• Progress in Medical Physics
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• v.24 no.1
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• pp.35-40
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• 2013

Recently, the uses of Multi-Detector Computed Tomography (MDCT) for radiation treatment simulation and planning which is used for intensity modulated radiation therapy with high technique are increasing. Because of the increasing uses of MDCT, additional doses are also increasing. The objective of this study is to evaluate the absorbed dose of body and skin undergoing in MDCT scans. In this study, the exposed dose at the surface and the center of the cylindrical water phantom was measured using an pencil ionization chamber, 30 cc ionization chamber and TL Powder. The results of MDCT were 31.84 mGy, 33.58 mGy and 32.73 mGy respectively. The absorbed dose at the surface showed that the TL reading value was 33.92 mGy from MDCT. These results showed that the surface dose was about 3.5% from the MDCT exposure higher than a dose which is located at the center of the phantom. These results mean that the total exposed dose undergoing MDCT 4 times (diagnostic, radiation therapy planning, follow-up et al.), is about 14 cGy, and have to be considered significantly to reduce the exposed dose from CT scan.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.211-220
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• 1994

The critical need of forest road for enchanting the additional values of various forest products, in addition, giving more recreational opportunity to citizen, has been recognized. In this study the present author aimed to ascertain the most effective construction working plan of forest road being tit to Korean geographic condition. To execute this research program, four locations in national forest of Kangweon-do district and other four locations in private forest in Chollabuk-do district both where forest roads have previously been constructed were selected to analyze the effectiveness basing upon the various factors separately or in combination. The results are summarized as follows ; 1. The investment efficiency in forest road construction showed to increase in the area where terrain factors and district social factors rate is high, and to decrease in the area where forest status factors and forest road structure factors rate is high. So in future the Forest Resource Development Model of forest road should take more importance particularly on those area having terrain factor ratio is low. The extractable value of constructed forest road based on forest status factors rate is expected to increase in case of high considerably. 2. To construct of forest road for increasing multiple use of forests, forest road should be construct with priority on area where obtained total score by evaluation factors is high. And these evaluation factors should take possible determine the position of forest road construction. 3. The following five types of forest road basing upon function performance are suggested with regard to the place where road is constructed. (1) Forest Utilization Model ; where forest status factors and forest road structure factors rate are over 60%. (2) Forest Resource Development Model ; where terrain factors, forest status factors, forest road structure factors and district social factors rate are less than 60%. (3) Community Development Model ; where terrain factors, forest road structure factors and district social factors rate are over 60% but forest status factors rate are less than 60%. (4) Recreation and Health Model ; where terrain factors, forest status factors, forest road structure factors and district social factors rate are over 60%. (5) Multiple Use Model ; where both forest status factors and district social factors rate are over 60%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.708-719
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• 2007

Glutathione S-transferase genotypes GSTT1, GSTM1 and GSTP1 were characterized in 104 healthy male and female subjects and compared with parameters of oxidative stress at the level of DNA and lipids, with antioxidant enzymes, and with plasma antioxidants in smokers and non.smokers. Of the 104 subjects studied, 57.4% were GSTT1 present and 47.6% were GSTM1 present. The GSTP1 polymorphisms a and b were represented as follows: a/a, 75.5%; a/b, 21.6%; b/b type, 2.9%. The GSTT1 null genotype was associated with decreased glutathione in erythrocytes and elevated lymphocytes DNA damage. GST-Px was higher in GSTT1 null compared with GSTT1 present type. The homozygous GSTP1 genotype was not associated with any antioxidant status or DNA damage. The difference in plasma ${\alpha}$-carotene and erythrocytes GSH-Px and GST activities between smokers and non-smokers was detected in the GSTT1 null genotype. Plasma ${\gamma}$-tocopherol and ${\beta}$-carotene decreased significantly in smokers having GSTM1 null genotype. When GSTT1 and GSTM1 were combined, plasma lycopene and erythrocyte GST were reduced in smokers in both null types of these genes. As for GSTP1 genotype, plasma ${\alpha}$-carotene and erythrocytes GSH-Px decreased significantly in smokers with GSTP1 b/b, while erythrocytes GSH-Px activities decreased in smokers with GSTP1 a/b. The different ${\beta}$-carotene level between smokers and non-smokers was seen with both GSTP1 a/a and a/b genotype. It seems that polymorphisms in the phase II metabolizing enzyme glutathione S-transferase may be important determinants of commonly measured biomarkers.

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.123-133
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• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.

