• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.844-851
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• 2009

Since 1990s, the European railway sector has undergone both a vertical separation and a vertical integration. Recently Simar and Wilson (2008) provides a bootstrap test procedure for testing whether two groups' mean efficiencies are equivalent. The purpose of this paper is to ascertain the relationship between vertical separation and operational efficiency of railway industry using the Simar and Wilson's bootstrap test procedure not used in previous studies with a data set of 20 European countries from 1998 to 2005. From the value of test statistic it seems that the mean operational efficiencies of vertically separated railway industry were higher than those of vertically integrated railway industry. However the p-value indicates that the differences of mean operational efficiencies are not significat at any meaningful level.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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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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• v.18 no.3
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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.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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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.

• Proceedings of the KSME Conference
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• 2000.04b
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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

• Fire Science and Engineering
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• v.27 no.5
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• pp.70-74
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• 2013

The flash point is one of the most important physical properties to charaterize fire and explosion hazard of liquid solutions. The maximum flash point of liquid mixture is larger than those of the individual components. In this study, the flash points of 2-pentanol+acetic acid system were measured by Seta flash closed cup tester. This system exhibited the maximum flash point behavior. The flash points were estimated by the Raoult's law and the optimization methods using the van Laar and Wilson equations. The calculated values by optimization methods were found to be better than those based on the Raoult's law.

• Fire Science and Engineering
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• v.29 no.2
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• pp.39-43
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• 2015

The flash point is the major property to characterize fire and explosion hazard of liquid mixtures. The flash point is the lowest temperature at which a liquid gives off enough vapor to form a flammable air-vapor mixture. The flash points of two aqueous mixtures, water-methanol and water-ethanol, were measured using Seta flash closed cup tester. A prediction method based on activity coefficient models, Wilson and UNIQUAC equations, was used to calculate the flash point. The calculated flash points were compared to the results by the calculating method using Raoult's law. The calculated values based on activity coefficients models were found to be better than those based on the Raoult's law.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.260-262
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• 1999

Abies koreana Wilson is a proper tree to Korea. We tested the antimicrobial activity of the lignans isolated from it. The lignans inhibited the growth of Klebsiella pneumoniae and Vibrio parahaemolyticus at the concentration of $10^3\;ppm\;and\;10^4\;ppm$. Especially, the compound V showed higher inhibition activity to Vibrio parahaemolyticus by 1.7 times compared with the control. The compound III showed activity of 36% of the control to Klebsiella pneumoniae. The compounds II and VI had the high growth inhibition activity of 48, 66% respectively to Vibrio parahaemolyticus.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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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.

• Journal of Korean Foot and Ankle Society
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• v.2 no.1
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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.