• Ocean and Polar Research
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• 제32권3호
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• pp.247-254
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• 2010

Single cell PCR analysis and light and scanning electron microscopic techniques were utilized to identify free living bivalve larvae in the coastal waters of Tae-an, on the west coast of Korea. Through DNA sequencing, venerid clam larvae were isolated and identified as Ruditapes philippinarum (99% similarity) and Meretrix lusoria (99%). Under microscopic observation, the D-veliger stage of R. philippinarum exhibited symmetrical shoulder angles and an elliptical ventral form. In contrast, M. lusoria displayed asymmetrical shoulder angles and a round ventral form in the umbonal stage. Size of the R. philippinarum larvae was $156{\pm}22{\mu}m$ in length, $126{\pm}12{\mu}m$ in height, $92{\pm}14{\mu}m$ in width with a length: height ratio of 1.23. Meretrix lusoria was $202{\pm}44{\mu}m$ in length, $161{\pm}35{\mu}m$ in height, $96{\pm}38{\mu}m$ in width with a length: height ratio of 1.25. Experimental results indicate that morphological and molecular characteristics provide evidence for the larval identification of these two venerid clam larvae species in nature.

• 대한전자공학회논문지TC
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• 제45권8호
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• pp.15-27
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• 2008

본 논문에서는 스트립라인 형태의 주파수 선택적 표면 덮개층을 이용하여 PCS대역의 기지국 안테나로 사용될 수 있는 EBG 공진기 안테나를 제안하였다. PCS대역의 기지국 안테나에서 요구되는 안테나 이득과 대역폭을 가지는 EBG 공진기 안테나를 설계하기 위하여 덮개층 주기 구조의 단위 셀 시뮬레이션을 이용한 다양한 설계 파라미터의 변화에 따른 공진주파수 및 대역폭의 특성을 분석하였다. 이를 위하여 여러 구조들 중에서 많이 사용되는 스트립다이폴과 스트립라인 구조의 특성을 비교하였으며, 스트립라인 구조가 스트립다이폴 구조에 비해서 EBG 공진기의 공진 길이가 더 짧고 대역폭 조정이 더 쉬움을 알 수 있었다. 단위 셀 시뮬레이션 결과를 이용하여 PCS대역을 만족하는 평면구조의 EBG 공진기 안테나와 원통형 EBG 공진기 안테나를 설계하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1295-1296
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• 2007

A lot of researches about dye-sensitized solar cell (DSC) are recently being conducted. Because DSC has several advantages to pass the limits of silicon solar cells such as a low manufacturing expense, a simple manufacturing process and its transparency. But most researches on DSC are still conducted about the unit cell and laboratory-centered. That is, present researches on DSC are not practical. Therefore, researches about large area cells and modules have to be prerequisites for DSC to have the practicality. Characteristics of large area DSC are so different from those of small area DSC in aspect of fill factor and efficiency. In this study, we made an experiment on finding suitable size of DSC that has the most effective power according to the variation of active area. In detail, the experiment was conducted about the optimum ratio of length to width and we introduced the ratio of active area to non-active area to find the active area which has the best output. Because small DSC doesn‘t have the best output in comparison with total area of cell although the smaller DSC has the better efficiency. As a result, we achieved the optimum ratio of length to width of 8:3 and active area of $8cm^2$ as the optimum size for upscaling DSC.

• Journal of Mechanical Science and Technology
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• 제14권8호
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• pp.861-866
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• 2000

Flow induced shape change is important for spatial interpretation of vascular response and for understanding of mechanotransduction in a single cell. We investigated the possible shapes of endothelial cell (EC) in a mathematical model and compared these with experimental results. The linearized analytic solution from the sinusoidal wavy wall and Stokes flow was applied with the constraint of EC volume. The three dimensional structure of the human umbilical vein endothelial cell was visualized in static culture or after various durations of shear stress (20 $dyne/cm^2$ for 5, 10, 20, 40, 60, 120min). The shape ratio (width: length: height) of model agreed with that of the experimental result, which represented the drag force minimizing shape of stream-lining. EC would be streamlined in order to accommodate to the shear flow environmented by active reconstruction of cytoskeletons and membranes through a drag force the sensing mechanism.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.950-952
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• 2001

This paper proposes a new zero-current transition (ZCT) pulse-width modulation (PWM) switch cell that overcomes the limitations of the conventional ZCT converters. The proposed ZCT cell provides zero-current-switching (ZCS) condition for the main switch and the auxiliary switch. The conduction loss and current stress of the main switch are minimized, since the circulating current for the soft switching does not flow through the main switch. The proposed ZCT PWM switch cell is suitable for the high power applications employing IGBTs. Design guidelines with a design example are described and verified by experimental results from the 1 kW prototype boost converter operating at 70kHz.

