• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.905-909
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• 2002

Characteristics of reflective LCDs, which have gained a lot of notice in recent years, rely largely on optical design of circular polarizers and the quarter-wave plates, as a component. Important design includes wavelength dispersion, viewing angle, uniformity of display and matching of refractive index. Our work has contributed to improving performance of reflective LCDs by enhancing the characteristics of polymer film using stretching and optical lamination technologies. To design that offers higher contrast and wider viewing angle, we have discovered that it is necessary to control viewing angle variation of the polarizing axis in order to compensate for the viewing angle of the polarizing film as well as the optical anisotropic properties of liquid crystal. Applying this technology to circular polarizers used for reflective LCDs enables design of wide viewing angle circular polarizers. In order to realize higher contrast for reflective LCDs, it is also necessary to design other optical materials including polarizing films. For design of hybrid optical film, it is particularly necessary to reduce surface reflection and interface reflection. This paper also reports our findings concerning this topic.

• Journal of information and communication convergence engineering
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• v.17 no.3
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• pp.221-226
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• 2019

In this work, a transmitter/receiver front-end module (T/R FEM) with an automatic Tx/Rx switching scheme for a 2.4 GHz microwave power transfer is developed for a retro-reflective beamforming scheme. Recently, research on wireless power transfer techniques has moved to wireless charging systems for mobile devices. Retro-reflective beamforming is a good candidate for tracking the spatial position of a mobile device to be charged. In Tx mode, the T/R FEM generates a minimum of 1 W. It also comprises an amplitude and phase monitoring port for transmitting RF power. In Rx mode, it passes an Rx pilot signal from a mobile device to a digital baseband subsystem to recognize the position of the mobile device. The insertion loss of the Rx signal path is 4.5 dB. The Tx and Rx modes are automatically switched by detecting the Tx input power. This T/R FEM is a design example of T/R FEMs for wireless charging systems based on a retro-reflective beamforming scheme.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.23 no.4
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• pp.430-439
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• 2016

Purpose: The purpose of this study was to contribute to the development of an efficient teaching-learning method by analyzing effects of writing reflective journals on meta-cognition and problem solving ability in nursing students in education applying blended learning for fundamental nursing skills. Methods: The research design was a one-group pretest-posttest design, done to assess changes in meta-cognition and problem solving ability. Participants were 63 nursing students taking the fundamental nursing skills course at one college in Gyeonggi Province. The course was offered from March 21 to June 3, 2016. Data were collected using pre and post tests given before and after writing of reflective journals in blended learning. Data were analyzed using t-test, ANOVA, $Scheff{\acute{e}}^{\prime}s$ test and paired t-test with SPSS Statistics version 20.0. Results: The results of this study show that scores for meta-cognition and problem solving ability of these students were all above average. There was a statistically significant difference in meta-cognition between pre and post writing of reflective journals but not for problem-solving ability. Conclusion: The findings indicate that writing a reflective journal in blended learning is an efficient teaching-learning method to improve meta-cognition in nursing students.

• Korean Journal of Child Studies
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• v.33 no.6
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• pp.207-225
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• 2012

This study examined the meanings of reflective utterances fathers regarding their paternal role and the relationship of this to the process of a reflective parent education program for fathers whose children had been referred to psychotherapy. The subjects were 2 fathers aged in their late-thirties of 2 children with emotional behavioral problems. The father education program consisted of contents based on object relation theory. The reflective dialogues between fathers and the parent educator in the process of the program were analyzed. The meanings of the reflective utterances made by the fathers were indicated to be the understanding of the relationship between child's problematic behaviors and family dynamics, a reflection on their oppressive child rearing behaviors, the awareness of the necessity for emotional exchange with family members, the importance of cooperation between both the mother and father when it comes to child rearing, and the values at the heart of being together with children. The implications of the results were also discussed.

• Journal of the Korean Ceramic Society
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• v.32 no.1
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• pp.57-62
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• 1995

The coating condition of reproducible anti-reflective coating film and the light transmittance characteristics of the prepared anti-reflective coating glass were investigated as a study for the preparation of single-layer anti-reflective coating glasss. In case of coating with the sol in which the solvent was substituted with the ethanol with the addition of 0.1 mol HNO3, the coated glass showed the minimum value of the refractive index of 1.464, light transmittance of 94.2% at 550nm standard wavelength which is 3.2% higher than that of the parent glass, and the reflectance in the entire wave range of visible light. The refractive index represented its minimum at the sol concentration of 1.0 mol per 100mols of water and the higher the sol concentration, the higher the refractive index, resulting in the decrease of the light transmitance. The production condition of the reproducible anti-reflective coating on glass with the maximum transmittance of 94.2% was 4cm/min of withdrawal speed, 40$0^{\circ}C$ and 1 hour of heat treatment temperature and time, resulting in the film thickness of 94nm.

