• Title/Summary/Keyword: reflective

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Reflective Thermochromic Display on Polyethylene Naphthalate Film

  • Heo, Kyong Chan;Son, Phil Kook;Sohn, Youngku;Yi, Jonghoon;Kwon, Jin Hyuk;Gwag, Jin Seog
    • Journal of the Optical Society of Korea
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    • v.17 no.2
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    • pp.168-171
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    • 2013
  • A reflective flexible display was fabricated by placing a thermochromic pigment on a polyethylene naphthalate (PEN) substrate coated with an indium tin oxide (ITO) film, and its thermo-optical characteristics were investigated. The reflective thermochromic display showed good image quality with a reflectance of approximately 65%. As a flexible display, the display showed reliability without damage to the image even after the display was bent strongly. The reflective display cell exhibits continuously the gray level according to the temperature controlled by applied voltage. This low cost display is expected be used in outdoor poster applications where information needs to be presented clearly.

An Analysis of Pre-Service Teachers' Reflective Thinking for Tasks on Polar Coordinates

  • Oh, Hye Mi;Park, Jee Hyun;Kwon, Oh Nam
    • Research in Mathematical Education
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    • v.17 no.2
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    • pp.119-131
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    • 2013
  • It is the first time that there is a subject, advanced mathematics in the 2009 revised high school curriculum. Therefore it is posing a challenge to the teachers who are teaching it. At the advanced level, it is important for learners to reflect on their mental mathematical activities. This research analysed pre-service secondary teachers' reflective thinking in solving the tasks specific for the teaching and learning of polar coordinates. We report how and through what process mathematical tasks that can create disequilibrium for pre-service secondary teachers enable reflective thinking and expand preservice secondary teachers' thoughts and recognition of defining reflective thinking in looking back on one's problem solving and thinking processes.

The Effect of Journal Writing on the Reflective Thinking of Pre-service Teachers for Young Children (예비유아교사의 반성적 사고력 향상에 대한 저널쓰기의 효과)

  • Won, Mi-Kyoung;Kang, Seung-Hee
    • Journal of Fisheries and Marine Sciences Education
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    • v.19 no.3
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    • pp.429-440
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    • 2007
  • The aim of this study is to search for the effect of journal writing on the reflective thinking of pre-service teachers for young children. The question for this study is as follows: Would the journal writing experiences improve reflective thinking experiences of pre-service teachers for young children? The subjects were 50 sophomores in junior college, J city, and they were divided into a experiment group, and a comparison group. The experiment group had journal writing experiences for 8 weeks. The data was analyzed using T-test. The results are as follows: Journal writing activity revealed positive effect on reflective thinking level improvement of pre-service early childhood teacher.

Fabrication of Three-Dimensional Reflective White Pattern using Dry-Film Resist

  • Jun, Hwa Joon;Na, Dae Gil;Kwon, Young Hoon;Kwon, Jin Hyuk
    • Journal of the Optical Society of Korea
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    • v.19 no.1
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    • pp.80-83
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    • 2015
  • White reflective patterns are very difficult to fabricate, due to the scattering and reflection of light, especially when the pattern size goes down to micron size. A reflective white barrier structure of height $50{\mu}m$ and width $80{\mu}m$ was fabricated using dry-film resist as an intermediate reverse pattern. The reverse dry-film resist pattern was coated with an $SiO_2$ layer by sputtering, to protect the resist from chemical attack by the radical molecules in UV white resin. The UV white resin was applied on the dry-film resist pattern and then cured with ultraviolet light. The fine three-dimensional reflective patterns were finished by removing the dry-film resist.

Facilitating Pre-Service Elementary Teachers' Productive Reflection on Their Science Teaching through Meta-Analysis of Their Reflective Journals (수업 반성 저널의 메타 분석 활동을 통한 초등 예비교사의 생산적 반성 증진)

  • Yoon, Hye-Gyoung
    • Journal of Korean Elementary Science Education
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    • v.33 no.2
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    • pp.322-334
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    • 2014
  • In this study, the researcher aimed to increase productive reflection of pre-service elementary teachers through meta-analysis of their own reflective journals. The meta-analysis activities are expected to enhance their learning effectively as a kind of self-assesment. During 8 week simulation teaching, 26 pre-service teachers kept individual journal writing and the meta-analysis activities were implemented twice (after the 3rd and 8th week). Right after the first meta-analysis, the pre-service teachers' productive reflection increased clearly. However this would not guarantee the effect would last long time period. By analyzing 8 week reflective journals, reports on meta-analysis activities and small group interview, this study shed light on practical ways of enhancing reflective teacher education.

