• 대한기계학회논문집A
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• 제24권1호
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• pp.173-181
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• 2000

Depending upon the method of the surface generation and the quality of the boundary curves provided, the resulting surfaces may have global or local irregularities in many cases. Thus it would be necessary for the designer to evaluate the surface quality and to modify the surface. This capability is very important because the defect of the surface requires the rework of the dies that causes a big loss in cost and delivery time. To simulate the reflection line test in the actual production line, a faster generation algorithm is presented. Among., various surface interrogation methods using reflection lines, Blinn-Newell type of reflection mapping is applied to generate reflection lines on the trimmed NURBS surface. The generation of reflection lines is formulated as a surface-plane intersection problem, and solved by surface-contouring techniques. In addition, a modified reflection map is proposed to eliminate the discontinuity of reflection lines due to the configuration of the reflection map. A fast reflection line algorithm is developed utilizing an efficient traced contouring technique, and proved to be well suited for real-time quality-assessment task.

• 디지털융복합연구
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• 제14권2호
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• pp.57-63
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• 2016

교수전문성 개발에 있어서 수업성찰이 중요함에도 불구하고 이에 대한 본격적인 연구가 없었다. 본 연구의 목적은 수업성찰의 이론적 토대가 되는 성찰의 개념, 절차 및 내용을 고찰하여 대학교수의 수업성찰 실천에 관한 시사점을 도출하는 것이다. 성찰의 개념은 $Sch{\ddot{o}}n$이 제시한 '행동 중 성찰'이며, 성찰의 절차와 내용은 Korthagen의 Core Reflection 모형을 통해 설명될 수 있다. Core Reflection 모형은 교수의 수행행동에 영향을 미치는 내면적 요인과 외현적 요인을 통합하도록 지원하며 교사 개인의 강점을 발전시키는 모형이다. 대학교수의 수업성찰 실천에 관한 시사점으로 첫째, 교수 개인은 수업 상황에서 지속적으로 자신의 행동을 관찰하고 성찰하면서 수업성찰 저널을 작성해야 한다. 둘째, 교수학습개발센타에서는 수업성찰의 내용과 절차에 관한 오리엔테이션 교육과 컨설팅을 제공해야 한다. 마지막으로 교수 개인의 성찰이 효과적이기 위해서 동료교수와의 수업나눔이 필요하다.

• Water Engineering Research
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• 제1권1호
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• pp.75-81
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• 2000

The bragg reflection of obliquely incident monochromatic water waves propagating over a sinusoidally varying topography is theoretically investigated in this study. The eigenfunction expansion method is first employed to calculate reflection coefficients of water waves due to depth changes. A reasonable agreement is observed. Obtained reflection coefficients of normally incident waves are compared with laboratory measurements. Reflection coefficients of obliquely incident waves are then calculated. The wavenumber providing the Bragg reflection agrees well with analytical predictions.

• 한국CDE학회논문집
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• 제2권3호
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• pp.133-141
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• 1997

In the process of car body design, various surfaces are generated from the given boundary curves. Depending upon the method of the surface generation and the quality of the boundary curves provided, the resulting surfaces may have global or local irregularities in many cases. Thus it would be necessary for the designer to evaluate the surface quality and to modify the surface or to use the different generation method based on the evaluation results. This capability is very important because the defect of the surface quality detected in the production stage will require the rework of the dies and will cause a big loss in cost and time. A method of surface interrogation using reflection line is introduced. In this paper, We applied reflection mapping to generate reflection lines on the trimmed NURBS surface. Since reflection lines are obtained from reflection mapping that uses simple and physically acceptable mapping algorithm, they can be efficiently used to simulate the reflection test on the real part in the production line.

• 한국초등과학교육학회지:초등과학교육
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• 제29권3호
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• pp.378-388
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• 2010

This study aimed at categorizing preservice teachers' reflections and understanding their characteristics in reflective journal writing after microteaching. Thirty-two preservice elementary teachers joined in this study. As results, three patterns were categorized: Reflection with practice, Reflection to be practice, Reflection with suspension of judgment. 'Reflection with practice' changed the topology of science class in active. 'Reflection to be practice' had clear focus in reflection and suggested orientations to succeed in the next teaching. 'Reflection with suspension of judgment' made something fall into abeyance, because it couldn't provide an orientation for teaching. After discussing these results, implications toward preservice teacher education were explored.

