• Journal of the Korean Society for Railway
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• v.3 no.3
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• pp.170-176
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• 2000

Nowadays, the vehicle structure weight of urban transit system has been reduced in order to save energy and materials. However, this light weighted vehicle structure is very important to verify the fatigue strength at the development stage. Bogie system consists of bogie frame, suspensions, wheel-sets, braking system and transmission system. Among these components, the bogie frame is most significant component subjected to the whole vehicle and passenger loads. In this study, the bogie frame for the standard EMU power car is evaluated to the static and fatigue strength. And, the evaluation method is used the JIS E4207 specification throughout the FEM analysis and static load test. The static and fatigue test results for the standard EMU bogie frame of power car has been appeared very safety and stable for the design load conditions.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.566-572
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• 2005

This paper describes the results of structural analysis and loading test of a bogie frame. The purpose of the analysis and test is to evaluate the safety and functionality of the bogie frame under maximum load. The bogie system consist of the bogie frame, suspensions, wheel-sets, a brake system and a transmission system. Of these components, the bogie frame is the major components subjected to the vehicle and passenger loads. The evaluation method used the JIS E 4207 specifications throughout the FEM analysis and static load test. The test results have shown the bogie frame to be safe and stable under design load conditions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.670-676
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• 2004

In this paper, a modeling method for the vibration analysis of rotating structures composed of beams and shells employing multi-reference frames is presented. The rotary inertia effect and the geometric stiffening effect that results from centrifugal inertia force we considered for beams and shells with lumped mass model. In most previous studies, single reference frame has been employed for the vibration analysis. In the present study, a modeling method employing multi-reference frames is presented and the effects of employing multi-reference frames on the analysis accuracy are investigated through solving numerical examples.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.16-24
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• 2009

In this study, fatigue crack growth rate of a cracked railway bogie frame under variable amplitude loading is predicted by applying linear elastic fracture mechanics. For this purpose, we find the critical points by reference surveying on cracked railway bogie frames. And we make an effective load history by synthesizing the dynamic load measured from the critical points of railway bogie frame during commercial line operation and the static load calculated from structural analysis. Crack growth analyses are performed at the 3 critical points under the commercial operation loading condition by assuming an initial crack size as 40 mm. and the results are compared with the experimental results from Japanese railway bogie frame crack growth case. From the analysis results, we find that around 500,000 km operating distance is necessary to bring crack growth from the initial crack to unstable crack. And it takes around 3.8 normal operating years. We conclude that it is enough time to detect the crack between normal maintenance period.

• Journal of the Korean earth science society
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• v.29 no.7
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• pp.586-601
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• 2008

The purpose of this study was to identify the scientists' abductive reasoning in three stages of hypothetical-deductive inquiry process; generating hypothesis, designing, and interpreting data and to suggest new analytic coding frames on abductive reasoning in each of the stages. For this purpose, the interview protocols collected through in-depth interviews with eight scientists were analyzed by the early frame with sub-elements derived from the literature reviews. The need of a new frame of analysis beyond the previously established elements arose from the result of this analysis because the processes of abductive reasoning were found in all three stages. Based on scientists' interview data, this study then designed a new frame of analytic coding frames on the abductive reasoning in each of the stages. The content validity index from four experts was 0.90, and these frames showed a good fit to analyze the scientists' real process of abduction in three stages of hypothetical-deductive inquiry process.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.607-616
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• 2016

In the 2009 revised science curriculum, comprehensive verbs such as 'know (38%)' and 'understand (46%)' are used in more than 80% of the achievement standard. Many readers, such as teachers, textbook makers, etc. have difficulties in interpreting the meaning of achievement standard sentences with these comprehensive verbs. On the other hand, 'Trends in International Mathematics and Science Study (TIMSS)' uses more various and specific verbs to express the cognitive domain. In this study, we analyzed the 2009 revised science curriculum achievement standard focusing on the TIMSS cognitive domain assessment framework. We divided achievement standard to 228 sentences and three teachers analyzed the meaning of verbs in achievement standard. There were two main results of this study. First, the verb 'Know' was analyzed into different kinds of meanings, such as 'Describe (27%)', 'Recall/Recognize (25%)' and 'Relate (17%)', etc; and the verb 'Understand' was analyzed into 'Explain (37%)', 'Relate (27%)' and 'Describe (21%)', etc. Second, there appeared to have a disagreement among the three analysts during the process of interpreting the achievement standards when the level and scope of the contents of each grade is not clear. This study concludes that there's a need for continuous discussion on the use of verbs in achievement standard to promote clearer expressions for better understanding.

