• 한국강구조학회 논문집
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• 제24권5호
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• pp.521-534
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• 2012

본 연구에서는 합성보의 특징을 활용하고, 일부 고강도강 적용이 가능한 단면을 개발하여 이에 대한 기초연구를 실시하였다. 본 논문은 그 첫 번째로 단위부재인 합성보의 휨성능을 실험을 통해 평가하였다. 실험결과를 통해 기존 합성보의 공칭강도 산정식 적용여부를 검토하였고, 각 구성부재를 주요변수로 하여 실험하였다. 실험결과 신형상 U형 합성보의 내력평가는 콘크리트 압축강도와 강재의 인장강도에 의한 우력모멘트로 소요모멘트에 저항하는 것으로 평가하는 것이 적합하며, 보 춤 및 강판 두께에 비례하여 내력이 안정적으로 증가하였으며, 연성거동을 하는 것으로 나타났다.

• Journal of Magnetics
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• 제7권4호
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• pp.160-164
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• 2002

A new discovery of the super-giant magneto-impedance (SGMI) effect was found out in a LC-resonator consisted of a glass-coated amorphous $CO_{83.2}B_{3.3}Si_{5.9}Mn_{7.6}$ microwire. The measurement was carried out at high frequency range from 100 MHz up to 1 GHz of an ac-current flowing along the wire and at varying axial dcmagnetic field in its range of $\pm$120 Oe. The wires, about 16${\mu}m$ in diameter, were fabricated by a glass-coated melt spinning technique. The shape of the impedance curves plotted vs. a dc-field is changing dramatically with the frequency. The phase angle was also strongly dependent on this field. The external dc-magnetic field changes the circumferential permeability as well as the penetration depth, both in turn change the impedance of the sample. The drastic increments of SGMI at high frequency can be understood in terms of the LC-resonance phenomena. The sudden change of the phase angle, as large as $180^{\circ}$ evidenced the occurrence of the resonance at a given intensity of the external dc-field. The maximum ratio of SGMI reached in the experiment by precise tuning frequency equals 450,000％ at the frequency of around 551.9075 MHz.

• 한국육종학회지
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• 제41권1호
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• pp.61-67
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• 2009

"Early Valley", is an early maturing potato cultivar with high yield potential. "Early Valley" is a clonal selection resulting from the cross between 'Suncrisp' and 'A87109-10'. It has medium plant height and light green foliage. "Early Valley" has medium flowering habit and white flowers. Tubers are smooth, yellow skin, light yellow flesh, round tuber shape, medium eye depth, and medium dormancy and good keeping quality. It has stable yield under wide range of climatic conditions. "Early Valley" is resistance to late blight, but moderately susceptible to common scab and hollow heart. This cultivar is also resistant to potato rotting at harvesting during the raining season. "Early Valley" has high level of antioxidant activity (about three times higher) and vitamin C (higher by 40%) than the 'Superior'. This cultivar has high level of tuber uniformity and capable of yielding 36.56 t/ha which is 17.07% higher than the control potato cultivar 'Superior' under optimum agronomical practices.

• 신재생에너지
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• 제8권1호
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• pp.44-51
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• 2012

Due to a high tidal range of up to 10 m on the west coast of Korea, numerous tidal current projects are being planned and constructed. The turbine, which initially converts the tidal energy, is an important component because it affects the efficiency of the entire system. Its performance is determined by design variables such as the number of blades, the shape of foils, and the size of a hub. To design a turbine that can extract the maximum power on the site, the depth and duration of current velocity with respect to direction should be considered. Verifying the performance of a designed turbine is important, and requires a circulating water channel (CWC) facility. A physical model for the performance test of the turbine should be carefully designed and compared to results from computational fluid dynamics (CFD) analysis. In this study, a horizontal axis tidal current turbine is designed based on the blade element theory. The proposed turbine's performance is evaluated using both CFD and a CWC experiment. The sealing system, power train, measuring devices, and generator are arranged in a nacelle, and the complete TCP system is demonstrated in a laboratory scale.

• 복식
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• 제51권7호
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• pp.147-165
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• 2001

The objective of this study was to develop the Jeogori Pattern for 9 to 10 year-old boys To determine the measurement items for the Jeogori Pattern making, applied factor analysis, correlation analysis and regression analysis to the 37 measurement items of the 9 to 10 year-old boys classified as a standard somatotype. To understand the shape and variation of the body surface, analyzed the replica of the upper body surface that was obtained by the method of using surgical tape. Be based on the results of the above studies, designed the Jeogori Pattern. The designed pattern was evaluated by the sensory test. The drafting methods of Jeogori Pattern obtained are as follows. $\circled1$ The measurement items are Bust Girth, Center Back Waist Length, Neck Width, and Hwajang Length. $\circled2$ Jeogori Length Center Back Waist Length$\times$4/3 $\circled3$ Front Body Girth(1/2) : B/2 + 1.5cm Back Body Girth(1/2) : B/2 + 3.5cm $\circled4$ Jin-Dong : B/4 + 3cm $\circled5$ Back Godae Width(1/2) : Neck Width/2 + 1.7cm Front Godae Width(l/2) : Back Godae Width(1/2) - 2cm $\circled6$Back Godae Point is 1.5cm higher than shoulder line, and Front Godae Point is 1.5cm lower than shoulder line. $\circled7$ Back Godae Depth: 1.2cm + 1.5cm = 2.7cm The Jeogori Pattern designed by the above method Is as (fig. 8) The results of the sensory test of the new pattern are as fellows. Except for 2 items, every mark of 24 test items has over 5.0 point and a total average mark is 5.25 point. Witch is a good mark. Therefore the new pattern is valid. Especially, the parts of Git, sleeves and back face have a high mark, so the appearances of those parts are excellent.

