• Journal of Aquaculture
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• v.1 no.1
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• pp.13-24
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• 1988

In order to investigate a reasonable rearing density and the possibility of high-density rearing, flounder, Paralichthys olivaceus, juveniles of 2.53$\pm$0.24 cm in total length and 1.12$\pm$0.12 cm in body height were used in this study. The initial rearing density of them was 10 (D10), 20 (D20), 30 (D30) and 40 (D40) individuals per 137.75 $cm^2$ of bottom area, respectively. Ranges of water temperature and specific gravity during the rearing period of 65 days were $21.0\~27.0^{\circ}C$ and 1.024$\~$1.026, respectively, showing relatively higher values than that of natural sea water. Dissolved oxygen during the rearing period was 5.4$\~$7.5 ml/$\iota$ and inorganic nitrate was 0.07$\~$0.48 ppm in $NH_4^+-N$, 0.006$\~$0.33 ppm in $NO_2^{-}-N$ and 3.89$\~$34.06 ppm in $NO_3^{-}-N$. Growth in total length and body height of the juveniles in four rearing density at the end of the experiment was 8.17$\pm$0.80 em and 4.16$\pm$0.39 em, the highest in D20 and 7.72$\pm$0.40 cm and 3.94$\pm$0.21 cm, the lowest in D10. Significant differences, however, were not recognized between the slope values of growth regressions in four rearing density. Slope values of the relative growth between total length and body height of the juveniles in four rearing density were 0.5346, the highest in D10 and 0.5165, the lowest in D30, but there were no significant differences in those values. Survival rate of juveniles at the end of the experiment was $90\%$ in D10, D20 and D30, but that of D40 was $75\%$. The relationship between total length X body height (X) and body surface area of ocular side (Y) to calculate the rate of Y to bottom area in rearing tank (covering rate) as an indicator of rearing density was expressed by a linear regression, Y=0.5994X+0.1840. Covering rate in four rearing density at the end of the experiment was ranged 1.2$\~$4.1 times. Judging from the covering rate above 4 times, it seems to be possible rearing the flounder juveniles in high-density.

• Korean Journal of Health Education and Promotion
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• v.18 no.2
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• pp.45-63
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• 2001