A New Reflective Display Mode for Antiferroelectric Liquid Crystal

  • Park, Won-Sang;Kim, Sung-Chul;Lee, Gi-Dong;Yoon, Tae-Hoon;Kim, Jae-Chang
    • Journal of Information Display
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    • v.1 no.1
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    • pp.48-51
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    • 2000
  • In this work, we proposed a reflective antiferroelectric liquid crystal display (AFLCD) using a half-wave cell whose inplane tilt angle is $22.5^{\circ}$. To check the validity of our design, we fabricated a reflective half-wave AFLC cell of which inplane tilt angle is $24.9^{\circ}$, and measured VIS reflection spectra, contrast ratio and response time. In the results, the half-wave AFLC cell in the reflective configuration exhibits high brightness, high contrast ratio of 20:1, and fast response time of $700{\mu}s$.

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A Study on the Mechanism and Design of Reflective Sheet (반사시트의 메커니즘 및 설계에 관한 연구)

  • Lee, Ho-Yeon;Jung, Ha-Kyu;Oh, Young-Tak;Kwon, Won-Tae
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.1
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    • pp.65-70
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    • 2008
  • The shape and the material of a reflective sheet affect the amount and the range of retroreflection on incident angle of light, significantly. In this study, the method to determine the shape and the material of the reflective sheet is introduced for the maximum retroreflection. Since the microprism shape with an equilateral triangle base has been used widely, the shape optimization of the microprism shape is carried out. The path of the light within the prism is geometrically calculated to find the relationship between incoming and outgoing light to and from a microprism. The optimal shape of a microprism found by the simulation has almost same figure with the one being used in industry for the maximum retroreflection. It is also found that the refraction index of the reflective sheet is another parameter to control for maximum retroreflection and the range of retroreflection.

Correlation Between the Optical Performance of the Reflective Polarizer and the Structure of LCD Backlight

  • Yu, Mi-Yeon;Lee, Byung-Woo;Lee, Jeong-Ho;Ko, Jae-Hyeon
    • Journal of the Optical Society of Korea
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    • v.13 no.2
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    • pp.256-260
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    • 2009
  • The optical performance of the reflective polarizer was investigated over three kinds of direct-lit backlights and/or different configurations of the optical sheets. The optical gain factor achieved by using the reflective polarizer increased as the diffuse nature of the optical sheet was enhanced, because of the more efficient polarization conversion. In addition, the gain factor decreased substantially in flat-lamp backlights compared to tubular-lamp backlights, which was ascribed to the high loss factor during the polarization recycling process due to the complex structure and large area of flat lamps. All these results suggested that reducing the loss factor of the backlight is very important for efficient polarization conversion and thus high optical gain of the reflective polarizer.

The effects on academic achievements of both recording reflective journals and receiving feedback in technical writing (이공계 글쓰기 교과목에서 학습 성찰일지 작성과 피드백이 학업 성취도에 미치는 영향)

  • Kim, Haekyung;Choi, Won-Young
    • Journal of Engineering Education Research
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    • v.20 no.3
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    • pp.42-49
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    • 2017
  • This study is about the influence of recording reflective journals and receiving feedback from professors on academic achievements in technical writing. We analyzed the differences between the test group who had recorded reflective journals and getting feedback, and the control group who had gotten feedback without reflective journals. And we compared academic achievements by conducting both professor evaluation and peer evaluation in technical writing. The results showed better learning effect, learning satisfaction and academic achievements in the test group than the other.

Facilitating Productive Reflection of Pre-service Elementary Teachers through Reflective Journal Writing and Discussion about Science Peer Teaching Practice (과학 모의 수업에 대한 반성 저널 쓰기와 토론을 통한 초등 예비교사의 생산적 반성 증진)

  • Yoon, Hye-Gyoung
    • Journal of Korean Elementary Science Education
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    • v.32 no.2
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    • pp.113-126
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    • 2013
  • In this study, the researcher aimed to increase productive reflection of pre-service elementary teachers through reflective journal writing and discussion after science peer teaching practice. 'Productive reflection' involves consideration and analysis of interrelationships among aspects of teaching including learners and learning, subject matter knowledge, assessment, and instruction. During 8 week efforts, productive reflection has increased gradually in both individual journal and class discussion. However half of individual journals didn't show productive reflection even in the final stage. This implicated that development of reflective thinking is an achievable but progressive change. By describing the progress in discussion and participants' responses on journal writing and discussion activity, this study shed light on practical ways of enhancing reflective teacher education.