• 한국공작기계학회논문집
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• 제12권6호
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• pp.92-96
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• 2003

Feul-Cell system consists of fuel reformer, stack and energy translator. Among these parts, stack is a core part which produces electricity directly. In order to set a stack module, fabrication of appropriate stack, design of water flow path in stack and control of coolant are needed. Especially, oater or air is used as a coolant to dissipate heat. The different temperature of each electric cell after cooling affects the performance of the stack. Therefore, it is necessary that the relationship between coolant hearing rate, width of stack, properties of stack, and the shape of water flow path must be understood. For the optimal design, the computational simulation by CFD-ACE has been conducted and the resulting database has been constructed.

• Journal of Electrochemical Science and Technology
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• 제6권1호
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• pp.26-33
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• 2015

In this study, cell performance and thermal stability of lithium-ion cells with a polyimide (PI) separator are investigated. In comparison to conventional polyethylene (PE) separator, the PI separator exhibits distinct advantage in microporous structure, leading to superior reliability of the cell. The cells with PI separator exhibit good cell performances as same as the cells with PE separator, but their reliability was superior to the cell with PE separator. Especially in the hot-box test at 150 and 180℃, PI separator showed a contraction percentage close to 0% at 150℃, while the PE separator showed a contraction percentage greater than 10% in both width and length. Therefore, the PI separator can be the promising candidate for separators of the next generation of lithium-ion battery.

• Journal of the Optical Society of Korea
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• 제13권3호
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• pp.335-340
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• 2009

Ultrashort pulse laser drilling of polycarbonate track-etched membrane (pTEM) material was used to fabricate a mouse embryo cell trapping device. Holes with a diameter of $2{\mu}m$ to $5{\mu}m$ were fabricated on a $10{\mu}m$ thick membrane using a femtosecond laser with a 150 fs pulse width and 775 nm wavelength and multiple-pulse irradiation. In cell trapping tests, the overall cell occupancy of the machined holes in the fabricated pTEM was found to be more than 80%. The results of a single pulse and multiple pulse irradiation were compared in terms of the surface quality. It was generally found that a single pulse with high energy was less desirable than irradiation with multiple pulses of lower energy.

• 대한본초학회지
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• 제20권3호
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• pp.9-18
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• 2005

Objectives : The purpose of this study is to investigate characteristics of cell morphology of two different agar woods (Aquilaria agallocha Roxburgh (AAR) and imitative agar wood (IAW)) using microscopic techniques. Methods : Both light and scanning electron microscopes were used to observe morphological and histological features of the cell of agar woods collected from commercial products in the market. Results : The cell morphology and tissue arrangements of AAR depending on either the adsorption of resin into vessels or no adsorption of resin were observed to compare these features with those of both IAW and Aquilaria sinensis Gilb (ASG). Conclusions : As a result, the vessels of AAR with the resin adsorption was packed with lots of yellow-brownish materials, which were quite different from those of IAW and ASG. The cell walls were thick, and had well-developed traumatic parenchyma tissues with squared cells of the same height and width, which appeared as a clump of small grains packed.

• 한국수소및신에너지학회논문집
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• 제20권6호
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• pp.492-498
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• 2009

Six sigma methode was applied for optimization of flow field design of a proton exchange membrane fuel cell (PEMFC). The optimization between number of channel and channel/rib width was suggested in this paper with six sigma method. With the help of six sigma design of experiment (DOE) the number of experiments may be reduced dramatically. The fuel cell channel design optimization with results of these experiments with a 100 $cm^2$ serpentine flow field indicates a optimization data for a given constant operating conditions.