The objective of this study is to give basic materials for selection and improvement of contents of safety education, which is substantially helpful to elementary students, by analysis of contents of safety education in some subjects and assessment of the needs of elementary students for safety education. For this purpose, this study was analyzed the contents of safety education in five subjects for elementary school and conducted the survey of 883 students in some elementary schools in Seoul from April 7 to 22, 2000. The results were as follows; 1. As a result of analysis of the proportion of contents regarding safety-related education in some subjects, Physical Education occupied the highest proportion (14.09％), and that was followed by Practical Subject (9.55％) and Moral Education (9.34％). However, the proportions in Social Study and Natural Science were very low, 1.85％ and 1.31％ each. In total lines of these five subjects, the numbers of line regarding safety education was contained by 5.78％. 2. Analyzing the proportion of domains of safety education in five textbooks, the Meaning of Safety and Basic Principles occupied the highest portion (29.5％), and that was followed by the Home Safety (24.0％), the Safety in School (17.1％), and the Play and Leisure Safety (14.0％). The Coping with Accidents and First Aid, the Safety from Fire and Explosion, and the Traffic Safety occupied relatively low portion, 6.9％, 5.7％, and 2.8％ each. 3. As a result of analysis of the proportion of the safety education domain in each subject, the Meaning of Safety and Basic Principles occupied the highest portion (23.6％) in Moral Education, the Home Safety (12.7％) in Practical Subject, and the Play and Leisure Safety (10.9％) in Physical Education. 4. Most of the participants in this survey experienced the Home Accidents (71.1％). And also, they experienced the Play and Leisure Accidents (57.9％), the Accidents in School (49.7％), the Traffic Accidents (45.3％), and the Fire and Explosion Accidents (24.7％) in order. 5. In the average proportion of the needs of participants for safety education in each domain, the Coping with Accidents and First Aid has the highest point (4.05). And, that was followed by the Home safety (3.79), the Safety from Fire and Explosion (3.73), the Meaning of Safety and Basic Principles (3.65), the Play and Leisure Safety (3.50), the Safety in School (3.37), and the Traffic Safety (3.35). The average proportion of the needs for safety education of total domains was 3.66. 6. In the needs for safety education regarding the feature of participants, it showed higher scores in female students than male ones (p〈0.001), in lower grader than higher grader (p〈0.05), and in the students born to wealth than those born poor (p〈0.05). Also, the children who recognize the necessity of safety education showed higher scores of the needs for safety education (p〈0.001). And it also showed the same results of high score to the children whose parents did the safety education (p〈0.00l) and to the children and their parents who have the higher degree of practicing safety (p〈0.001), and these differences were statistically significant. 7. In the extent of preference for methods of safety education, it showed high score to the Field Learning, followed by the Audio- Visual Education, the Discussion, and the Instruction of teacher. In the extent of preference for subjects regarding the contents of safety education by each domain, it showed high score to the subject of Safety for 4 domains - the Meaning of Safety and Basic Principles, the Traffic Safety, the Safety from Fire and Explosion, and the Coping with Accidents and First Aid. And also, they preferred Moral Education for 2 domains - the Home safety and the Safety in School, and Physical Education for a domain of the Play and Leisure Safety. 8. While 27 of 36 detail items was contained the contents of safety education, the proportion of needs of participants for safety education showed more than average 3.00 score in 34 of 36 detail items. However, none of 9 detail items was included in five textbooks. Also, 2 detail items - the Coping with Disasters and the Safety from Poisoning - were included together 2 parts; One part had the higher ranked 7 items acquired by analysis of the needs, and the other had the higher ranked 7 items acquired by analysis of the contents. But, except those 2 items, none of items were matched with each part.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.2
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• pp.242-249
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• 2015

This study examined the antioxidant and antimicrobial activities of 70% ethanol extracts and water extracts of Allium hookeri root. We evaluated the effects of water extracts of A. hookeri root on storage of seasoned pork added with water extracts at $4^{\circ}C$ for 21 days in order to evaluate its potential as a functional food material. A. hookeri root water extracts displayed antioxidant activities (total polyphenol content and DPPH and ABTS radical scavenging activities) that were superior to those of 70% ethanol extracts. The 70% ethanol extracts and water extracts of A. hookeri root showed antimicrobial activities against food-borne Staphylococcus aureus bacteria that were about 1/400 times greater than that of vancomycin. Chemical composition analysis was conducted on pork seasoned with sauce containing 5%, 10%, and 15% water extracts. Moisture and crude ash contents significantly decreased as the amount of water extracts increased (P<0.05), and the highest crude protein content was in the 10% group. Acidity of seasoned pork increased proportionally in the early stages of storage, whereas it significantly decreased as the amount of water extracts increased after day 12 (P<0.05). Although the total number of bacteria in seasoned pork continuously increased during storage, growth of bacteria was significantly restricted as level of A. hookeri root water extracts increased (P<0.05). In the sensory evaluation, pork seasoned with 10% A. hookeri root water extracts showed the highest scores for taste, texture, and overall acceptance (P<0.05). In summary, A. hookeri water extracts display antioxidant and antimicrobial activities that can improve quality characteristics of seasoned pork and have potential as natural preservatives to restrict bacteria growth. Regarding the amount of extracts, 10% was determined to be the most appropriate level to minimize changes in seasoned pork during storage and improve sensory quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.149-155
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• 2011