• Journal of the Korean association of regional geographers
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• v.16 no.4
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• pp.355-368
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• 2010

This study is to make a framework of newly interpretating the dynamic change of regional or local landscape rapidly occurred after the establishment of the nation state and capitalistic system. The basic concepts of making an interpretative framework are power, subjectivity, and performativity. The framework of closely interrelating the three concepts developed in the near future will be applied to the interpretation of variety of (de)centralized landscapes in regions or locals. A centralized political power under the nation state has destroyed or marginalized the historically developed landscapes, traditional culture, and subjects' values in regions or locals by the political implementation of the nation state, the establishment of national identity, a centralized economic development, and so on. The landscapes produced by the political power of the nation state can take a role as a cause of conflicts in regions or locals in terms of a historical perspective. Landscapes are being made by various subjects, and the produced landscapes also positively or negatively will influence the emotion, cognition, and behavior of the subjects particularly in a performative perspective. The dynamics interrelation between subjects and landscapes has been disguised or marginalized by reason/rationality, totality/collectivity, the separation between reason and emotion mainly made by modernism, the nation state, a capitalistic system. The interrelation between landscapes and subjects is especially emphasized on people's resistibility and creativity. Lastly, landscape is not a concept given as a priori or (re)presented objectively. It is not also a material or an object independently existed from a subject's emotion and cognition. It should be interpreted through a performative relation with subjects. Performativity will take an active role of combining the materiality of landscape, power, and subjectivity. It is also important to understand the active role of landscapes.

• Journal of the Korean earth science society
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• v.26 no.8
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• pp.751-758
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• 2005

The purpose of this study was to develop an inquiry analysis framework based on the features of earth science inquiry methodology and to analyze inquiry activities in the 8th grade 'Earth History and Diastrophism' unit by using this framework. The framework classified earth science methods as logical inference, hermeneutic, and historical methods, each of which was subdivided in consideration of its subordinate methods and characteristics. The analysis revealed that the logical inference method reflected in the unit as the 'abductive method' (70%) was used more frequently than the 'inductive' (23%) and 'deductive' (22%) methods. The hermeneutic method was found in terms of the 'forestructures of understanding' (92%), 'circular reasoning' (9%). and 'historical nature of human understanding' (17%). The historical method also used as the 'constructing proper taxonomy' (53%), 'adhering to the modem principle of uniformitarianism' (47%), and 'relic interpretation' (41%) were identified with ratios more fester than those for the 'place substituting for time in stage theorizing' (3%) and 'evaluating independent lines of inquiry for convergence' (3%).

• Journal of Gifted/Talented Education
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• v.21 no.2
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• pp.309-335
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• 2011

Writings of gifted students were classified by the writing analysis protocol built on the scientific inquiry process and writings of scientific journals. These writings were classified 7 types based on the existence of tentative explanations and types of conclusion. In addition the writings were classified by linear form, double linear form, supporting-conclusion form based on the number and position of writings. The characteristics of writings show that, first, the tentative explanation is located at the beginning and the drawing conclusion at the end of articles. Secondly, students prefer the linear form writing to explain their logics. Finally, supporting-conclusion writings are shown when answers of question is written only in the drawing conclusion without estimation.

• Journal of Educational Research in Mathematics
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• v.25 no.2
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• pp.157-175
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• 2015

This study was conducted with the aim to develop and improve the assessment literacy of teachers which enables it to develop and utilize the assessment items using a wide range of contexts on the basis of an understanding of math contents and mathematical process specified in the math curriculum and to analyze the results in an effective way. To analyze the changes in the development and improvement of the assessment literacy of preservice math teachers, the author of this study, using PISA items and assessment framework, analyzed the changes through the 1st and 2nd development of assessment items. The results showed the assessment literacy of preservice math teachers and their ability have been improved, implying that there is the necessity to develop a wide range of programs to improve the assessment literacy of preservice math teachers and provide such programs on a regular basis, which will facilitate effective math teaching and learning.