• Steel and Composite Structures
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• v.34 no.1
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• pp.107-122
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• 2020

Moment resisting stub columns (MRSCs) have increasingly adopted in special moment-resisting frame (SMF) systems in steel building structures, especially in Asian countries. The MRSCs typically provide a lower deformation capacity compared to shear-panel stub columns, a limited post-yield stiffness, and severe strength degradation as adopting slender webs. A new MRSC design with cored configuration, consisting of a core-segment and two side-segments using different steel grades, has been proposed in the study to improve the demerits mentioned above. Several full-scale components of the cored MRSC were experimentally investigated focusing on the hysteretic performance of plastic hinges at the ends. The effects of the depths of the core-segment and the adopted reduced column section details on the hysteretic behavior of the components were examined. The measured hysteretic responses verified that the cored MRSC enabled to provide early yielding, great ductility and energy dissipation, enhanced post-yield stiffness and limited strength degradation due to local buckling of flanges. A parametric study upon the dimensions of the cored MRSC was then conducted using numerical discrete model validated by the measured responses. Finally, a set of model equations were established based on the results of the parametric analysis to accurately estimate strength backbone curves of the cored MRSCs under increasing-amplitude cyclic loadings.

• Journal of the Korean School Mathematics Society
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• v.4 no.1
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• pp.91-101
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• 2001

Nowadays the number of students that is losing their interest as well as learning desire in mathematics is increasing because of lack of logical thought creative power and abstract expression that present-day mathematics requires by reason of discrepancy of extreme scholastic ability by speciality of mathematics. In these conditions, we reduce the number of learning depression by bringing about learning desire or learning interest on mathematics, and students learn effective learning methods to be voluntary learning of discovery themselves that studies basic concepts, principles, rules through logical thought of students to solve difference of scholastic ability, thus we assumed that debate studies through small group activities in ability group would be one of ways to improve learning power, so the results of our research are as follows; 1. Debate studies through small group activities were very effective because of reinforcing the achivement level of students. 2. By this learning method, an individual or cooperrative learning was fostered, and lively discussions were accomplished. And learning attitudes of students were changed by the extension of cooperative learning abilities through advices or by themselves. 3. A personal opinion is payed regard by accepting an individual idea in the process of making questions. Learners can correct wrong concepts in the process of correcting wrong answers. So if we apply above-mentioned studies with easy contents from the lower grades, the effectiveness would increase as learners go to the higher grade. According to the results of various researches as follows; "The teaching-learning method oriented coopperative debate studies is effective to find solutions to mathematical problems." If small group activities are applied in the educational situation to search the course of a desirable cooperation learning through small group activities to improve scholastic abilities for a discoverable problem-solving power. I think that the teaching-learning method oriented cooperative debate studies is one of the most desirable methods to increase the problem-solving ability.

• Journal of Korean Home Economics Education Association
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• v.21 no.4
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• pp.127-144
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• 2009

The purpose of this study was to develop and to examine the effect on sex education program to middle school student. The subjects were 8 grade students and to examine 10 session education. Collected data was analyzed by SPSS WIN 12.0 program. The major results of this study were as follow ; First sex education program was developed into four areas : human and sex psychology, physical development and sex healthy, sex social environment and equality, marriage and healthy family. Included program contents were human dignit communication, sex curiosity, difference of sex, genital organs, pregnancy and birth, family violence, sexual violence, equality, parent-children relationships, family role. Second, sex education program was effective to improve degree of sex knowledge and to change sex attitude. Finally, sex education program needs to be continuously offered even to lower grades in elementary school.

• Korean Journal of Health Education and Promotion
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• v.19 no.3
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• pp.121-133
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• 2002

