• Journal of the Korean Geotechnical Society
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• v.18 no.6
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• pp.141-152
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• 2002

This paper is the result of the experimental and numerical research on the distribution of vertical earth pressure due to surcharge loads acting on cantilever retaining wall close to a rigid slope with a stiff angle. Centrifuge model experiments were performed with changing the roughness of adjacent slope to the wall, distance between the wall and the slope and gravitational levels. Vertical earth pressures were measured by earth cells embedded in the backfill of the wall. Test results of vertical earth pressures due to surcharge loads were compared with theoretical estimations by using two different methods of limit equilibrium and the numerical analysis. For limit equilibrium methods, the modified silo and the wedge theories, proposed by Chung(1993, 1997), were used to analyze test results. Based on those modified theories, the particular solution with the boundary condition of surcharge loads on the surface of backfill was obtained to find the vertical stress distributions acting on the backfill. FLAC with the hyperbolic constitutive model was also used for the numerical estimation. As a result of comparison of test results with theoretical and numerical estimations, distribution of vertical earth pressures obtained from centrifuge model tests is generally in good agreement with numerical estmated values by using FLAC whereas the wedge theory shows values close to test results in case the distance between the wall and the slope is narrow.

• Journal of the Korean Geotechnical Society
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• v.31 no.10
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• pp.5-16
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• 2015

Considering the conversion of the Korea Construction Standards to Limit State Design (LSD), we analyzed the resistance bias factor for pullout resistance, as a part of the development of the Load and Resistance Factor Design (LRFD) for soil nailing; very few studies have been conducted on soil nailing. In order to reflect the local characteristics of soil nailing, such as the design and construction level, we collected statistics on pullout tests conducted on slopes and excavation construction sites around the country. In this study a database was built based on the geotechnical properties, soil nailing specifications, and pullout test results. The resistance bias factors are calculated to determine the resistance factor of the pullout resistance for gravity and pressurized grouting method, which are the most commonly used methods in Korea; moreover, we have relatively sufficient data on these methods. We found the resistance bias factors to be 1.144 and 1.325, which are relatively conservative values for predicting the actual ultimate pullout resistance. It showed that our designs are safer than those found in a research case in the United States (NCHRP Report); however, there was an uncertainty, $COV_R$, of 0.27-0.43 in the pullout resistance, which is relatively high. In addition, the pressurized grouting method has a greater margin of safety than the gravity grouting method, and the actual ultimate pullout resistance determined using the pressurized grouting method has low uncertainty.

• Journal of Korean Home Economics Education Association
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• v.15 no.3
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• pp.13-28
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• 2003

This study presents a development of internet-based consumer education program for children. We also investigate how this program affects on the children's consumer competency and how much children are interested in this program. This program consists of 6 domains: the concept of consumer. wants and scarcity. advertisement, tips on purchasing. consumer's rights. and consumer's problem imd solutions. In order to attract children. multimedia data such as pictures. drawings. and animations were included in designing the screens. The subjects of this study were 40 children at forth grade to participate in consumer education program. Surveys were conducted twice to collect data for consumer competency and children's interest in the program. According to the results of t-test. We found that consumer education has a positive effect on consumer knowledge and consumer-role attitude but has not a positive effect on consumer skill. We also found that children's interest on this program was very high.

• Journal of Korean Home Economics Education Association
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• v.28 no.4
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• pp.139-158
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• 2016

The purpose of this study was to explore the effects of career experiential learning and parental support on career maturity of high school students. The number of subjects for this study was 290 high school students. The results are as follows. First, the effects of attitude in career maturity were higher for students with communication, field trip and visiting, and field experience in career experiential learning. However, career planning did not have any correlation with field experience types of attitude in career maturity. The effect of competency in career maturity was positively correlated with student experience with theory, communication, and field trip and visiting in career experiential learning. Second, parental support showed a significant positive correlation with all factors of career maturity. Third, results identify career maturity impacts on career experiential learning. The types of communication as well as field trip and visiting significantly affected all components of career maturity. The type of theory was a factor affecting competency. In addition, the results reveal the impact of parental support on the career maturity. Emotional support had a significant influence on all factors for career maturity, except for career exploration. Informative support was found to have a significant influence on career planning, career independency and career exploration. Financial support had a significant influence on occupational attitude, career independency and career exploration.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.488-494
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• 2015

This study aims to develop and apply a standard management self-diagnostic table for forestry households to better manage their astringent persimmon production. The diagnostic table consisted of 3 categories (general status of a forestry household, management performance indicators, level of management) and 18 subcategories. The current management status across 241 households was surveyed among 10 chief astringent persimmon producing municipalities. Scores from the 18 subcategories were aggregated for a total score to evaluate and compare different levels of management. The respondents scored an overall average of 57.4, 62% of which were placed between 40 and 60. Upon close examination Chungcheongnam-do scored a very low score in the 'management system-tree height' subcategory with respect to the average score potentially because of the large population of aged trees in the region. The national average in the 'production skills-time of fruit load adjustment' subcategory was only 1.96 because unlike sweet persimmons astringent persimmons adjust their own load by inducing physiological fruit drop. The national average in the 'management/sales skills-material purchase' subcategory was 2.01; over 60% of the respondents indicated a preference for independent selection and purchase for most materials. The households preferring a group purchase tended to utilize the regional co-op.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.957-963
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• 2013

