• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.916-927
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• 2010

In general water treatment process, the disinfection process by chlorine is used to prevent water borne disease and microbial regrowth in water distribution system. Because chlorines were reacted with organic matter, carcinogens such as disinfection by-products (DBPs) were produced in drinking water. Therefore, a suitable injection of chlorine is need to decrease DBPs. Rechlorination in water pipelines or reservoirs are recently increased to secure the residual chlorine in the end of water pipelines. EPANET 2.0 developed by the U.S. Environmental Protection Agency (EPA) is used to compute the optimal chlorine injection in water treatment plant and to predict the dosage of rechlorination into water distribution system. The bulk decay constant ($k_{bulk}$) was drawn by bottle test and the wall decay constant ($k_{wall}$) was derived from using systermatic analysis method for water quality modeling in target region. In order to predict water quality based on hydraulic analysis model, residual chlorine concentration was forecasted in water distribution system. The formation of DBPs such as trihalomethanes (THMs) was verified with chlorine dosage in lab-scale test. The bulk decay constant ($k_{bulk}$) was rapidly decreased with increasing temperature in the early time. In the case of 25 degrees celsius, the bulk decay constant ($k_{bulk}$) decreased over half after 25 hours later. In this study, there were able to calculate about optimal rechlorine dosage and select on profitable sites in the network map.

• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.153-163
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• 2002

In vitro matured porcine oocytes have very small volume of perivitellinspace (PVS). In these respect, the effect of sucrose and polybrene on the efficiency of gene transfer was investigated. As a gene (hGH) transfer vehicle, vesicular stomatitis virus glycoprotein pseudotyped retroviral vector (VSV-G) was used. Sucrose treatment has no detrimental effect on the rates of cleavage and resulted in the enlargement of PVS for the efficient introduction of retroviral vector stocks. Introduction rates of retrovirus in 0.5, 1, 2, 3 % sucrose treatment group were higher than that of the non-treatment group (39.3, 43.3, 35.7, 40.7 % vs. 8.3 %), respectively. In addition, we observed that sucrose pretreatment during injection procedure significantly reduce the frequency of polyspermy. In general, polybrene is a polycation essential for retrovirus transduction. The groups with the addition of 0.5, 5, 50$\mu\textrm{g}$/$m\ell$ polybrene exhibited a significant effect on gene transfer compared to that of the non-addition group (56.5, 50.0, 57.1 % vs. 34.6 %), respectively But, when the oocytes were co-injected with retrovirus and 50$\mu\textrm{g}$/$m\ell$ polybrene, the rates of cleavage and blastocyst development were 43.3 and 4.6%, respectively. This rates were lower than those of the non-addition group (70.0 and 17.3 %). In conclusion, sucrose pretreatment have increased efficiency of retroviral mediated gene transfer in porcine oocytes with no damage on in vitro fertilization and embryo development. In addition, sucrose pretreatment was beneficial in polyspermy inhibition. Presence of polybrene during microinjection showed a beneficial effect on the gene transfer in porcine oocytes, in low concentration. And these results will provide an useful tool for production of transgenic pigs by retroviral mediated gene transfer.

• Journal of Bio-Environment Control
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• v.14 no.2
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• pp.95-105
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• 2005

This study was carried out to file up using effect and requirement of energy for environmental design data of Pleurotus eryngii growing houses. Heating and cooling Degree-Hour (D-H) were calculated and compared for. some Pleurotus eryngii growing houses of sandwich-panel (permanent) o. arch-roofed(simple) type structures modified and suggested through field survey and analysis. Also thermal resistance (R-value) was calculated for the heat insulating and covering materials of the permanent and simple-type, which were made of polyurethane or polystyrene panel and $7\~8$ layers heat conservation cover wall. The variations of heating and cooling D-H simulated for Jinju area was nearly linearly proportional to the setting inside temperatures. The variations of cooling D-H was much more sensitive than those of heating D-H. Therefore, it was expected that the variations of required energy in accordance with setting temperature or actual temperature maintained inside of the cultivation house could be estimated and also the estimated results of heating and cooling D-H could be effectively used far the verification of environmental simulation as well as for the calculation of required energy amounts. When the cultivation floor areas are all equal, panel type houses to be constructed by various combinations of materials were found to by far more effective than simple type pipe house in the aspect of energy conservation maintenance except some additional cost invested initially. And also the energy effectiveness of multi-span house compared to single span together with the prediction of energy requirement depending on the level insulated for the wall and roof area could be estimated. Additionally, structural as well as environmental optimizations are expected to be possible by calculating periodical and/or seasonal energy requirements for those various combinations of insulation level and different climate conditions, etc.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.277-287
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• 2016

