• Title/Summary/Keyword: geometry changes

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Shadow and Highlight Invariant Color Models

  • Lee, Ja-Yong;Kang, Hoon
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.557-560
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    • 2005
  • The color of objects varies with changes in illuminant color and viewing conditions. As a consequence, color boundaries are influenced by a large variety of imaging variables such as shadows, highlights, illumination, and material changes. Therefore, invariant color models are useful for a large number of applications such as object recognitions, detections, and segmentations. In this paper, we propose invariant color models. These color models are independent of the object geometry, object pose, and illumination. From these color models, color invariant edges are derived. To show the validity of the proposed invariant color models, some examples are given.

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On Hilbert's 'Grundlagen der Geometrie' (힐베르트의 저서 '기하학의 기초'에 관하여)

  • Yang, Seong-Deog;Jo, Kyeong-Hee
    • Journal for History of Mathematics
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    • v.24 no.4
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    • pp.61-86
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    • 2011
  • In this article we introduce old and new references for 'Grundlagen der Geometrie' written by Hilbert and summarize its contents. We then compare the 1902 English translation of the first (German) edition and the 1971 English translation of the 10th (German) edition focusing on the changes of the contents, terminologies, expressions, etc. We then finally discuss about the implications of these changes in translating mathematics classics into modern Korean and in creating mathematics books in modern Korean.

Surface Quality Improvements on the Spherical Shaped Mold using Ball End Milling (볼 엔드밀을 이용한 금형 구면 가공의 표면품질 향상에 관한 연구)

  • Yun, Il-Woo;Hwang, Jong-Dae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.19 no.3
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    • pp.71-76
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    • 2020
  • Various machining methods are being studied to improve the processing quality of the spherical R shape in press die. In this paper, we confirmed that changes in machining quality were associated with changes in cutting direction, path, and cutting angle, which are commonly used in the machining of molds. We obtained a surface roughness graph with each condition change in one specimen using an instrument that measured geometry and surface roughness simultaneously. The results of the study showed that the best surface roughness in the finish cut of the spherical surface was obtained using upward pick feed machining.

Changes of Mathematical Knowledge and Mathematical Revolution (수학에서의 지식의 변화와 수학혁명)

  • Park, Chang-Kyun
    • Journal for History of Mathematics
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    • v.23 no.4
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    • pp.17-30
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    • 2010
  • The aim of this paper is to classify mathematical revolutions by discussing the concept of revolution, and to suggest criteria to judge mathematical revolutions. I examine the relation between the types and the criteria of mathematical revolutions, and explore what types of revolutions several instances of changes in mathematical knowledge are.

Appearance-based Robot Visual Servo via a Wavelet Neural Network

  • Zhao, Qingjie;Sun, Zengqi;Sun, Fuchun;Zhu, Jihong
    • International Journal of Control, Automation, and Systems
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    • v.6 no.4
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    • pp.607-612
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    • 2008
  • This paper proposes a robot visual servo approach based on image appearance and a wavelet function neural network. The inputs of the wavelet neural network are changes of image features or the elements of image appearance vector, and the outputs are changes of robot joint angles. Image appearance vector is calculated by using eigen subspace transform algorithm. The proposed approach does not need a priori knowledge of the robot kinematics, hand-eye geometry and camera models. The experiment results on a real robot system show that the proposed method is practical and simple.

Theoretical Study of the Relationships between Excited State Geometry Changes and Emission Energies of Oxyluciferin

  • Li, Zhong-Wei;Min, Chun-Gang;Ren, Ai-Min;Guo, Jing-Fu;Goddard, John D.;Feng, Ji-Kang;Zuo, Liang
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.895-900
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    • 2010
  • In order to find a relationship between firefly luciferases structure and bioluminescence spectra, we focus on excited substrate geometries which may be affected by rigid luciferases. Density functional theory (DFT) and time dependent DFT (TDDFT) were employed. Changes in only six bond lengths of the excited substrate are important in determining the emission spectra. Analysis of these bonds suggests the mechanism whereby luciferases restrict more or less the excited substrate geometries and to produce multicolor bioluminescence.