The purpose of this study was to set up the basic model to monitor the health status of the middle and high school students in the adolescent period, as well as to provide the fundamental data which might serve as the new standards for their better health maintenance and promotion. The collected data comprised the characteristics of the subjects in the three different fields of life such as school, family and everyday, which could affect their physical fatigues, and they were analyzed to determine the factors of significant influence upon their physical fatigues and to reveal their relativity. A total of 5,954 students at 6 boys' and girls' middle and high schools in Taejon City completed self-administered questionnaires(to measure Health Practice Index and others) asking about each of three life domains during the period March through June, 2000. The key study results were as follows; 1. The middle school students showed more subjective symptoms of fatigue which may be a marker reflecting physical health status, than the high school students. The higher scores were associated, based on school life, with the groups who were boys, who were in lower school grades, who achieved better academic performances and had better relationship with friends. 2. As for family life, the higher scores were in the groups whose financial conditions were better, whose parents showed more interest to their children, whose sense of satisfaction with family life was higher, and whose health status was better. 3. As for life styles, the individuals showed the higher scores in the groups who had breakfasts daily, who didn't have inter-meal snacks, who took regular exercises, who didn't smoke and drink than, their counterparts. 4. The higher level of fatigue was associated with the groups whose health conditions were good, who are satisfied with school life, who were boys rather than girls, who are satisfied with family life, who didn't have inter-meal snacks, who were in good relationship with friends, who achieved greater academic performances, who took regular exercises, who didn't smoke, and whose parents showed more interest in their children.

• Journal of the Korean Home Economics Association
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• v.41 no.1
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• pp.249-257
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• 2003

For the efficiency in extracting gromwell colorant, methanol, ethanol and aceton were used as solvents. Also, to compare the results when dyed in various conditions and on various fabrics, the ratio of water-dye mixture, pH, temperature, and varieties of fabrics -wool, silk, cotton, nylon, ramie- were selected. L, a, b, ΔE, munsell and K/S value of each sample was measured and compared for the practical use. Water-dye mixture of 5:5 ratio showed the optimum dyeability. Not to mention wool and silk, but also cotton showed a satisfying dying result at the acidity of pH4. As the temperature increased, the dyeability of all three fabrics improved greatly. Especially, wool showed the highest improvement in terms of dyeability as the temperature increased. K/S values for wool and nylon showed superior results to the others in the gromwell colorant. The resulting color turned out somewhat different depending on the solvents used and the sort of fabric that was tested on. When the gromwell colorant extracted with methanol or ethanol was applied, the color of fabrics came out as purple or purpleblue. When the colorant extracted with acetone was used, the color of fabrics came out to be redpurple. The colorfastness to light showed low glades regardless to whichever solvents were used. The grades of colorfastness to laundering were recorded low numerical values, and its record became even lower when the gromwell colorant extracted with aceton was applied. The staining grade of the colorfastness to laundering showed a good grade in the range of 4 to 5. All the dyed fabrics showed a excellent drycleaning fastness.

• Journal of Korean Elementary Science Education
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• v.23 no.1
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• pp.50-60
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• 2004

The purpose of this study was to define teachers' learning motivation strategies and students' responses by analyzing science classes and interviews. The subjects were first grade and sixth grade teachers and students of an elementary school. The analysis tools are based on Keller's ARCS theory. The differences of teachers' motivation strategies were analyzed by grades and teachers' and students' backgrounds. The interviewers were composed of three teachers and three students of first grade, and three teachers and three students of sixth grade. The data were collected by recording of the classes using tape recorders, video cameras, and notebooks written by researchers. The results are as follows. First, teachers had their own styles of teaching strategies in their classes. Especially teachers' teaching backgrounds affected on the teachers' instructional strategies. The teachers who had long teaching experiences of lower grade students used to show a lot of attention strategies. While the teachers with long teaching experiences of higher grade students used to show few learning motivation strategies. Especially, sixth grade teachers used to show fewer confidence strategies than first grade teachers. Second, all of the teachers used to show few satisfaction strategies commonly in all the classes observed. Third, the students' recognition of the motivation strategies were not different according to their conceptions or activities of the classes. Commonly first grade students focused on the attention strategies, while sixth grade students focused on negative motivation strategies. Fourth, the teachers who believed that students need detail guidance and control recognized the needs of satisfaction strategies by students' autonomous activities after observing video tapes of other teachers' classes.

• Journal of Korean Elementary Science Education
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• v.22 no.2
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• pp.163-172
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• 2003