Purpose: This study was performed to compare total phenolic contents, in vitro antioxidant capacity, and reduction effect of Korean food groups on ex vivo DNA damage in human cells and analyze correlations between each indicator. Methods: Vegetable foods in the Korean diet based the results of the KNHANES V-2 (2011) were classified into 10 food groups: cereals, fruits, vegetables, nuts, kimchi, seaweeds, potatoes, mushrooms, legumes, and oils. Eighty-four foods constituted more than 1% of the total intake in each food group and finally designated as vegetable foods in the Korean diet. Total phenolic content of each food group was measured. Further, in vitro antioxidant capacity was measured based on DPPH radical scavenging assay, TEAC assay, and $ORAC_{ROO{\cdot}}$ assay. Ex vivo DNA damage in human lymphocytes was assessed using comet assay. Results: Total phenolic contents of food groups of the Korean diet increased in the order of mushrooms, fruits, vegetables, seaweeds, and kimchi. Meanwhile, antioxidant rankings of food groups as mean values from the three in vitro test methods increased in the order of mushrooms, seaweeds, vegetables, kimchi, and fruits. Protection against ex vivo DNA damage in human lymphocytes was highest in mushrooms, followed by vegetables, fruits, seaweeds, and kimchi. The rankings of the food groups for total phenolic content, in vitro DAC, and ex vivo DNA protection activity were similar, and correlations between each indicator were significantly high. Conclusion: Mushrooms, fruits, vegetables, and seaweeds among the tested food groups in the Korean diet showed high total phenolic contents, in vitro antioxidant capacities, and protection against DNA damage. Correlations between each indicator in terms of total phenolic content, in vitro antioxidant capacity, and ex vivo DNA protection between each food group were found to be particularly high.

• Journal of Nutrition and Health
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• v.50 no.1
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• pp.85-97
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• 2017

Purpose: This study was conducted to investigate dietary habits related to weight reduction and snack intake habits of $4^{th}$ to $5^{th}$ grade elementary students located in Jeju-si, Jeju, South Korea. Methods: The $4^{th}$ and $5^{th}$ grade elementary school students (total n = 234, equally matched numbers of normal weight children and overweight/obese children (n = 117/group)) were surveyed using a questionnaire and a 24-hour dietary recall method in Oct 2015. Results: The percentage of students who experienced reduced food intake to control weight was 26.3% in the normal weight group (NG) and 77.6% in the obese group (OG). Most frequently answered meal for reduced intake was snacks in the NG and dinner in the OG. Percentages of daily calorie intake among subjects were 17.2% for breakfast, 33.8% for lunch, 29.7% for dinner, and 19.3% for snacks. Frequency of snack intake was 2.1 times a week in NG and 1.6 times a week in OG, which showed a statistical difference between body weight groups. Types of snack foods were distinctly different depending on where children consumed them, although no difference was observed between NG and OG. In addition, snack intake level of low energy and nutrient-dense foods was significantly lower in the OG compared to the NG, whereas snack intake level of energy dense and low-nutritive foods was not different between the OG and NG. Conclusion: Taken together, snack intake level with consideration of frequency and amount of snack intake showed that children in the OG consumed significantly less low energy and nutrient-dense foods compared to the NG. Therefore, nutritional education for choosing healthy snack foods for children regardless of body weight status is crucial based on family-school links.

