• 한국태양에너지학회 논문집
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• 제31권2호
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• pp.53-62
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• 2011

Heliostat in the tower type solar thermal power plant is a sun tracking mirror system to reflect the solar energy to the receiver and the optical performance of it affects to the efficiency of whole power plant most significantly. Thus a proper design of structure of the heliostat reflective surface could be the most important step in the construction of such power plant. The work presented here is a design of structure of optical surface of heliostat, which will be used in 200kW solar thermal power plant. The receiver located at 43(m) high from ground in tower has $2{\times}2$(m) rectangular shape. We first developed the software tool to simulate the energy concentration characteristics of heliostat using the ray tracing technique. Then, the shape of heliostat reflective surface is designed with the consideration of heliostat's energy concentration characteristics, production cost and productivity. The designed heliostat's reflective surface has a structure formed by canting four of $1{\times}1$(m) rectangular flat plate mirror facet and the center of each mirror facet is located on the spherical surface, where the spherical surface is formulated by the mirror facet mounting frame.

• 한국보육지원학회지
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• 제17권2호
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• pp.89-101
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• 2021

Objective: The purpose of this study is to verify the effect of directors' coaching leadership on teachers' play implementation competencies and the mediation effects of teachers' reflective thinking and creative job performance by conducting a structural relationship analysis. Methods: The subjects of this study were child care teachers who were purposefully sampled from the metropolitan area which includes Seoul, Incheon, and Gyeonggi Province. A total of 267 questionnaires were analyzed after excluding poor or incomplete questionnaires by use of SPSS Statistics 25.0 and the AMOS 21.0. Results: Directors' coaching leadership was positively correlated with teachers' reflective thinking, creative job performance, and their play implementation competencies. Directors' coaching leaderships directly and indirectly influenced teachers' play implementation competencies, which was mediated by teachers' reflective thinking and their creative job performance. Conclusion/Implications: Directors' coaching leadership has a significant implication for teachers' play implementation competencies which became more important after the national curriculum standards had been revised.

• International journal of advanced smart convergence
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• 제11권2호
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• pp.194-204
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• 2022

This study is a one-group pretest-posttest design to evaluate the effect of problem-based learning (PBL) for patient safety on self-leadership, patient safety competencies, and reflective thinking of nursing students. The research was conducted from March 2 to April 15, 2022, in which 57 nursing students participated. PBL for patient safety was examined in a total of 8 sessions in the order of motivation, problem identification, task performance planning, problem-solving methods, summary and solution, presentation, and evaluation. The following topics of patient safety were selected for each team: nursing records, high-alert medication, medication error and intravenous fluid regulation, blood transfusion care, fall, bedsore, infection control, and pain management. We provided feedback on the learning process and outcomes of nursing students. According to the results, self-leadership showed a statistically significant improvement in self-expectations (t=2.60, p=0.01), goal setting (t=2.84, p<0.01), self-reward (t=3.32, p<0.01), and self-criticism (t=2.32, p=0.02). Patient safety competencies showed a statistically significant improvement in patient safety knowledge (t=13.05, p<0.001) and patient safety skills (t=4.87, p<0.001) but not in reflective thinking. The results prove that PBL for patient safety is an effective teaching-learning strategy to improve self-leadership and patient safety competencies. Future studies must develop and validate specific and long-term teaching-learning methods to improve reflective thinking.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.292-294
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• 2008

We have developed new reflective LCD for Mixed twist nematic LC mode with high quality image. We have found out an optimal twist angle of LC and optical film's axis by simulation. Also we measured electro-optic characteristics for new design panel. As a result, high reflectance and wide viewing angle characteristics were achieved.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.94.1-94
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• 2002

This paper is concerned with parallel FFT and Quick-Merge Sort. They are implemented on computers interconnected by VMIC 5579 reflective memory and a cluster of workstations (PCs) interconnected via Fast Ethernet. Message passing interface (MPI) parallel library is used for communication in a cluster of workstations. An improved parallel FFT is also presented to decrease an execution time in the case of a small number of hosts. Distributed shared memory (DSM), VMIC 5579 reflective memory (RM), a cluster of workstations (COW) and message passing interface (MPI) parallel library are described.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.730-734
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• 2003

A beamforming method is a kind of spatial filter that focus the amy's signal capturing abilities in a desired direction. In this paper, we detect the location of a source under reflective condition using the multi-dimensional MUSIC algorithm then, we can iud the image source locations from the experimental geometry, and we reconstruct the partial fields for direct wave and reflected wave by using Adaptive nulling algorithm. Numerical simulations are performed to verify its performance under various conditions.

• 한국수학교육학회지시리즈A:수학교육
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• 제47권2호
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• pp.221-224
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• 2008

The article shows that the concept 'weight' and the concept 'heaviness' give rise to different abstractions in the sense of Piaget and that these two concepts are differentiated by set-theoretic devices. The failure of differentiation of these two concepts 'weight' and the 'heaviness' can cause the failure of learning of the difference between reflective abstraction and empirical reflective abstraction. To explain the Piagetian abstrcation in a classroom, the author suggests to use the concept 'color' instead of the concept 'weigtht'.

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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• pp.127-134
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• 2001

With the increasing demands for hand-held devices with lightweight and low-power-consumption displays, the role of reflective liquid crystal displays (LCDs) is becoming more and more important. Especially, the single polarizer mode is considered as a suitable structure for reflective LCDs because it can provide high brightness. However, the single-polarizer LCDs have demerit in that the contrast is lower than double-polarizer LCDs because of the light leakage in thedark state. (omitted)

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.101-104
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• 2007

We propose a novel optical configuration for transmissive and reflective mode in the IPS LC cell to improve the viewing angle characteristics in a diagonal direction. The optical design was performed on a Poincar$\dot{e}$ sphere. From the calculation, we confirmed that the proposed configuration provides excellent viewing angle characteristics.

• 아동학회지
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• 제26권5호
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• pp.331-350
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• 2005

The study examined the effects of an intervention program based on reflective thinking on mother-child interaction behaviors. Three mothers with problematic mother-child interactions and their 4-year-old socially delayed boys participated in the program that consisted of four main activities like journal and video feedback, lectures on interactive strategies, mother-child interactive play and program evaluations and ran for twenty 120 minutes weekly sessions. The level of reflective thought was determined by analyzing interview transcripts, journal entries. The videotaped mother-child interaction behaviors were rated by the Maternal Behavior Rating Scale and Child Behavior Rating Scale. It was concluded that the program enhanced mother's reflection on mother-child interactions and changed interaction behaviors of 3 mother-child pairs positively.