• Journal of Mechanical Science and Technology
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• 제15권2호
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• pp.160-171
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• 2001

Depending upon the method of the surface generation and the quality of the designed boundary curves, the resulting surfaces may have global or local irregularities in many cases. Thus, it would be necessary for the designer to evaluate the surface quality and to modify the surface. This is very important because the defect of the surface causes the rework of the dies, increasing cost and delivery time significantly. To simulate the reflection line test in the actual production line, a faster algorithm for generating reflection lines is presented. In this paper, among various surface interrogation methods using reflection lines, Blinn-Newell type of reflection mapping is applied to generate the reflection lines on the trimmed NURBS surfaces. The derivation of reflection lines is formulated as a surface-plane intersection problem (Jung 1994) and is solved by surface-contouring techniques. Also, for eliminating the discontinuity of reflection lines due to the configuration of reflection map, a modified reflection map is proposed. An efficient traced contouring technique is utilized for the computational efficiency and proves to be well suited for the real-time quality-assessment task.

• 의학교육논단
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• 제19권3호
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• pp.169-174
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• 2017

This study explores the phenomenon of learner reflection in writing. Sixty-nine reflection logs were submitted by students after medical interview role plays. Using thematic analysis methodology, the following three steps were carried out: (1) the entire contents of the logs were analyzed and coded, (2) the coded contents were reclassified and categorized into higher themes, and (3) all reflection logs were re-analyzed to derive the frequency according to their classifications. The learners' reflection contents were classified into 'preparation,' 'experience,' and 'future plan.' The levels of reflection were 'simple information and appreciation,' 'acquisition and application of knowledge,' and 'analysis and criticism.' The types of reflection were identified only at the level of 'analysis and criticism' and could be classified into 'relativization,' 'objectification,' and 'internalization.' Students' reflection levels were highest in the levels of 'acquisition and application of knowledge' (49.3%), and 'analysis and criticism' (37.7%). A total of 14.5% of the students showed 'internalization.' In order to enable internalized reflection at a critical level, instructional strategies to induce and promote reflection are needed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.855-860
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• 2005

For the accurate measurement of acoustic properties of a surface, efforts have been made to reduce errors caused by external disturbance. If the reflection coefficient is considered as a transfer function between reflected wave and incident wave, causality is required between them and the reflection coefficient should be of minimum phase. In this thesis, the minimum phase condition is applied to measure correct reflection coefficient. The reflection coefficient is approximated as a rational function in the Z domain by minimizing the sum square error. Then the minimum phase reflection coefficient is reconstructed using the distribution of poles and zeros of the reflection coefficient model. The incident wave, the reflected wave and the impulse response function of causality are recalculated from the minimum phase reflection coefficient for further applications.

• 한국소음진동공학회논문집
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• 제15권10호
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• pp.1131-1136
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• 2005

For the accurate measurement of acoustic properties of a surface, efforts have been made to reduce errors caused by external disturbance. If the reflection coefficient is considered as a transfer function between reflected wane and incident wave, the causality is required between them and the reflection coefficient should be of minimum phase. In this thesis, the minimum phase condition is applied to measure correct reflection coefficient. The reflection coefficient is approximated as a rational function In the Z domain by minimizing the sum square error. Then the minimum phase reflection coefficient is reconstructed using the distribution of poles and zeros of the reflection coefficient model.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.618-621
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• 2014

This research is to review the possibility of reducing the noise radiated from the tube exit by controling the sound reflection coefficient at the inclined exit. The sound reflection coefficient at the inclined exit of flanged tube was measured by both transfer function method and standing wave ratio method. Accuracy on the sound reflection coefficient measured by transfer function method was verified through comparison with sound reflection coefficient measured by standing ratio method. The flanged tube had lower sound reflection coefficient than the tube which have no flange. Also the sound reflection coefficient was decreased in accordance with increasing the inclined angle of unflanged tube.