The purpose of this study was to develop the analytic framework of Creative Problem Solving(CPS) for elementary school science textbook. For this purpose, we developed the framework based on the theories of problem, definition of problem solving and various kinds of CPS model. The six elements of the framework for content analysis were extracted through theoretical examination: problem introduction, problem statement, solution thinking, formulating hypothesis, testing hypothesis, and assessment. The developed framework was applied to the extbooks for the 5th and the 6th grades 1st semester in elementary science textbook of the 7th national curriculum. The results of this study were as follows: 1. The scores of the framework for content analysis in the 5th grade were slightly higher than those of the 6th grade, but there were no significant difference. 2. The comparison of the scores between the elements of the framework was found that the scores on the elements of testing hypothesis and formulating hypothesis were higher than those of the other elements. 3. The comparison of the scores between the units was found that the scores of the framework for the 9th unit (“trip of water”) of the 5th grade were higher than those of the other units, which were presented lower level than 1.0 (50.0%) score of the framework. 4. The comparison of the scores between the intensive course and the regular coures in the 6th grade textbook was showed that the scores on the intensive course were higher than the basic course. In conclusions, it was found that the problem introduction and problem statement in the textbook should be amended, and that various information and activities should be presented in the textbook.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.313-324
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• 2011

The purpose of this study is to present the raw data for establishing the plan of top soil conservation in soil environment and preventing the soil loss by establishing the potential amount of soil loss using RUSLE. The results are as follows. To apply the RUSLE model, we calculated the potential amount of soil loss by using 5 factors; rainfall erosion factor(R), topographical factor(LS), soil erosion factor(K), land cover factor(C) and erosion control factor(P). The assessment map of soil loss was drawn up by classifying 5 grades. According to the soil loss estimation by the RUSLE, it showed that approximately 83.9% of the study area had relatively lower possibility of soil loss which was the 1 ton/ha in annual soil loss. Whereas, the 7.0% of the study area was defined as high risk area which was the 10 ton/ha in annual. Therefore, this area was needed that there was environment-friendly construction of farm land, improvement of cultivation environment and so forth. In future, if we will analyze the amount of soil loss of Gyeongju national park and Hyeongsan river watershed, we will offer the help to establishing the conservation plan of soil environment in Gyeongsangbuk-do.

• Korean Journal of Community Nutrition
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• v.2 no.5
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• pp.680-686
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• 1997

The purpose of this study is to examine the relationships among body composition, dietary intake, exercise, and life style in children(M=80, f=102) of the 5th and 6th grades of elementary school. Anthropometry and multifrequency bioelectrical impedance analysis were conducted to estimate body composition. Dietary intake, exercise, and life style were determined by using questionnaires. When obesity was classified greater than 120% of the ideal body weight, the prevalence rates of obesity were 31.2% for boy and 20.6% for girl. There were significant differences in body composition between nonobese(NO) and obese(OB) groups. Mean fat mass(FM) and lean body mass(LBM) were 8.6kg and 27.7kg for NO group and 16.7kg and 32.3kg for OB group, respectively. Also a significant difference was found in hydration rate(TBW/body weight)between groups( <0.01). No significant difference was found I total calorie intake and nutrient intakes between groups. No difference was found in the frequency and duration of outdoor exercise and indoor activities. Mean sleeping hours was 8-9hours for 62% of nonobese children and for 59% of obese children. However, calorie intake per body weight was significantly lower inobese children than in nonobese. The present study showed that significant differences existed in their body size and composition between NO and OB groups , while no differences existed in daily calorie intake, excercise , and life style. This may indicate that important obesity-promoting factors of early onset obesity may rely on other factors such as hereditary or environmental factors besides factors considered. Further studies are required to understand obesity-promoting factors in children. (Korean J Community Nutrition 2(5) : 680∼686, 1997)

• Journal of Wetlands Research
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• v.12 no.2
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• pp.1-12
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• 2010

This study examined geological characteristics of a wetland in Mountain Geumjeong in Busan Metropolitan City. Field survey and laboratory tests were performed to identify topographic features, geological and structural geological characteristics, rock strength along the distance from the wetland, soil profile in the wetland, and chemical property of the wetland soil. The bedrock of the wetland consists of hornblende granite. Hornblende granite and rhyolitic rock around the wetland have the joints with strikes of N-S, E-W, and NE-SW directions and with higher dips greater than $60^{\circ}$. Lower rock strength and higher weathering grades take place towards the wetlands. According to X-ray diffraction analysis of wetland soil samples, kaolinite, montmorillonite, and gibbsite appear which demonstrate weathered products of feldspars in the hornblende granite. The soil profile in the wetland comprises O, A, B, and C horizons from the land surface. The contents of the organic matters decrease from shallow parts to deeper parts of the soil profile. In addition, $K^+$ and $Na^+$ originating from the weathering of feldspars are dominant components among inorganic ions in the wetland soil.