• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.229-234
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• 2014

We analyzed drainage water from coir substrate in which cucumber plants were grown in winter and elucidated changes in pH, EC, and major nutrients according to the growth stages to recommend nutrient solution management appropriate to each growth stage. From the analysis of drainage solution the growth stages of cucumber were desirable to be divided into two, planting to fruit setting and fruit setting to harvest in case of nutrient solution management. The time required was about 3 weeks from planting to the first fruit setting and thereafter 7~10 days more until the first harvest. Approximately every 3~4 days were needed until the upper flowers bloomed. The time required from fruit setting to harvest was not different much among flowers as cucumber plants grew. From the experimental results, EC of supplied solution was recommended to maintain a little high to $3.0dS{\cdot}m^{-1}$ until before fruit setting and lower a little to $2.0{\sim}2.3dS{\cdot}m^{-1}$ after that. Of course, the amount of solution supply should be increased as plants grew. In case of each nutrients, the recommendation of concentrations of nitrogen, phosphorus and calcium were 700, 60, and $110mg{\cdot}L^{-1}$ each until before fruit setting, and then 660, 50, and $100mg{\cdot}L^{-1}$ each after fruit setting. The concentrations of potassium and magnesium are recommended to start from 400 and $80mg{\cdot}L^{-1}$ until fruit setting and lower a little after that.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.18-24
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• 2018

The policy-making and technological development of eco-friendly automobiles designed to increase their supply is ongoing, but the internal combustion engine still accounts for about 95% of the automobiles in use. Also, in order to meet the stricter emission regulations of internal combustion engines based on fossil fuels, the proportion of after-treatments for vehicles and (ocean going) vessels is gradually increasing. Natural gas is a clean fuel that emits few air pollutants and has been used mainly as a fuel for city buses. In the long term, we intend to develop a new NGOC/LNT+NGCO/SCR combined system that simultaneously reduces the toxic gases, $CH_4$ and NOx, emitted from CNG buses. The objective of this study is to investigate the characteristics of $de-CH_4/NOx$ according to the ceramic and metal substrates of the SCR (Selective Catalytic Reduction) catalysts mounted downstream of the combined system. The V and Cu-SCR catalysts did not affect the $CH_4$ oxidation reaction, the two NGOC/SCR catalysts each coated with two layers began to oxidize $CH_4$ at $400^{\circ}C$, and the amount of $CH_4$ emitted was reduced to about 20% of its initial value at about $550^{\circ}C$. The two NGOC/SCR catalysts each coated with two layers showed a negative (-) NOx conversion rate above $350^{\circ}C$. The ceramic-based combined system reached LOT50 at $500^{\circ}C$, which was about 20% higher in terms of the $CH_4$ conversion rate than the metal-based combined system, showing that the combined system of NGOC/LNT+Cu-SCR is a suitable combination.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.12
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• pp.886-892
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• 2011

In a study on THMs formation at the distribution facilities in Seoul water supply for past 3 years from 2007 to 2009, THMs production was increased from inlet to outlet during the process in water treatment plant. However, such increased THMs amount was very small compared to THMs production formed after pre-chlorination and post chlorination. Accordingly, this study is aimed to investigate the characteristics of water quality parameters of Han River related to THMs formation in 6 water treatment plants in Seoul. The results showed that THMs and other factors such as temperature (r = 0.539~0.846) and turbidity (r = 0.421~0.863) had positive correlation while THMs had negative correlation with pH (r = -0.613~-0.800) and algae (r = -0.582~-0.901). There is no correlation between THMs and $NH_3-N$. According to the factor analysis, generally metabolite and organic matter factor $X_1$ (pH, BOD, algae), and seasonal and natural factor $X_2$ (temperature, turbidity) played an important role in the formation of THMs. Multiple regression analysis for THMs formation showed significance of regression appeared in most water systems.

• Journal of the Korean Institute of Gas
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• v.24 no.2
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• pp.1-8
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• 2020

Centrifugal pump is a facility that transfers energy to fluid through centrifugal force, which is usually generated by rotating the impeller at high speed, and is a major process facility used in many LNG production bases such as vaporization seawater pump, industrial water and fire extinguishing pump using seawater. to be. Currently, pumps in LNG plant sites are subject to operating conditions that vary depending on the amount of supply desired by the customer for a long period of time. Pumps in particular occupy a large part of the consumption strategy at the plant site, and if the optimum operation condition is not available, it can incur enormous energy loss in long term plant operation. In order to solve this problem, it is necessary to identify the performance deterioration factor through the flow analysis and the result analysis according to the fluctuations of the pump's operating conditions and to determine the optimal operation efficiency. In order to evaluate operation efficiency through experimental techniques, considerable time and cost are incurred, such as on-site operating conditions and manufacturing of experimental equipment. If the performance of the pump is not suitable for the site, and the performance of the pump needs to be reduced, a method of changing the rotation speed or using a special liquid containing high viscosity or solids is used. Especially, in order to prevent disruptions in the operation of LNG production bases, a technology is required to satisfy the required performance conditions by processing the existing impeller of the pump within a short time. Therefore, in this study, the rotation difference of the pump was applied to the ANSYS CFX program by applying the modified 3D modeling shape. In addition, the results obtained from the flow analysis and the curve fitting toolbox of the MATLAB program were analyzed numerically to verify the outer diameter correction theory.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.374-390
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• 2021

