• 제목/요약/키워드: Clark

검색결과 398건 처리시간 0.027초

A Generalized Scheme for Constructing Polyhedral Meshes of Catmull-Clark Subdivision Surfaces Interpolating Networks of Curves

  • Abbas, Abdulwahed;Nasri, Ahmad
    • International Journal of CAD/CAM
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    • 제5권1호
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    • pp.91-98
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    • 2005
  • This paper presents a scheme for interpolating intersecting uniform cubic B-spline curves by Catmull-Clark subdivision surfaces. The curves are represented by polygonal complexes and the neighborhoods of intersection points are modeled by X-Configurations. When these structures are embedded within a control polyhedron, the corresponding curves will automatically be interpolated by the surface limit of subdivision of the polyhedron. The paper supplies a construction which clearly shows that interpolation can still be guaranteed even in the absence of symmetry at the X-configurations. In this sense, this scheme generalizes an already existing technique by the same authors, thereby allowing more freedom to designers.

내린천 유역의 HEC-HMS 모형 적용에 관한 연구 (A Study on Application of HEC-HMS Model to the Naerinchon Basin)

  • 최한규;백효선;정병하
    • 산업기술연구
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    • 제22권A호
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    • pp.211-218
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    • 2002
  • HEC-HMS model should be calibrated to be applied to these basins in Gangwon-do unlike the general basins. In the study, it is investigated whether the HEC-HMS model may be applied or not to Naerinchon basin where is the typical basin of Gangwon-do Additionally, the straightforword module of HEC-HMS for simulating the hydrologic characteristic of Gangwon-do basins well will be suggested by comparison of the numerical results with the observed data. The hydrologic results estimated by several modules such as Clark, SCS and Snyder methods in HEC-HMS model have been compared with the observed data for 1999~2000 storm events. It is concluded that Clark method are relatively applicable to the basins in Gangwon-do rather than the others methods. The parametric studies for HEC-HMS model should be studied further in order to apply to Gangwon-do basins more accurately.

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SNP과 Haplotype 분석의 통계적 문제점들

  • 김호;조성일;서유신;현순주;노재정;이복주
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2002년도 추계 학술발표회 논문집
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    • pp.203-207
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    • 2002
  • Post-genome 시대를 맞이하여 인류는 전 유전체에서의 염기서열에 대한 정보를 가질 수 있게 되었다. 이러한 정보를 이용하여서 인간에게 나타나는 다양성을 설명하기 위해서 SNP(Single Nucleotide Polymorphism)의 연구가 활발히 되고 있다. 하지만 인간 체세포의 염색체는 2쌍으로 되어있기 때문에 이러한 정보가 어떠한 쌍의 조합(haplotype)으로 나타나는가를 고려하여야한다. 현재 실험적 방법으로 이를 고려하기에는 여러 가지 제약이 따르므로 통계적인 방법으로 이를 모형화하려는 노력(in silico haplotyping)이 시도되고 있다. 이 논문에서는 통계적으로 haplotype을 정하는 대표적인 알고리즘인 Clark's algorithm, E-M algorithm 등에 대한 고찰을 통하여 유전체통계학에 대한 소개를 하고자 한다.

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소하천 유역의 유출변화 특성분석 (An Analysis of Runoff Characteristics at Creeks)

  • 정재욱;윤세의
    • 한국방재학회 논문집
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    • 제1권2호
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    • pp.75-83
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    • 2001
  • 본 연구에서는 자연형하천으로 정비된 소하천의 실태조사를 통해 정비현황의 문제점을 조사하였다. 수원천 수계에 포함된 창사천을 대상으로 현장관측을 실시하였다. 창사천에서 관측된 강우량, 유속, 수심 등의 자료를 이용하여 운동파 모형의 적용성을 평가하였으며, 실무에서 널리 사용되고 있는 SCS, Clark, RRL 모형과도 비교하였다. 운동파방정식을 창사천유역에 적용했을 때 실측치와 비교적 유사한 결과를 얻을 수 있었다.

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A New Method for Reconstruction of Smooth Branching Surface from Contours

  • Jha, Kailash
    • International Journal of CAD/CAM
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    • 제12권1호
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    • pp.29-37
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    • 2012
  • A new algorithm has been developed to construct surface from the contours having branches and the final smooth surface is obtained by the reversible Catmull-Clark subdivision. In branching, a particular layer has more than one contour that correspond with at least one contour at the adjacent layer. In the next step, three-dimensional composite curve is constructed from contours of a layer having correspondence with at least one contour at the adjacent layer by inserting points between them and joining the contours. The points are inserted in such a way that the geometric center of the contours should merge at the center of the contours at the adjacent layer. This process is repeated for all layers having branching problems. Polyhedra are constructed in the next step with the help of composite curves and the contours at adjacent layer. The required smooth surface is obtained in the proposed work by providing the level of smoothness.

