• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.651-657
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• 1993

The protective effects of dietary vatamin E and selenium on peroxidative damage and hematopoietic inhibition by lead poisoning were investigated in rats. Male Sprague-Dawley rats weighing 150$\pm$5g were divided into six groups according to dietary vitamin E and / or selenium levels, i.e. control(vitamin E, 40mg/kg diet), 0E(without vitamin E, Se), 40E(vitamin E, 40mg/kg diet ; without Se), 200E(vitamin E, 200mg/kg diet ; without Se), 200ES(vitamin E, 200mg/kg diet ; Se, 0.5ppm) and 0Es(without vitamin E ; Se, 0.5ppm) groups. All experimental groups were fed ad libitum 2000ppm lead in diet except control for 4 weeks. Hemoglobin contents and hematocrit values of lead groups were lower than control group except 200ES group and were the lowest in 0E group. Aminolevulinic acid dehydratase(ALAD) activities of blood and liver were sequentially reduced in 200ES, 200E, 0ES, 40E and 0E groups, compared to control, were as urinary aminolevulinic acid (ALA) excretions were increased in the groups which represented low ALAD activity. Heapatic superoxide dismutase(SOD) activities was lower in 0E, and higher in 40E, 200E and 200ES groups, compared with control. Glutathione peroxidase(GPX) activities of liver were reduced in 0E and 40E groups, but those of 0ES, 200E and 200ES groups were significantly increased. Especially GPX activities in 200ES and 200ES groups were not different from control group. The reduced glutathione contents in liver were lowest in 0E and 40E groups, compared with control, whereas levels of the oxidized form were opposite phenomena of that. Liver lipid peroxide values of 0E, 0ES, 40E and 200E groups were 6.4, 2.9, 2.1 and 1.3 fold higher than control, respectively, but 200ES groups was not different from control.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.588-596
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• 2006

The surface of polystyrene membrane treated by Ar, $O_2$ plasma, and the effects were observed before and after the treatment and permeability of $CO_2$, $N_2$ and selectivity of $CO_2$ relative to $N_2$ was measured using continuous flow gas permeation analyzer (GPA). The mole ratio of O over C in the surface was increased from 0 to 0.179 with Ar plasma treatment and route mean square of surface was increased from $15.86{\AA}$ to $71.64{\AA}$. Therefore the contact angle was decreased from $89.16^{\circ}$ to $18.1^{\circ}$. Thus Plasma treatments made surface of membrane tend to be highly hydrophilic. The optimum condition for the $CO_2$ permeability and ideal selectivity of the plasma treated membrane was as follows: the measurement of Ar (60 W, 2 min, $70^{\circ}C$) plasma treatment was $1.14{\times}10^{-12}[m^3(STP){\cdot}m/m^2{\cdot}sec{\cdot}atm]$ and 4.22. In the case of $O_2$ plasma treatment, the contact angle was decreased at $13.56^{\circ}$ with increase of O/C ratio ($0.189{\AA}$) and route mean square of surface ($57.10{\AA}$). The optimum condition for the $CO_2$ permeability and ideal selectivity of the plasma treated membrane was as follows: the measurement of $O_2$ (90 W, 2 min, $70^{\circ}C$) plasma treatment was $7.1{\times}10^{-12}[m^3(STP){\cdot}m/m^2{\cdot}sec{\cdot}atm]$ and 11.5. After plasma treatment, the changes of membrane surface were all subtly linked with both cross-linking and etching effects. Finally, it was confirmed that the gas permeation capacity and selectivity of the modified membrane with plasma could be improved by an appropriate control of the plasma conditions such as treatment time, the power input and sort of plasma gas.

• Korean Chemical Engineering Research
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• v.48 no.2
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• pp.259-267
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• 2010

The catalytic wet oxidations of the wastewater containing azo dye Reactive Black 5(RB5) with heterogeneous catalyst of CuO have been carried out to investigate the effects of temperature($190{\sim}230^{\circ}C$) and catalyst concentration(0.00~0.20 g/l) on the removals of colour and total organic carbon TOC. The wastewater colour was measured with spectrophotometer, and the oxidation rate was estimated with TOC. About 90% of colour was removed during 120 min in thermal degradation of the RB5 wastewater at $230^{\circ}C$, while TOC was not removed at all. As increasing reaction temperature and catalyst concentration, the removal rates of colour and TOC increased in the catalytic wet oxidations of RB5 wastewater. The effects of catalyst were already considerable even at 0.01 g CuO/l, while the removal rates of colour and TOC increased negligibly with increasing the catalyst concentration above 0.05 g CuO/l. The initial destruction rates of the wastewater colour have shown the first-order kinetics with respect to the wastewater colour. TOC changes during catalytic wet oxidations have been well described with the global model, in which the easily degradable TOC was distinguished from non-degradable TOC of the wastewater. The impacts of reaction temperature on the destruction rate of the wastewater colour and TOC could be described with Arrhenius relationship. Activation energies of the colour removal reaction in thermal degradation, wet oxidation, and catalytic wet oxidation(0.20 g CuO/l) of the RB5 wastewater were 108.4, 78.3 and 74.1 kJ/mol, respectively. The selectivity of wastewater TOC into the non-degradable intermediates relative to the end products in the catalytic wet oxidations of RB5 wastewater was higher compared to that in phenol wet oxidations.

