• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.33-36
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• 2004

The current Korea bridge design specifications have no provisions about concrete Barrier. And there are no test results of registence strength of the concrete barrier at the vehicle collision sites. This paper reports experimental results of concrete barrier on bridge deck conctructed by standard drawing of SB5 grade. Eight specimens were tested under static test. The specimens are divided by two groups (D-series and B-series). D-series is to show failure pattern of bridge deck. B-series is to show failure pattern of concrete Barrier. The test results compared with calculation results using Yield-Line theory of AASHTO LRFD Bridge Design Specifications.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.7-10
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• 2011

In this study, evaluation system of impact resistance performance is proposed. Compressive strength of concrete is 40, 60 and 80MPa. It evaluate impact resistance performance to use projectile 6, 7 and 8mm size. As a result, safety performance is more higher when the compressive strength is increased in. Compared with Hughes's formula, evaluation system of impact resistance performance is appropriated.

• Journal of the Korean Home Economics Association
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• v.36 no.3
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• pp.87-104
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• 1998

The purpose of this study was to examine the relations among family structural environment, materialism, and adolescents' delonquency. The instruments of measurement were Materialism Inventory and Delinquency Scale. The 483 male adolescents were selected randomly from the second grade of high schools in the city of Taegu. Factor analysis, Cronbach's α, MANOVA, and Scheffe test were conducted for the data analysis. The major findings of this study were as follows: 1. The materialistic level of adolescent was different with maternal occupation and education level. 1) Adolescent of mother whose occupation was general administrator indicated higher degree of possessiveness. 2) Adolescent of mother whose occupation was professional technician or administrator more regarded possessiveness as success or happiness than the other. 3) Adolescent of mother whose education level was junior college graduation or higher indicated more envy. 2. Each sub-dimension of materialism affected on the adolescents' delinquency differently.

• Structural Engineering and Mechanics
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• v.7 no.3
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• pp.319-330
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• 1999

The design of composite space trusses is a demanding task that involves taking several decisions on the truss depth, number of panels, member configuration, number of chord layers and concrete slab thickness and grade. The focus in this paper is on the design of top concrete slabs of composite space trusses, and in particular their thickness. Several effects must be considered in the process of designing the slab before an optimum thickness can be chosen. These effects include the inplane forces arising from shear interaction with the steel sub-truss and the flexural. and sheer effects of direct lateral slab loading. They also include a constructional consideration that the thickness must allow for sufficient cover and adequate space for placing the reinforcement. The work presented in this paper shows that the structural requirements on the concrete slab thickness are in many cases insignificant compared with the constructional requirements.

• Journal of Gifted/Talented Education
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• v.21 no.4
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• pp.961-977
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• 2011

The purpose of this study was to investigate the relationship between learning motivation and task commitment and find sub factors of learning motivation that affect task commitment. For this study 30 science gifted student (4th and 5th grade in elementary school) participated. The survey instruments used for this study were Academic Motivation Scale and Task Commitment Scale. The statistical methods employed for data analysis were the correlation analysis and multiple regression analysis. The result of this study were as follows: First, the learning motivation and task commitment of science gifted students showed similar levels. But there was differences of strength each sub factors of learning motivation and task commitment. Second, there was a significant positive correlation between learning motivation and task commitment. Also, learning motivation has the explanatory power of predictive variable for the task commitment approximately 49.3%. Expecially learning motivation has significant positive correlation with responsibility and self-control that sub factors of task commitment. Among the sub factor of learning motivation, confidence has most correlations with sub factors of task commitment and significant impact on task commitment. This result indicate that we need to develop learning motivation to improve task commitment and especially develop learning motivation program to grow up confidence of science-gifted.

• Journal of Korean Home Economics Education Association
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• v.33 no.2
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• pp.173-187
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• 2021

The purpose of this study was to investigate high school students' needs for home economics elective courses in line with the introduction of the high school credit system and the development of the next home economics curriculum. To this end, 1,689 high school students across the country were analyzed for needs of home economics elective courses (eighteen elective courses and six sub-disciplines of home economics) and differences in the needs of home economics elective courses based on gender, grade levels, and completion of home economics science subject. The research results were as follows. Among the six sub-disciplines, the preference for 'dietary life' was the highest, and in terms of teaching types, experiment and practice class had significantly higher preference in 'dietary life' than other sub-disciplines. Girls showed higher preferences for home economics elective courses than boys, and the third graders showed significantly higher preferences only for the 'dietary life' sub-discipline than the first graders. High school students who are learning or have learned the home economics science subject showed higher preference for home economics elective courses in all the sub-disciplines than those who have not learned it. Based on the results of this study, it is suggested for the national curriculum development that further researches should be actively carried out to develop home economics career elective subjects.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.132-141
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• 2022

