• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.150-159
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• 2011

This study was conducted to gather the basic data on the alpine leek (Allium victorialis) for the expand of consumption and the production of its manufactured goods. Amino acid content in alpine leek leaves and various physiological activities were examined. Seventeen component amino acids and 38 free amino acids from alpine leek leaves were analyzed, and the total contents were 2,693.28 mg/100g for component amino acids and 535.39 mg/100g for free amino acids. Total phenolic compounds in the leaves of alpine leek showed the highest level from the methanol extract (37.7 mg/l), and followed by ethanol extract (31.9 mg/l) and hot water extract (25.4 mg/l). Total flavonoid contents in 1,000 mg/l extract was the highest in the methanol extract (22.2 mg/l). DPPH radical scavenging activity at 1,000 mg/l extract was high in the order of ethanol extract (51.6%), methanol extract (47.3%) and hot water extract (37.2%). nitrite radical scavenging activity Methanol extract from Allium victorialis leaves was the highest nitrite radical scavenging activity (79.5%). Hyperplasia suppression of lung cancer cells (Calu-6) and gastric cancer cells (SNU-601) by the methanol extract from the bulb of alpine leek were 99.9% in the extracting concentration of over 200 mg/l. No significant difference in antimicrobial activity among the 3 different solvents and extract concentrations was observed, and the inhibition zones against the gram-positive and negative microorganisms were ranged from 8.23 to 10.15 mm. It was concluded that physiological activities in a human body could be improved by the intake of alpine leek as a pharmaceutical material, and that it would be useful for the prevention of health risk such as lung and gastric cancers.

• Geophysics and Geophysical Exploration
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• v.9 no.4
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• pp.291-298
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• 2006

Resistivity method is a practical and effective geophysical technique to detect leakage zones in embankment dams. Generally, resistivity survey conducted along the crest assumes that the embankment dam has a 2D structure. However, the 3D topography of embankments distorts significantly resistivity data measured on anywhere of the dam. In this study, we analyse the influence from 3D effects created by specific dam geometry through the 3D finite element modeling technique. We compared 3D effects when resistivity surveys are carried out on the upstream slope, left edge of the crest, center of the crest, right edge of the crest and downstream slope. We ensure that 3D effect is greatly different according to the location of the survey line and data obtained on the downstream slope are most greatly influenced by 3D dam geometry. Also, resistivity data are more influenced by the electrical resistivity of materials constituting reservoir than 3D effects due to specific dam geometry. Furthermore, using resistivity data synthesized with 3D modeling program for an embankment dam model with leakage zone, we analyse the possibility of leakages detection from 2D resistivity surveys performed along the embankment dam.

• Geophysics and Geophysical Exploration
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• v.9 no.3
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• pp.225-230
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• 2006

Fluid replacement and conductivity logging have been applied to three boreholes in coastal aquifer in order to identify permeable fractures and to estimate the origin of saline groundwater. Fluid replacement technique measures and monitors the change of borehole fluid conductivity with depth under ambient or pumping condition after replacing the original borehole fluid with different one (by pumping out original one and injecting simultaneously new one at the hole bottom). After the replacement of borehole fluid, the change of fluid conductivity can be the direct indicator of the intake flow of formation water through aquifer such as permeable fractures or porous formations. The conductivity profiles measured with times therefore indicate the locations of permeable zone or fractures within the open hole or the fully slotted casing hole. As a result of fluid conductivity logging for three boreholes at coastal area in Yeonggwang, Jeonam Province, it is interpreted that the seawater intrusion in this area is not by remnant saline groundwater after land reclamation but mainly by intrusion of saline water through fractured rock. This approach might be useful for assessing the characteristics of seawater intrusion, the design of optimal pumping, the mitigation of seawater intrusion using freshwater injection, and estimating the hydraulic characteristics in coastal aquifer.

• Spatial Information Research
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• v.16 no.1
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• pp.19-32
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• 2008

Usually in South Korea, land cover type and topographic undulation are frequently changed even in a narrow area. However, most of researches using aerial LIDAR(LIght Detection And Ranging) data in abroad had been acquired in the study areas to be changed infrequently. This research was performed to explore reconstruction methodologies of 3D surface models considering the distribution of land cover type and topographic undulation. Composed of variously undulatory forests, rocky river beds and man-made land cover such as streets, trees, buildings, parking lots and so on, an area was selected for the research. First of all, the area was divided into three zones based on land cover type and topographic undulation using its aerial ortho-photo. Then, aerial LIDAR data was clipped by each zone and different 3D modeling processes were applied to each clipped data before integration of each models and reconstruction of overall model. These kinds of processes might be effectively applied to landscape management, forest inventory and digital map composition. Besides, they would be useful to resolve less- or over-extracted problems caused by simple rectangle zoning when an usual data processing of aerial LIDAR.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.8
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• pp.855-860
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• 2011

We numerically simulated a dissolved air flotation (DAF) tank to predict the performance of the pilot facility. The flow was assumed to be two-dimensional and two-phase. The velocity distributions in the separation zones of differently shaped DAFs were compared to find the effect of the shape on the performance. The results showed that the typical flow pattern that appeared in a well-designed DAF-tank was generated in the separation zone of the base model. This flow pattern could be maintained while the baffle height was sufficiently tall regardless of the other geometric parameters. However, the baffle height and angle, the contact zone width, and the perforated plate affected the uniformity of the downward flow in the separation zone. Except for the baffle height, the base model used in this study showed a better uniformity of downward flow than did other models with different geometric parameters.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1145-1151
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• 2015

