• 한국철도학회논문집
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• 제12권6호
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• pp.844-851
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• 2009

본 논문에서는 수직분리 및 수직통합의 경험이 함께 존재하는 유럽철도의 자료를 기존연구에서 사용된 바 없는 Simar and Wilson(2008)의 붓스트랩을 활용한 효율성에 관한 가설검정방법으로 분석하여 수직분리가 철도산업의 운영효율성과 어떤 관련성을 가지고 있는지를 밝혀보고자 하였다. 1998년부터 2005년까지의 20개 유럽국가의 자료를 분석한 결과 검정통계량의 관측값은 수직분리구조를 가진 국가의 철도산업이 수직통합구조를 가졌거나 또는 지주회사의 형태로 수직통합을 유지하고 있는 국가의 철도산업보다 상대적으로 운영효율성이 높게 타나났으나 그러한 차이가 통계적으로 뒷받침되지는 못하였다.

• 천문학회보
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• 제37권1호
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• pp.58.2-58.2
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• 2012

Wilson and Bappu (1957), for the first time, and other precedent studies (Lutz & Kelker 1975; Pasquini et al. 1988; Dupree & Smith 1995; Wallerwstein et al. 1999; Pace et al. 2003) found a tight correlation (called Wilson-Bappu relationship - WBR) between stellar absolute visual magnitude and the width of the Ca II K line emission feature for late type stars. Here we re-visit WBR to claim that WBR can be an excellent indicator of stellar surface gravity of late type stars as well as a good indicator of distance. We have analyzed 103 high-resolution spectra of G, K and M type stars obtained by UVES and BOES by following the method by Pace et al. (2003) for measuring the widths of Ca II K lines(W). WBR found in our samples is Mv=33.26-17.79logW and the correlation is very tight. In this study, the stellar gravity(log g) has been derived using Kurucz ALAS9 model grid and MOOG code, which can determine $T_{eff}$ and [M/H] too.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제18권3호
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• pp.202-208
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• 2015

Progressive familial intrahepatic cholestasis type 3 (PFIC3) is an autosomal recessive disorder of cholestasis of hepatocellular origin, typically seen in infancy or childhood caused by a defect in the ABCB4 located on chromosome 7. Here we report on an older patient, aged 15, who presented with biochemical testing that led to an initial consideration of a diagnosis of Wilson disease (WD) resulting in a delayed diagnosis of PFIC3. Diagnosis of PFIC3 was later confirmed by molecular studies that identified novel mutations in the ABCB4 gene. Cholestasis due to PFIC3 can cause elevated hepatic copper and increased urine copper excretion that overlap with current diagnostic criteria for WD. Molecular diagnostics are very useful for establishing the diagnosis of PFIC3. Ursodeoxycholic acid ameliorates cholestasis in PFIC3, and may help mediate a reduction in hepatic copper content in response to treatment.

• 천문학회보
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• 제35권1호
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• pp.87.2-87.2
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• 2010

Near-Earth asteroid-comet transition object 4015 Wilson-Harrington is a possible target of the joint European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA) Marco Polo sample return mission. 4015 W-H was discovered showing cometary activity by Albert G. Wilson and Robert G. Harrington at Palomar Observatory in 1949. After recovered in 1979, 4015 W-H has been observed at every apparition, it always was seen as a point source. We made time series observations for 4015 W-H using the 1.8m telescope with 2K CCD at Bohyunsan Observatory, on the nights of 2009 November 17-19. The geocentric distance of 4015 H-W was about 0.38 AU at that time. No trace of cometary activity is seen from our images. From the light curve analysis, we find a double-peaked rotational period of 2.2 hours with amplitude of 0.4 magnitude. Our result is much shorter than previous measurements of 3.6 hours (Harris & Young 1983) and 6.1 hours (Osip et al 1995). We will discuss possible origin of the period variations.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.270-275
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• 2000

In this study, heat transfer and Pressure drop characteristics for R-718 in the plate and shell heat exchanger (P&SHE) investigated experimentally. The plates are circular and welded into a stack which fits into a cylindrical shell in P&SHE. Although apparently very different from rectangular the compact brazed plate heat exchanger (CBE), the underlying flow passage structure through the P&SHE is the same as in the CBE. The R-718 between plate side and shell side was performed a counterflow heat exchange. Heat transfer characteristic of R-718 were measured for turbulent flow in P&SHE by using wilson plot technique. Heat transfer experiment Ivas performed in the $200{\leq}Re{\leq}500$ regime and Pressure drop experiment was performed in the $150{\leq}Re{\leq}1600$ regime. The purpose of this study is to investigate heat transfer and friction factor correlations for R-718 in P&SHE and to offer fundamental data for experiment