• Korean Journal of Organic Agriculture
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• v.17 no.4
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• pp.519-527
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• 2009

The main nutritional problem of sorghum$\times$sudangrass hybrid silage is low quality and dry matter (DM) contents. This experiment was conducted to evaluate whether field pre-wilting treatment of sorghum$\times$sudangrass hybrid silage increases DM content and forage quality of the silage. The experiment was a randomized complete block design with three replications. The treatments were consisted of five different wilting days: 0 day (direct cut silage), 0.5 day, 1 day, 2 days and 3 days. Sorghum$\times$sudangrass hybrid silage with pre-wilting showed low 4.00 pH values, however direct cut silage (control) showed a 4.30 value because of its high moisture content. The DM content of sorghum$\times$sudangrass hybrid silage with pre-wilting was high above 25.1% after 1 days, however that of direct cut silage had 17.6%. And the effluent of wilted silage was decreased with prolonged wilting period, but that of direct cut silage produced effluent of 183 mL/kg. Crude protein and ether extract with wilted silage were decreased, however crude ash was increased with prolonged wilting period. Silage with pre-wilting had higher acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents than control silages, while its non-fiber carbohydrate (NFC) showed the opposite results. Lactic acid and total organic acid were increased with prolonged wilting period. For the palatability of dairy goat, silage with 2 days wilting was highest among silages. The experiment results indicate that wilted sorghum$\times$sudangrass hybrid silage could be recommended as effective method for reducing effluent, increasing pH and forage quality more than direct cut silage. Optimum pre-wilting day of sorghum$\times$sudangrass hybrid silage may be 1 days.

• Journal of Korea Water Resources Association
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• v.49 no.7
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• pp.589-597
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• 2016

In this study, we investigated the use of satellite-derived flow (SDF) signals and a data-based model for the estimation of outflow for the river reach where in situ measurements are either completely unavailable or are difficult to access for hydraulic and hydrology analysis such as the upper basin of Imjin River. It has been demonstrated by many studies that the SDF signals can be used as the river width estimates and the correlation between SDF signals and river width is related to the shape of cross sections. To extract the nonlinear relationship between SDF signals and river outflow, Artificial Neural Network (ANN) model with SDF signals as its inputs were applied for the computation of flow discharge at Imjin Bridge located in Imjin River. 15 pixels were considered to extract SDF signals and Partial Mutual Information (PMI) algorithm was applied to identify the most relevant input variables among 150 candidate SDF signals (including 0~10 day lagged observations). The estimated discharges by ANN model were compared with the measured ones at Imjin Bridge gauging station and correlation coefficients of the training and validation were 0.86 and 0.72, respectively. It was found that if the 1 day previous discharge at Imjin bridge is considered as an input variable for ANN model, the correlation coefficients were improved to 0.90 and 0.83, respectively. Based on the results in this study, SDF signals along with some local measured data can play an useful role in river flow estimation and especially in flood forecasting for data-scarce regions as it can simulate the peak discharge and peak time of flood events with satisfactory accuracy.

• Applied Microscopy
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• v.39 no.1
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• pp.27-40
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• 2009

Acute respiratory distress syndrome (ARDS), also known as an acute inflammatory lung disease is developed by various factors that is originated from the destruction of alveolar-capillary barrier, and neutrophils plays an important role in the destruction. The study intended to confirm, the anti-inflammatory effect of germanium, whether a lung injury has been mitigated with the reduction of injury in alveolar-capillary barrier resulting from inhibition of neutrophils migration in lung tissue. Test groups were divided in saline administered CON, 5 hours of endotoxin administered LPS and 5 hours of endotoxin administered Ge+LPS following 1 hours of pre-processed germanium. $100{\mu}g$ endotoxin was melted in 0.5 mL saline and sprayed into airway and 26 mg germanium per 100 g weight was administered into abdominal cavity. The endotoxin group which induced an acute lung injury with administered endotoxin showed dramatic increase of pulmonary edema (p<0.001), protein contents in bronchoalveolar lavage fluid, BALF (p<0.05) and neutrophils of infiltration in BALF (p<0.001) comparing with a control group, while a pre-treated germanium group showed significant decrease in all categories comparing to the endotoxin administerd group. In the result of a microscopic observation, the structure of alveolar-capillary barrier which is constructed with basal lamina, alveolar type I cells and endothelial cell were preserved of the pre-treated germanium group relatively well compare to the endotoxin administered group. And the construction of lamellar body, microvilli and basal lamina of alveolar type II cells were also preserved relatively well. Hence, germanium activates as an anti-Inflammatory mediator in other words, it interfered neutrophils migration into lung tissue, thereby reduced injury of alveolar-capillary barrier from toxic substances of activated neutrophils. Consequently, the study has determined that the acute lung injury induced by endotoxin has been decreased by the pre-treated germanium.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.96-115
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• 2017