• Journal of Nutrition and Health
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• v.50 no.5
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• pp.504-518
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• 2017

Purpose: The objective of this study was to develop a processed foods database (DB) for estimation of processed food intake in the Korean population using data from the Korea National Health and Nutrition Survey (KNHANES). Methods: Analytical values of processed foods were collected from food composition tables of national institutions (Development Institute, Rural Development Administration), the US Department of Agriculture, and previously reported scientific journals. Missing or unavailable values were substituted, calculated, or imputed. The nutrient data covered 14 nutrients, including energy, protein, carbohydrates, fat, calcium, phosphorus, iron, sodium, potassium, vitamin A, thiamin, riboflavin, niacin, and vitamin C. The processed food DB covered a total of 4,858 food items used in the KNHANES. Each analytical value per food item was selected systematically based on the priority criteria of data sources. Results: Level 0 DB was developed based on a list of 8,785 registered processed foods with recipes of ready-to-eat processed foods, one food composition table published by the national institution, and nutrition facts obtained directly from manufacturers or indirectly via web search. Level 1 DB included information of 14 nutrients, and missing or unavailable values were substituted, calculated, or imputed at level 2. Level 3 DB evaluated the newly constructed nutrient DB for processed foods using the 2013 KNHANES. Mean intakes of total food and processed food were 1,551.4 g (males 1,761.8 g, females 1,340.8 g) and 129.4 g (males 169.9 g, females 88.8 g), respectively. Processed foods contributed to nutrient intakes from 5.0% (fiber) to 12.3% (protein) in the Korean population. Conclusion: The newly developed nutrient DB for processed foods contributes to accurate estimation of nutrient intakes in the Korean population. Consistent and regular update and quality control of the DB is needed to obtain accurate estimation of usual intakes using data from the KNHANES.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.181-189
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• 1979

In order to establish fertilizing technique for the increase of grain yield and its stability, the total absorbed amount of nutrients and nutritional status of rice plants at different growth stages were studied with respect to the nutrient contents and its relation to grain yield and yield components. This experiment was carried at three different level of nitrogen fertilization; two different seeding and transplanting times, and eight cultivars including both Japonica-and Tongil-type. The results of a part of these experiments are summarized as fallows: 1. The culm length tended to Increase with increasing fertilizer amount, but no significant difference between ordinary and heavy fertilization was observed in Tongil-type cultivars. 2. The panicle length was some what longer in ordinary and heavy fertilization than non-fertilization. 3. As the N-fertilizer level increases, the number of panicles per plant increased with higher response in Japonica-type cultivars than in Tongil-type cultivars. 4. The number of grains per panicle increased significantly in ordinary and heavy fertilization, compared to non-fertilization, but the difference in grain number per panicle among fertilizer treatment was smaller in Japonica-type cultivars than Tongil-type. 5. The 1,000 grains weight showed no significant difference among fertilization levels in ordinary transplanting, but indicated gradual decreasing tendency as the transplanting delayed. 6. In percentage of ripeness, there was no significant difference in ordinary transplanting, but hightly significant in late transplanting among N-fertilization levels and cultivars. 7. In yield, highly significant difference was shown among N-fertilizer levels and cultivars In Tongil-type variety, higher yield was obtained in ordinary fertilization than heavy fertilization. 8. The straw weight showed the tendency to increase in higher nitrogen level, but no significant difference between ordinaly and heavy fertilization was observed in Tonsil-type cultivars.

• 대한공업교육학회지
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• v.45 no.1
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• pp.63-83
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• 2020

The purpose of this study is to provide the basic materials needed to plan the NCS Learning Module to be used effectively in practical courses. In this study, teachers and students' satisfaction surveys were collected about the NCS (National Competency Standards) learning module, career and field practice, practical environment used in the construction subject course. This study was conducted on public high schools in Chungcheong province (including Daejeon), which is operating practice course using the NCS learning module. The research questions are as follows; First, how was the satisfaction of teachers and students in the practical subject class using NCS learning module? Second, what is the degree of satisfaction of teacher's career and field practice guidance, student's career decision and field practice after the practical course using NCS learning module? Third, the satisfaction level of the developed NCS learning module and practical subject class using the same was determined by setting whether the number of training of NCS-related teachers or the presence or absence of on-the-job training of students were affected? The results of the study are as follows; As a result of comparing the teachers' and students' satisfaction, the students showed satisfaction in all items, whereas the teachers showed 'content level', 'interest', 'necessary knowledge', 'skill acquisition', 'Improvement of practical skills (level of skill performance)', 'scale of experimental practice', and 'items of experimental practice equipment' were dissatisfied. It was found that the number of NCS related teachers' training (or absence) or the presence of students on the field had an effect on the satisfaction of the developed NCS learning module and the practical course using it. In order to fully utilize the developed NCS learning module in the practical course, it is required to develop and construct the teaching material of the teacher who can serve as an intermediary for conceptualization and understanding of job skills. It is necessary to increase the number of education and training specialists to positively reflect the demands of the education field.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.1
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• pp.96-105
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• 2011

