• Title/Summary/Keyword: Ellipsoid

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4 반사경 ANASTIGMAT 의 ZOOMING 에 관한 연구

  • 나승유;이상수
    • Proceedings of the Optical Society of Korea Conference
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    • 1988.06a
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    • pp.59-67
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    • 1988
  • 연속적으로 aplanat 조건을 만족하는 4 반사경의 zooming에서 aplanat 4구면 반사광학계가 갖는 astigmatism을 줄이기 위하여 4구면 중 하나의 반사경에 원추곡면을 사용함으로써 줌 궤적상의 한점에서 anatsigmat 조건을 만족하도록 하였다. 이방법에 의한 astigmatism 의 보정효과는 제 1 면에 ellipsoid를 사용하였을 때 가장 우수하였다.

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Formation of Teleomorph of Rhizoctonia solani AG 2-2(IV) Isolated from Zoysiagrass (한국들잔디에서 분리한 Rhizoctonia solani AG 2-2(IV)의 완전세대 형성)

  • 이재홍;이두형
    • Korean Journal Plant Pathology
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    • v.11 no.3
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    • pp.278-281
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    • 1995
  • An isolate of Rhizoctonia solani AG 2-2(IV) from zoysiagrass was examined on development of its teleomorph by the modified soil-on-agar culture method. The most effective growth medium for sporulation was Czapek's 1/2 agar medium added with yeast extract and peptone. The characters of teleomorph of R. solani AG 2-2 (IV) are as follows. Hymenia developed on soil surface after the development of vegetative hyphae. Basidia were barrel-shaped, short clavate or obovate and were 11.4~17.9$\times$7.1~11.4 ${\mu}{\textrm}{m}$ (mean : 15.1$\times$9.0 ${\mu}{\textrm}{m}$) in size. Sterigmata were horn-shaped and slightly bent to the inner side and 4.3~18.6 ${\mu}{\textrm}{m}$ (mean : 10.3 ${\mu}{\textrm}{m}$) in size. Two to four sterigmata developed on each basidium. Basidiospores were obovate, ellipsoid to oblong-ellipsoid, hyaline, smooth, thin walled, with an apiculus, and 3.6~10.4$\times$2.9~5.7 ${\mu}{\textrm}{m}$ (mean : 7.8$\times$4.4 ${\mu}{\textrm}{m}$) in size.

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First Records of Two Spirostomum Ciliates (Heterotrichea: Heterotrichida: Spirostomidae) from Korea

  • Jang, Seok-Won;Kwon, Choon-Bong;Shin, Mann-Kyoon
    • Animal Systematics, Evolution and Diversity
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    • v.28 no.1
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    • pp.29-35
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    • 2012
  • Two Spirostomum species collected from freshwater in Korea were identified as S. caudatum (Muller, 1786) and S. teres (Claparede and Lachmann, 1858). They are recorded for the first time in Korea. The description was based on the observation of living specimens and protargol impregnated specimens. Diagnostics of these species are as follows. Spirostomum caudatum: body size $400-450{\times}20-30\;{\mu}m$ in vivo, shaped long and slender with a tapered posterior part, highly contractile; macronucleus ellipsoid; adoral zone of membranelles occupied 30% of body length; somatic kineties 14-22 in number. Spirostomum teres: body size $240-460{\times}25-40\;{\mu}m$ in vivo, shaped long and slender with a flattened posterior end, highly contractile; cortical granules arranged in 2-3 rows; adoral zone of membranelles occupied 50% of body length; somatic kineties 20-30 in number; macronucleus ellipsoid; micronuclei 2-3 in number. Spirostomum caudatum and S. teres are the most similar congeners, but they are different in the posterior part of body (tail-like posterior part vs. flattened posterior end), length of adoral zone of membranelles in body length (1/3 vs. 1/2), and the number of somatic kineties (14-22 vs. 20-30). These populations match with European populations in morphological characters.

National Datum Transformation Parameters of South Korea Using Weighted Parameter Constraints (가중변수법에 의한 국가좌표계 변환요소의 산정)

  • 이영진
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.15 no.1
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    • pp.29-39
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    • 1997
  • The need of transformation parameters from local geodetic datums to a geocentric coordinate system is becoming more common, with the increasing application of satellite positioning techniques to LIS/GIS survey with cadastral management. In this paper, the national transformation parameters between the Korean geodetic coordinates which is based on the Bessel 1841 ellipsoid and the WGS84 ellipsoid are determined by the least square methods with weighted parameter constraints. Three-dimensional geocentric coordinates are based on GPS observation at 31 stations in the geodetic network, the datum parameters are computed within a standard deviation of less than 1 meter. In South Korea, the national transformation parameters with Bessel geoid-heights are useful for GPS baseline processing and for middle-scale map/database transformation.

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A study on the Bessel geoidal height to improve the accuracy of coordinate transformation (좌표변환의 정확도 향상을 위한 Bessel 지오이드고에 관한 연구)

  • Shin, Bong-Ho;Kang, Joon-Mook;Kim, Hong-Jin;Choi, Jong-Hyun
    • Journal of Korean Society for Geospatial Information Science
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    • v.2 no.2 s.4
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    • pp.143-151
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    • 1994
  • 3-D coordinates that result form GPS survey are not applied directly in korea because they are based on WGS 84 ellipsoid. Thus they must be transformed into longitude, latitude on the Bessel ellipsoid and orthometric height. Transformation parameters must be determined in order to perform the coordinate transformation. Also, coordinate transformation be preformed on longitude, latitude and ellipsoidal height. First estimation of Bessel geoidal height must be accomplished to acquire Bessel ellipsoidal height This paper suggests accuracy of coordinate transformation according to the estimation method of Bessel geoidal height. Also, This paper suggests that Bessel geoidal height have influence on the coordinates transformation.

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Human Limbs Modeling from 3D Scan Data (3차원 스캔 데이터로부터의 인체 팔, 다리 형상 복원)

  • Hyeon, Dae-Eun;Yun, Seung-Hyeon;Kim, Myeong-Su
    • Journal of the Korea Computer Graphics Society
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    • v.8 no.4
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    • pp.1-7
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    • 2002
  • This paper presents a new approach for modeling human limbs shape from 3D scan data. Based on the cylindrical structure of limbs, the overall shape is approximated with a set of ellipsoids through ellipsoid fitting and interpolation of fit-ellipsoids. Then, the smooth domain surface representing the coarse shape is generated as the envelope surface of ellipsoidal sweep, and the fine details are reconstructed by constructing parametric displacement function on the domain surface. For fast calculation, the envelope surface is approximated with ellipse sweep surface, and points on the reconstructed surface are mapped onto the corresponding ellipsoid. We demonstrate the effectiveness of our approach for skeleton-driven body deformation.

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