• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.91-97
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• 2001

The effects of sudden changes of water temperature (WT) on the stress response and physiological change of the cultured olive flounder in large (FL) and small (FS) size, and fat cod (FC) were examined by manipulating WT (2 types) in a flow through seawater culture system with 6 tanks (water vol. 270 L/tank). The WT was decreased from $20^{\circ}C$ to $10^{\circ}C$ within 5 hours ($2^{\circ}C/hour$) and maintained at $10^{\circ}C$ for 21 hours (Exp. I), and it was raised from $20^{\circ}C$ to $30^{\circ}C$ within 5 hours and maintained at $30^{\circ}C$ for 21 hours (Exp.II). In Exp. I, the levels of blood hematocrit at 5 hours ($10^{\circ}C$) in FS was significantly decreased from $13.5\pm2.0\%\;to\;11.3\pm2.3\%$, but FC at 2.5 hours ($15^{\circ}C$) ($19.0\pm0.3\%\;to\;23.2\pm3.8\%$) was increased, The blood hemoglobin concentration of all fish in Exp, II was significantly increased until 8 hours after raising WT from $20^{\circ}C$ to $30^{\circ}C$. In Exp. I and II , the levels of plasma cortisol in FL, FS and FC was changed from $5.2\pm8.5ng/mL,\;4.4\pm4.5ng/mL\;and\;2.7\pm0.4ng/mL$, respectively, before sudden drop and rise of WT. The levels of plasma cortisol of in FL ($164.0\pm53.1ng/mL$) and FC ($207.9\pm25.4ng/mL$) were significantly increased by the lowering WT sharply during whole experiment. The FL ($12.6\pm2.0ng/mL$) and FS ($4.0\pm3.9ng/mL$) showed no significant differences in cortisol level according to sudden rise of WT (5 hours). But it in FC ($44.7\pm18.2ng/mL$) was increased. In Exp. I, the plasma glucose levels of all fish groups were decreased after 5 hours ($10^{\circ}C$), The plasma lactic acid concentration of FL and FS showed no significant differences until 5 hours after raising WT from $20^{\circ}C$ to $30^{\circ}C$, But it in FC was significantly increased with WT raise.

• The Journal of the Korea Contents Association
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• v.6 no.6
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• pp.64-73
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• 2006

In this paper, I explored the direction of ICT used learning that can improve the access ability of e-learning to activate a neglected class's lifelong education by e-learning. I had a good grasp of a neglected class's actual condition of the access ability of e-learning and presented the direction of basic ICT used learning for the adults that can improve the access ability for the lifelong education by e-learning. According to the result of this research, it was found that the adult learners had a considerable disparity by age group. Therefore, it is desirable that they had to learn ICT used learning with considering the actual condition by age. Teenagers and 20 years of age need to be learned in order of an Internet club, word processor, moving picture and etc. It needs to be teamed for the $30{\sim}40$ age bracket lil order of a chat, an Internet club, searching engines and etc and for the $30{\sim}40$ age bracket in order of a chat, an Internet club and moving picture and etc. And also it needs to induce a neglected class to develope participation abilities for themselves by activating an internet club activity.

• Korean Journal of Plant Resources
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• v.9 no.2
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• pp.143-149
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• 1996

The study was carried out to find the optimum planting density classified by the different using types in Anthriscus sylvestylis Hoffm. In the different using types, plant height of vegetable type in $30\times20cm$ was 35.2cm, but plant heights of other types were much lower than that of vegetable type. Fresh leaf yield was highest in the vegetable type at the $30\times20cm$ with 3,300kg, in the medicinal type at the $60\times30cm$ with 2,800kg, and in the combination type at the $40\times20cm$, In comparison of underground parts of dry root weight, the highest yield was 3,320kg at $30\times20cm$ of the vegetable type, 2,170kg at $60\times20cm$ of medicinal type, and 2,210kg per ha. at $45\times20cm$ of combination type, respectively. It was showed that the optimum planting densities were $30\times20cm$ in vegetable type, $60\times30cm$ in medicinal type, and $45\times20cm$ in combination type.