• 대한기계학회논문집
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• 제16권6호
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• pp.1121-1140
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• 1992

본 연구에서는 부착형 칩절단구의 경사면 대신에 원고면으로 형성한 형태 칩 절단구를 고찰하고, 재래형과 비교하여 더 효과적인 칩절단구를 개발 실용화하고자 한 다. 가공법으로서는 연속칩의 처리가 가장 곤란한 선삭을, 공작물로서는 연속칩이 가장 잘 생성되는 SM 20 C의 연강을, 공구재료로서는 P계열의 초경합금을 써서 저속에 서 고속절삭속도까지 시험하였다.

• 한국육종학회지
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• 제41권1호
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• pp.51-55
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• 2009

'자영'은 2003년 '대서' 품종과 AG34314 계통 간의 교잡 후대에서 유래되었으며, 국립식량과학원 고령지농업연구센터의 감자육종 프로그램을 거쳐 선발되었다. 2006년과 2007년 대관1-104호라는 계통명으로 지역적응시험을 수행하여 주요 생육특성, 괴경특성, 수량성 및 병해특성을 검토하였으며, 2007년 '자영'으로 명명하여 국립종자관리원에 신품종으로 출원하였다. '자영' 감자는 모양이 비교적 둥글고 눈이 얕으며 껍질과 속이 모두 자주색이다. ha당 평균 수량은 37.4톤이었고 봄재배에서 가장 높은 수량성을 나타냈다. '자영'은 감자더뎅이병과 잎말림바이러스병에 높은 저항성을 나타내었으나, 역병에는 감수성이었다. 건물함량은 비교적 높은 20.3%로서 칩가공용으로도 적합하였다. 안토시아닌 함량은 가을재배에서 가장 높은 43.7 mg/100 g이었고, 작형별 평균 함량은 '자심' 품종보다 4.7배 정도 더 많았다.

• Electronic Materials Letters
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• 제14권6호
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• pp.700-711
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• 2018

CdS synthesized by the chemical bath method at $70^{\circ}C$, has been used as an electron transport layer in the planar structure of the perovskite solar cells. A two-step spin process produced a mixed halide perovskite of $CH_3NH_3PbI_{3-x}Cl_x$ and a mixture of $PbCl_2$ and $PbI_2$ was deposited on CdS, followed by a sub-sequential reaction with MAI ($CH_3NH_3I$). The added $PbCl_2$ to $PbI_2$ in the first spin-step affected the structure, orientation, and shape of lead halides, which varied depending on the content of Cl. A small amount of Cl enhanced the surface morphology and the preferred orientation of $PbI_2$, which led to large and uniform grains of perovskite thin films. In contrast, the high content of Cl produces a new phase PbICl in addition to $PbI_2$, which leads to the small and highly uniform grains of perovskites. An improved surface coverage of perovskite films with the large and uniform grains maximized the performance of perovskite solar cells at 0.1 molar ratio of $PbCl_2$ to $PbI_2$. The depth profiling of elements in both lead halide films and mixed halide perovskite films were measured by Rutherford backscattering spectroscopy, revealing the distribution of chlorine along with the thickness, and providing the basis for the mechanism for enhanced preferred orientation of lead halide and the microstructure of perovskites.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.167.1-167.1
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• 2011

Sustainable energy generation is becoming extremely imperative due to the expected limitations in current energy resources and to reduce pollution. Especially, because of its considerable energy potential, ocean wave energy has been investigated with regard to power generation. To develop large high power wave generator system, it is important to make a small scale proto type and to test that. Thus the objective of this research is to examine the characteristics of a mechanically excited generator system having small power capacity experimentally. The water reservoir (4 m length, 1.5 m width and 1.8 m depth) having a wave maker to make arbitrary height and period of the water wave was made. The proto type consists of three main parts; a buoy, rack-pinion base one-way mechanism, and a wave generator(Fig.1). The water wave is going up and down and the hexahedron buoy is following the wave. The rack gear attached to the buoy is also going up and down to roll the pinion connected to an electric generator then it produces electricity. The experiments were performed with several conditions of water waves, and the power outputs over 30 W could be measured for some conditions. In future works, to achieve higher performance for the proto type, the effects of primary parameters (buoy shape and mass, etc.) on the system efficiency will be identified.

• 한국진공학회지
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• 제18권2호
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• pp.116-126
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• 2009

반도체 소자의 축소로 인한 처리속도의 향상이 더욱 어려워지고 있다. 따라서 반도체 산업의 새로운 도약을 위해서 실리콘을 이용한 광전소자의 출현(Silicon photonics)이 더욱 절실해지고 있다. 제조의 간단성, 반복성, 안정성, 고속성, 일반실리콘 반도체 공정과의 병존성 등의 특성으로 인해 애벌런치 항복에 의한 발광 소자는 실리콘 발광소자의 구현에 유력한 후보 중의 하나이다. 애벌런치 발광현상에 대해 전기적, 광학적 측정을 하고, 간단한 모델링과 시뮬레이션을 통하여 발광부위의 형태, $n^{+}-p$ 접합의 깊이, 불순물의 농도, 에피층의 높이 등의 설계요소가 발광특성에 미치는 영향을 분석하였다. 시뮬레이션의 결과와 실제의 계측 결과를 비교하여, 차이점을 야기하는 이유, 애벌런치 항복의 발광현상을 설명하였고, 개선방안을 제시하였다.