• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.243-245
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• 2013

Rate equations are exactly solved for the reversible consecutive reaction of the first-order and the time-dependence of concentrations is analytically determined for species in the reaction. With the assumption of pseudo first-order reaction, the calculation applies and determines the concentration of product accurately and explicitly as a function of time in the unimolecular decomposition of Lindemann and in the enzyme catalysis of Michaelis-Menten whose rate laws have been approximated in terms of reactant concentrations by the steady-state approximation.

• 약학회지
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• 제16권4호
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• pp.155-161
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• 1972

The hydrolysis of phenobarbital is decelerated in alkaline solution by betacyclodextrin. The betacyclodextrin inhibits the degradation of phenobarbital up to 1.5 fold in the system containing 1% betacyclodextrin. The degradation mechanism in systems containing betacyclodextrin is the same that in system without complexing agent, although the rate constants are different. The pH dependence of the hydrolysis rate deceleration is compared with the ionization percent of betacyclodextrin. The results indicate that a direct relationship does not exist between the ionization of betacyclodextrin. It seems reasonable therefore that the phenobarbital undergoes a stable complex with betacyclodextrin and complex formation would provide a better shield for the phenobarbital from hydroxyl ion attack.

• Bulletin of the Korean Chemical Society
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• 제5권5호
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• pp.207-208
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• 1984

The tris(hydroxymethyl)aminomethane (Tris)-catalyzed hydrolysis of p-nitrotrifluoroacetanilide was kinetically studied. On the contrary to the previously reported results (R. M. Pollack and T. C.Dumsha, J. Am. Chem. Soc., 1973, 95, 4463), the dependence of the rate on [Tris] consists of an initial curve portion and a subsequent linear increase. This indicates that erroneous conclusions were made in the reported work due to the insufficient amount of data. The initial portions of the rate[Tris] profiles are attributed to the catalyzed breakdown of the tetrahedral intermediate, and the linear portions to the general base-catalyzed water attack at the substrate.

• Communications for Statistical Applications and Methods
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• 제15권1호
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• pp.137-145
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• 2008

We present formulas for two types of cap pricing under fBm-HJM model reflecting the empirical long range dependence in the interest rate model. In particular, we propose a new approach to pricing the cap with the default risk.

• 한국광학회:학술대회논문집
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• 한국광학회 2005년도 제16회 정기총회 및 동계학술발표회
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• pp.78-79
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• 2005

• Journal of the Korean Statistical Society
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• 제27권2호
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• pp.153-163
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• 1998

We investigate density estimation problem in the L$^{\infty}$ norm and show that the iii optimal minimax rates are achieved for smooth classes of weakly dependent stationary sequences. Our results are then applied to give uniform convergence rates for various problems including the Gibbs sampler.

• 대한지역사회영양학회지
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• 제29권4호
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• pp.278-287
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• 2024

Objectives: This study investigates the relationship between smartphone usage and eating behavior among elementary school students. Methods: This survey was conducted on 4th- to 6th-grade students at elementary schools in Gangneung from September 6th to September 15th, 2023. Of the 129 copies of the questionnaire that were distributed to 5 schools, 66 copies (51.2%) were returned. Results: Compared to the nationwide statistics, the smartphone ownership rate of elementary school students in Gangneung was lower, but the rate of smartphone overdependence was higher. Smartphone dependence was 21.12 points for study subjects and 26.00 points for the overdependence risk group (Org). Compared to national statistics, the self-control failure factor was higher, so study participants in Gangneung City are thought to have great difficulty with self-control. The Org's weekend smartphone use time of 7.54 hours was significantly more than the general user group (Gug)'s 4.06 hours. The number of days in which the Org consumed late-night snacks per week was 2.92 days, and the Gug had 2.15 days, but the difference was not significant. Eating fast food showed a positive correlation with eating sweet food, eating fatty food, and eating heavily seasoned food. It was found that frequent consumption of fast food is closely correlated with unhealthy eating behavior. Weekend smartphone use time showed a significant positive correlation with smartphone dependence and the number of days late-night snacks consumed per week. Conclusions: Study participants in Gangneung are more dependent on smartphones than national statistics. Smartphone dependence had a negative correlation with healthy eating behavior and a correlation with average unhealthy eating behavior.

• 천문학회보
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• 제40권1호
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• pp.48.1-48.1
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• 2015

We investigate the role of small-scale and large-scale environments in triggering nuclear activity of the local galaxies using a volume-limited sample with $M_r$ < -19.5 and 0.02 < z < 0.0685 from the Sloan Digital Sky Survey Data Release 7. To fix the mass of the supermassive black hole in its host galaxy, we limit the central velocity dispersion of the sample galaxies. The active galactic nuclei (AGN) host sample is composed of Type II AGNs identified with flux ratios of narrow emission lines with S/N > 6. In this study, we find that the AGN fraction of late-type host galaxies are commonly larger than of early type galaxies. The AGN fraction of host galaxy with late-type nearest neighbor starts to increase as the host galaxy approaches the virial radius of the nearest neighbor (about a few hundred kpc scale). Our result may support the idea that the hydrodynamic interaction with the nearest neighbor plays an important role in triggering the nuclear activity of galaxy. The early-type galaxies in high density regions show decline of AGN activity compared to ones in lower density regions, whereas the direction of the environmental dependence of AGN activity for late-type galaxies is rather opposite. We also find that the environmental dependence of star formation rate is analogous to one of AGN activity except in the high density region.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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• pp.15-16
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• 2010

We used Brewster's Law to examine the mechanism of liquid crystal (LC) alignment on an organic insulation layer when subjected to ion-beam irradiation. Brewster's Law implies that the maximum rate polarized rayon a slanted insulation layers on the substrate and it illustrates the dependence of polarization and themechanical structure on the ion beam irradiation process. The pretilt angle of nematic LCs on the organic insulation surface was about $1.13^{\circ}$ for an ion beam exposure of $45^{\circ}$ for 1 minute at 1800eV. This shows the dependence of LC alignment on the polarization ratio in a slanted organic insulation layer. We also discussed the electro-optical characteristic of twisted nematic (TN) LCD using ion beam irradiation on organic overcoat layer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.103-103
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• 2010

Dependence of radical and ion densities on Plasma Parameters is theoretically investigated in $Cl_2$/Ar plasma discharges. Firstly, a set of reliable rate coefficients is obtained by direct calculations with cross section data set and by comparing them with previously reported values. Then, some global discharge simulations are performed for ICP(inductively coupled plasma) discharges and the results are compared with experimental results. Finally, the validated data set is used to analyze the dependence of radical and ion densities, which are usually not easy to be measured, on electron density arid temperature.