• Title/Summary/Keyword: spatial moment

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Tracking of eyes based on the iterated spatial moment using weighted gray level (명암 가중치를 이용한 반복 수렴 공간 모멘트기반 눈동자의 시선 추적)

  • Choi, Woo-Sung;Lee, Kyu-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.5
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    • pp.1240-1250
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    • 2010
  • In this paper, an eye tracking method is presented by using on iterated spatial moment adapting weighted gray level that can accurately detect and track user's eyes under the complicated background. The region of face is detected by using Haar-like feature before extracting region of eyes to minimize an region of interest from the input picture of CCD camera. And the region of eyes is detected by using eigeneye based on the eigenface of Principal component analysis. Also, feature points of eyes are detected from darkest part in the region of eyes. The tracking of eyes is achieved correctly by using iterated spatial moment adapting weighted gray level.

Tracking of eyes based on the spatial moment using weighted gray level (명암 가중치를 이용한 공간 모멘트기반 눈동자 추적)

  • Choi, Woo-Sung;Lee, Kyu-Won;Kim, Kwan-Seop
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.198-201
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    • 2009
  • In this paper, an eye tracking method is presented by using on iterated spatial moment adapting weighted gray level that can accurately detect and track user's eyes under the complicated background. The region of face is detected by using Haar-like feature before extracting region of eyes to minimize an region of interest from the input picture of CCD camera. And the region of eyes is detected by using eigeneye based on the eigenface of Principal component analysis. And then feature points of eyes are detected from darkest part in the region of eyes. The tracking of eyes is achieved correctly by using iterated spatial moment adapting weighted gray level.

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Investigation and Numerical Analysis of Node Connectors in Free-Form Spatial Structures

  • Hwang, Kyung-Ju;Park, Don-U;Park, Sun-Woo;Knippers, Jan
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.3 s.25
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    • pp.87-95
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    • 2007
  • The recent completions of free-form spatial structures provide us a very attractive form. To realize such an extraordinary shape, it is absolutely necessary that the connector systems have to be investigated the characteristics of the systems and analyzed with a practicable method. In this context, this research consists of not only literature research but also numerical analysis with selected connector systems, which was adopted in real free-form spatial structures. For numerical analysis, especially, finite element analysis (FEA) is performed with a various test parameter using a commercial program ANSYS. Consequently, the general characteristics of node connectors the moment-rotation-curves are presented by considering a large deformation effect as well as a multi-linear material properties.

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FREE SURFACE FLOW COMPUTATION USING MOMENT-OF-FLUID AND STABILIZED FINITE ELEMENT METHOD (Moment-Of-Fluid (MOF) 방법과 Stabilized Finite Element 방법을 이용한 자유표면유동계산)

  • Ahn, H.T.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.228-230
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    • 2009
  • The moment-of-fluid (MOF) method is a new volume-tracking method that accurately treats evolving material interfaces. Based on the moment data (volume and centroid) for each material, the material interfaces are reconstructed with second-order spatial accuracy in a strictly conservative manner. The MOF method is coupled with a stabilized finite element incompressible Navier-Stokes solver for two fluids, namely water and air. The effectiveness of the MOF method is demonstrated with a free-surface dam-break problem.

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Motion Error Analysis of the Porous Air Bearing Stages Using the Transfer Function (전달함수를 이용한 다공질 공기베어링 스테이지의 운동오차해석)

  • 박천홍;이후상
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.7
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    • pp.185-194
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    • 2004
  • In order to analyze the motion errors of the aerostatic stage, it is necessary to consider the influence of the moment variation occurred inside the pads. In this paper, a motion error analysis method utilizing the transfer functions on the reaction force and moment is proposed, and general characteristics of the transfer functions are discussed. Calculated motion errors by the proposed method show good agreement with the ones calculated by Multi fad Method, which is considered the entire table as an analysis object. Also, by the introduction of the transfer function of motion errors, which represent the relationship between the spatial frequency components of the rail form error and motion errors, motional characteristics of the porous aerostatic stage can be generalized. In detail, the influence of the spatial frequencies is analyzed qualitatively, and the patterns of the insensitive frequencies which almost do not affect the linear motion error or angular motion error according to the rail length ratio and the number of the pad are verified. The relationship between the moment variation occurred inside the pads and the motion errors is also verified together.