유효강우강도를 고려한 저류상수의 적용성 검토 (An Examination for Application of Storage Constant Considered the Effective Rainfall Intensity)

  • 박상우;장석환;오경두;전병호
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2004년도 학술발표회
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    • pp.328-332
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    • 2004
  • 본 연구에서는 자연하천유역에 적합한 저류상수 산정공식을 개발하기 위하여 섬진강 유역에 대한 유역특성인자 및 강우특성인자를 분석하고, 이의 단계별 회귀분석으로부터 유역면적, 하도연장, 하도경사의 유역특성인자뿐만 아니라 강우특성인자인 유효강우강도를 설명변수로 갖는 저류상수 산정공식을 개발하였다. 그리고 개발된 공식의 적용성을 검토하고자 Clark의 단위도 모형에 기존의 경험공식 및 본 인구에서 개발된 공식을 이용하여 섬진강 유역의 실제 호우사상에 대한 유출수문곡선을 분석하여 관측수문곡선과 비교 검토한 겉과, 본 연구에서 개발된 공식에 의한 유출수문곡선이 관측치에 가장 적합하였다. 또한, 남한강의 지류인 섬강 유역에 대한 빈도별 설계강우량을 적용하여 저류상수 및 설계홍수량을 산정하고 기존에 분석된 저류상수 및 홍수량과 비교 검토한 결과 빈도별 유효강우강도의 변화를 고려한 저류상수의 적용 가능성 및 그 타당성을 확인할 수 있었다.

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A newly recorded brittle star, Amphiura (Amphiura) digitula (H.L. Clark, 1911)(Ophiuroidea: Amphilepidida: Amphiuridae), from Geoje Island, Korea

  • Lee, Taekjun;Shin, Sook
    • Journal of Species Research
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    • 제9권3호
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    • pp.273-279
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    • 2020
  • We describe a newly recorded brittle star to South Korea, Amphiura (Amphiura) digitula (H.L. Clark, 1911), that was collected from Geoje Island, at a depth of 47 m. The species is characterized by a small disk, covered by numerous fine scales, small radial shields that are wider than long, a small stumpy hook at the distal end of the radial shield, two tooth papilla, two adoral shield spines, 2nd adoral shield spine longer than other, tapered dramatically toward dull tip, five arms with four proximal arm spines, and two tentacle scales. We also obtained a 657 bp sequence from COI gene and the amplified sequence matched the general DNA barcoding region. The NJ and ML phylogenetic analyses revealed A. (A.) digitula as monophyletic in the Amphiura clade. This species is clearly distinguished from other Amphiura species by morphological characteristics and the mitochondrial COI sequence, and thus represents the sixth Amphiura species reported to occur in Korea.

Three New Species of Collocheres (Copepoda, Siphonostomatoida, Asterocheridae) Associated with Crinoids and Ophiuroids from Korea

  • Shin, Sook;Kim, Il-Hoi
    • Animal cells and systems
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    • 제8권4호
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    • pp.267-280
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    • 2004
  • Three new species of Collocheres are described as associates of crinoid and ophiuroid echinoderms from Cheju Island, Korea: Collocheres brevipes n. sp. from the crinoids Comanthus solaster A. H. Clark and Decametra tigrina (A. H. Clark); C. solidus n. sp. from two species of the crinoids Comanthus solaster and Comanthus japonicus (Muller) and one species of ophiuroid-Ophiomastax mixta (Lutken); and C. tamladus n. sp. from the crinoid Catoptometra rubroflava (A. H. Clack). The three species are distinguished from one another and other congeners by the body size, dimension of caudal ramus and free segment of leg 5, and shape and ornamentation of urosome.

CAD/CAE 적응을 위한 근사 서브디비전 방법의 고찰 (Study on approximating subdivision schemes for the application to CAD/CAE)

  • 서홍석;조맹효
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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    • pp.237-243
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    • 2002
  • Recently, in computer-aided geometric modeling(CAGD), subdivision surfaces are frequently employed to construct free-form surface. Subdivision schemes have been very popular in computer graphics and animation community, but the community of CAGD adopts this tool only recently to handle surface geometry. In the present study, Loop scheme and Catmull-Clark scheme are applied to generate smooth surfaces. To be consistent with the limit points of target surface, the initial sampling points are properly rearranged. The pointwise curvature errors and coordinate value errors between the points in the sequence of subdivision process and the points on the target surface are evaluated In the numerical examples in both Loop scheme & Catmull-Clark subdivision scheme.

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