• Journal of Magnetics
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• v.5 no.1
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• pp.1-3
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• 2000

We have theoretically investigated changes in reflection coefficients induced by misfit strain located near the interface between an iron-yttrium garnet magnetic film and a nonmagnetic gadolinium-gallium garnet substrate in a transverse magneto-optical configuration.

• Journal of Science Education
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• v.44 no.2
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• pp.225-239
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• 2020

This study aims to analyze the characteristics of reflective thoughts of students during experiments in general physics experiments. The participants were 32 college students, they submitted 10 experiment reports including answers to questions for reflective thinking. The results were as follows: First, students show reflective thinking broadly in the experiment, levels were followed by practical reflection, technical reflection, and critical reflection. Also, they actively accepted the knowledge related to experiments, but were passive in connecting new knowledge and experiences obtained through the experiments or forming new questions. Second, the reflective thinking of students show high correlation with experiments related to prior knowledge or the easy-to-understand process. Third, through the qualitative analysis of open-ended questions, it was confirmed that technical reflection occurs in individual evaluation, practical reflection in group evaluation, and practical reflection and critical reflection in improvement proposal. While the students' reflective thinking were superficial or mainly functional, however, they recursively examined the learning contents and the experimental process concurrently.

• 대한공업교육학회지
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• v.39 no.1
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• pp.227-246
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• 2014

The purpose of this study is to suggest the desirable direction toward the creative hand-on activities suitable for the characters of the technical high school students by examining the teachers' recognition of sub-factors of creative activities in technical high school and analysing whether the factors are properly utilized. Respondents of this study were 393 teachers at the Technical high school in South Korea. The questionnaire survey on the recognition of creative hand-on activities consisted of questions, which are importance and reflection, from 32 sections in 5 fields. The summary of the results through this study is as following. First, In the results of importance analysis of teachers in technical high school, in club activity field, 'the invention' of 'academic activity', 'film-art' in 'culture-art activity', 'challenge activity' in 'sports activity', 'school specialized major' in 'work practice activity', 'scout federation', 'Red Cross youth activity' in 'youth group activity' were seemed to be higher. Second, In the results of reflection analysis, it was found that the 'academy, culture-art', 'sports activity' fields were similarly reflected in importance thought by teachers in technical high school. However, for 'the work practice activity' and 'youth group activity', except 'the school specialized major', all fields are not properly reflected, independent of importance. For 'the work practice activity', analyses of importance and reflection seemed to be alike but for 'the youth group activity', there was a significant difference between them.

• Journal of The Korean Association For Science Education
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• v.32 no.9
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• pp.1405-1416
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• 2012

This study aims to analyze how pre-service science teachers' reflective thinking is presented during the microteaching process. The subjects of this study were 13 students who attended a lecture course on science teaching methods offered by the Department of Science Education of the College of Education at a national university. The simulated lessons that were performed during the microteaching process went through peer assessment and self-assessment. Then, the next set of lessons was conducted based on the assessment results. After the first set of simulated lessons, the pre-service teachers' reflection at the routine and technical levels was most remarkable in the focus dimension. In the inquiry and change dimensions, technical reflection stood out. Dialogic or transformative reflection was rarely presented. In addition, most of the pre-service teachers displayed mingling patterns of reflection levels in all of the three dimensions. The results of this study, in particular, prove that microteaching has a high level of applicability in terms of reflective thinking and instructional technology. Accordingly, there is a need for subsequent studies to create a new model that can encourage pre-service teachers' reflective thinking by structuralizing peer and self-assessment during the process of microteaching.

• Journal of Ocean Engineering and Technology
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• v.1 no.1
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• pp.138-143
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• 1987

Friction welding has emerged as a reliable process for high-production commercial applications with significant economic and technical advantages. But nondestructive test in friction weld was not clearly developed. Therefore the experimental verification is necessary in order to understand the characteristcs of the pulse echo effects according to various change in welding conditions. This paper presents an attempt to determine the relationship between the varios welding conditions and the coefficients of reflection using the ultrasonic pulse echo method in dissibilar metals friction weld. The new approach of calculating the coefficients of reflection based on measured amplitudes of the echoes is applied in this paper. These coefficients provides a single quantitative measurement which involves both acoustic energy reflected at the welded interface as well as transmitted across the interface. As a result, it was known that the quantitave relationship between welding conditions and the coefficients of reflection using the ultrasonic pulse echo exists in dissimilar metals friction weld.

• Transactions on Electrical and Electronic Materials
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• v.16 no.5
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• pp.264-267
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• 2015

AlCrNO cermet films were prepared on aluminum substrates using a DC-reactive magnetron sputtering method and a water-cooled Al:Cr target. The Al₂O₃/AlCrNO (LMVF)/AlCrNO (MMVF)/AlCrNO (HMVF)/Al/substrate of the 5 multi-layers was prepared according to the Ar and (N₂ + O₂) gas-mixture rates. The Al₂O₃ of the top layer is the anti-reflection layer of triple AlCrNO (LMVF)/AlCrNO (MMVF)/AlCrNO (HMVF) layers, and an Al metal forms the infrared reflection layer. In this study, the crystallinity and surface properties of the AlCrNO thin films were estimated using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), while the composition of the thin films was systematically investigated using Auger electron spectroscopy (AES). The optical properties of the wavelength spectrum were recorded using UH4150 spectrophotometry (UV-Vis-NIR) at a range of 0.3 μm to 2.5 μm.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.290-292
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• 2007

A twisted nematic type liquid crystal electro-optic modulator (TN-LC modulator) was developed. The modulator used single polarizer and the reflection on-off ratio was maximized by optimization of twist angle and retardation of liquid crystal cell. The TNLC modulator shows better sensitivity and response time than conventional liquid crystal modulator.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.2
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• pp.35-45
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• 2014

Confocal Reflection Microscopy (CRM) was applied to investigate external fibrillation of different types of fibers such as Kajaani reference fiber, Whatman filter fiber, thermomechanical pulp (TMP), and recycled TMP fiber. It was confirmed that the CRM images are created from surface structures of the fiber cell wall. Confocal Laser Scanning Microscopy (CLSM) captured overall shape of the fiber, but minute details of the surface of the fiber were missed. CRM captured the minute details of the fiber surface. From the CRM and CLSM images, it was observed that the CRM images mainly appeared on the fiber surfaces. External fibrillation of the fiber occurs at the fiber surface, not inside the cell wall. Thus, it was concluded that investigation on the external fibrillation of the fiber was possible by utilizing CRM images. A direct qualtitative and quantitative method for analysis of external fibrillation of fiber was demonstrated by utilizing surface area to volume ratio, volume fraction, and roughness calculated from 3-dimensional images reconstructed from stacks of CRM images from the different fibers.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.26-32
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• 2013

The earth reflection effect on the induced voltage by line source such as power line occurring induction inteference is analyzed to scrutinize how much it would reduce the induced voltage. Using hankel transformation including bessel function, directly calculation formulae for extracting a refelction coefficient is a most important technical application in this paper since the reflection coefficient on the earth cannot be deduced by a general coefficient calculation formulae according to a plain wave. The electric field is utilized to transform the electromagnetic field into an induced voltage. The composed efficiency to a source induction voltage by an earth reflection is about a range of 60~70% for the axis constellation of each object like observation point, source position and other material parameters.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.215-218
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• 2003

We have developed a reflective 3.5" QVGA color TFT-LCD with high reflection within viewing angle. For this, We have introduced new pixel design and asymmetric reflector. Based on these technical concepts, we get a high aperture ratio of 93.5% and much higher reflection up to 64% with a 3.5" prototype panel.