• Title/Summary/Keyword: 조밀도

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An Efficient Method to Combine PatchMatch-Based and Segmentation-Based Dense Depth Maps (패치매치 기반 및 분할 기반 조밀 깊이지도의 효율적인 결합 방법)

  • Hanshin Lim;Jeongil Seo
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2022.11a
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    • pp.161-163
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    • 2022
  • 본 논문에서는 패치매치 기법 및 분할 기법의 조밀 깊이지도들의 효율적인 결합을 통해 기존의 패치매치 기반의 방법들이 낮은 깊이값 추정 정확도를 보인 영역들인 텍스처가 부족한 영역과 기존의 분할 기반 방법들이 깊이값 추정에 한계를 보인 세밀한 영역에서의 깊이값 추정 정확도를 동시에 높이고 고품질의 조밀 깊이지도를 얻는 것을 목표로 한다. 이를 위해 제안한 방법에서는 신뢰지도를 바탕으로 패치매치 기법의 조밀 깊이지도, 조밀 노말지도와 분할 기법의 조밀 깊이지도, 조밀 노말지도의 초기 결합 깊이지도 및 초기 결합 노말지도를 생성한다. 이후 각 픽셀에서 원래 픽셀과 주변 픽셀에서의 깊이값, 노말값들로 업데이트를 위한 후보들을 만든다. 이후 각각의 후보들에 대해서 깊이값, 노말값, 컬러값들을 바탕으로 비용을 계산한다. 이후 가장 최적의 비용을 가지는 후보값으로 각 픽셀의 깊이값과 노말값을 업데이트한다. 이를 통해 패치매치 기법 및 분할 기법의 조밀 깊이지도들의 장점을 합친 결합 조밀 깊이지도를 생성한다.

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Optimal Design of I-type Girders in 2-Span Continuous Steel Bridges by LRFD (LRFD에 의한 연속보 주부재의 조밀 및 비조밀 단면 최적화 설계)

  • Gook, Joong-Sik;Shin, Yung-Seok
    • Journal of Korean Society of Steel Construction
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    • v.12 no.3 s.46
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    • pp.329-337
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    • 2000
  • The Load and Resistance Factor Design(LRFD) Specification defines two sets of limiting width-to-thickness ratios. On the basis of these limiting values, steel sections are subdivided into three categories: compact, noncompact, and slender sections. In this paper, I-Type girders of a 2 span continuous steel bridge are divided into compact and non-compact sections and analyzed. In the design process, an optimization formulation was adopted and ADS, a Fortran program for Automated Design Synthesis, was used. In this study, we studied about change of the section between compact and non-compact using optimization formulation.

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Simulation for the center-wavelength shift of interference filters by temperature variation (온도변화에 따른 간섭필터의 중심파장 이동의 전산모의)

  • 김성화;황보창권
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.02a
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    • pp.80-81
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    • 2003
  • DWDM 필터와 같은 간섭필터는 밴드폭이 좁아지고 투과파장에 해당하는 채널의 수가 증가함에 따라 투과파장의 외부환경에 대한 안정성이 중요하다. 기존의 전자빔 증착법으로 증착된 유전체 다층박막은 일반적으로 미세기둥구조로 인해 낮은 조밀도를 가지기 때문에 외부의 습도나 온도 변화 등에 민감하다. 낮은 조밀도의 유전체 다층박막을 대기 중에 노출되었을 때, 대기 중의 습기가 기둥과 기둥 사이로 침투되어 유효굴절률의 증가로 인하여 박막의 광학두께가 증가하게 되고 결국 스펙트럼이 장파장으로 이동하게 된다. (중략)

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Cross-Sectional Compactness for Negative Moment Region of I-girder with High-Performance Steel (고강도강 적용 I-거더 부모멘트부의 조밀단면 기준 평가)

  • Cha, Sang-Ho;Joo, Hyun-Sung;Choi, Hyung-Ho;Lee, Hak-Eun
    • 한국방재학회:학술대회논문집
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    • 2010.02a
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    • pp.84.2-84.2
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    • 2010
  • 본 연구는 소수주거더 교량에 적용된 I-거더에 고강도 강재인 HSB800 강재를 사용하였을 때, 휨 연성 R값을 이용하여 AASHTO LRFD(2007)의 조밀단면기준에 대한 경향성에 대해 수치해석적으로 수행되었다. 복부판 세장비, 플랜지 세장비, 비지지 길이를 변수로 하여 휨 연성 R값을 구해서 기존의 AASHTO LRFD(2007)의 조밀단면기준에 적용하여 휨 연성에 대한 경향성을 나타내었다.