The objective of this study was to evaluate the antioxidant and antigenotoxic activities of sansuyu fruit (Corni fructus, CF) at temperatures of $25^{\circ}C$, $50^{\circ}C$, and $90^{\circ}C$ using a water extraction method. Total phenolic content (TPC), DPPH radical-scavenging activity (RSA), and superoxide dismutase (SOD)-like activity, and ORAC (Oxygen radical absorbance capacity) values were determined. Also the antigenotoxicity of CF was determined by measuring inhibitory effects of $H_2O_2$ induced DNA damage in human leukocytes using the comet assay. The TPC in the CF extracts was 4.2, 4.6, and 5.5 g/100 g GAE in $25^{\circ}C$, $50^{\circ}C$, and $90^{\circ}C$, respectively. The DPPH RSA of the CF extracts increased in a dose-dependent manner over the range of $50\sim1000\;{\mu}g$/mL in all temperatures and the $SC_{50}$ of DPPH RSA of the CF extracts were not significantly different at different extraction temperatures. The $SC_{50}$ of SOD-like was the highest in CF extracted at $25^{\circ}C$ (1.1 mg/mL) followed by $90^{\circ}C$ (1.2 mg/mL) and $50^{\circ}C$ (1.3 mg/mL). The ORAC values of the CF extracts were not significantly different in low concentration ($10\;{\mu}M$/mL) and was in order of $25^{\circ}C$ ($5.7\;{\mu}M$ TE)< $90^{\circ}C$ ($6.2\;{\mu}M$ TE)< $50^{\circ}C$ ($8.5\;{\mu}M$ TE) in high concentration ($50\;{\mu}M$/mL). $200\;{\mu}M$ $H_2O_2$ induced DNA damages in human leukocytes were significantly reduced by the pretreatment with the CF extracts. These results suggest that sansuyu fruit (Corni fructus) can be used as a natural source for antioxidant activities and as antigenotoxic agents regardless of the water extraction temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1767-1775
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• 2013

The purpose of this study is to investigate the total polyphenol and antioxidant activities of radish buds (Raphanus sativus L.) based on sprouting periods and extraction solvents in order to present basic data that are needed for using the radish buds as functional food material. The antioxidant activities were assessed by using various antioxidant models (DPPH, TBARS, Rancimat method, POV). The total polyphenol contents according to the extraction solvents were 84.11 and 296.51 mg/g, and the ethanol extract on day 4 of showed the highest value as 296.51 mg/g. As for DPPH radical-scavenging activity, on the day 4 of sprouting, water extracts indicated the highest scavenging activity by 86.67%, and the acetone extracts indicated a rather low scavenging activity as 77.23%. As for TBARS measurement of the radish bud extracts on day 4 of sprouting the extract of 70% ethanol was highest (71.48%). On day 8 of sprouting the TBARS value was increased and the methanol extract was highest (78.99%). As for the oxidative induction period on day 4 of sprouting in Rancimat measurement, the methanol extract was highest (6.07 hours) on day 4 and the antioxidant index was 1.16. On day 12 of sprouting, the general oxidative induction period tended to be reduced to 5.25 to 5.91 hours. In the peroxide value measurement on day 4 of sprouting and beginning of the storage, the extracts showed no difference between 3.02 meq/kg oil and 4.12 meq/kg oil, and on the day 60 of storage, the water extract (43.83 meq/kg oil) and the methanol extract (45.42 meq/kg oil) were lowest with higher antioxidant effect. In conclusion, the radish bud extract with higher total polyphenol contents and antioxidant activities may serve as functional material for food additives, such as natural antioxidants and food preserving agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1732-1739
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• 2016