The purpose of this study is to investigate the effect of science classes using elementary school distance science classes on science academic achievement and creative personality. The research group and non-research group were selected for 6th grade elementary school students. After 10 weeks of experimental treatment, science classes were conducted with the contents of the elementary school science section, 'Changes of the seasons'. In the three domains of 'knowledge', 'inquiry', and 'attitude', which are sub-domains of science academic achievement, as a result of the pre-post test, there was a positive effect in 'inquiry' and 'attitude', which are sub-domains of science academic achievement. However, it was found that there was no positive effect in 'knowledge', a sub-domain of academic achievement. However, it was found that there was a positive effect in the overall test result of academic achievement. Therefore, it is interpreted that science classes using elementary school distance science classes had an effect on academic achievement. There was a significant effect in the sub-domains of the creative personality test, 'persistence/obsession', 'self-confidence', 'humor', 'imagination', 'openness', 'adventure', and 'independence'. However, it was found that there was no effect in the sub-domain 'curiosity'. The overall test results of the creative personality test showed a significant effect. Therefore, it is interpreted that science classes using elementary school distance science classes are effective in cultivating creative personality. Students' perceptions of science classes using elementary school distance science classes also showed positive responses.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.1
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• pp.41-51
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• 2020

The purpose of this study was to investigate the possibility of eco-friendly/efficient recovery of valuable resources, such as Au from mine tailings, which are environmental pollutants in the Mongolian mine sector. For this purpose, this study selected 4 place of mine tailings of the Mongolian mines sector and carried out mineralogy evaluation of the valuable resources in the tailings. In this study, flotation was performed to separate and concentrate valuable resources in the tailings. Microwave nitric acid leaching was used to leach the valuable resources contained in the sample and to improve the Au grade. Chloride leaching attempted to leach Au from the leaching residues. XRD analysis of the tailings samples showed that most of the samples consisted of silicate minerals. As a result of confirming the content of the element through XRF analysis, the SiO₂ content was very high, the Fe₂O₃ content was 2.32-4.23%, and the content of PbO, CuO and ZnO components were all within 2%. As a result of flotation for the tailings samples, the recovery of Au was the highest in Bayanairag sample (95.38%). As a result of microwave nitric solution experiment on Au concentrate sample obtained by flotation, the content of Au in the microwave nitrate leaching residue increased by 12.15% from 192.72 g/ton to 216.14g/ton in Khamo sample, the highest increase was 57.58% in Bayanairag sample. TCLP tests on tailings generated after flotation showed dissolution characteristics within EPA. Chloride leaching test was performed to recover Au from solid residues. The leaching rate was 87.43-89.35% within 10 minutes. For Khamo sample, 100% Au was leached after 60 minutes of leaching time. Therefore, in order to process the tailings continuously generated in Mongolia, applying the same process as the present study is expected to effectively recover the valuable resources contained in the tailings.

• Journal of Energy Engineering
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• v.21 no.1
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• pp.68-74
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• 2012

Sub-bituminous coals have been used increasingly in coal-fired power plants with a proportion of over 50% in the blend with bituminous coals. As a result, the unburned material in fly ash has increased and is causing problems in utilizing the fly ash as an additive for concrete production. In this study, analysis of fly ash obtained from a 500 MWe power plant was carried out and unburned material in the fly ash found to be soot. The coals used in the plant were analyzed with CPD model to investigate the sooting potential depending on the coal type and blending ratio.

• Journal of the Korean Society of School Health
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• v.26 no.3
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• pp.169-183
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• 2013

Purpose: The purpose of this study was to develop a safety education system and its contents for technical high schools including textbooks and instruction manuals for teachers. Methods: Reference materials and surveys were both employed in the study. Basic theory and relevant contents were estimated. The contents of safety education included in the current curriculum in technical high schools were evaluated and the laws and regulations related to safety education in such schools were analyzed by researching references. In addition, the status of safety education in technical high schools and the demand for safety education were reviewed. Results: The goal of safety education has been established based on the status and theory of the estimated safety education, The goal was classified into an overall goal and sub-goals, setting five areas of safety education. Furthermore, the contents of safety education, total 17 hours per year for each grade, were organized into 20 content goals and 47 activity elements. These activity factors of safety education has been systemized by grade. Conclusion: All technical high-schools need to carry out safety education based on the contents related to safety education. The operation of this systematic safety education will be more efficient and effective than the current system and the knowledge, attitude, and behavior regarding safety at technical high schools are expected to undergo positive changes. Moreover, the result from this study will contribute to the establishment of various policies for safety education in technical high schools.