• Korean Medical Education Review
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• v.11 no.1
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• pp.11-20
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• 2009

The purpose of this study was to introduce the concepts of experiential learning and the Kolb's model, and to review some applications of experiential learning theory in graduate medical education. The published literature on GME and education for general practitioners applying the experiential theory and the Kolb's model was reviewed. Experience learning defined the cyclical learning process which emphasizes the learners' reflective thinking of the learners' concrete experiences and their active participation in continuous learning actives. Kolb includes this 'cycle of learning' as a central principle in his experiential learning theory. This is typically expressed as a four-stage cycle of learning. Kolb's cycle moves through concrete experience(CE), reflective observation(RO), abstract conceptualization(AC) and active experimentation(AE). Components of continuing education of the adult learner were based on autonomy, context of learning, and competence and performance as educational objectives. Some strategies for graduate medical education were reflective thinking, self-directed learning, morning reporting and feedback with peer review, etc. Opportunities for learning from experience in practical life can be made to enhance reflective thinking and performance of practitioners. Strategies to develop reflective practice among physicians should be explored by further research.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.5
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• pp.427-431
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• 2006

We have studied electro-optic characteristics of reflective $45^{\circ}$ twisted nematic liquid crystal display which implement the new LC orientation using of in-cell retarder film. For the embodiment of reflective liquid crystal display, essentially the optic compensation films was always needed and attached to the outside of glass substrate. In our study, these optic compensation film were not employed in reflective LC cell. On other hand we have employed the in-cell retarder to substitute the optic compensation film and were able to orient the LC molecules using this in-cell retarder. So we have developed the reflective LC cell that has good optical performances without any additional coating process on the in-cell retarder.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.292-298
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• 1997

These studies were conducted to verify the effect of the supplementary lighting by reflective film mulching and its establishment in the north side of greenhouse on the utility of light at tomato by means of investigating changes of leaf temperatures, stomatal features, transpiration rates and photosynthetic rates. Stomatal density of leaves were high in the reflective film mulching but sizes of stomata were not different. As the osmotic potential in rooting zone was low, the stomatal resistance was high, transpiration rate was low, and leaf temperature was increased by 40.62$^{\circ}C$. And also in the block of reflective film mulching photosynthetic rates were decreased hut chlorophyll contents were not different. Especially, there is an effect of controlling greenhouse whiteflies by treatment of reflective film mulching. It is thought that the reason of high quality or increasing yield at several crops by supplementary lighting, such as reflective film mulching, would be caused by influences of absorption and distribution of nutrients through high transpiration rate and photosynthesis which resulted from increase of stomata.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1109-1116
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• 2016

There are various test methods for evaluating the reflective cracking resistance of asphalt concrete pavement. Repeated direct tensile test is cheap and simple compared to the other traditional experimental methods. Determination of failure criteria is needed to apply a repeated direct tensile test. Various methods were used to determine the number of failure of repeated direct tensile test. The number of failure was defined as the time to reach 10% of the initial load, this method can be satisfied with specified tolerance of 10%. When the thickness of specimen is increased to 50 mm from 30 mm, the failure number is increased by 13.6 times. Thus, this result shows that the thickness of pavement is a big influence on the reflective cracking resistance. Reflective cracking resistance of asphalt concrete is decreased according to the increase in opening displacement. The repeated direct tensile test can be used as a reflective cracking resistance factor in pavement design, because it can evaluate the reflective cracking resistance according to the pavement thickness, opening displacement, material properties etc.

• Education of Primary School Mathematics
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• v.22 no.4
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• pp.281-294
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• 2019

The purpose of this study is to analyze errors and treatment behavior during the course of mathematics learning of academic achievement by applying reflective activities in the second semester of the third year of elementary school. The study participants are students from two classes, 21 from the third-grade S elementary school in Seoul and 20 from the comparative class. In the case of the experiment group, the multiplication unit was reconstructed into a mathematics class that applied reflective activities. They were pre-post-test to examine the changes in students' mathematics performance, and mathematical communication was recorded and analyzed for the focus group to analyze the patterns of learners' error handling in the reflective activities. In addition, they recorded and analyzed students' activities and conversations for error type and error handling. As a result of the study, the student's mathematics achievement was increased using reflective activities. When learning double digit multiplication, the error types varied. It was also confirmed that the reflective activities helped learners reflect on the multiplication algorithm and analyze the error-ridden calculations to reflect on and deal with their errors.