• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.201-212
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• 2021

Curriculum content interest has been studied in terms of teachers rather than students in ways that help revise curriculum and develop textbooks. In this study, 227 first-year high school students were interested in what they learned in middle school and what they learned in high school, focusing on meaningful assumptions and contents for middle school and high school students. We analyze this difference in interest by gender and achievement level. According to the research results, first-year high school students, who are in the middle and high school transition period, have relatively high interest in themselves, such as youth development, compared to family needs or interest in family life. There were no gender differences, but there were differences in content interest depending on the level of achievement. This means that the content interest should be interpreted by considering various variables such as the development of learners, the situation of learners in the school-level transition period, and the entrance examination of universities. The results of this study will provide implications for future curriculum revisions, textbook development, and curriculum considerations, and will need to be carefully analyzed and utilized based on a learner-centered perspective.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.353-358
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• 2018

In this study, it is describe to an optimization analysis process for the weight reduction of the voltage converter in the electric vehicle charging systems. The optimization design is a technique that finds the optimal material distribution under a given material quantity constraint by combining the design sensitivity with the material properties and the mathematical optimization. Among the topology optimization, a lightweight design is performed by a solid isotropic material with penalization with simple formula and well-convergence. The lightweight design consists of three steps. As a first step, a finite element model for the basic design of the on-board voltage converter was constructed and static analysis was performed on the load. In the second step, the optimum shape is obtained for the lightweight by performing the topology optimization using the solid isotropic material with penalization applying the stiffness coefficient of the isotropic material to the static analysis result. As a final step, impact analysis was performed by applying a half-sinusoidal pulse shape impact load which satisfies the impact test standard of the vehicle-mounted part with respect to the optimum shape. In the topology optimization, the design domain was defined as the mounting bracket area, and the design technology was finally achieved by optimizing the mounting bracket to achieve a weight reduction of 20% over the basic design.

• Journal of The Korean Association For Science Education
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• v.29 no.8
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• pp.978-989
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• 2009

In this study, we investigated high school students' errors in constructing and interpreting graph on experimental results by students' science achievement level. Two tests regarding constructing and interpreting graph about 'the relationship between the pressure and volume of a gas' were administered to 11th-graders (N=140). Analysis of the results revealed that most students exhibited many errors in the processes of constructing and interpreting graph. In the processes of constructing graph, there were 16 types of errors on the categories of 'misinterpreting the variables', 'mis-marking the graphical elements', and 'misusing the data'. The students of lower achievement level had more errors than those of higher achievement level in the four error types, that is, 'missing the variables', 'representing the best fit line using a broken line', 'adding the data', and 'neglecting the data'. However, the results were reversed in the error type of 'not marking the origin.' In the processes of interpreting graph, there were 9 types of errors on 'misreading the data', 'wrong interpolation and extrapolation', and 'establishing the wrong relationship'. The students of lower achievement level had more errors than those in the higher achievement level in the error types of 'wrong interpolation' and 'misdescribing the relationship between variables'. Educational implications of the findings are discussed.

• Journal of the KSME
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• v.18 no.4
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• pp.20-25
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• 1978

이 제2차대전시부터 시작되여 금일에 이르기까지 발전과 개발을 거듭하여 응력측정및 공업 계측, 제어분문의 일대혁신을 일으켜 응력해석 뿐만 아니라 오히려 응용면에서는 변환기부문의 비중이 더욱 크게 되고 있다. 변환기의 전망은 고정도에 소형화로 내구도가 강하면서도 특수환경하에서 도 안정성을 유지해야 되는 트랜스주셔개발이 활발하게 진전되고 있는 싯점에 있다. 스트레인 게 이지 자체도 고분자재료의 개발로서 많은 진전을 보이고 있으나 아직 고온용, 저온용게이지에 대 대해서는 연구과제로 봐야 되겠다. 끝으로 우리나라 기계공업의 고등화와 국제경쟁력강화를 위해 서도 새로운 트린스쥬서의 활용은 물론, 국산화 및 개발연구도 아울러 서둘러야 될 것으로 안다.