High pressure components of a gas turbine engine must operate for a long life under severe conditions in order to maximize the performance and minimize the maintenance cost. Enhanced cooling design, thermal barrier coating techniques, and nickel-base superalloys have been applied for overcoming them and furthermore, material modeling, finite element analysis, statistical techniques, and etc. in design stage have been utilized widely. This article aims to evaluate the effects on the low cycle fatigue life of the high pressure turbine nozzle caused by different turbine inlet temperature profiles and installation conditions and to investigate the most favorable operating condition to the turbine nozzle. To achieve it, the structural analysis, which utilized the results of conjugate heat transfer analysis as loading boundary conditions, was performed and its results were the input for the assessment of low cycle fatigue life at several critical zones.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.139-147
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• 2020

The number of deaths from child traffic accidents in Korea is currently higher than the average figure of OECD members, and attention needs to be paid to reduce the school zone accident rate. According to the TAAS statistics of the Traffic Accident Analysis System, the number of deaths from traffic accidents in children (under 12 years of age) in Korea has been steadily decreasing recently, but the number of accidents and injuries has been continuously increasing and decreasing. With the number of accidents and injuries of children in Korea continuing to increase and decrease, the number of traffic accidents, deaths, and injuries of children in the school zone (under 12 years of age) has also been on the rise since 2019. Therefore, we were different from the preceding study (Study on Improvement through School Zone Accident Risk Survey, Study on Improvement of Children's Traffic Safety Facilities through Simulation Program). In order to prevent traffic accidents among school zones, which have the highest accident rate among children, a survey was conducted on traffic safety facilities and safety awareness of drivers. After that, we will analyze the problems and present measures for improving traffic safety in the school zone and improving drivers' safety awareness.

• Journal of Korean Medicine for Obesity Research
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• v.20 no.1
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• pp.40-51
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• 2020

Objectives: We aimed to compare the quality of sleep, tongue diagnosis, oral microbiology differences in insomnia of Liver qi stagnation (LQS) and Non-Liver qi stagnation (NLQS). Methods: 56 patients were classified as LQS or NLSQ type insomnia through the insomnia differentiation questionnaire. The depression scores between the groups were compared through beck depression inventory (BDI), and the sleep quality was compared through Pittsburgh sleep quality index (PSQI) and Insomnia Severity Index (ISI). We analyzed the sleep efficiency, total sleep time, total awake frequency, total and average awake time through actigraph. For the tongue diagnosis, the distribution of tongue coating in six areas were measured through Winkel tongue coating index (WTCI). Linear discriminant analysis was performed to observe the differences in composition of microbial strains between the groups. Results: The scores of BDI, ISI and PSQI were significantly higher in LQS group. The total sleep time in LQS group was significantly less than that of NLQS group. Among the areas of tongue, according to the WTCI, the amount of tongue coating in zones A and C was significantly small. In oral microbial analysis, there was no significant difference between the groups at the phylum level. At the genus level, Prevotella, Veillonella, and Streptococcus were predominant in LQS group, whereas Prevotella, Neisseria, and Streptococcus in NLQS group. Conclusions: It was meaningful that insomnia was more likely in LQS group than in NLQS group, and the composition of oral microorganisms was significantly different, which could lead to the diseases caused by stress.

• Elastomers and Composites
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• v.41 no.3
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• pp.147-156
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• 2006

To investigate the influence of the foaming temperature and carbon black content on the cure behaviors and foaming characteristics of the foams. natural rubber (NR) was foamed at five temperature zones (145, 150, 155, 160 and $165^{\circ}C$) and different feeding ratios of the carbon black. A decreasing trend of the scorch time, $t_{s2}$ and cure time, $t_{90}$ was observed upon increasing foaming temperature and carbon black content. The optimal temperature for vulcanization and foaming of NRs in this study was considered to be $165^{\circ}C$ where density of the loomed NRs is lower than those at other four temperature regions. The rule rate index of the NRs foamed at $145^{\circ}C$ is smaller than those at 150, 155, 160 and $165^{\circ}C$. The results of the expansion ratio and micrographs of the foamed NRs were founded to support the density characteristics. The thickness of each of the struts formed inside the rubber matrix decreases with increasing the foaming temperature, while it increases with increasing the carbon black content.

• Journal of Biomedical Engineering Research
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• v.19 no.5
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• pp.469-476
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• 1998

In the case of acquisition and displaying medical Images such as ultrasonography and endoscopy on VGA monitor of PC system, image degradation of tear-drop appears through scan conversion. In this study, we compare several methods which can solve this degradation and implement the hardware system that resolves this problem in real-time with PC. It is possible to represent high quality image display and real-time processing and acquisition with specific de-interlacing device and PCI bridge on our hardware system. Image quality is improved remarkably on our hardware system. It is implemented as PC-based system, so acquiring, saving images and describing text comment on those images and PACS networking can be easily implemented.metabolism. All images were spatially normalized to MNI standard PET template and smoothed with 16mm FWHM Gaussian kernel using SPM96. Mean count in cerebral region was normalized. The VOls for 34 cerebral regions were previously defined on the standard template and 17 different counts of mirrored regions to hemispheric midline were extracted from spatially normalized images. A three-layer feed-forward error back-propagation neural network classifier with 7 input nodes and 3 output nodes was used. The network was trained to interpret metabolic patterns and produce identical diagnoses with those of expert viewers. The performance of the neural network was optimized by testing with 5~40 nodes in hidden layer. Randomly selected 40 images from each group were used to train the network and the remainders were used to test the learned network. The optimized neural network gave a maximum agreement rate of 80.3% with expert viewers. It used 20 hidden nodes and was trained for 1508 epochs. Also, neural network gave agreement rates of 75~80% with 10 or 30 nodes in hidden layer. We conclude that artificial neural network performed as well as human experts and could be potentially useful as clinical decision support tool for the localization of epileptogenic zones.