Growth and yield of field vegetable crops would be affected by climate conditions, which cause a relatively large fluctuation in crop production and consumer price over years. The yield prediction system for these crops would support decision-making on policies to manage supply and demands. The objectives of this study were to compile literatures related to onion and garlic and to perform data-mining analysis, which would shed lights on the development of crop models for these major field vegetable crops in Korea. The literatures on crop growth and yield were collected from the databases operated by Research Information Sharing Service, National Science & Technology Information Service and SCOPUS. The keywords were chosen to retrieve research outcomes related to crop growth and yield of onion and garlic. These literatures were analyzed using text mining approaches including word cloud and semantic networks. It was found that the number of publications was considerably less for the field vegetable crops compared with rice. Still, specific patterns between previous research outcomes were identified using the text mining methods. For example, climate change and remote sensing were major topics of interest for growth and yield of onion and garlic. The impact of temperature and irrigation on crop growth was also assessed in the previous studies. It was also found that yield of onion and garlic would be affected by both environment and crop management conditions including sowing time, variety, seed treatment method, irrigation interval, fertilization amount and fertilizer composition. For meteorological conditions, temperature, precipitation, solar radiation and humidity were found to be the major factors in the literatures. These indicate that crop models need to take into account both environmental and crop management practices for reliable prediction of crop yield.

• Journal of Nutrition and Health
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• v.51 no.5
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• pp.386-399
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• 2018

Purpose: This study examined whether the supply of healthy Korean diets for 12 weeks is effective in improving the risk factors related to serum GGT and cardiovascular diseases in patients with hypertension and diabetes. Methods: This study selected 41 patients, who were treated with hypertension and diabetes. The Korean diet was composed of cooked-rice, soup, kimchi, and various banchan with one serving called bapsang, which emphasize proportionally high consumption of vegetables and fermented foods, moderate to high consumption of legumes and fish, and low consumption of animal foods. The control group was instead instructed to "eat and exercise as usual" while following the Korean Diabetes Association's dietary guidelines with an intake that can assist in glycemic control, maintain adequate weight, and meet the nutritional requirements. The Korean diet group (21 patients) were served three healthy Korean meals a day for 12 weeks, and the control group (20 patients, who trained in the diet guideline of diabetes) maintained their usual diabetic diet. The serum GGT, blood pressure, heart rate, glycemic control data, cardiovascular risk indicators, and changes in diet measured at the four visits (week 0, 4, 8, and 12) during the course of 12 weeks were compared and evaluated. Results: The serum GGT (p < 0.001), HbA1c (p = 0.004), heart rate (p = 0.007), weight (p = 0.002), Body Mass Index (p = 0.002), body fat mass (p < 0.001), body fat (%) (p < 0.001), and free fatty acid (p = 0.007) in the Korean diet group decreased significantly after the dietary intervention compared to the control group. The amount of intake of rice, whole grains, green vegetables, Kimchi, and soybean fermented food were increased significantly compared to the control group (p < 0.001). The Korean diet group showed significant decreases (p < 0.001) in the intake of animal protein, lipid, and cholesterol derived from animal foods compared to the control group but significant increases (p < 0.001) in the intake of total calories, folic acid, dietary fiber, sodium, potassium, and vitamins A, E, and C. Conclusion: In patients with hypertension and diabetes, it was confirmed that regular eating of a healthy Korean diet helps improve the risk factors for GGT and cardiovascular diseases.

• Korean journal of communication and information
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• v.17
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• pp.85-111
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• 2001

In this article, Channel 4 in Britain is the main theme since its alternative broadcasting system can shed the light to the Korean case. Korea is getting into the era of multimedia and including webcastings there are over thousands channels are available. However the infra-structure fur the broadcasting contents never seems to be matured to match its need. Instead Korean production system is rather vertically integrated into the Networks(KBS, MBC and SBS) which oligopolise the broadcasting in terms of supply. Even though 'Program Quota Regulation' has been established under the new Broadcasting Art(1999), the old habits die hard and still the independent producers have the unfair relationships with the Networks. Under this circumstance, Channel 4 can be the good example to show how well the alternative system can serve to the diversity of broadcasting and the taste of the minority. Channel 4 took almost 20 years to establish since there were enormous amount of debates about its public missions, ideal broadcasting system, whom it should serve for, etc. between all the social sectors including the independent producers. The social agreement was reached on the point that the new broadcaster should not produce but publish and it is called the 'publishing broadcaster'. In this sense, it can be managed effectively with comparatively little fund and at the same time, it can always have all different sorts of contents as well as genres very freely through 'commissioning process' or buying programs from even the most innovative producers. The 'commissioning process' is one of the key points which makes the Channel 4 so unique. The commissioning process is literally open to anybody, in particular, to the small scale producers with much innovative ideas. Channel 4 will support financially as well as with facilities and human resource to produce the program once after their program idea is accepted by the commissioning editor. Even better side of Channel 4 is about their financial success. From the beginning, the 'funding formula' helped in great deal to make the Channel 4 doing all sorts of innovative experiments. The history of 'funding formula' and its contribution are explained in the article, too. With all this effort, the article is hoped to bring discussion about the alternative broadcasting system which might help to prepare the new era of broadcasting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.391-418
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• 1983