Shape Design of Initial Section for Non-circular Shaped Mold Spring (비원형 단면을 갖는 금형스프링의 단면설계)

  • Lee, Hyoungwook;Choi, Hwaryong
    • Journal of Institute of Convergence Technology
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    • v.1 no.1
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    • pp.24-28
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    • 2011
  • The purposes of this study are predictions of the changes in the section geometry and determination of the initial cross section so that opposite side in height direction is exactly parallel after coiling process. Finite element analysis is carried out for the calculation of the sectional changes for mold spring item. Analysis results reveal that the slope of the top and bottom sides varies in the range of 5 to 8 degrees and the amount depends on the dimension of the outer diameter. The slopes of the sides should be defined first among design variables.

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A Study on the Sensitivity Analysis of Submersibles' Manoeuvrability (수중운동체의 조종성능에 대한 민감도 해석법의 적용)

  • Yeo, Dong-Jin;Rhee, Key-Pyo
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.5 s.143
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    • pp.458-465
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    • 2005
  • Sensitivity Analysis(SA) is used to predict how the model response varies according to changes in the model parameters. With SA, confidences in models which are developed to approximate certain processes and their predictions can be increased. The influences of hydrodynamic coefficients on the prediction of manoeuvrability are examined by SA of direct method. The equations of motion used are the standard equations of motion for submarine(Gertler 1967), and submerged bodies with three different appendages are considered. Through numerical simulations of three kinds of sea trials, the sensitivities of motions to hydrodynamic coefficients are found. Changes of sensitivities during trials are found to be highly dependent on the actuator scenarios and geometry of submerged body.

A Study on Free-form Design Shape Creation through Geometric Transformation of Digital Design Tool (디지털디자인도구의 Geometry 변형을 통한 비정형 디자인 형태 생성 방법에 관한 연구)

  • Park, Sang-Jun
    • The Journal of the Korea Contents Association
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    • v.16 no.5
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    • pp.306-317
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    • 2016
  • Both the formal type of architecture and free-form architecture have basic factors and methods for basic expression. Because the use of digital design tools for creation of free-form design mostly depends on the character and ability of designer, this study aims to propose establishment of free-form design creation method as a prototype, including the method to create free-form design, through setting up rules that can be used in common. This study is carried out on the basis of the application of digital design tools used for creation of conceptual free-form styles at the phase of conceptualization and development, which is different from the general theory of free-from design. The free-from style in the modern architecture has begun with the changes in digital design tools and design concepts. In the case study based on the free-form designs in precedent studies, the morphological characteristics have been analyzed and interpreted by using the language of digital design tools, so that this study will suggest the techniques to realize the free-form style on the basis of geometric transformation by using the digital design tools, as well.

An Exploration of Justification Types represented in the Geometry field of Middle School Mathematics Textbook (중학교 수학 교과서 분석을 통한 정당화 방안 탐색)

  • Lee, Hwan-Chul;Ha, Young-Hwa
    • Journal of the Korean School Mathematics Society
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    • v.14 no.3
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    • pp.325-337
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    • 2011
  • There have been several studies regarding strict and formal proof in the field of geometry in middle school curriculum, and the level of proof has been gradually lowered along with the changes in the curriculum. In the 2011 Revised Middle School Math Curriculum, there have been efforts to eliminate the term 'proof' and instead to replace it with the new one, 'justification'. Therefore, this study intends to present specific and practical examples of justification by analyzing the current math textbook especially in the field of geometry. As a result, it identified that strict and practical proof has been sharply increased in the second year of middle school. It also witnessed the possibility of justification from the various examples presented in the first, second, and the third year of the middle school math textbook.

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