• 한국초지조사료학회지
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• 제20권1호
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• pp.25-30
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• 2000

이탈리안 라이그라스 (Lolium multiflorum Lam.) 종자로부터 직접 갤러스를 유도하고, 형성된 캘러스로부터 식물체를 재분화하는데 조건을 확립하였다. 캘러스 유도시 사용한 SH (Schenk and Hildebrandt), MS (Murashige and Skoog) 및 N6(Chu). 배지중에서 MS 배지가 캘러스 유도에 유리한 것으로 나타났으며, 캘러스 유도시에는 2,4-D $5\;mg/{\ell}$를 첨가한 조건, 캘러스 증식시에는 2,4-D $3\;mg/{\ell}$을 첨가한 조건이 가장 효율이 좋았다. 식물제 재분화 조건은 MS 배지에 BA $1.0\;mg/{\ell}$와 NAA $0.1\;mg/{\ell}$를 첨가한 재분화배지에서 계대배양하며 재분화를 완성한 처리구 9의 조건에서 재분화율 (15%)이 가장 높았다.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1972년도 춘계종합 학술대회 초록집
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• pp.17.2-17
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• 1972

현재 일반적으로 Neurilemmoma 또는 Schwannoma라고 부르는 일련의 종양들은 1908年 Verocay에 의해 처음으로 기술되었으며, 1910년 그는 이것을 "Neurinoma"라고 명명하였다. Neurilemmoma라는 명칭은 1935년 Stoutdp 의하여 처음으로 소개되었다. Neurilemmoma는 신경초(Newe Sheath)를 소유하고 있는 어떤 신경에서나 발생할 수 있는 종양으로서 비교적 희유한 양성종양이며 연령, 성병, 그리고 발생장소에 따른 어떤 우월성은 없었으나 이 종양의 약 25% 이상이 두경부에 발생한다. 다른 부위로 전이를 일으키지 않으며 완전 제거 후에는 재발되지 않으며 방사선에 대한 감수성은 거의 없었다. 저자들은 과거 5년간 본 병원 이비인후과령역에서 수술제거한 5예의 Neurilemmoma를 문헌고찰과 함께 보고하는 바이다.

• 한방안이비인후피부과학회지
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• 제21권1호
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• pp.104-112
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• 2008

Objective : This experimental study was preformed to investigate the effect of ethanol extract of Belamcandae Rhizoma (EBR) on dermal bioactive properties related to cosmeceuticals such as radical scavenging activity and depigmentation. Methods : The free radical scavenging activity of EBR was assayed in cell free systems using 1,1-diphenyl-2-picrylhydrazyl (DPPH). Antibacterial potency was measured by the size of inhibition zone with change of volume. Cell viability was measured by MTT assay and tyrosinase activity was assessed using L-DOPA. Results : EBR showed slightly radical scavenging activity and protected against UVB-induced cell cytotoxicity. Futhermore, EBR showed antibacterial activities on S. epidermidis and S. aureus. Although the proliferation of B16/F10 cells was decreased by EBR, necrosis was not revealed. EBR augmented tyrosinase activity and dendrite outgrowth in B16/F10 cells. Conclusions : These results suggest that EBR has antioxidative ＆ antibacterial activities, and stimulate melanogenesis.

• 한국분말재료학회지
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• 제2권1호
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• pp.44-52
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• 1995

Effects of the extrusion temperature and die angle on the tensile properties of SiCIyAl composites in powder extrusion have been investigated. SiCP/Al composites were extruded at various extrusion temperatures (450, 500, $550^{\circ}C$) under the extrusion ratio of 25 : 1. The ram speed was maintained at 13 cm/min for all the extrusion conditions. The surface of the extruded rod appeared to be smooth without tearing at 450 and 50$0^{\circ}C$, whereas it was very rough due to tearing at $550^{\circ}C$. It was found that the tensile strength and elongation of the composites extruded at $500^{\circ}C$ are greater than those of composites extruded at $450^{\circ}C$ This is due to the easier plastic deformation of composite extruded at $500^{\circ}C$, compared with the composites extruded at $450^{\circ}C$. The effect of die angle was examined under 20=60, 120, $180^{\circ}$die angles at extrusion temperature of $500^{\circ}C$ under 25:1 extrusion ratio. The tensile strength of the composites extruded with 20=$60^{\circ}$approved to be higher than that of the composties extruded with 28 : 120 and $180^{\circ}$This is attributable to the higher extrusion pressure, which mixed composite powders could be densely consolidated at elevated temperatures, resulting from high friction force between billet and sliding surface of conical die.