• Journal of Environmental Policy
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• v.4 no.1
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• pp.93-111
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• 2005

Defining soil quality in scopes and applications is one of the prerequisite for the sustainable management of soil environment to orient researches, strategies and policies. However, definition of soil quality is controversial depending upon a viewpoint of soil science or soil environment. Soil quality can be, irrespective of the disciplines, defined as the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality and promote plant and animal health. Common to all of the soil quality concepts can be summarized as the capacity of soil to function effectively at present and in the future. The OECD includes soil quality as one of the agri-environment indicators. This article intends to i) summarize the current soil quality research, and ii) provide information on protocol of soil quality assessment. A framework for soil quality was divided into three steps: indicator selection as minimum data set (MDS), scoring of the selected indicators, and integration of scores into soil quality index. Korean government suggested possible physical and chemical indicators such as bulk density and organic matter for paddy and upland soils to OECD. The framework of soil quality assessment is not yet implemented in Korea. Countries such as USA, Canada and New Zealand have constructed the framework on soil quality assessment and developed a user-friendly version of soil quality assessment tools to evaluate the integrated effects of various soil management practices. The protocol provided in this review might help policymakers, scientists, and administrators improve awareness about soil quality and understand the way of soil environment management.

• Journal of Environmental Policy
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• v.9 no.1
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• pp.137-154
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• 2010

These objectives of this study were to compute heavy metal and accumulation carbon dioxide fixing quantity from urban green space(street trees and urban parks) in Cheong-ju city and Chungju-city and thus to estimate the effect of urban green space for improving the urban environment. The results are summarized below. 1. Results of the total accumulation of the carbon dioxide fixing quantity of street trees, Cheong-ju city and Chungju-city street tree was 1, 230,000kg-C, 1,270,000 kg-C, respectively. Total accumulation carbon dioxide fixing quantity of Balssan urban park had a 25,000kg-C in Cheong-ju city, Degami sports park had a 6,400kg-C in Chungju-city. 2. Results of heavy metal for street trees, fell in the order Zn > Cu > Cr > Ni >, the highest accumulated heavy metal was Zn, and the lowest was Ni. Total heavy metal concentration according to land-use area, was observed in order, for residental areas(157.26 mg/kg) > industrial areas(141.71 mg/kg) > commercial areas(118.55 mg/kg) > and greenspace areas(61.95 mg/kg) in Cheong-ju city. 3. Total heavy metal concentration for street trees fell in the order of commercial areas(84.48 mg/kg) > residental areas(83.70 mg/kg) > and greenspace(48.23 mg/kg) according to land-use area in Chungju-city. Comparatively, Cheong-ju city had more total heavy metal concentration than Chungju-city. 4. Heavy metal for soil that planted street trees was observed in order of Zn > Cu > Pb( > Ni > Cr > As > Cd), and Zn was highest, and Cd was lowest. Total heavy metal concentration for soil fell in the order commercial area(91.82mg/kg) > industrial area(85.96mg/kg) > residental area(67.55mg/kg) > greenspace(43.13mg/kg) according to land-use area in Cheong-ju city. 5. Heavy metal for soil that planted street trees was observed in order of Zn > Pb > Cu( > Ni > Cr > As > Cd, and Zn was highest. Total heavy metal concentration for soil fell in the order commercial area(87.66mg/kg) > greenspace(72.73mg/kg) $${\geq_-}$$ residental area(70.10mg/kg) in Chungju-city.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.106-110
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• 2009

