• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3481-3485
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• 2010

In this paper, we propose a concept and model of an additional service system as a kind of convergence system of broadcast and telecommunication. The proposed system use existing back-bone network such as broadcasting or communication networks. For this, we derive channel capacity formula as an approximated closed-form expression in order to show how many reliable additional data can be transmitted through wireless fading channel. From the derived formula, we confirm that the channel capacity is varied according to channel and system parameters.

• Journal of Korean Neurosurgical Society
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• v.38 no.5
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• pp.350-354
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• 2005

Objective : The aim of this study is to assess the immediate and long-term efficacy of percutaneous vertebroplasty for treating painful vertebral osteoporotic fractures. Methods : A retrospective review of 149patients who had undergone 167 vertebroplasty procedures for osteoporotic fractures was performed. Clinical, radiologic, and procedural datas were analyzed as parameters of prognostic significance, including age, sex, bone marrow density score, symptom duration, bone cement filling grade, number of fractured vertebrae, compression grade of vertebrae, leakage of bone cement, volume of bone cement injected and complications. Results : In 158 of the 167 procedures assessed, immediate pain relief was obtained [94.6%]. The extent of collapse of the vertebral body was assessed as a parameter for prognostic significance [p=0.015]. Three months postoperatively, no improvement of the pain was observed in four of the 167 procedures that had undergone the vertebroplasty [2%]. At long-term follow-up, the improvement of pain was not correlated with the compression grade of vertebrae [p=0.420]. Conclusion : The immediate outcome of vertebroplasty are less effective in vertebrae more collapsed.

• Journal of the Korean Society of Safety
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• v.29 no.6
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• pp.76-80
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• 2014

The flash point is one of the most important physical properties used to determine the fire hazard of flammable liquid mixture and defined as the lowest temperature at which a liquid produces sufficient vapor to form a combustible mixture with air. The main purpose of this paper is to measure and predict the flash point of binary flammable miscible mixtures. The flash points for n-hexanol+n-butyric acid and n-butanol+propionic acid, were measured by using Seta-flash closed cup method. The experimentally derived data were correlated with the binary interaction parameters of the van Laar and NRTL equations through the optimization method. The flash points estimated by these correlations were compared with those calculated by the method based on Raoult's law. The optimization method were found to be better than the method based on the Raoult's law.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.3
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• pp.72-86
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• 1991

In the study I analyzed the relationship between the characteristics of the user's residential environment and his or her use of openspace. I find out that there are little correlationship between building form and use factors. Also, there are no relationship between persons per room and use factors. Only the physical distance and the location of the building site is correlated with the use factor. In testing the hypotheses, I discovered very little to support the "physical deterministic" notion. I generally was not able to explain the behavior of open space users on the basis of the physical parameters selected to describe the user's residential environment. This, I believe, indicates that there probably are many other variables that play a more important role than those pertaining to the density and form of the residential environment. It is necessary to find out more variables affecting the use of openspace in the neighbourhoods, such as the charecteristics of user group. Also, it is necessary to apply the study to the other sites or the other cities in Korea to compare with the results.

• Journal of KIISE:Software and Applications
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• v.31 no.11
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• pp.1534-1542
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• 2004

A novel vision-based scheme of extracting real-time traffic information parameters is presented. The method is based on a region classification followed by a spatio-temporal image analysis. The detection region images for each traffic lane are classified into one of the three categories: the road, the vehicle, and the shadow, using statistical and structural features. Misclassification in a frame is corrected by using temporally correlated features of vehicles in the spatio-temporal image. Since only local images of detection regions are processed, the real-time operation of more than 30 frames per second is realized without using dedicated parallel processors, while ensuring detection performance robust to the variation of weather conditions, shadows, and traffic load.

