• Transactions of Materials Processing
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• v.3 no.1
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• pp.97-109
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• 1994

Closed-die forging of the spur gears with circular are fillet has been analyses by using the upper-bound method. A kinematically admissible velocity field has been developed, wherein, the tooth profile consists of the involute curve and the circular arc fillet. In the analysis, the deformation regions have been divided into eight zones. A constant frictional stress has been assumed on the contacting surfaces Utilizing the formulated velocity field, numerical calculations have been carried out to investigate the effects of various parameters, such as module, number of teeth, addendum modification coefficient and friction factor, on the relative forging pressure of spur gears. As the result of numerical calculations, the relative forging pressure does not change so much against the variation of module. On the other hand, the relative forging pressure increases at the final filling stage as the addendum modification coefficient increases.

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.201-212
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• 2007

This study examined the influences of current education programs for preservice chemistry teachers upon preservice science teachers' self-images as science teachers by using Draw-A-Science-Teacher-Test Checklist (DASTT-C). Seventy-two juniors and fifty-three seniors were selected from the department of chemistry education or department of science education (chemistry major) in three colleges of education. DASTT-C was administered to the juniors before having science education courses, and to the seniors before and after teaching practices. The results revealed that preservice science teachers' self-images as science teachers were more ‘teacher-centered' than ‘student-centered'. Only a few preservice science teachers exhibited ‘student-centered' images after having science education courses including the contents on constructivism. The self-images of some preservice science teachers even changed from ‘student-centered' to ‘teacher-centered' after having teaching practices. Many preservice science teachers answered that the main factors affected to their self-images as science teachers were prior teaching-learning experiences and/or the lim itations in the real situations. Educational implications of these findings are discussed.

• Journal of Preventive Medicine and Public Health
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• v.33 no.2
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• pp.184-192
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• 2000

Objectives : To inquire the prevalence and the risk factors for myofascial pain syndrome (MPS) on young boys in order to use these results as the fundamental data for the prevention of their MPS. Methods : For 7 days in May 1999, this research was taken on 489 male students ranging from 6th to 12th grade. We randomly selected a class for every group and from these classes we operated physical examinations, self-reported questionnaires and from a rehabilitation doctor, MPS test was taken. Thoracic kyphosis and lumbar lordosis were also taken by using the inclinometer. We defined MPS as a regional pain complaint, palpable taut band that is painful on compression. Results : The shoulder MPS prevalence of the subjects were 29.7 persons/100 persons. The statistics revealed that as grades went up, the percentage significantly increased in the MPS prevalence. As of case-control study, 145 students who were tested postive in all aspects were placed as cases, and 176 students who were perfectly normal as controls on risk factors. As a result of comparing the student groups who were stisfied with their chairs to the student groups were not satisfied, the taller showed a significantly higher odds ratio (p<0.01). By the multiple logistic regression test, we concluded that the MPS disease was prevailed far more in the students in the higher grades (Odds ratio: 1.16, 95% C.I.: 1.03-1.31), and also those who were dissatisfied with their chairs than in the ones who were satisfied (Odds ratio: 1.92, 95% C.I.: 1.17-3.17). Conclusions : Significant correlations showed between the MPS diagnosed group and the students who are dissatisfied with their chairs. As a result, more research and observation has to be made concerning this disease, and the desks and chairs should be adjusted to suit the student's physical standards.

• Journal of the Korean School Mathematics Society
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• v.18 no.3
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• pp.281-309
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• 2015

The purpose of this study is provides an implication of further teaching learning process by analyze the common and difference and characteristic of mathematical self-efficiency between three peer tutoring groups discourse in the mathematical teaching leaning process that use peer tutoring. To achieve this goal, three groups formed that consist of one peer tutor who received a first grade of mathematic achievement and one peer student. Peer student of each group is divided into high grade, middle grade, low grade of mathematic achievement. Then analyze the discourse in the exponential function problem solving process. Based on the results of study, this paper provides a concrete example of merit of peer tutoring on the peer tutor. Result of study also provides a practical help to make a peer tutoring group by considering a difference of grades between peer tutor and peer student. Because there is a possibility of mutual discourse on the tutoring group that consist of similar grades.

• Journal of Korean Elementary Science Education
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• v.33 no.2
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• pp.242-257
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• 2014

Researchers have employed a diversity of definitions and measurement methods for creativity. As a result, creativity research is underrepresented in the literature and the findings of different studies often prove difficult to draw into a coherent body of understanding. With regard to assessment, there are some important problems both in creativity research and practice, such as originality bias and Big-C creativity bias in teachers' perceptions about creativity and creative thinking, and additive rather than multiplicative scoring systems of creativity assessment. Drawing upon most widely accepted conceptions of the creativity construct, I defined 'student's scientific creativity' as the ability to make a product both original and useful to the student in terms of little-c creativity, and 'scientist's scientific creativity' as the ability to come up with a product both original and useful to the science community in terms of Big-C creativity. In this study, an 'Assessment Formula for Scientific Creativity' was developed, which is consisted of the multiplication of originality and usefulness scores rather than the sum of the two scores, and then, with scores calculated from the assessment formula, the scientific explanations generated by children were categorized into four types: routine, useful, original, and creative types. The assessment formula was revealed to be both valid and reliable. The implications of the assessment formula for scientific creativity are examined. The new assessment formula may contribute to the comprehensive understanding of scientific creativity to guide future research and the appropriate interpretation of previous studies.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.130-135
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• 2009

These days, the super high-rise buildings construction plans are increased in Korea. But the stack effect in the super high-rise building interrupts the smoke control system's operation because of pressure difference, so it is more dangerous than the general building when firing. Therefore it needs to study about the pressure difference in the super high-rise buildings. We research the smoke control influence factor in the super high-rise building. Reflecting the influence factor, the simulation is practiced the case by case.