In order to reduce the bitter taste and improve the bioavailability of red ginseng extract(RGE), inclusion complexes (RGE-CD) of the extract with ${\alpha}-,\;{\beta}-,\;{\gamma}$-cyclodextrin were prepared and studied for their sensory quality and bioavailability compared to RGE. By complexation, the bitter taste-reducing efficacies of ${\alpha}$-CD and ${\beta}$-CD were much lower than that of ${\gamma}$-CD. In comparative sensory analysis for the bitter taste, RGE-${\gamma}$-CD10, prepared using 10%(w/w) of ${\gamma}$-CD, showed a score of 1.93(decreased by about 78%) compared to RGE as the control. In addition, in sensory analysis for flavor, RGE-${\gamma}$-CD10showed a score of 5.60. Upon increasing the amount of ${\gamma}$-CD to 15%(w/w) and 20%(w/w), respectively, the bitter taste of RGE-${\gamma}$-CD was removed and the flavor of RGE disappeared(scores of 2.67 and 1.67, respectively). Therefore RGE-${\gamma}$-CD10 was chosen as an optimum. The same dosages of RGE and RGE-${\gamma}$-CD10 were orally administered to SD(Sprague-Dawley) rats on a saponin basis, and the plasma concentrations of ginsenoside Rg1 and Rb1 were measured over time to estimate the average AUC(area under the plasma concentration versus time curve) of the ginsenosides. After the oral administration, there were no significant differences in the AUC values of the RGE and RGE-${\gamma}$-CD 10 groups for ginsenoside Rg1. However, AUC values for ginsenoside Rb1 were $25.8{\mu}g{\cdot}hr/mL$ in the RGE group and $81.5{\mu}g{\cdot}hr/mL$ in the RGE-${\gamma}$-CD 10 group, respectively. Therefore, the bioavailability of ginsenoside Rb1 in the RGE-${\gamma}$-CD 10 group was significantly higher by up to 315% compared with that in the RGE group(p = 0.0029). These results show that the bitter taste of RGE can be simultaneously removed by the complexation of RGE and ${\gamma}$-CD(RGE-${\gamma}$-CD) along with increased bioavailability.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.10-27
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• 2017

Recently, the importance of recognizing the natural environment and the need for its conservation are increasing due to rapid urbanization. Suncheon Bay, designated as Scenic Site No. 41 and one of the World's Five Greatest Coastal Wetlands, is the only tideland among the tidal flats in Korea, which has salt marsh reserves. It has high conservation value from the ecological aspect. In addition to the Suncheon Bay National Garden, it provides various benefits not only to visitors but to local residents as well in terms of economics, environmental issues, and history and cultural aspects. Two million tourists visit the site annually, which has constantly highlighted the limits of ecological capacity. The valuation of the Suncheon Bay wetland is more important for the sustainability of the Suncheon Bay wetland than for its value as a tourism resource for the activation of the local economy. This study used the Logit model, which is commonly used among probabilistic choice models, to evaluate the economic value of Suncheon Bay wetland with the contingent valuation method(CVM). Applying the conservation value of the Suncheon Bay wetland to the benefit of KRW 8,200 for 1 person and 1 day, the benefit from exploration is KRW 2,050, the management and conservation value is KRW 3,034, and the heritage value is KRW 3,116. The results of this study are that benefit from the annual exploration of Suncheon Bay wetland was KRW 44.3 in billion, the management and conservation value was KRW 6.55 in billion, and the heritage value was KRW 6.73 in billion. When converted to the number of paying visitors per year, the conservation value is about KRW 177.1 billion. This study was conducted to evaluate the use and conservation aspects of the economic value of Suncheon Bay wetland. Based on the latent value of the Suncheon Bay wetland, it provides basic data about the efficient management and policy establishment of Suncheon Bay wetland. The study is significant in that the ecological sustainability of the Suncheon bay wetland and the value of non-marketable were evaluated based on the recognition of 'benefit through exploration', 'management and conservation value' and 'value of heritage'. It can be used as policy decision data on the integrated collection of the admission fee of the Suncheon Bay wetland and Suncheon Bay National Garden.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.2
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• pp.60-76
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• 2020