This study evaluated the quality characteristics of muffins prepared with different amounts (0%, 4%, 8%, or 12%) of apricot powder. The moisture content was higher in groups containing 8% and 12% apricot powder. The specific volume of muffins decreased as the amount of apricot powder increased. The lightness value was lower in groups containing apricot powder, with redness and yellowness values increasing with increasing amounts of apricot powder. Rheology tests showed no significant differences in hardness, springiness, and cohesiveness between control muffins and muffins with apricot added. Scanning electron microscopy showed that the number and size of air cells decreased with increasing levels of apricot powder. The substitution of wheat flour with apricot powder yielded muffins with a higher DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity and total polyphenol content. Consumer acceptance tests revealed no significant differences in appearance, smell, and texture between muffin samples, but the taste and overall acceptability scores were lowest for muffins with 12% apricot added. Therefore, up to 8% apricot powder can be incorporated into muffins to meet the sensory quality and functional needs of the consumer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.904-910
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• 2013

The aim of this study was to investigate the eating behavior and nutritional status of subjects according to their purpose of exercise. A total of 214 subjects, 20 to 30 years of age, who visited fitness centers in Seoul were enrolled. Anthropometrics, exercise habits, nutritional knowledge, and eating behaviors were analyzed using a questionnaire. Nutritional status was assessed by serial 24 h recalls. The subjects were divided into two groups based on their purpose of exercise: increasing muscle (Muscle growth, n=107) or losing body weight (Weight loss, n=107). The Muscle growth group contained a higher percentage of men, whereas the Weight loss group contained a higher percentage of women. The Muscle growth group showed significantly higher scores of nutritional knowledge and eating behaviors compared to the Weight loss group. The Muscle growth group also had a significantly higher intake of energy and protein compared to the Weight loss group. In fact, the intake of energy in the Weight loss group was lower than the estimated energy requirement (EER) for both men and women subjects. The intake of protein in the Muscle growth group was twice as much as the recommended nutrient intake (RNI). The intake of calcium in both groups was less than the RNI. In conclusion, those who exercised with the aim of increasing muscle took excess dietary protein and those who exercised with the aim of weight loss had a lower energy intake than the EER.

• Composites Research
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• v.30 no.1
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• pp.46-51
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• 2017

Structural battery has been researched extensively to combine the functions of the battery and structure without gravimetric or volumetric increments compared to their individual components. The main idea is to employ carbon fabric as the reinforcement and electrode, glass fabric as the separator, and solid-state electrolyte which can transfer load. However, state-of-the-art solid-state electrolytes do not have sufficient load carrying functionality and exhibiting appropriate ion conductivity simultaneously. Therefore, in this research, a system which has both battery and load carrying capabilities using glass fabric separator and liquid electrolyte was devised and tested to investigate the potential and feasibility of this structural battery system and observe electric properties. It was observed that elongating separator decreased electrical behavior stability. A possible cause of this phenomenon was the elongated glass fabric separator inadequately preventing the penetration of small particles of the cathode material into the anode. This problem was verified additionally by using a commercial separator. The characteristic of the glass fabric and the interface between the electrode and glass fabric needed to be further studied for the realization of such a load carrying structural battery system.

• Journal of Mushroom
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• v.18 no.3
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• pp.234-243
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• 2020

The physicochemical characteristics and antioxidant activities of Lentinula edodes cultivated with liquid spawn were compared according to the harvest cycle (1-3 cycles). There was no significant difference in moisture content. The crude lipid and crude protein contents tended to decrease according to harvest cycle. The content of β-glucan was the highest in mushrooms after one cycle. The β-glucan content in cycles 2 and 3 was 68.5% and 62.3% that of the content after cycle 1, respectively. Mineral content in the pileus and stipe was similar. The mineral content was highest in the pileus after two cycles. Composition and contents of free amino acids tended to decrease according to the harvest cycle. Contents of essential amino acids were higher in mushroom after one cycle. Total phenol content was highest in the pileus (31.96 mg/100 g) and the stipe (21.10 mg/100 g) after one cycle and tended to decrease with subsequent cycles. The flavonoid content was 11.13 mg/100 g after one cycle and significantly decreased according to the harvest cycle. Antioxidant activities were also highest after one cycle and significantly decreased according to the harvest cycle. When compared to L. edodes cultured for one cycle, L. edodes cultivated with liquid spawn for three cycles was considered to have similar marketability in terms of quality characteristics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.306-316
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• 1989

We examined the state of Korean pomfret(Pampus echinogaster) in Korean waters and considered the management strategy of the stock based on the theory yield Per recruit. It is not facile to discriminate Korean pomfret distributed in Korean waters from silver pomfret (p. argenteus) due to the similarities in their external morphologies. For this rea- son, Korean pomfret has been treated in silver pomfret in fisheries statistics of Korea. In this study, we asserted Korean pomfret from pomfrets caught commercially by the morphology, from which we recognized that Korean pomfret took $60\~70\%$ in catch(in weight) and that the smaller the body length, the higher the proportion of Korean pomfret. Parameters estimated for Korean pomfret were as follows: natural mortality(M) = 0.6, fishing mortality(F) =0.924(mean value for $1986\~1988$), age at recruit to fishery($t_r$) =0.19 yrs, age at first capture($t_c$) : 0.49 yrs, and the rate of recruit of age-0 fish to fishery(Q) = 0.29. The results obtained from the theory of yield per recruit indicated that the present state of stock was below the optimum level of exploitation and that the control of fishing intensity rarely had an effect on the increasing of yield. Accordingly, we conclude that proper management can be made by increasing the current age of 0.49 yrs at first capture to 1.5 yrs.