• The Journal of Korean Academic Society of Nursing Education
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• v.17 no.2
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• pp.235-245
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• 2011

Purpose: The purpose of this study was to identify effectiveness of fundamental nursing practices in clinical settings. Method: This study adopted the triangulation method. Using one group pre-post test design, this study identified differences in self efficacy between pre and post clinical practice. The study was also designed to describe the nursing student's experience of clinical practice by using content analysis Results: 1) All students experienced bedmaking, BST check, V/C check, positioning, transferring, assisting with moving and positioning, and ROM. Sixty percent of students experienced giving oral care, and forty percent experienced shampooing patient's hair. 2) While the mean score of self efficacy was 3.88 in the pre-test, it decreased to 3.76 in the post-test. They were statistically different from each other. 3) Seven categories were elicited from the result of content analysis on the nursing student's experience, which were 'ignorant stranger', 'facing the gap between theory and practice', 'resolving the uncertainty of clinical setting', 'getting used to fundamental nursing practice', 'motivated by a desire to study and self-development', 'understanding the nursing profession's job', and 'being helpful for the future career'. Conclusion: Fundamental nursing practice in clinical settings is a useful strategy that improves fundamental nursing skills and motivates student's self-development.

• Education of Primary School Mathematics
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• v.25 no.4
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• pp.433-457
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• 2022

An effective teacher community helps the participating teachers improve their instructional quality. This study reports a teacher community consisting of 15 elementary school teachers and one teacher educator. This paper analyzed 15 mathematics lessons in which the teachers implemented the five practices for orchestrating productive mathematics discussions by Smith and Stein (2018) based on the grade-specific discussions as well as the whole community's discussions. The results of this study showed that the overall levels of each practice either increased gradually or maintained at the highest Level 4, as mathematics lessons had been implemented. Specifically, the following practices were quite successful: setting goals for a lesson, selecting an appropriate task, anticipating student responses, and selecting student solutions. However, both sequencing and connecting student solutions were implemented at various levels. Monitoring student work tended to remain at Level 2 which included incorrect implementation of the practice. This paper closes with implications related to the skillful implementation of the five practices through a teacher community.

• Education of Primary School Mathematics
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• v.23 no.4
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• pp.175-189
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• 2020

The purpose of the present study was to investigate the structural relationships between elementary teachers' mathematics instruction, teachers' mathematics teaching efficacy, students' mathematical interest, and mathematics achievement. To achieve this goal, we used TIMSS 2015 Korean data and implemented multilevel structural equation modeling given that student data were nested within the school data. The findings reveled that at the student level, the instructional quality rated by students positively affected student mathematical interest. Additionally, student mathematical interest positively affected student mathematics achievement. Although the direct effect of instructional quality on student mathematics achievement was insignificant, the total was significant. At the school level, there were positive direct effects of instructional quality and teacher's mathematics teaching efficacy on student mathematical interest. The direct effects of instructional quality, teachers' mathematics teaching efficacy, and student mathematical interest on mathematics achievement were not significant. However, the total effects of instructional quality and teachers' mathematics teaching efficacy on mathematics achievement were significant. Based on the results, we discussed the implications of the study.

• Journal of the Korean earth science society
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• v.23 no.2
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• pp.194-206
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• 2002

This article describes the major themes to change in historical and philosophical perspectives of science education that lead the US and Korean science curriculum reform movements since 1957. Inquiry teaching and criticism of teaching science as inquiry in the late 1950s and the 1960s, Science-Technology-Society (STS) Curricula, and Science Literacy and the 1980s science literacy crisis are discussed. In the US, three major curricular projects as responses to the scientific literacy crisis are exemplary such as the Project 2061 sponsored by the American Association for the Advancement of Science, the Project on Scope, Sequence, and Coordination (SS&C) initiated by the National Science Teachers Association (NSTA), and the National Science Education Standards (NSES) published by the National Research Council. To identify how each set of national content standards differ, we compared specific content standards related to the theory of plate tectonics in Earth and Space science in grades 9-12 over the three national standards: Benchmarks of AAAS, NSES of the NRC, and SS&C of the NSTA. Against this historical background of the US science education reform movements, the curriculum reform movements in Korea is briefly discussed. In general, Korean science curriculum reform movements have reflected and resembled the recommendations of the US reform movements. In addition, it is important to note that throughout the history of curriculum revision in Korea, there have been continuing pendulum swings between a theoretical, discipline-centered curriculum and a liberal, humanistic, and student-centered curriculum, which pays more attention to students in terms of their interest and psychological preparedness. In conclusion, the sixth and seventh national science curriculum revisions reflect rather a student-centered movement by reducing technical and sophisticated topics, taking constructivism learning theory into consideration, and adding more STS related topics.