• 제목/요약/키워드: slant curves

검색결과 26건 처리시간 0.021초

팔의 유형화와 상반신 부분체형과의 대응에 관한 연구 (Classifications of Arm and Correspondence with Partial Somatotype of Upper Body)

  • 이정란
    • 한국의류학회지
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    • 제23권6호
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    • pp.864-875
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    • 1999
  • This study was done to classify type os arms and to correspond these types with partial somatotype of upper body such as lateral views of upper body shapes of shoulder. The subjects of this study were female college students of twenties 58 anthropometric and photographic data were measured. The results were as follows : 1. Form the factor analysis arm girth/armscye size factor arm length factor the slope of lower arm, arm factor the curves of armscye the roundness of arm/shapes of shoulder the slope of upper arm factor were obtained. 2. By using factor scores 4 clusters of arm types were extracted. The characteristics of these clusters were projections of armscy slant of lower arm thick-set canelike. 3. Four types of arm were corresponded with the specified lateral views of upper body directions of shoulder slopes of shoulder.

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LOXODROMES AND TRANSFORMATIONS IN PSEUDO-HERMITIAN GEOMETRY

  • Lee, Ji-Eun
    • 대한수학회논문집
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    • 제36권4호
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    • pp.817-827
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    • 2021
  • In this paper, we prove that a diffeomorphism f on a normal almost contact 3-manifold M is a CRL-transformation if and only if M is an α-Sasakian manifold. Moreover, we show that a CR-loxodrome in an α-Sasakian 3-manifold is a pseudo-Hermitian magnetic curve with a strength $q={\tilde{r}}{\eta}({\gamma}^{\prime})=(r+{\alpha}-t){\eta}({\gamma}^{\prime})$ for constant 𝜂(𝛄'). A non-geodesic CR-loxodrome is a non-Legendre slant helix. Next, we prove that let M be an α-Sasakian 3-manifold such that (∇YS)X = 0 for vector fields Y to be orthogonal to ξ, then the Ricci tensor 𝜌 satisfies 𝜌 = 2α2g. Moreover, using the CRL-transformation $\tilde{\nabla}^t$ we fine the pseudo-Hermitian curvature $\tilde{R}$, the pseudo-Ricci tensor $\tilde{\rho}$ and the torsion tensor field $\tilde{T}^t(\tilde{S}X,Y)$.

Side Scan Sonar 탐사자료의 영상처리와 해저면 Backscattering 음향특성 (Digital Processing and Acoustic Backscattering Characteristics on the Seafloor Image by Side Scan Sonar)

  • 김성렬;유홍룡
    • 한국해양학회지
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    • 제22권3호
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    • pp.143-152
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    • 1987
  • SMS 960(Seafloor Mapping System) Side Scan Sonar에 자기테이프기록계 (Kennedy 900)를 연결하여 해저면 탐사자료를 수치적으로 처리할 수 있는 시스템을 개발, 이를 제주도 성산포 근해에서 시험적으로 적용하여 그 결과를 검토 하였다. 처리시스템은 주로 VAX 11/780 (4MB)를 사용하여 FORTRAN-77로 작성 되었으며 자료의 변환, 보정, 수치분석 및 도면제작 (cartography)을 주요기능으로 가지고 있다. SMS960에 의해 얻어진 수치자료는 특수한 형태를 가지고 있으므로 독자적으로 제작한 자료선별 계수기(Data Selecting Counter와 개인용 컴퓨터 personar computer을 사용하여 주처리 전산시스템에서 처리할 수 있도록 그 형태를 변환시켰으며, 경사거리(slant range)의 보정과 자료의 질적 개선을 위한 전처리 과 정을 거친 다음, 색상표현 으로 해저면 영상도면을 제작하였다. 후방산란 (backscattering) 음파자료를 통계처리하여 4가지 색상으로 제작된 영상도면을, 해저 퇴적물의 물성분포도와 비교해 본 결과 주로 평균입도와 분급도에 잘 대비되었다. 따라서 Side Scan Sonar에 의한 해저면 후 방상란 음향특성을 적절히 분석하므로 써 해저퇴적물의 퇴적상분포연구에 상당한 응용 효과가 있을 것으로 판단된다.

