• 아동학회지
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• 제25권5호
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• pp.29-40
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• 2004

Three groups of maltreated Korean children (Grades 1 through 3) drawn from Child Protective Services (CPS) agencies were compared to a control group of nonmaltreated children on academic achievement as measured by standardized tests of reading, spelling, arithmetic, and writing. Findings were that maltreated children performed significantly below their nonmaltreated children on the standardized tests, in particular in arithmetic. In first grade, maltreated children did not perform below nonmaltreated children on writing and reading, but maltreated children gradually declined in academic performance in these skills. The older, grade 3, children showed more serious academic problems than the younger children (Grades 1 and 2) on four academic skills. This suggests that early experience of child abuse have a strong affect on children's academic achievement.

• 아동학회지
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• 제18권1호
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• pp.39-52
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• 1997

This study focused on factors influencing Internal and external problem (depression and antisocial) behavior among late-elementary children. Subjects were 481 boys and girls enrolled in the fourth. fifth. and sixth grades of public school. The contribution of grade. sex. stress, self-esteem. and social support from parents, teachers, and friends as well as school performance were studied. The instruments were the Adolescent Perceived Events Scale, the Self-Esteem Scale, the Social Support Scale for Children, the Revised Korean Version of the Center for Epidemiologic Studies' Depression Scale and Antisocial Behavior Scale. Results indicated that sex, stress, self-esteem, and the support of parents, teachers and friends reduced the level of depression. Grade, sex, stress, self-esteem, and teachers' support were related to the level of antisocial behavior. The results were discussed in terms of the effects of stress, personal and social resources, and school achievement on depression and antisocial behavior.

• 한국생산제조학회지
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• 제21권1호
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• pp.150-155
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• 2012

Water jet propulsion system has low efficiency than screw propeller at low speed, but has been applied in high speed ship due to its better cavitation performance and high rotation capacity. In this study, a numerical analysis was conduct to understand the flow in the propulsion system of 200HP grade water jet for small ship. As the result, it could be confirmed that total pressure and force of the flow was increased through the impeller and the straight-ability of discharging flow to outlet was improved by guide vane. Also, the reliability of numerical analysis was secured by comparing peripheral velocity calculated by design values with that calculated by numerical analysis.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2014년도 제50차 하계학술대회논문집 22권2호
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• pp.399-400
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• 2014

컴퓨터 프로그래밍 수업의 특성상 교수자가 평소 학습자들의 학습 수준 및 학습 이해도를 파악하는 것은 다음 수업을 준비하는데 있어서 매우 중요하다. 학습자들의 평소 학습 이해도를 파악하는 방법으로 형성평가가 가장 많이 이용되는데, 동일한 과목에도 형성평가 방법은 매우 다양할 수 있다. 본 연구에서는 다년간 컴퓨터 프로그래밍 수업에 적용해본 다양한 형태의 형성평가 방법들이 학습자들의 성적 변화에 어떤 영향을 미치는가를 분석해보았다. 그 결과 형성평가 수행 시기는 중간고사나 기말고사처럼 큰 시험을 앞둔 1~2주전과 같이 학습자들이 학습에 대한 필요성을 절실히 느낄 때 실시하는 것이 성적 상승에 더 긍정적인 영향을 주었고 평가방법으로는 프로그래밍 수업을 특성상 퀴즈와 프로그래밍 평가를 함께 실시하는 것이 성적 상승에 좋은 영향을 미쳤다.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.597-603
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• 2016

In this paper a comparative thermodynamics analysis is carried out for organic Rankine cycle (ORC) and ammonia-water Rankine cycle (AWRC) utilizing low-grade heat sources. Effects of the working fluid, ammonia concentration, and turbine inlet pressure are systematically investigated on the system performance such as mass flow rate, pressure ratio, turbine-exit volume flow, and net power production as well as the thermal efficiency. Results show that ORC with a proper working fluid shows higher thermal efficiency than AWRC, however, AWRC shows lower mass flow rate of working fluid and lower pressure ratio of expander than ORC.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.449-450
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• 2006

This paper described the preparation method for composing high-grade synthetic diamond by water atomizing using FeNi30 powder catalyst. The objective of this article is about powder making process using super high water atomizing in the atmosphere of inert gas, and then corroded the powder with a corrosion inhibitor. Finally, FeNi30 catalyst powder with lower oxygen content and good sphericity is produced. The experiment of making diamonds by using cubic press and the performance of the diamonds are also discussed.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.44-51
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• 2003

By blending of various low boiling point oxygenated agents to lower grade fuels, significant improvements were simultaneously obtained in smoke, CO, PM, SOF and BSEC. Especially, our trends were remarkably obtained by retarding injection timing, by decreasing boiling point and increasing blending contents of additives in case of oxygenated agents rather than non-oxygenated agents. Also, it was revealed that when 20vo1.% DMM added to high viscosity fuels and injection timing was retarded, NOx-smoke trade off relationship was much better than that of ordinary diesel fuel. Thus, lower grade fuels with high viscosity could be expected to be used efficiently and cleanly in diesel operation by blending low boiling point oxygenates.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.686-689
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• 2005

This study aims to analyzed the acoustics characteristics of Korean Traditional Houses in Chonnam Province varied with lay out and floor plane to reflect the way of control for environmental condition. These houses are surveyed the reverberation time and level difference between rooms of the main living room and other main floored room, master room and kitchen. As a result, the reverberation time of traditional rooms are below 0.6 second, and the sound insulation performance of Korean traditional door are mostly very low grade with D-15. The level difference between rooms are low grade not to meet minimum class except between main living room and master room away from main living building.

• East Asian mathematical journal
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• 제37권2호
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• pp.149-167
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• 2021

The six core competencies included in the mathematics curriculum revised in 2015 are problem solving, reasoning, communication, attitude and practice, creativity and convergence, information processing. In particular, the reasoning is very important for students' enhancing much higher mathematical thinking. Based on this competency, this study selected the four elements of investigation and fact guess, justification, the logical performance of mathematical content and process, reflection of reasoning process, And also this study selected the domain of function which is comprised of the content of the coordinate plane, the graph, proportionality in the seventh grade mathematics textbook. By the subject of the ten kinds of textbook, this study examined how the four elements of the reasoning competency were shown in each textbook.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제25권2호
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• pp.135-158
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• 2022

This study aimed to building models to understand the relationships between reasoning resources and content knowledge. We applied Support Vector Machine and linear models to the data including fifth graders' scores in the Cornel Critical Thinking Test and the Iowa Assessments, demographic information, and learning science approach (a student-centered approach to learning called the Science Writing Heuristic [SWH] or traditional). The SWH model showing the relationships between critical thinking domains and academic achievement at grade 5 was developed, and its validity was tested across different learning environments. We also evaluated the stability of the model by applying the SWH models to the data of the grade levels. The findings can help mathematics educators understand how critical thinking and achievement relate to each other. Furthermore, the findings suggested that reasoning in mathematics classrooms can promote performance on standardized tests.