Seismic Performance and Design Process of a Ceiling Bracket-Typed Modular Connection (천장 브래킷형 모듈러 시스템의 접합부 내진 성능과 설계 프로세스)

  • Lee, Seungjae;Kang, Changhoon;Park, Jaeseong;Kwak, Euishin;Shon, Sudeok
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.3
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    • pp.27-34
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    • 2020
  • This paper examines the seismic performance and structural design of the ceiling bracket-type modular connection. The bracket-type system reduces the cross-sectional area loss of members and combines units using fitting steel plate, and it has been developed to be fit for medium-story and higher-story buildings. In particular, this study conducted the cyclic loading test for the performance of the C-type and L-type brackets, and compared the results. The test results were also compared with the commercial FEA program. In addition, the structural design process for the bracket-type modular connection was presented. The two connections, proposed as a result of the test results, were all found to secure the seismic performance level of the special moment steel frame. In the case of initial stiffness, the L-type bracket connection was found to be great, but in the case of the maximum moment or fully plastic moment, it was different depending on the loading direction.

An Analytical Study on Moment Response of Welded Steel Pipe for Loading Rate (재학속도에 따른 용접강관의 모멘트 응답특성에 관한 해석적 연구)

  • Chang, Kyong-Ho;Jang, Gab-Chul
    • Journal of Korean Association for Spatial Structures
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    • v.11 no.4
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    • pp.37-47
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    • 2011
  • This article aims to analytically research for influence of residual stresses on bending moment responses against welded steel pipes subjected to quasi -static or dynamic loadings. The residual stresses of the welded steel pipe are computed by three-dimensional welding simulation. The bending moment responses of the welded and seamless steel pipes are determined by using three-dimensional dynamic elastoplastic FE analysis as a function of loading rate. It is seen from analytical results that the welded steel pipe shows lower moment response comparing to the seamless steel pipe, and moment difference between seamless and welded steel pipes tends to decrease as loading rate increases.

Structural Design of Angola Stadium (앙골라 주경기장 구조설계)

  • Kim, Jong-Soo;Shin, Chang-Hoon;Kim, Jeong-Hyeon
    • Proceeding of KASS Symposium
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    • 2008.05a
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    • pp.212-217
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    • 2008
  • This paper is concerned with the structural design of Angola Stadium. The Angola stadium is composed of a Steel moment frame system and a Cantilever steel truss roof. Whole structural analysis is necessary to ensure the stability. Considered FEM analysis, Design of Wind load & Seismic, Stand diaphragm, interaction between stand and Roof, Serviceability.

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A Study on the Evaluation of Flexural Capacity and Design Equation of FRP Reinforcement-Concrete Beams (FRP보강근-콘크리트보의 휨성능과 휨설계식의 평가 연구)

  • Ko, Dong Woo
    • Journal of Korean Association for Spatial Structures
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    • v.22 no.1
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    • pp.59-66
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    • 2022
  • In this paper, the flexural capacity equation of FRP-bar reinforced concrete beams was verified by comparing the experimental results and flexural capacity obtained according to the ACI procedure. And, also the economic feasibility of FRP-bar reinforced concrete beams was analyzed by comparing nominal moment capacity of beams. The results of analysis were as follows, 1) GFRP concrete beams have lower flexural performance than reinforced concrete beams, whereas CFRP concrete beams have similar flexural performance to reinforced concrete beams under the same reinforcement ratio 2) Although the design moment increased as the compressive strength of concrete increased, the flexural performance of GFRP reinforced concrete beams was found to be lower than the reinforced concrete beams for all reinforcement ratios.

Motion Error Analysis of an Porous Air Bearing Table (다공질 공기베어링 테이블의 운동오차 해석)

  • Park, Cheon-Hong;Lee, Hu-Sang
    • 연구논문집
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    • s.34
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    • pp.101-112
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    • 2004
  • In order to analyze the motion errors of the aerostatic stage, it is necessary to consider the influence of the moment variation occurredinside the pads. In this paper, a motion error anaysis method utilizing the transfer functions on the reaction force and moment is proposed, and general characteristics of the transfer functions are discussed. Calculated motion errors by the proposed method show good agreement with the ones calculated by Multi Pad Method, which is considered the entire table as an analysis object. Also, by the introduction of the transfer function of motion errors, which represent the relationship between the spatial frequency components of the rail form error and motion errors, motional characteristics of the porous aerostatic stage can be generalized. In detail, the influence of the spatial frequencies is analyzed quantatively, and the patterns of the insensitive frequencies which almost do not affect the linear motion error or angular motion error according to the rail length ratio and the number of the pad are verified. The relationship between the moment variation occurred inside the pads and the motion errors is also verified together.

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