• Korean Journal of Medicinal Crop Science
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• v.3 no.1
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• pp.1-4
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• 1995

To determine the optimum sowing time and nursery period in Perilla frutescens in the southern areas of Korea, perilla frutescens cv. red Perilla local cultivar was grown under three different sowing dates and nursery periods. The blooming period of the area which was sown on the seedbed in Apr.10 and carried out the growing seedling in 30days is Aug. 12 and it is two days earlier than that of the area, Aug.14, sown on the seedbed in Apr. 20 and carried out the growing seedling in 30days of the same month and it is also six days earlier than that of the area, Aug.18, sown on the seedbed in April 30 and conducted the growing seedling in the same date. The stem lengths are 135cm,131cm and 125cm respectively and the number of branches are 26.4, 25.3 and 23.6 respectively. The fresh weight of stem and leaf at the area sown on the seedbed in Apr.10 and conducted the growing seedling in 30days with the width of leaf over 5cm in the middle of Aug. and at the beginning of Sep. is 2,476kg/10a and it shows more increase of 172kg than that of fresh weight of stem and leaf with 2,304kg/10a which was sown on the seedbed in Apr.20 and earned out the growing seedling in 30days, and it also shows more increase of 411kg than that of fresh weight of stem and leaf with 2,065kg/10a at the area sown on the seedbed in April 30 and con­ducted the growing seedling in the same date, The fresh weight of seeds are 609.5kg/10a,509.3kg/10a and 463.2kg/10a respectively and $100.2{\sim}146.3kg$ is more increased. Therefore, the seedling period of the proper seedbed for high yield bumper crop of perilla frutescens for exporting to Japan is April 10 and the number of days for seedling is 30 days.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.511-514
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• 1992

The effects of soaking conditions (time and temperature) of rice on the water absorption behaviors and the consequent textural properties after cooking were investigated. Water absorption during soaking was completed in 30 min at $23^{\circ}C$, while the hydration continued up to 60 min at $4^{\circ}C$. The hardness (H) of the cooked rice decreased, while the stickiness (S) and S/H ratio increased with increased soaking time. Soaking at $23^{\circ}C$ gave higher values of S and S/H of cooked rice than soaking at $4^{\circ}C$. Soaking for $10{\sim}40\;min$ at $4^{\circ}C$ or for $10{\sim}20\;min$ at $23^{\circ}C$ resulted the value of S/H between 0.15 and 0.20, which had been found at acceptable textural parameters of the cooked rice.

• Fashion & Textile Research Journal
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• v.15 no.4
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• pp.596-605
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• 2013

This study investigates the wearing trend and purchase facts for adult females in their 20s and 30s along with their fitting satisfaction for woven jackets and circular knitted jackets. A questionnaire survey on consumers investigated satisfaction with jackets according to clothing materials and repair trend after wearing. Subsequently, a preference for circular knitted jackets was shown higher than woven jackets. Females in their 20s preferred woven jackets than those in their 30s; however, the latter preferred circular knitted jackets than the former. For woven jackets, they showed the highest satisfaction with size; however, for circular knitted jackets, they showed the highest satisfaction with fitting. In the question on their satisfaction by jacket part, satisfaction with circular knitted jackets was higher in all items except for bust measurement, bottom edge measurement, elbow circumference, shoulder width, and clothes length. Circular knitted jackets had lower repair rates than woven jackets and woven jackets had significant differences by age in satisfaction with back width. The research results indicate that females in their 20s and 30s who value fit preference and practicality will increasingly wear knit clothes. Therefore, we can address the fitting satisfaction requirement of females in their 20s and 30s by taking the clothing material properties of circular knitted clothes into consideration. In addition, further research is required on jacket patterns in consideration of clothing materials.

• Korean Journal of Human Ecology
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• v.23 no.3
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• pp.501-514
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• 2014

In this study, visual images were analyzed with the representative seven kinds of selected skirts, by the differences of shape and length which are affecting to the images of skirts. In addition, the purpose of the study is to present the basic data for the skirt design and patterns those are appropriate to the preferred images of 20-30s. The results of this study are as follows. First, analyzed by the visual evaluation about the composing factors are as follows. Factor 1 is a Cute image factor, factor 2 is a charming image factor, factor 3 is a transversal factor, Factor 4 is active image factor, Factor 5 was classified as a longitudinal factors. Second, analyzed by the visual evaluation according to the shape and length of the skirt, 20-30s women's most preferred form of the skirt is pleated skirt which was highly evaluated looks good, beautiful, favorite, attractive factors. Non-prefered skirts are gored skirt which was highly evaluated not corny, not pretty, heavy, unattractive factors and gored skirt which was negatively evaluated with classic and dislike factors. In the length of skirt, the knee length short skirt is attractive, active and positively evaluated by the 20-30s women than long skirt. Therefore, the results of this study, there are almost no differences according to the age groups of 20-30s women. They are more affected from the length of the skirt rather than the shape.