The purpose of this study was to examine the spatial and visual arrangement characteristics of Imsil Yi Ung-jae's old house's spatial and visual aspects in order to discover the value of landscape and traditional house garden. The results of this study are as follows. Dongchon-village in Dundeok-ri, where old house is located, is a typical form of with "Back to the mountain and facing the water(背山臨水)", and is located in the north of the three streams of water, forming a Jeonchaghugwan(前窄後寬). Dongchon Village, which has a traditional scenic spot between Danguidae(丹丘臺) and Samgyeseokmun(三溪石門), is understood to be the main street of Nojeokbong Peak and Gyegwanbong Peak, which is Ansan(案山), where the "A centipede flying in the sky(飛天蜈蚣形)". Yi Ung-jae's old house is the oldest existing high-priced house in the North Jeolla region and the closing price of a royal family of the Joseon Dynasty, which was arranged by Chunseongjeong(春城正), Yi Dam-son(李聃孫) in the mid-16C. The Japanese Invasion of Korea in 1592 and Japanese colonial era, the loyalty of the gate quarters, the filial piety of the gate quarters, and the faithfulness of the tablet(扁額) and Juryeons(柱聯) are enough to contribute to the rise of the value of a physical house. The men's quarters(Sarangchae), which are placed on a high-pocket or a layout without going against the sloping terrain, have the effect of making the distance as far as possible, enhancing its dignity and hierarchy as a royal building. In addition, the entrance to the main quarters(Anchae) through the four pillar gates(四柱門), the extensive support and the appropriation of the Chaewon(vegetable garden), and the official base for the Anchae are very unique compared to the general nobility. However, in the context of the postwar relationship, the shrine seeks to realize Confucian ideals while harmonizing with nature by arranging wide sponsorships around it. On the other hand, it is confirmed that there was a pond in the form of a circle in a square(方池圓島型) with a relatively large area, which is now disturbed and damaged. Written by the high priced planting species are sponsored pine trees, hackberry, persimmon trees, Japanese apricot flower, Ohmomiji, and plum tree in the side garden, as well as cotyledon trees in the outside garden. However, although flower bed(花階), which is built on the stone axis, is a place that clearly shows the expensive garden, it seems to have lost the texture of the plant due to the extremely high variety of species and the splendor that does not match the plant landscape of the flower world. Yi Ung-jae's old house is highly valuable as it is a portrait house of a prince of the blood in the mid-Joseon Dynasty. Based on these findings, this study proposed a plan to improve the management of high prices that could be met.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.11
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• pp.509-520
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• 2015

College Scholastic Ability Test(CSAT) is a primary test to evaluate the study achievement of high-school students and used by most universities for admission decision in South Korea. Because its level of difficulty is a significant issue to both students and universities, the government makes a huge effort to have a consistent difficulty level every year. However, the actual levels of difficulty have significantly fluctuated, which causes many problems with university admission. In this paper, we build two types of data-driven prediction models to predict correct answer rate and to identify significant factors for CSAT English test through accumulated test data of CSAT, unlike traditional methods depending on experts' judgments. Initially, we derive candidate question-specific factors that can influence the correct answer rate, such as the position, EBS-relation, readability, from the annual CSAT practices and CSAT for 10 years. In addition, we drive context-specific factors by employing topic modeling which identify the underlying topics over the text. Then, the correct answer rate is predicted by multiple linear regression and level of difficulty is predicted by classification tree. The experimental results show that 90% of accuracy can be achieved by the level of difficulty (difficult/easy) classification model, whereas the error rate for correct answer rate is below 16%. Points and problem category are found to be critical to predict the correct answer rate. In addition, the correct answer rate is also influenced by some of the topics discovered by topic modeling. Based on our study, it will be possible to predict the range of expected correct answer rate for both question-level and entire test-level, which will help CSAT examiners to control the level of difficulties.

• The Korean Journal of Physiology
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• v.20 no.1
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• pp.1-7
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• 1986

It has been well documented that the peripheral autonomic nervous system plays an important role in exocrine pancreatic secretion. However, the role of the central nervous system in pancreatic function is still obscure even though the central nervous system has been known to control gastrointestinal functions through the autonomic nervous system. Since the reticular formation in the mesencephalone seems to integrate the autonomic function, the present study was undertaken to investigate a possible influence of the reticular formation upon the exocrine pancreatic secretion. Twenty·two albino rats fasted for 24 hours were anesthetized by intraperitoneal injection of urethane in a dose of 1 g/kg, The pancreatic duct was cannulated to collect pancreatic juice and bile juice was diverted to the jejunum. The gastroduodenal junction was ligated to Prevent passage of gastic juice into the duodenum. A pair of electrodes were bilaterally inserted in the reticualr formation of the mesencephalone with aid of a stereotaxic apparatus. When the volume of pancreatic juice secreted for 10 min became constant, the reticular formation was electrically stimulated for 10 min. Parameters of the electical stimulation was 1.3V, 40 Hz and 2 msec. When the pancreatic secretion returned to the level before the electrical stimulation, cervical vagotomy (11 rats) or administration of propranolol (11 rats) in a dose of 0.1 mg/kg through the jugular vein was carried out. Ten minutes after the treatment, the electrical stimulation of the reticular formation was repeated. The brain was fixed by perfusion of 10% formaline solution through the heart, and then placement of the electrode tip was examined histologically. Protein concentration and amylase activity in samples of Pancreatic secretion were measured. The electrical stimulation of the reticular formation significantly increased in volume $({\mu}l/10\;min)$, Protein output $({\mu}g/10\;min)$ and amylase output (U/10 min) in the pancreatic secretion. The stimulatroy effects were not affected by the cervical vagotomy but completely abolished by propranolol. Meantime, it was also observed that both vagotomy and propranolol significantly reduced the pancreatic secretory function. These results indicate that the reticular formation in the mesencephalone may exert a stimulatory effect upon the Pancreatic secretory function not through the vagus nerve but through the sympathetic pathway in anesthetized rats.