This study analyzed literary works and references related to Dok-Rak-Dang(獨樂堂) and the attributes of managing the landscape in Dok-Rak-Dang Garden based on the assumption of position and the spatial structure revealed in the site. Hoe-Jae Lee Eon-Jeok(1491-1553), a distinguished scholar of Neo-Confusionism, built Dok-Rak-Dang and managed the surrounding areas during his retirement years. He called the mountains, stream, and rock along and near the Ja-Ge Stream Four Mountains and Five Platforms(四山五臺). Before he named these, they were not considered special. The Four Mountains which are Do-Duk in north, Mu-Hak in south, Hwa-Gae in east, and Ja-Ok in west enclose Dok-Rak-Dang and the surrounding areas. The Five Platforms, Se-Sim, Gwan-Eo, Yeong-Gue, Jing-Sim, and Tak-Yeong, in order from downstream, are places with beautiful scenery in Ja-Ge Stream. The attributes of managing the landscape in Dok-Rak-Dang Garden are the following: One is the spatial integration of what is natural and artificial as the attitude of aesthetic experience in accord with nature. Another is flexible territorialization as the way of organizing spaces in nature from the experiential aspect. The other is place making of personalized nature through a series of processes such as observing, choosing, and naming landscapes in nature. Four Mountains and Five Platforms function as landscape bases and elements to appreciate nature aesthetically. Those attributes are different from the attitude of constructing spaces. Rather, they originate from the traditional view on the appreciation of nature. Above all, place-making in nature was acquired from designed spatial structure and experiential aesthetic appreciation in the space through observing, choosing, and naming landscapes in nature reflecting creator's own ideological and aesthetic thoughts, and it might be explained as one of practical ways of Korean traditional gardening.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.2
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• pp.16-26
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• 2016

In this paper, we collected information on Palgyeong of the Gangneung area that were scattered around several literatures, and analyzed and interpreted regional distribution, elements of scenery and inherent meanings from various angles. we shed light on the origin and the meaning of Palgyeong, which have been passed down in the Gangneung area. Palgyeong of the Gangneung area have been accumulated and expanded for a long period of time, since Goryeo up to the modern times, and it does not simply reflect the beauty of natural scenery, but also reflect historical facts and sentiments rooted in this region. In addition, given the comprehensive veiw of Palgyeong of the Gangneung area and in consideration of its type and distribution of the eight sceneries the most common format is similar to Sosang(瀟湘類似型). What are repeatedly appearing among them include 'smoke from cooking supper' and 'catching fish', showing the living conditions of local residents of Gangneung at the time, which refers to the fact that Palgyeong consisted of village units. Palgyeong in the Gangneung area are distributed in diverse ranges between the city and Nujung. Most of Palgyeong are clustered in the east of Gangneung city and in the region tangent to Gangdong-myeon and Gujeong-myeon. When we consider the situation where most of Palgyeong in the Gangneung area are distributed in this region, it suggests that the region occupies the heart of scenery of Gangneung. Palgyeong of the Gangneung area consists of 60% natural factors, 36% humanity factors, and 4% other factors, where the natural factors hold the beauty of nature itself and the humanities and other factors hold the legends and history contained in the targets. The sceneries expressed by Palgyeong cannot be individually separated. Namedaecheon, Jukdobong, Sumseokcheon, Sumdulmaeul, Gunseongang, Pungho and Kyungpoho were connected to Nujung and Hongjamam, and they eventually became a panorama. Hansongjung, Hwanseondeung, Hansongsa, Pungho and Gunseongang are related to Hwarang of Silla and have become representative historical sceneries of the Gangneung area. Judging from the fact that currently non-existing sceneries such as Kyeonjodo, Hansongjung and Gulsansa remained in Palgyeong and been passed, Palgyeong have positioned imaginary spaces of the Gangneung people beyond simply expressing sceneries. In conclusion, Palgyeong in the Gangneung area are aesthetical objects and while at the same time, they are historical and cultural space, and furthermore, we can see that they still remain as imaginary spaces.