• Journal of the Korean Chemical Society
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• v.63 no.5
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• pp.376-386
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• 2019

The purpose of this study was to explore the learning progression of logical thinking in acid and base chemical reactions and to evaluate its validity. For this purpose, we collected 387 participants in 9 schools of elementary, middle and high schools nationwide. The questionnaire developed in this study was composed of nine items. The questionnaire presented the acid and base reactants and products, and the students pictured their thoughts on how these substances change, and answered the reasons of their thoughts. Situation contexts of the questionnaire were divided into two groups: one kind of solute dissolved in a solvent, and two kinds of solute dissolved in a solvent. In this study, six levels of learning progression were assumed by combining material conservation logic, combination logic, proportion logic, and particle number conservation logic. By analyzing the data, Infit and Outfit values of Person reliability, Item reliability, MNSQ and ZSTD were obtained from the Rasch model. As a result of the analysis of data, it was found that lower levels of learning progression prevailed up to the younger grade students till $8^{th}$ grade. The higher levels of learning progression(Level 2~Level 5) prevailed up to the older grade students. However, higher levels of learning progression dropped sharply in Grade 12. The 5 level of learning progression was very low in all grades, and $9^{th}$ grade had highest percentage of students belonging to the 5 level. Interpretation of these unusual results suggests a future research related to explanation differences of textbooks.

• Journal of The Korean Association of Information Education
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• v.25 no.4
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• pp.591-601
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• 2021

This study focuses on the ICT literacy, the perceived value of ICT utilization, and the perceived use of ICT environment as the factors influencing the activation of ICT using classes, in order to identify how these differences affect intended use of ICT. A total of 3,942 high school teachers participated in the survey. Two factor analyses were conducted to verify and check the validities of measurement items for independent and dependent variables. With the research questions, a multiple regression analysis was implemented to verify the predictive power of the independent variables on the teachers' ICT utilization. All the independent variables set in the research issue had a significant influence on the intended use of ICT, which is a dependent variable. ICT utilization was found as the most influential variables followed by the perceived value of ICT utilization, the affective domain of ICT literacy, and the psychomotor domain of ICT literacy, the cognitive domain of ICT literacy, and the perceived use of ICT environment. In order to enhance teachers' ICT utilization in school settings, teachers should understand the educational value of ICT utilization and recognize its necessity and importance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.19-25
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• 2019

We have developed a tool that uses finite element analysis (FEA) to rapidly evaluate a shaft-bearing system of machine tools. We extracted commercial data on suitable clamping units and defined the inner profile of the shaft to avoid needing direct user input to define the profile. We use a splitting algorithm to convert the shaft into beam elements with two diameters and length. To validate the tool, we used it to design and evaluate a shaft-bearing system and found that our tool automated the construction of an FE system model in a commercial FEA package as well as the static stiffness evaluation; both tasks were completed in seconds, demonstrating a significant reduction from the minutes normally required to complete these tasks manually.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.70-75
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• 2006

The cabin pressurization system response should be consistent with the design limits such as the cabin pressure schedule, the pressure regulation tolerance, the maximum rate of pressure change during normal and abnormal operation and the maximum cabin air inflow rate change. In this paper, the results of pressure loss analysis and flight test for cabin pressurization system of T-50 advanced trainer are introduced. The pressure tolerance at unpressurized condition using calculated exit area of pressurization components through pressure loss analysis is predicted. Pressurization components of D company are selected and the predicted pressure tolerance is in good agreement with flight test results. Finally, T-50 pressurization system is verified by some flight tests of T-50 advanced trainer to comply with various pressurization design criteria of MIL-E-18927.

• Journal of the Korea Society of Computer and Information
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• v.19 no.9
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• pp.185-196
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• 2014

This study has analyzed the learning objectives in 6 Informatics textbooks that were published this year in the basis of 2009 revised curriculum using Anderson's taxonomy of Educational Objectives that was a revision of Bloom's taxonomy and Fuller's taxonomy that was presented for programming activities. Some dimensions of Anderson's taxonomy, such as conceptual and procedural knowledge, understand and apply in cognitive process are much more used in learning objectives in 6 Informatics textbooks. Interpreting and producing dimensions of taxonomy are well presented to balance in 6 Informatics textbooks by analysis of Fuller's taxonomy. This results will be a good case study in research about taxonomy of educational objectives and development of Informatics textbooks.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.179-184
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• 2020

According to the 'low self-esteem hypothesis', low self-esteem plays a causal role in aggression among adolescents, whereas 'threatened egotism theory' postulates that aggression is related to a highly favorable view of the self. The primary purpose of the present study was to investigate the effect of self-esteem on aggression among adolescents. Based on the theoretical background, a research model was constructed. The present study analyzed the 5th and 6th wave data from Korea Children and Youth Panel Study (KCYPS). The results showed that self-esteem had a significant negative effect on aggression among high school students. Finally, research implications which contribute to enhancing self-esteem as well as decreasing aggression were also discussed.