• Title/Summary/Keyword: Geometric quality

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Target Identification using the Mahalanobis Distance and Geometric Parameters (마할라노비스 거리와 기하학적 파라메터에 의한 표적의 인식)

  • 이준웅;권인소
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.7
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    • pp.814-820
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    • 1999
  • We propose a target identification algorithm for visual tracking. Target identification is realized by finding out corresponding line segments to the hypothesized model segments of the target. The key idea is the combination of the Mahalanobis distance with the geometrical relationship between model segments and extracted line segments.

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The Optimized Design Method of Vehicle for Weight-Reduction (무게절감을 위한 차량 최적 설계 기법)

  • Lee, Jeong-Ick
    • Korean Journal of Computational Design and Engineering
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    • v.12 no.5
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    • pp.376-381
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    • 2007
  • The geometric configuration in the weight-reduced structure is very required to be started from the conceptual design with low cost, high performance and quality. In this point, a structural-topological shape concerned with conceptual design of structure is important. The method used in this paper combines three optimization techniques, where the shape and physical dimensions of the structure and material distribution are hierachically optimized, with the maximum rigidity of structure and lightweight.

Optimal Strategies for Robust Design of Products of Processes

  • Hwang, Inkeuk;Park, Kongjin
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.23 no.56
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    • pp.55-64
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    • 2000
  • There is more than a single quality characteristic and they are often of varying or mixed target types. The purpose of this paper is to develop general strategies for solving the multiple response robust design problem. The desirability function provides an important tool to solve problems that have different types of target since the desirability values all the range between zero and one. Several combinations of arithmetic averages, geometric averages, and standard deviations are used in the various strategies to find the best design point.

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An analysis of elementary students' reasoning on the sum of triangle angles ('삼각형 세 각의 크기의 합'에 관한 초등학생의 추론 연구)

  • Kim, Ji Hyun
    • Education of Primary School Mathematics
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    • v.27 no.2
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    • pp.155-171
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    • 2024
  • This study compared and analyzed students' reasoning processes and justification methods when introducing the concept of "the sum of angles in a triangle" in mathematics classes with a focus on both measurement and geometric aspects. To confirm this, the research was conducted in a 4th-grade class at H Elementary School in Suwon, Gyeonggi-do, South Korea. The conclusions drawn from this study are as follows. First, there is a significant difference when introducing "the sum of angles in a triangle" in mathematics classes from a measurement perspective compared to a geometric perspective. Second, justifying the statement "the sum of angles in a triangle is 180°" is more effective when explained through a measurement approach, such as "adding the sizes of the three angles gives 180°," rather than a geometric approach, such as "the sum of the angles forms a straight angle." Since elementary students understand mathematical knowledge through manipulative activities, the level of activity is connected to the quality of mathematics learning. Research on this reasoning process will serve as foundational material for approaching the concept of "the sum of angles in a triangle" within the "Geometry and Measurement" domain of the Revised 2022 curriculum.

Deterministic Water Quality Analysis in the Midstream of the Nakdong River (낙동강 중류부에서의 확정론적 수질해석)

  • 한건연;이정식
    • Water for future
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    • v.27 no.1
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    • pp.53-67
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    • 1994
  • Water quality analysis in the midstream of the Nakdong river is studied. Deterministic model RQ1 which contains two code, RQ1-1 for hydrologic and hydraulic analysis and RQ1-2 for water quality analysis are developed. Monthly mean and minimum discharges in the basin (from Waegwan to Jindong) are estimated. A varied flow analysis is performed based on the geometric data of channel and RQ-1 model. The maximum concentration of BOD and minimum concentration of DO are occurred at the confluence of Keumho river and immediately downstream of Hyunpoong, respectively. The computed concentrations of BOD at several points have good agreements with observed data. Maximum allowable BOD loads from the Keumho River are provided to attain the goal of water quality in the basin.

