• Journal of Korean Society of Steel Construction
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• v.24 no.5
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• pp.521-534
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• 2012

In this research, we carry this study into effect on the basis of utilizing character of composite beam and developing applicable section to some of high strength steel. We evaluated flexural capacity of composite beam that is a unit member through experiments. The existing nominal strength formula of Composite Beam which is a previous method was reviewed and the experiment had been progressive by using each composite members as main variables though the result. Capacity evaluation of U-shape Hybrid Forming Beam(HyFo Beam) which is a new shape show as follow from the result. First, it is resonable to resist demand moment by couple moments which are occurred in concrete compressive-strength and steel tensile-strength. Second, the capacity was stably increased in proportion to the depth of beams and the thickness of steel plates. The last, HyFo Beam was showed as ductile behavior.

• Journal of Magnetics
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• v.7 no.4
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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.

• Korean Journal of Breeding Science
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• v.41 no.1
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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.

• New & Renewable Energy
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• v.8 no.1
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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.

• Journal of the Korean Society of Costume
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• v.51 no.7
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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.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.6
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• pp.1121-1140
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• 1992

In metal cutting the shape of generated chip varies according to cutting conditions, characteristics of workpiece and geometry of cutting tool. The best surface roughness of machined workpiece is obtained when generating flow type contrinuous chip. If the generated chip is not broken, that is not only tangled workpiece and cutting tool, but also may give damage on the machined surface of workpiece or danger for a operator. The flow type continuous chip may bring the low productivity in high speed any heavy cutting, automatic machining process and non-human factory. There are two type of chip break process ; controlling cutting condition and using chip breaker. In present study we carried out the experiment on new type chip breaker compared with conventional type and proved the efficiency of a new type and showed the chip break condition to be applied in actual metal cutting. In the experiment SM 20 C as a workpiece material and WC as a tool material were used and cutting speed of 30-150m/min, feed of 0.071-0.210mm/rev and depth of cut of 1mm were applied as cutting condition. The results of the experiment are as follows : (1) The mechanism of chip curl can be explained more clearly by plastic flow of workpiece material and moment of shearing force. (2) The most effective radius of curled chip and flat distance from cutting edge is 2.0-2.5mm and 1.5mm in both types. (3) The effective inclination angle of chip break surface and side cutting edge angle are 30.deg.- 45.deg. and 20.deg. in conventional type, while the radius of arc surface, lower arc angle A, upper arc angle B and side cutting edge angle are 3mm, 20.deg.- 45.deg., 0.deg.- 45.deg. and 10.deg.- 20.deg. in new type. (4) The probability to be obtained 100% chip breaking ratio is much higher in new type than in conventional type.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.51-55
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• 2009

Jayoung was bred within the potato breeding program of Highland Agriculture Research Center (HARC), National Institute of Crop Science. It was originated from a cross made between Atlantic as a female and AG34314 as a male parent in 2003. Jayoung was evaluated as a clone number Daegwan 1-104 for the growth and tuber characteristics, yielding ability, and resistance to major potato diseases in the regional yield trials from 2006 to 2007. Finally, this clone was renamed as Jayoung and was presented to Korean Seed & Variety Service in 2007 for registration as a new potato cultivar. Jayoung has a oval shape, shallow eye depth, dark purple skinned and fleshed tuber characteristics. Its mean tuber yields from the regional yield trials was 37.3 MT/ha, and it showed the highest yield in spring cropping. Jayoung showed high resistance to both common scab (Streptomyces scabies) and potato leaf roll virus (PLRV), however it was susceptible to late blight (Phytophthora infestans). The dry matter content of Jayoung was fairy high 20.3%, therefore it is suitable for both chip processing and table usage. Its anthocyanin content was the highest in autumn cropping as 43.7 mg/100 g fresh weight and its mean anthocyanin content was 4.7 times higher than that of Jasim.

• Electronic Materials Letters
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• v.14 no.6
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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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• 2011.05a
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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.

• Journal of the Korean Vacuum Society
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• v.18 no.2
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• pp.116-126
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• 2009

It is becoming more difficult to improve the device operating speed by shrinking the size of semiconductor devices. Therefore, for a new leap forward in the semiconductor industry, the advent of silicon opto-electronic devices, i.e., silicon photonics is more desperate. Silicon Avalanche LED is one of the prospective candidates to realize the practical silicon opto-electronic devices due to its simplicity of fabrication, repeatability, stability, high speed operation, and compatibility with silicon IC processing. We conducted the measurement of the electrical characteristics and the observation of the light-emitting phenomena using optical microscopy. We analyzed the influence of the design elements such as the shape of the light-emitting area and the depth of the $n^{+}-p^{+}$ junction with simple device modeling and simulation. We compared the results of simulation and the measurement and explained the discrepancy between the results of the simulation and the measurement, and the suggestions for the improvement were given.