The general components and cyclitol compounds of ice plant (Mesembryanthemum crystallinum) were analyzed to examine the possibility of using extracts as functional food materials, the antioxidant effects and antidiabetic activities of the extracts by solvent fraction were tested. Among the mineral contents, contents of K and Na were the largest ($1,213.33{\pm}2.52$ and $545.53{\pm}12.01mg/100g$, respectively), followed by S, Ca, P, and Mg in order of precedence. Among cyclitol compounds, content of D-pinitol was the largest ($4.04{\pm}0.08mg/g$) while contents of chiro-inositol and myo-inositol were relatively small ($2.82{\pm}0.01$ and $0.25{\pm}0.01mg/g$, respectively). Among total phenol contents by solvent fraction, contents of chloroform and ethyl acetate fractions were large ($35.80{\pm}1.33$ and $23.70{\pm}0.62mg\;GAE/g$, respectively). Among antioxidant activity levels examined by DPPH, ABTS, FRAP, and lipid/MA assays, the chloroform fraction commonly showed the highest level of activity while the ethyl acetate fraction showed relatively high levels of activity. The antioxidant activity levels were proportional to total phenol contents by solvent fraction. As for antidiabetic effects, all solvent fractions showed at least 50% ${\alpha}-glucosidase$ inhibitory activity levels while the ethyl acetate, butanol, and chloroform fractions showed high levels activity of $90.33{\pm}0.40$, $87.98{\pm}0.16$, and $86.38{\pm}0.51%$, respectively. The ${\alpha}-amylase$ inhibitory actively levels were in the range of $25.63{\pm}1.45{\sim}60.34{\pm}2.67%$, which was lower than the ${\alpha}-glucosidase$ inhibitory activity levels, but the inhibitory activity levels by solvent fraction were similar. Given the above study results, ice plant can be utilized as a natural material with antioxidative and antidiabetic functionality.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.3
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• pp.61-74
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• 2015

This study attempts to empirically examine the influence of entrepreneurial education in university on entrepreneurial intentions of undergraduate and graduate students as potential entrepreneur and new moderating factors on the relationship between entrepreneurial education and entrepreneurial intentions. We suggested EO(innovativeness, risk-taking propensity, proactiveness and locus of control) and environmental factors(entrepreneurial family background and resource accessibility) as new moderating factors in the relationship. For this study, the following research questions are raised : First, is there a significant difference in entrepreneurial intentions of enrolled and unenrolled students in entrepreneurial education? Second, does entrepreneurial education affect entrepreneurial intentions positively? Finally, do EO and environmental factors have moderating effects in the relationship between entrepreneurial education and entrepreneurial intentions? In order to test our research model, the current study collected data from 265 undergraduate and graduate students who are majoring in natural sciences or engineering in Seoul National Univ., Hanyang Univ., and KAIST. To investigate our research questions and hypotheses, independent-sample T-test and hierarchical regression analysis were employed. The results of empirical analysis revealed that entrepreneurial education positively related to entrepreneurial intentions and that the relationship between entrepreneurial education and entrepreneurial intentions moderated by EO and environmental factors. First, the result showed the significant difference in entrepreneurial intentions between enrolled and unenrolled students in entrepreneurial education. Entrepreneurial intentions of students who enrolled entrepreneurial education was higher than others. Second, entrepreneurial education affected the entrepreneurial intentions positively. Finally, the moderating effects of innovativeness, risk-taking propensity, proactiveness and entrepreneurial family background among investigated six moderators were significant. entrepreneurial education-entrepreneurial intentions relationship was even stronger under high innovativeness and high proactiveness. But risk-taking propensity and entrepreneurial family background decreased the effect of entrepreneurial education on entrepreneurial intentions.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.2
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• pp.41-51
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• 2013