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Design Optimization of Roller Straightening Process for Steel Cord using Response Surface Methodology (반응표면법을 이용한 스틸코드의 롤러교정기 설계 최적화)

  • Lee, Jong-Sup;Huh, Hoon;Lee, Jun-Wu;Bae, Jong-Gu;Kim, Deuk-Tae
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.10a
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    • pp.238-241
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    • 2007
  • A roller straightening process is a metal forming technique to improve the geometric quality of products such as straightness and flatness. The geometrical quality can be enhanced by eliminating unnecessary deformations produced during upstream manufacturing processes and minimizing any detrimental internal stress during the roller straightening process. The quality of steel cords can be achieved by the roller straightening depends the process parameters. Such process parameters are the roll intermesh, the roll pitch, the diameter of rolls, the number of rolls and the applied tension. This paper is concerned with the design optimization of the roller straightening process for steel cords with the aid of elasto-plastic finite element analysis. Effects of the process parameters on the straightness of the steel cord are investigated by the finite element analysis. Based on the analysis results, the optimization of the roller straightening process is performed by the response surface method. The roller straightening process using optimum design parameters is carried out in order to confirm the quality of the final products.

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Accuracy Assessment of Topographic Volume Estimation Using Kompsat-3 and 3-A Stereo Data

  • Oh, Jae-Hong;Lee, Chang-No
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.4
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    • pp.261-268
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    • 2017
  • The topographic volume estimation is carried out for the earth work of a construction site and quarry excavation monitoring. The topographic surveying using instruments such as engineering levels, total stations, and GNSS (Global Navigation Satellite Systems) receivers have traditionally been used and the photogrammetric approach using drone systems has recently been introduced. However, these methods cannot be adopted for inaccessible areas where high resolution satellite images can be an alternative. We carried out experiments using Kompsat-3/3A data to estimate topographic volume for a quarry and checked the accuracy. We generated DEMs (Digital Elevation Model) using newly acquired Kompsat-3/3A data and checked the accuracy of the topographic volume estimation by comparing them to a reference DEM generated by timely operating a drone system. The experimental results showed that geometric differences between stereo images significantly lower the quality of the volume estimation. The tested Kompsat-3 data showed one meter level of elevation accuracy with the volume estimation error less than 1% while the tested Kompsat-3A data showed lower results because of the large geometric difference.

Interactive 3D Stereoscopic Image Editing System using Image-based modeling (영상 기반 모델링 기법을 이용한 대화식 3차원 입체 영상 저작 시스템)

  • Yun, Chang-Ok;Yun, Tae-Soo;Lee, Dong-Hoon
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.10 no.2
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    • pp.53-66
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    • 2006
  • Recent technique has shown high interest in 3D stereoscopic image, one out of high immersion appearance techniques. Unlike general 2D image, 3D stereoscopic image is generated by 3D geometric information. Therefore, the lack of 3D geometric information sometimes imposes restrictions or makes editing more tedious. We propose a new unsupervised technique aimed to generate stereoscopic image which is estimated by depth-map information using image-based modeling from a single input image. The proposed system is implemented as the Adobe Photoshop(R) plug-in for considering generality and expandability, and also supports a preview function of interactive 3D stereoscopic image to determine stereoscopic view of high quality.

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The Strength Analysis of Passenger Car Seat Frame (승용차 시트프레임의 강도해석)

  • 임종명;장인식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.6
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    • pp.205-212
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    • 2003
  • This paper may provide a basic design data for the safer car seat mechanism and the quality of the material used by finding out the passenger's dynamic behavior when protected by seat belt during collision. A computer simulation with finite element method is used to accomplish this objective. At first, a detailed geometric model of the seat is constructed using CAD program. The formation of a finite element from a geometric data of the seat is carried out using Hyper-Mesh that is the commercial software for mesh generation and post processing. In addition to seat modeling, the finite element model of seat belt and dummy is formed using the same software. Rear impact analysis is accomplished using Pam-Crash with crash pulse. The part of the recliner and right frame is under big stress in rear crash analysis because the acceleration force is exerted on the back of the seat by dummy. The stress condition of the part of the bracket is checked as well because it is considered as an important variable on the seat design. Front impact model which including dummy and seal belt is analyzed. A Part of anchor buckle of seat frame has high stress distribution because of retraction force due to forward motion of dummy at the moment of collision. On the basis of the analysis result, remodeling and reanalysis works had been repeatedly done until a satisfactory result is obtained.