• 한국화재소방학회논문지
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• 제27권5호
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• pp.70-74
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• 2013

인화점은 액체 용액의 폭발과 화재의 위험성을 특징짓는 가장 중요한 물성치 중 하나이다. 액체 혼합물의 최대인화점은 용액을 구성하는 개별 성분들의 인화점보다 높은 것을 의미한다. 본 연구에서는 2-pentanol+acetic acid 계의 인화점을 Seta flash 밀폐식 장치를 통해 측정하였다. 이 계는 최대인화점 현상을 나타내었다. 또한 인화점은 Raoult의 법칙을 이용하여 예측하였고, van Laar 식과 Wilson 식을 활용한 최적화 기법에 의해서도 예측하였다. 최적화 기법에 의한 예측 방법이 Rauolt의 법칙에 의한 예측 방법 보다 측정치를 잘 모사하였다.

• 한국화재소방학회논문지
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• 제29권2호
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• pp.39-43
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• 2015

인화점은 액체 혼합물의 화재와 폭발의 위험성을 특징짓는 주된 성질이다. 인화점은 가연성 액체에 불꽃이 가해졌을 때 점화가 발생하는 가장 낮은 온도로 정의된다. Seta flash 밀폐식 장치를 이용하여 이성분계 수용성 혼합물인 water-methanol계와 water-ethanol계의 인화점을 측정하였다. Wilson 식과 UNIQUAC 식과 같은 활동도 모델식을 활용한 방법을 이용하여 인화점을 계산하였다. 이 계산치와 라울의 법칙에 의한 계산치를 비교하였다. 그 결과, 활동도 계수 모델식에 의한 계산치가 라울의 법칙에 의한 계산치 보다 측정값에 보다 근접하였다.

• 한국식품과학회지
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• 제31권1호
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• pp.260-262
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• 1999

한국의 특산수종인 구상나무(Abies koreana Wilson) 목부 에탄올 추출물의 diethyl ether가용부로부터 단리된 리그난류의 항균활성 결과를 요약하였다. 디에틸에테르 가용부로부터 단리된 각 화합물의 $10^3\;ppm$ 및 $10^4\;ppm$ 농도에서 공시균에 대한 활성은 타균에 비해 K. pneumoniae와 V. parahaenolyticus균의 2개균에 대하여 높은 활성을 보였다. 특히, 화합물 V는 V. parahaenolyticus균에 대해 $10^4\;ppm$ 농도의 처리에서 약 1.7배의 활성을 보였으며, 화합물 III은 K. pneumoniae 및 S. aureus 두 균에 대하여 대조구의 약 36%와 37%의 저해활성을 보였다. 그리고 화합물 II와 VI은 V. parahaenolyticus 균에 대하여 각각 48%와 66%의 생장 저해활성을 보였다.

• 천문학회보
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• 제38권1호
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• pp.59.2-59.2
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• 2013

Wilson and Bappu found a tight correlation between the stellar absolute visual magnitude (MV) and the width of the Ca II K emission line for late-type stars in 1957. Here, we revisit the Wilson-Bappu relationship (hereafter, WBR) to claim that WBR can be an excellent indicator of stellar surface gravity of late-type stars as well as a distance indicator. We have measured the width (W) of the Ca II K emission line in high resolution spectra of 125 late-type stars, which were obtained with Bohyunsan Optical Echelle Spectrograph (BOES) and adopted from the UVES archive. Based on our measurement of the emission line width (W), we have obtained a WBR of $M_V=33.76-18.00{\log}W$. In order to extend the WBR to be a surface gravity indicator, the stellar atmospheric parameters such as effective temperature ($T_{eff}$), surface gravity (logg), metallicity ([Fe/H]), and micro-turbulence (${\xi}_{tur}$) have been derived from the self-consistent detailed analysis using the Kurucz stellar atmospheric model and the abundance analysis code, MOOG. Using these stellar parameters and logW, we found that ${\log}g=-5.85\;{\log}W+9.97\;{\log}T_{eff}-23.48$ for late-type stars.

• 대한족부족관절학회지
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• 제2권1호
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• pp.1-5
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• 1998

In a retrospective study, we compared the results of 24 cases of Chevron osteotomies with those of 17cases of Wilsons osteotomies in the treatment of hallux valgus. We used FFSS(Fore Foot Scoring System) and radiographic findings. There were no differences between the two operations in terms of pain relief and appearance. All patients in the Chevron and Wilsons osteotomy group had good functional results and were more satisfied with the appearance of the foot. We conclude Wilsons osteotomy is useful method for correction of hallux valgus.