The tidal creek dependent mass transport characteristic in Gyeong-Gi Bay (west coast of Korea) was studied using field measured data and numerical model. Gyeong-Gi Bay consists of 3 main tidal channels and contains a well-developed vast tidal flat. This region is famous for its large tidal difference and strong current. We aim to study the effect of tidal creek in the tidal flat on the mass exchange between the estuary and the ocean. For numerical application, the application of unstructured grid feature is essential, since the tidal creek has complicated shape and form. For this purpose, the FVCOM is applied to the study area and simulation is performed for 2 different cases. In case A, geographic characteristics of the tidal creek is ignored in the numerical grid and in case B, the tidal creek are constructed using unstructured grid. And these 2 cases are compared with the field measured cross-channel mass transport data. The cross-channel mass transport at the Yeomha waterway mouth and Incheon harbor was measured in June, 9~10 (Spring tide) and 17~18 (Neap tide), 2009. CTD casting and ADCP cross-channel transect was conducted 13 times in one tidal cycle. The observation data analysis results showed that mass transport has characteristic of the ebb dominance Line 1 (Yeomha waterway mouth), on the other hand, a flood dominant characteristic is shown in Line 2 (Incheon harbor front). By comparing the numerical model (case A & B) with observation data, we found that the case B results show much better agreement with measurement data than case A. It is showed that the geographic feature of tidal creek should be considered in grid design of numerical model in order to understand the mass transport characteristics over large tidal flat area.

• The Journal of Engineering Geology
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• v.28 no.1
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• pp.69-79
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• 2018

The Korean government attempts to reduce $CO_2$ emissions by 37% to 314.7 Mt $CO_2$, down from the estimated 850.6 Mt $CO_2$ until 2030 in order to confront green house effect. In this context, in 2014, Korean government launched $CO_2$ Storage Environmental Management Research (K-COSEM) Center for carrying out pilot-scale research on $CO_2$ leakage from underground $CO_2$ storage facilities. For the detection of $CO_2$ leakage, it is necessary to identify hydrologeological and geophysical characteristics of the subject area. In the study site of Naesan-ri, Daeso-myeon, Eumseong-gun, Chungbuk Province, two times injection tests (June 28-July 24, 2017 and August 07-September 11, 2017) of $CO_2$ and $SF_6$ dissolved waters, respectively, was conducted to understand the leakage behavior of $CO_2$ from underground. The injection well was drilled to a depth of 24 m with a 21-m casing and screen interval of 21~24 m depth. Two times resistivity surveys on August 18, 2017 and September 1, 2017, were conducted for revealing the flow of the injected water as well as the electrical properties of the study site. The study results have shown that the high-resistivity zone and the low-resistivity zone are clearly contrasted with each other and the flow direction of the injected water is similar to natural groundwater flow. Besides, the low resistivity zone is widely formed from the depth of injection to the shallow topsoil, indicating that the weathered zone of high permeability has high $CO_2$ leakage potential.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.1
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• pp.10-19
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• 2000

Due to the urbanization, concentrated population, and limited land exploitation in the modern society, the environment surrounding that we live in is getting polluted more and more, and it has become hard even to let urban children experience the nature. This research was conducted to help people recognize the importance of our natural resources through the environmental education of elementary school and to use school's practical open-space for the Indigenous Plants education. The results of this study are as follows : First, the status of a plant utilization in our institutional education : There were 362 species totally of 124 species of Trees, 156 species of Herbs, 63 species of Crops, and 19 species of Hydrophytes which appear in the elementary school text book. Of all, the most frequently appearing species of tree were the Malus pumila var. dulcissima, Pinus densijlora, Citrus unshiu, Diospyros kaki. Second, the effect of plant education using the land around schools : The result of research on the open-space of the 19 elementary schools located in Mapo-gu showed that most of the species planted are the Juniperus chinensisrose, Hibiscus syriacus. Pelargonium inquinans in the order of size, and the plants appearing in text book were grown in the botanical garden organized in 7 schools. Especially most of the Indigenous Plants were being planted in botanical garden, and Pinus densijlora, Abeliophyllum distichum, Polygonatum var. plurijlorum, Liriope platyphylla and so on. Last, the result of this research on recognition of Environment, Planting education and Indigenous plants : It showed that educational necessity of students and teachers about environment and Indigenous Plants was more than 80%. The management of botanical garden was conducted by some teachers and managers. The results of this study suggested that we needed the reconstruction of curriculum, the efficient application of plant education for effectiveness of using school environment and monitoring continually and construction information sources for the better environment education in the elementary schools.