• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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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.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.57-63
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• 2016

The purpose of this study is to draw implications about a practice of university faculty member's teaching reflection by considering the concept, process, and content of reflection as a theoretical basis of teaching reflection. The concept of reflection is based upon 'reflection-in-action' suggested by $Sch{\ddot{o}}n$, and the process and content of reflection is explained through Korthagen's Core Reflection model. The following three implications conclude: First, a faculty member should write a reflection journal by observing and reflecting consistently one's own behavior in a context of teaching. Second, the center for teaching and learning should provide an orientation and consultation about the content and process of teaching reflection. Finally, sharing lessons with the colleague faculty member is required to make an effective reflection for each faculty member.

• Water Engineering Research
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• v.1 no.1
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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.

• Korean Journal of Computational Design and Engineering
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• v.2 no.3
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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.

• Journal of Korean Elementary Science Education
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• v.29 no.3
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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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• v.15 no.2
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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.

• Korean Medical Education Review
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• v.19 no.3
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.10 s.103
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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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.