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몸체 형상이 수중운동체의 공동 발달과 항력특성에 미치는 영향에 대한 수치적 연구 (A Numerical Study of Effects of Body Shape on Cavity and Drag of Underwater Vehicle)

  • 김형태;강경태;최정규;정영래;김민재
    • 대한조선학회논문집
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    • 제55권3호
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    • pp.252-264
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    • 2018
  • The calculation of steady-state cavitating flows around Supercavitating Underwater Bodies (SUB's), which consist of a circular disk head (cavitator), a conical fore-body, a cylindrical middle-body and either a boat-tail or a flare-tail, are carried out. To calculate the axisymmetric cavitating flow, used is a commercial computational fluid dynamics code based on the finite volume method, Fluent. From the analysis of numerical results, the cavity and drag, affected by the fore-body and tail of the SUB's, are investigated. Firstly, the effect of the fore-body shape is investigated with the same disk cavitator and a cylindrical rear-body of fixed diameter. Then with the same cavitator and a fixed fore-body, the effect of the rear-body shape is investigated. Before the cavity generated by the cavitator covers the slant of fore-bodies sufficiently, the larger the cone angle of the fore-body(i.e., the shorter the slant length), the larger the drag and the slower the development of cavity. After the cavity covers the fore-body completely so that the pressure drag component of the body is vanished, the characteristics of drag-velocity curves are identical. Also, as the tail angle is bigger, the cavity generated by the cavitator is suppressed further and the drag becomes larger. The peak of the drag appears for the flare-tail, i.e., when the tail angle is positive(+). On the contrary, the trough of the drag appears for the boat-tail, i.e., when the tail angle is negative(-). When the tail angle is 5 degrees, the peak of the drag appears at the body speed of 80m/s and the value of the drag is 43% larger than that at the design speed of 100m/s. When the tail angle is -5 degrees, the trough of the total drag appears at 75m/s and that drag is 30% smaller than that of the cavitator, which means the rest of the body has a negative drag.

이상적인 인체미 구현을 위한 복식 디자인의 착시효과 - 고대 이집트 시대부터 낭만주의 시대까지 - (Optical illusions in Clothing Form Designs for the Ideal Beauty of Human bodies - from the Ancient Egypt to the Romantic Period -)

  • 이옥희
    • 복식
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    • 제51권4호
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    • pp.15-30
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    • 2001
  • The purpose 7f this study is to investigate the change of the ideal beauty of human bodies and the related clothing form designs from the ancient Egypt to the Romantic Period in the aspect of optical illusions effects to achieve the ideal beauty so that we can accumulate the knowledges for the modern clothing form design and the related optical illusion effects. The scope of this study is limited to the female body forms and female dress forms. The analysis on the optical illusions in the dress forms of the various period relied on the literatures and some representative photographs and figures. The important results are as follows : 1. In the body Priority type designs of Egypt, Greece and Rome, the natural Beauty of human bodies was represented by H type silhouett, the smooth and transparent drapery materials were used with radiant line pleats resulting in slant optical illusions. 2. In the clothing priority type designs of Byzantine, Gothic, Renaissance, Baroque, Rococo and Romantic Period, manteau, cotehardie, hennin and poulain were used to emphasize long arms and legs, high waists, belly curves and large heads resulting in optical illusions of vertical emphasize. Also long train, farthingale and panier were used to emphasize body expansion resulting in the optical illusions of Titchener alld Lipps. Large and complex patterns showed the optical illusions of Aubert. 3. In the clothing priority/body concealment type of Byzantine period, thick materials with precious gems and voluminous silhouettes were used to emphasize body expansion resulting in optical illusions of materials.

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Zr-2.5Nb 중수로 압력관의 조사후 강도 및 파괴거동 특성 (The Strength and Fracture Behavior characteristics of Irradiated Zr-2.5Nb CANDU Pressure Tube Materials)

  • 안상복;김영석;김정규
    • 대한기계학회논문집A
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    • 제25권3호
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    • pp.510-519
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    • 2001
  • The tensile and fracture toughness tests have been conducted to investigate the degradations of mechanical properties induced mainly by neutron irradiations in Zr-2.5Nb CANDU pressure tube materials operated in Wolsung Unit-1. the tests were performed at room, 150, 200, 250, 300 $\^{C}$ for the irradiated and unirradiated specimens in hot cell. The specimens were directly machined from the tube retaining original curvature using specially designed electric discharge machine(EDM). From the tensile tests of the irradiated specimens, it was found that tensile strength was increased and total elongation was decreased compared to those of the unirradiated ones. The active voltages in the fracture toughness tests for the irradiated showed the discontinuous abrupt increases caused by crack jumping in lower temperature. In the crack resistance curves we found the stable crack growth in the unirradiated, whereas the unstable and three crack growth stages in the irradiated specimens due to the accumulated irradiation defects. The various fracture characteristic values in the irradiated are remarkably lower than those of the unirradiated. Through the fractography, we found in the irradiated that smaller dimple and shorter fissures than the unirradiated, and that the fractured surface had three regions that were flat, transition and slant/shear area. These can explain the difference in the crack growth characteristic values of the irradiated and the unirradiated ones.