• Journal of computational fluids engineering
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• v.6 no.1
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• pp.21-30
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• 2001

A numerical study on the similarity of the developing laminar flows between in a straight duct rotating about an axis perpendicular to that of the duct and in a stationary curved duct was carried out. In order to clarify the analogy of two flows, dimensionless parameters K/sub LR/ = Re/(equation omitted) and Rossby number, Ro, in a rotating straight duct were used as a set corresponding to Dean number K/sub LC/ = Re/(equation omitted), and curvature ratio, λ, in a stationary curved duct. For the large values of Ro and λ, it is shown that the flow field satisfies the 'asymptotic invariance property', that is, there are strong quantitative similarities between the two flows such as flow patterns, friction factors, and maximum axial velocity magnitudes for the same values of K/sub LR/ and K/sub LC/ if they are correlated with dimensionless axial distances Z/sub R/ = z/(equation omitted) for a rotating duct flow and Z/sub C/ = z/(equation omitted) for a stationary curved duct flow.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.81-86
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• 1988

This experiment was carried out for estimating genetic parameters, such as heritabilities, the phenotrpic and genotypic correlations of major agronomic characters with 64 cultivars in wanggol. Heritabilities of leaf length, number of leaf, stem length, stem diameter, number of stem and dry weight of medulla were higher, but that of dry weight of cortical were relatively lower. The genotypic correlation coefficients between stem length and dry weight of medulla, and between stem length and dry weight of cortical showed highly positive correlation, and stem length, stem diameter and dry weight of medulla were significantly correlated with dry weight of cortical, those characters gave high direct effect as same level in path-coefficient analysis.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.55-65
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• 2007

This paper sought to investigate pupil size variability, pupil size parameters in terms of time domain and frequency domain, the autonomic activity change induced by posture change, degree of sleepiness and cognitive task (math task). With a specially designed pupil image acquisition system in the dark room, these three kinds of experiments were performed to induce a dominant state of sympathetic or parasympathetic activation. Electrocardiogram and pupil size were measured in all the experiments. Based on three experiments, we calculated heart rate variability. In the pupil size analysis, we calculated the mean and standard deviation of pupil size (in time domain), and proposed several frequency bands that exhibit different autonomic activation between different sessions. The results indicate that in terms of heart rate variability, posture change exhibited significant differences but not between sleepiness level, or between cognitive task. Pupil sizes differed only during the postures. And we found some frequency bands that correlated with autonomic activation in each experiment. While heart rate variability reflects posture change that need cardiac control, pupil size variability reflects not only posture induced autonomic activation but sleepiness and cognitive load, which is processed in the brain, in time and frequency domain parameter.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.932-938
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• 2009

Browning of tea infusion is an obstructive factor influencing shelf life of ready-to-drink green tea. Effects of temperature and illumination on the browning of green tea infusion were investigated. It was shown that both elevated temperature and illumination led to the browning of green tea infusion, but temperature had greater effect on infusion color and level of catechins than illumination. The levels of unoxidized catechins such as (-)-epigallocatechin gallate (EGCg), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epicatechin (EC), and total catechins remaining in the tea infusion were significantly correlated to color parameters of the tea infusion. Sodium ascorbate inhibited the infusion browning by suppressing the oxidation of tea catechins and it is considered to be a more suitable preservative for prolonging shelf life of ready-to-drink green tea than ascorbic acid because it has less effect on tea taste. The effects of temperature and illumination on the epimerization of catechins were also discussed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.259-264
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• 1995

Several benefits provided by white clover (Tnifoliurn repens L.) can be elevated as relationship between its morphological and physiological characteristics is clarified. The experiment was done to analyze the relationship between them in the clover with different leaf size. Individual plants of Osceola (large leaf), Grasslands Huia (medium leaf) and Aberystwyth S184 (small leaf) were grown in 15m plastic pot containing a 1:2:1 soil:sand:Promix mixture for 55 days, and then clipped to remove all fully expanded leaves every 7, 14 or 28 days. To measure the cultivar response, plants were sampled for morphological and physiological parameters on the date (0) after final harvest and 1, 3, 7, 14 and 28 days after the final harvest and then their relationship was analyzed. Osceola had greater leaf area per trifoliolate but less no. of leaves per plant to result in similar total leaf area per plant of all cltivars. Stolon length and no. of growing tips per plant declined with smaller leaf size although the result in biomass was reverse. Stolon of all cultivars showed the greatest fluctuation in total nonstructud carbohydrate during the regrowing period but nitrogen concentrations of all their fractions and dinitrogen fixation did similar patterns. Stolon and root of Osceola, moreover, were the highest ones. Biomass, stolon length and total leaf area per plant of all cultivars were positively correlated to carbohydrate concentration of all frauions and dinitrogen fixation. In Osceola relationship between nitrogen concentration of stolon and the characters showed in Osceola was positively done.