• Title/Summary/Keyword: reflection mapping

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Efficient generation of reflection lines to evaluate car body surfaces (자동차 외형설계곡면의 검사를 위한 효율적인 반사선의 생성)

  • 최인진;이건우
    • 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.

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Efficient Algorithm for the Real-time Generation of Reflection Lines (자동차 스타일링을 위한 반사선의 실시간 생성 및 표현 알고리듬)

  • Gang, Ju-Yeop;Lee, Geon-U
    • 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.

A Bump Mapping Method Using Camera Lens (카메라 렌즈를 이용한 범프 맵핑)

  • Koh, Wook
    • Journal of the Korea Computer Graphics Society
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    • v.3 no.1
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    • pp.9-15
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    • 1997
  • Most rendering research has concentrated on two sub-problems: modeling the reflection of light sources, and calculating the direct and indirect illumination from light sources and other surfaces. As Kolb wrote in [1], the camera and lens model is an important key component of a rendering system. In this paper we describe a bump-mapping method using camera lens. It allows another level of control in rendering. We developed an efficient framework to develop customized bump mapping lens and combine with other sequence of lens elements to create various effects as shown in Figure 2,3,4,5.

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A reconstruction of the G$\ddot{o}$del's proof of the consistency of GCH and AC with the axioms of Zermelo-Fraenkel set theory

  • Choi, Chang-Soon
    • Journal for History of Mathematics
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    • v.24 no.3
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    • pp.59-76
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    • 2011
  • Starting from a collection V as a model which satisfies the axioms of NBG, we call the elements of V as sets and the subcollections of V as classes. We reconstruct the G$\ddot{o}$del's proof of the consistency of GCH and AC with the axioms of Zermelo-Fraenkel set theory by using Mostowski-Shepherdson mapping theorem, reflection principles in Tarski-Vaught theorem and Montague-Levy theorem and the fact that NBG is a conservative extension of ZF.

Efficient Algorithm for Real-time Generation of Reflection Lines

  • Kim, Tae-wan;Juyup Kang;Lee, Kunwoo;Park, Sangkun
    • 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.

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A Study on the Integrated Seismic Reflection and Refraction for Shallow Marine Site Survey KSEG.KGS Joint Symposium (천해저 조사를 위한 탄성파 반사법 및 굴절법 통합연구)

  • Kim, Chan-Su;Lee, Sang-Chul;Shin, Sung-Ryul;Kim, Hyun-Do;Jo, Chul-Hyun
    • 한국지구물리탐사학회:학술대회논문집
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    • 2007.06a
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    • pp.349-352
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    • 2007
  • Estimating the physical properties of the survey area and mapping the geotechnical basement play an important role in ocean engineering and construction field. In this study, we performed marine seismic reflection and refraction survey as an engineering application at shallow marine. We made use of the dual boomer - single channel streamer as a source-receiver in reflection seismic survey and air-gun source - the manufactured OBC(Ocean Bottom Cable)-type streamer in refraction survey. In the seismic reflection data, we could easily find the geological layers and basement. Moreover, seismic refraction data could present sediment thickness and velocity distribution.

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Mapping of the lost riprap in shallow marine sediments using SBP (SBP를 이용한 해저 천부에 유실된 사석의 조사)

  • Shin, Sung-Ryul;Kim, Chan-Su;Yeo, Eun-Min;Kim, Young-Jun;Ha, Hee-Sang
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.11a
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    • pp.220-221
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    • 2005
  • Sub-bottom profiler(SBP) has been used extensively for the mapping of basement in the foundation design of offshore structure, for pre- and post-dredging operations within harbors and channels, for selection of pipeline routes, sitting of drilling platforms, and in the exploration for an aggregates such as sands and gravels. During the construction of Siwha embankment for irrigation water and the expansion of arable land, the breaking of an embankment unfortunately occurred so that a lot of riprap was swept away and widely dispersed by the tide and strong current. The feasibility study for the construction of the tidal-powered electric plant in Siwha embankment was performed quite recently. Therefore we made use of SBP survey to investigate the distribution of the lost riprap. We could successfully map out the distribution of the lost riprap from the reflection amplitude characteristics of the sediments in SBP data set. We demonstrated the variation of reflection amplitude versus the sediments with and/or without riprap by means of the numerical modeling of acoustic wave equation using finite difference method. Also we examined an amplitude anomaly of the ripraped area through the physical modeling using ultrasonic.

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The Computing System for Location Movement by a Pupil Reaction (동공의 움직임에 의한 커서 위치 이동 컴퓨팅 시스템 구현)

  • Kim, Min-Ki;Lim, Jae-Hoon;Park, Gwi-Tae
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.273-275
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    • 2009
  • The currently used methods to get this information include corneal reflection, electro-oculograph, and so on. In this paper, we propose an algorithm that is developed for the reflection of pupil by infrared. I assume that the pupil is a perfect circle in the captured eye images. The method to recognize an existing image has many data throughput very much. And the time to deal with an image data is very long. So, we did not use the camera. However we studied the algorithm to pursue the pupil to a mapping technique.

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High Performance Reflection Effect Processing for Moving Pictures in 3 Dimensional Graphics (3차원 그래픽스의 동영상에 대한 반사 효과의 고속처리)

  • Lee, Seung-Hee;Lee, Keon-Myung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.3
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    • pp.444-449
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    • 2009
  • With the advance of high performance computing hardware, many applications have been emerging which exploit real-time computer graphics capabilities. This paper is concerned with an effective realization method for reflection effect for the situations in which moving pictures are played in 3D computer graphics modeling world. The method determines in an geometric way the locations of the projection plan into which the playing areas of moving pictures are mapped, and then realizes the reflection effect with texture mapping. Compared with the traditional stencil buffer-based reflection method, the processing time of the proposed method does not significantly deteriorate for the models with moving pictures and reflection surfaces, and its throughput was improved by 30% at minimum and 127% at maximum for the models used in the comparative studies.

Geological Mapping using SWIR and VNIR Bands of ASTER Image Data

  • Shanmugam, Sanjeevi;Singaravelu, Jayaseelan
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1230-1232
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    • 2003
  • This study aims to extract maximum geological information using the ASTER (Advanced Spaceborne Thermal Emission and Reflection radiometer) images of a part of south India. The area chosen for this study is characterized by rock types such as Migmatite, Magnetite Quartzite, Charnockite, Granite, dykes, Granitoid gneiss and Ultramafic rocks, and minerals such as Bauxite, Magnesite, Iron ores, Calcite etc. Advantage was taken of the characteristic reflectance and absorption phenomenon in the VNIR, SWIR and TIR bands for these rocks and minerals, and they were mapped in detail. Image processing methods such as contrast stretching, PC analysis, band ratios and fusion were used in this study. The results of the processing matched with the field details and showed additional details, thus demonstrating the usefulness of ASTER (especially the SWIR bands) data for better geological mapping.

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