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Automatic Leather Quality Inspection and Grading System by Leather Texture Analysis (텍스쳐 분석에 의한 피혁 등급 판정 및 자동 선별시스템에의 응용)

  • 권장우;김명재;길경석
    • Journal of Korea Multimedia Society
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    • v.7 no.4
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    • pp.451-458
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    • 2004
  • A leather quality inspection by naked eyes has known as unreliable because of its biological characteristics like accumulated fatigue caused from an optical illusion and biological phenomenon. Therefore it is necessary to automate the leather quality inspection by computer vision technique. In this paper, we present automatic leather qua1ity classification system get information from leather surface. Leather is usually graded by its information such as texture density, types and distribution of defects. The presented algorithm explain how we analyze leather information like texture density and defects from the gray-level images obtained by digital camera. The density data is computed by its ratio of distribution area, width, and height of Fourier spectrum magnitude. And the defect information of leather surface can be obtained by histogram distribution of pixels which is Windowed from preprocessed images. The information for entire leather could be a standard for grading leather quality. The proposed leather inspection system using machine vision can also be applied to another field to substitute human eye inspection.

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A Study on the Bearing Capacity of the Sand Foundation Including the Dense Sand Layer (조밀한 층을 포함하는 사질 지반의 지지력에 관한 연구)

  • Park, Eun Young;Lee, Sang Duk;Kwon, Oh Yeoh;Hu, Chang Tack
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.2
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    • pp.237-242
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    • 1993
  • The bearing capacity of the sand foundation including a thin dense sand layer depends on the stiffiness, thickness and the location of the dense sand layer. In this paper was the influence of the dense sand layer on both the bearing capacity and the failure configuration is studied by means of K.E.M(Kinematic Element Method). K.E.M was implemented to get the excat solution starting from the upper bound of the analysis. The result show that the bearing capacity of the foundation and the failure configuration is greatly influenced by the dense sand layer, when the layer is located not deeper than 3/5 of the foundation width.

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H-refined Shape Design Sensitivity Analysis of Elastic Structures using Multi-Resolution Approach (다중 조밀도를 이용한 탄성 구조의 h-세분화 아이소-지오메트릭 설계민감도 해석)

  • Lee, Taeho;Yoon, Minho;Cho, Seonho;Koo, Bonyong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.3
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    • pp.155-163
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    • 2018
  • One of the major disadvantages of isogeometric analysis(IGA) is that local refinement is nearly impossible in a conventional manner because of the tensor product nature in NURBS. In this research, we investigate a local refinement scheme for isogeometric analysis, named multi-resolution approach where different resolutions are employed at each subdomain, using h-refinement relation to endow displacement compatibility on an interface of subdomains. Then, we develop shape sensitivity analysis possessing same compatibility condition as in the analysis. Numerical examples are shown to demonstrate the computational efficiency of the method in analysis especially stress concentration problem and accurate sensitivity results which is also compatible on the interface.

Evaluation of Flexural Strength of Hybrid Girder composed of HSB800 and HSB600 Steel (HSB800 및 HSB600 강재를 적용한 하이브리드거더의 휨강도 평가)

  • Park, Yong Myung;Kang, Ji Hoon;Lee, Kun Joon;Kim, Hee Soon
    • Journal of Korean Society of Steel Construction
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    • v.26 no.6
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    • pp.581-594
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    • 2014
  • In this paper, flexural resistance of hybrid girder under uniform bending moment was evaluated, which is composed of HSB800 and HSB600 steel for the flange and web, respectively. Doubly-symmetric and monosymmetric sections with noncompact or compact flange and slender, noncompact or compact web were considered. Nonlinear analyses with 3-dim. shell element model were performed to determine the 'flexural resistance of section' and the 'lateral torsional buckling strength' by taking initial imperfection and residual stress into account. The numerical results were compared with the AASHTO LRFD and Eurocode 3 specifications and also the applicability of AASHTO LRFD appendix A6 was examined for the sections with noncompact and compact web.

Design of 3-Dimensional Cross-Lattice Signal Constellations with Increased Compactness (조밀도가 증가된 3차원 십자격자형 신호성상도의 설계)

  • Li, Shuang;Kang, Seog Geun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.4
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    • pp.715-720
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    • 2016
  • In this paper, a method to design 3-dimensional (3-D) cross-lattice signal constellations with increased compactness is presented and analyzed. Here, the symbols located at the outermost sides in the conventional lattice constellation are moved symmetrically to fill in empty sides and sunken corners. While the minimum Euclidean distance (MED) among adjacent symbols remains unchanged, the presented cross-lattice constellations have 3~5% reduced average power and upto 25% reduced total volume as compared with the conventional ones. Due to the increase compactness, average power of the new 3-D constellations is lower than that of the conventional ones. As a result, computer simulation verifies that the presented cross-lattice constellations can improve symbol error performance of a digital transmission system about 0.4 [dB]. Hence, the proposed 3-D cross-lattice constellations are appropriate for low-power and high-quality digital communication systems.