Urea and ammonium sulfate without and with sulfur group, respectively, were compared with respect to their nutritive effects on the rice plants, Suweon 264 and Jinheung, under the nursery trial on the protected upland and lowland seedbed, the pot trials with their various combination ratios and with added sodium sulfate to urea and the trials on the paddy fields which have undergone urea and ammonium sulfate application for many years. The rice seedlings fertilized with ammonium sulfate surpassed those with urea in growth performance and nutrients absorption of the rice seedlings at nursery period. Such stimulating effect of ammonium sulfate on the growth and nutrients uptake was more remarkable under the upland nursery than under the lowland one. The pot trial with the various combination ratios of urea and ammonium sulfate revealed that the chlorophyll content in leaf blade increased with the increment of sulfate ratio in the combination and the sole application of urea caused the chlorosis of leaf which was more conspicuous in Suweon 264 than in Jinheung. Fertilized with the same active ingradient amount of nitrogen, the rice plants supplied with ammonium sulfate surpassed those with urea in the chlorophyll content consistently under the nursery, the pot and the paddy field trials. The photosynthesis of flag leaf at heading stage increased with the combination rate of ammonium sulfate in the pot trial. The sulfur applicated as supplementary element of nitrogen in the nursery, the pot and the field trials were observed to be in positive relationship to the nitrogen and potassium content, but to be in negative correlation to the calcium content. The sulfur content in the rice plants was higher at early growth stage and decreased with the advance in growth stage. The nitrogen content also showed a similiar tendency to the sulfur content, and the N/S ratio was higher at early growth stage than at later one. The N/S ratio was negatively correlated with the chlorophyll content. In the field experiment, ammonium sulfate surpassed urea in the number of productive tiller, dry matter production and unhulled rice yields, but much stimulating effect of ammonium sulfate on the grain production was shown to be less effective than that on the straw production. The nitrogen and major nutrients content in the rice straw at harvest were higher in the paddy field with long-term ammonium sulfate application than in that with long-term urea application, suggesting that the former might have greater potentiality in nutrients supply than the latter.

• Proceedings of the Korean DIstribution Association Conference
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• 2003.02a
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• pp.123-166
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• 2003

Marketing channel is recognized as one of the society systems which have the character of functional organization. These organizations are related to each other for specialized and cooperative work. Channel members in distribution channel are striving to accomplish exchange through reciprocal action. Thus channel members exercise their power to take better position in exchange. There will be struggling between members about satisfaction and conflict during this power exercise. Now a days, buyers use more harsh power as large retail firms are increasing. This phenomenon is occurring in the distribution channel. However, there will be different phenomenon in case of agricultural products. Not like industrial product suppliers, agricultural product suppliers have various supply channels and many agricultural products are seasonal. It has also unstable amount supplies. There should be differentiated marketing in agricultural products. Relatively weaker powered suppliers have to strengthen comparative factors and also have to be technically specialized through assessed experience in order to establish strong product sales chain. Making a brand of agricultural product would be also a good idea to increase the product comparability. Channel members need to be recognized their specialized functions in order to make balanced distribution channel. There have to be conversion of concept of relation between suppliers and buyers from subordinate relationship to cooperative relationship.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.565-575
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• 2021

The purpose of this study was to identify the amount of alcohol and drinking frequency among high school students based on social alcohol drinking supply. The data was on 161 drinkers aged between 16 and 19 from 21 high schools across the country using a questionnaire of the International Alcohol Control(IAC) Study, which was developed in 2012. Results show that the higher the number of social suppliers offering alcoholic beverages to high school students, the greater the consumption of alcohol per episode(59.433 g for one person, 113.40 g for two, and 133.56 g for three or more people). On the other hand, alcohol consumption among 'Honsul' people, a group that drinks alone without a social drinking supplier, was 167.84 grams, higher than that of groups that receive social drinking services. As a social drinking supplier for teenagers, drinking was the highest by their father (29.3 %), while friends (25.0 %) and mothers (20.7 %) were the main drinking suppliers. In particular, the provision of drinking due to father(𝛽=-.32, t=3.55, p<.01) and mother(𝛽=.22, t=2.71, p<.01) showed statistical significance as a factor in increasing the frequency of providing social drinking in adolescents. On the other hand, partner/boy or girl friend (𝛽=-.23, t=-2.73, p<.01) was a factor in reducing the frequency of alcohol provision. Friends(𝛽=.24, t=3.02, p<.01) and senior-junior schoolmates(𝛽=.16, t=2.04, p<.05) were the factors that increase the total alcohol intake of adolescents. This is due to the increase in the frequency of alcohol provision. This suggests that alcohol harm education should be expanded from students to parents, considering the role of parents as a social drinking supplier and the link between high alcohol intake among teenagers due to senior-junior friends and schoolmates.