• 간호행정학회지
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• 제21권5호
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• pp.552-560
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• 2015

Purpose: This study was performed to identify the mediating effect of empowerment in the relationship between head nurses' servant leadership and organizational commitment among clinical nurses. Methods: A cross-sectional survey design was used. A convenience sample of 249 nurses was recruited from three hospitals located in J province, South Korea. Data were collected by self-report questionnaires, including general characteristics, servant leadership, empowerment, and organizational commitment. Data were analyzed with descriptive statistics, Pearson correlation coefficients, independent t-test, One-way ANOVA, and linear regression using the SPSS 22.0 program. Results: Head nurses' servant leadership perceived by clinical nurses significantly influenced their organization commitment. Empowerment partly mediated the effect of servant leadership on organizational commitment. Conclusion: The findings suggest the importance of improving nurse managers' servant leadership and empowering nurses to increase their organizational commitment.

• 한국전산유체공학회지
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• 제16권3호
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• pp.75-81
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• 2011

The turbo blowers having large power capacity are generally composed of the variable inlet guide vane, the impeller and the variable diffuser. In the present study, the effect of the stagger angles on the aerodynamic performances has been investigated by CFD methods. The design specifications of the reference model having 400kW power were given as 7.43kg/s of mass flow rate, 1.66 of pressure ratio with 12000rpm of impeller rotating speed. As the first simulation parameter, the diffuser vane angle was varied in the range of ${\pm}$20 degree from the initial-design point. The inlet guide vane angles, as the second one, was changed in the range of ${\pm}$40 degree from the initial-design point. The commercial Navier-Stokes solver, ANSYS-CFX, was applied to solve the three-dimensional unsteady flow fields inside the turbo blower. Through the numerical results, the desirable setting angles were proposed to fit the best performance to the variation of the operating conditions.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2357-2362
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• 2008

LHP is different from a conventional heat pipes in design and heat and fluid flow passages. The situations of the former is much complex than the latter. In LHPs, evaporation occurs at the contact interface between the heating plate and the porous wick, so some micro channels machined at the contact interface serve to let the vapor flow out of the evaporator. This complexity of contact geometry was known to cause a high resistance to heat flow. The present work was to study the problem of heat passage across the contact surface for LHPs and determine those values contact resistance. For two cases of contact structures, the thermal contact resistances were examined experimentally, one being obtained through mechanical contact under pressure and the other through sintered bonding. Nickel powder wick and copper plate were used for specimens. The result showed that a substantial reduction of contact resistance of an order of degree could be obtainable by sintered bonding.

• 한국자기학회지
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• 제8권3호
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• pp.161-168
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• 1998

본 논문에서는 라플라스 변환과 유환요소법의 결합에 의하여 확산반정식의 과도해석에 적용이 가능한 알고리즘을 제안하였다. 제안한 방법은 시간항을 라플라스 변환을 이용아여 제거한 후 유한요소법을 적용하여 해를 구한다. 이렇게 주파수 영역에서 구해진 해는 라플라스 역변환을 이용하여 시간영역의 값으로 변환한다. 제안된 방법의 타당성을 검증하기 위하여 열전도문제를 해석하엿으며, 제안한 방법이 해석해와 잘 이치한다는 것을 알 수 잇었다. 제안한 방법은 시간 차분이 필요하지 않기 때문에 여러 가지 확산방정식을 해석함에 있어서 매우 유용할 것으로 사료된다.

• 응용통계연구
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• 제30권1호
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• pp.181-193
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• 2017

본 논문에서는 계층적 시계열 자료 분석을 위한 대표적인 두 가지 방법인 상향식과 최적조합 예측법을 소개한다. 이러한 예측법은 계층적 시계열을 구성하는 모든 계열을 예측해야 하는 독립적 예측과 달리, 임의의 조정 과정이 없이 하위 계층 계열의 예측값의 합은 항상 상위 계층의 예측값과 일치하게 된다. 또한, 독립적 예측과 비교하여 예측력을 향상시킨다. 계층적 예측법의 효율성을 살펴보기 위하여 국내 16개 시도별 남녀 교통사고 발생건수 시계열 자료를 예측하였다. 이를 통하여 교통사고 발생건수에 대한 각 계층의 예측에서 계층적 방법과 독립적 방법의 차이점 및 우수성을 비교하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1710-1716
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• 2008

The Loop Heat Pipe (LHP) operates to pump the working fluid by means of the capillary force in a wick structure. Particularly, it is difficult to design and manufacture the evaporator consisted of a grooved container and a compensation chamber as well as the wick structure. This study is related to design and manufacture the grooved container coupled with wick structure, the properties of the wick structure such as the permeability, the porosity, and the maximum capillary pressure were measured to apply the cooling technology for Insulated Gate Bipolar Transistor (IGBT). The container of the LHP was manufactured by the electrical discharge process and the wick structure was sintered with the nickel particle by an axial-press apparatus with the pulse electronic discharge. As results, the properties of the wick were experimentally obtained about 60% of the porosity, 35kPa of the maximum capillary force and $1.53{\times}10-13m2$ of the permeability.