Understanding effects of thermal pollution and acidification has long been a concern of aquatic ecologists, but it remains largely unknown in Korea. This study was performed to elucidate the effects of thermal wastewater effluent (TWE) and acid rain on water quality and attached algae in a small mountain stream, the Buso Stream, a tributary located in the Hantan River basin. A total of five study sites were selected in the upstream area including the inflowing point of hot-spring wastewater (HSW), one upstream site (BSU), and three sites below thermal effluent merged into the stream (1 m, 10 m and 300 m for BSD1, BSD2, and BSD3, respectively). Field surveys and laboratory analyses were carried out every month from December 2015 to September 2016. Water temperature ranged $1.7{\sim}28.8^{\circ}C$ with a mean of $15.0^{\circ}C$ among all sites. Due to the effect of thermal effluent, water temperature at HSW site was sustained at high level during the study period from $17.5^{\circ}C$ (January) to $28.8^{\circ}C$ (September) with a mean of $24.2{\pm}3.7^{\circ}C$, which was significantly higher than other sites. Thermal wastewater effluent also brought in high concentration of nutrients(N, P). The effect of TWE was particularly apparent during dry season and low temperature period (December~March). Temperature effect of TWE did not last toward downstream, while nutrient effect seemed to maintain in longer distance. pH ranged 5.1~8.4 with a mean of 6.9 among all sites during the study period. The pH decrease was attributed to seasonal acid rain and snow fall, and their effects was identified by acidophilic diatoms dominated mainly by Eunotia pectinalis and Tabellaria flocculosa during March and August. These findings indicated that water quality and periphyton assemblages in the upstream region of Buso Stream were affected by thermal pollution, eutrophication, and acidification, and their confounding effects were seasonally variable.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.345-354
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• 2009

The barley (Hordeum vulgare L.) is now widely grown as a whole crop silage in Korea, but the quality of that silage does not examined from farms. Therefore, this experiment was conducted to evaluate the forage quality of whole crop barley that was participated in Silage Quality Contest in 2008. These data were classified by region, dry matter (DM) yield, with or not additive, planting and harvest date. Difference on the lactic acid content of barley silage was detected in the region, DM yield, additive and harvest date (p<0.05), however, there were partially significant differences in chemical composition. There were significant differences among moisture content in DM yield, pH in additive, and crude ash content in additive and planting date of barley silage. Crude protein content was significant difference in the region, and ether extract content was in region, DM yield and harvest date, however, non-fiber carbohydrate was significant difference in planting date of barley silage. Neutral detergent fiber, acid detergent fiber and relative feed value were significant difference only in the cultivation region of whole crop barley. According to this experiment, differences in the silage quality were observed among whole crop barley silages. Therefore, nutritive value as well as moisture and pH are important in silage quality evaluation of whole crop barley. Especially, lactic acid is an important factor for the evaluation of whole crop barley silage.

• Journal of Korean Home Economics Education Association
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• v.18 no.4 s.42
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• pp.39-54
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• 2006

The main purpose of this study is to analyze the influence of gender equality consciousness of middle and high school student on the preference for Technology Home Economics and its teaming effectiveness. For this purpose, the gender equality consciousness, the preference and learning effectiveness of Technology Home Economics were measured among a number of 404 middle and high school students in Chuncheon city. The results of this study were summarized as following: 1. The gender equality consciousness of female students was higher than that of male students. 2. Middle and high school students had the higher preference and learning effectiveness for the Home Economics area in Technology Home Economics than they had for the Technology. 3. Female student's preference and learning effectiveness for the Home Economics area in Technology Home Economics were higher than male student's. Male student's preference and Loaming effectiveness for the Technology area in Technology Home Economics were higher than female student's. 4. The group which had relatively high gender equality consciousness score showed the higher preference and learning effectiveness for the Home Economics area in Technology Home Economics than the group with low gender equality consciousness score. In contrast, the group with low gender equality consciousness score had the higher preference for the Technology area in Technology Home Economics than the group with high gender equality consciousness score. In conclusion, gender equality consciousness and gender type had the most strong influence on the preference and learning effectiveness for Technology Home Economics among middle-high school students.