.458GHz대에서 0.85%의 대역폭을 가지며 크기는 $2.6cm\times1cm$이다.