• Journal of Fashion Business
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• v.25 no.4
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• pp.1-13
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• 2021

As interest in skin care increases, this study aims to contribute to the development of the beauty self-care market by providing basic data through the measurement of the oil and moisture skin condition of women in their 20s and 30s. The study was conducted from November 27, 2020 to January 31, 2021, with 20 women in their 20s and 30s divided into 4 groups, A~D, by age, 5 per group. Skin measurements were taken four times at 4 hour intervals at 0H, 4H, 8H, and 12H based on the first measurement that was taken within 30 minutes after waking up, and the oil and moisture indices were observed over time. As a result, both T and U zones showed significant differences in moisture levels over time, with no difference between groups for both T and U zones. Moisture decreased the most between 0H to 4H, and moisture changed the least between 4H to 8H. Changes in moisture increased the similar at 0H and 12H. The oil condition changed more irregularly compared to moisture over time, but all groups showed lower oil content in the U-zone compared to the T-zone. Overall, the facial oil and moisture conditions of women in their 20s and 30s changed over time, indicating that the skin changes in real time. The fact that the skin data, which was measured in the primary activity living environment, can be used as basic research data in the beauty self-care market is meaningful.

• Korean Journal of Community Nutrition
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• v.28 no.5
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• pp.392-403
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• 2023

Objectives: This study was intended to investigate adults' health behaviors and eating habits according to their levels of social media use. Methods: From May 27 to July 11, 2022, an online survey was conducted of 452 male and female social media users in their 20s and 30s, and their eating habits and health behaviors were compared and analyzed according to their degree of social media use. For each of the three levels of food content use, the frequency of social media content use, and the total score range of average social media viewing time per day were divided into three parts, and a group with a score of less than 2 points was classified as low-use; a group with a score of 2 or more and less than 3 points was classified as middle-use; and a group with a score of 3 points or more was classified as high-use. Results: The use of food content was higher in women than in men (P < 0.001), and higher in those in their 20s than in those in their 30s (P < 0.001). The group with a high level of food content use showed a higher rate of post-use hunger than the group with a low level (P < 0.01). The experience of eating after using food content was also higher in the group with a high level of use than in the group with a low level of use (P < 0.001). The group with a normal or high level of food content use had more negative eating habits than the group with a low level. Conclusions: The study highlighted the need to provide desirable food content to people in their 20s and 30s with negative eating habits and to promote them so that they can use the right healthy nutrition-related content.

• Clean Technology
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• v.24 no.3
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• pp.221-232
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• 2018

This research was conducted to evaluate the operational performance of landfill facility and landfill gas energy facility from the questionnaire survey. In order to evaluate overall operational performance, three types of weighting methods were applied to each technical, economical, and environmental item. There was no significant difference between an equal weighted method, a weighted method of 40% for technology, 30% for economy, and 30% for environment, and a weighted method of 30% for technology, 40% for economy, and 30% for environment. In technical performance, large and middle scales of landfill facilities showed higher scores of 14.8 ~ 19.7 and 14.3 ~ 19.0 than 9.8 ~ 13.0 of small scale one. In environmental performance, large, middle, and small scales of landfill facilities showed 21.3 ~ 23.7, 17.6 ~ 19.6, and 20.8 ~ 23.1 scores, respectively. However, in economical performance, there was significant difference between them with scale. Large and middle scales of landfill facilities showed higher scores of 22.0 ~ 29.3 and 20.5 ~ 27.3 than 6.0 ~ 8.0 of small scale one. As a result of evaluation for landfill gas energy facility, large scale facility showed 19.2 ~ 25.6 and 17.8 ~ 23.7 scores in technical performance and 23.1 ~ 25.7 and 21.3 ~ 23.7 scores in environmental performance, respectively. However, in economical performance evaluation, large scale of landfill gas energy facility showed relatively higher of 27.8 ~ 33.3 score than 18.8 ~ 25.1 of small scale one. From these results, it was shown that economy evaluation heavily effect on the operational performance of landfill facility and landfill gas energy facility compared to technology and environment evaluation.