• Title/Summary/Keyword: 유연판

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Dynamic Modeling of a Satellite with Solar Array Flexible Modes (태양전지판의 유연 모드를 고려한 위성의 동적 모델링)

  • Kim, Dae-Kwan;Park, Young-Woong;Park, Keun-Joo;Yang, Koon-Ho;Yong, Ki-Lyuk
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.9
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    • pp.837-842
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    • 2009
  • The efficient dynamic modeling of a satellite with flexible solar arrays is established by using the component mode synthesis technique. A flexible satellite model can be defined as the assembly of two sub-structures, central body and solar array. The reduced models of each substructure, which are expressed in each local frame, are coupled with respect to the satellite reference frame. The dynamic modeling method is applied to the numerical example of a satellite with a single solar array, and is verified by investigating the transfer function results with considering the solar array rotation.

Form-finding Analysis of Cable Networks Considering a Flexibility of the Structures for Mesh Reflector Antennas (구조 유연도를 고려한 메쉬 반사판 안테나의 케이블 네트워크 형상 설계)

  • Roh, Jin-Ho;Choi, Hye-Yoon;Jung, Hwa-Young;Kim, Hyo-Tae;Yun, Ji-Hyeon
    • Journal of Aerospace System Engineering
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    • v.16 no.4
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    • pp.68-76
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    • 2022
  • The purpose of this paper was to design the cable networks for mesh reflector antennas, considering the flexibility of structures. An effective form-find methodology is proposed. The whole parts of the cable networks are described by the absolute nodal coordinate formulation. Additionally, nonlinear deformation of the cable can be obtained. The form-finding analysis of the reflector with standard configuration is performed, to validate the proposed methodology. The truss ring structure is numerically modeled using the frame elements. To consider the flexibility of the truss ring as well as the cable net structure, an iteration analysis between the truss ring and the cable net under tensional forces is also performed in the form-finding process. The finial configuration of the reflector with tensioned cable networks is demonstrated.

A Finite Difference Large Displacement Analysis of Rectangular Thin Glass Plate (대변형을 가지는 사각형 박형유리판의 비선형 차분해석)

  • Kim, Chi-Kyung
    • Journal of the Korean Society of Safety
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    • v.10 no.2
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    • pp.129-133
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    • 1995
  • A new approach to the analysis of thin. rectangular window giass glass supported on flexible gaskets. and subjected to uniform lateral pressures was evolved. Based on the Von Karman theory of plates and using the finite difference method. a computer program which determines the deflections and stresses in simply supported thin glass plates was developed.

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Design and Implementation of a Slang Remover Program on Web board (웹 게시판 비속어 처리 프로그램의 설계 및 구현)

  • Cho, Ah-Young;Ock, Cheol-Young
    • Proceedings of the Korea Information Processing Society Conference
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    • 2001.10b
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    • pp.1075-1078
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    • 2001
  • 현재까지 게시판의 비속어 처리프로그램은 비속어를 발견하면 입력을 할 수 없도록 차단하는 차단식 프로그램이었다. 이런 프로그램은 사이버 상의 의사표현의 자유를 차단한다. 또한 어떤 단어의 경우는 비속어가 아닌데도 차단되어 입력을 원천봉쇄하기도 한다. 그래서 비속어를 차단하지 않고 처리해 주며 신생 비속어도 처리를 쉽게 해 주며 검출에 유연성을 제공하는 프로그램이 필요하다. 본 논문에서는 데이터베이스 상에서 구현된 게시판을 대상으로 비차단식, 유연성이 있는 비속어 추출 프로그램을 설계하고 구현하였다.

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A Method of Contact Pressure Analysis between Half-space and Plate (탄성지반과 판의 접촉압력해석에 관한 연구)

  • Cho, Hyun Yung;Cheung, Jin Hwan;Kim, Seong Do;Han, Choong Mok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.1
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    • pp.1-8
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    • 1992
  • A method analizing contact pressure between plate and elastic half space is presented by using F.E.M. With the method, the pressure intensities at surface nodes of half space cae be directly calculated by using flexibility matrix of half space. The method is originally presented by Y.K. Cheung et al.(3) Insted of Y.K. Cheung's method, which use a conception of equi-contact pressure area around each surface nodes of half space in the noded rectanqular element area. We use the equi-contact pressure area around the Gaussian integration points of half space surface in the noded isoparametric element area. Numarical examples are presented and compared with other's studies.

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Measurements of 3-D Deflection Characteristics of a Flexible Plate Levitated by Non-Contact Grippers Using SPIV Method (SPIV 기법을 이용한 비접촉 그리퍼에 의해 공중부양된 유연판의 3차원 변형 특성 측정)

  • Kim, Jaewoo;Kim, Joon Hyun;Lee, Yung Hoon;Sung, Jaeyong
    • Journal of the Korean Society of Visualization
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    • v.19 no.3
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    • pp.54-62
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    • 2021
  • This study has investigated the 3-D deflection characteristics of a flexible plate levitated by non-contact grippers using SPIV method. The measuring instrument consisted of a flexible plate located under four non-contact grippers and two cameras at the bottom of a transparent acrylic plate. Measurements were made on two materials (PVC and PC) for the plate with 50×50 cm2 area and 1 mm thickness. The deflection characteristics and flatness vary depending on the plate material, the gripper position and the air flow supplied to the gripper. For the material of PVC, the overall defection is convex. As the gripper position goes outward from the plate center, the upmost bending point also moves to the outside of the plate with the flatness increasing. However, the air flow rate does not affect the deflection pattern except for the small increase of flatness. For the material of PC, the shape of deflection changes from convex to concave as the gripper position goes out. The flatness is the highest at the point of transition from convex to concave, but the air flowrate has little effect on the flatness.

Practical Vibration Analysis of Deck Floor Slab (데크 바닥판 구조물의 실용적인 진동해석)

  • Kim, Gee-Cheol
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.18 no.1
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    • pp.61-69
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    • 2005
  • As long-span and light-weight deck floor slab are flexible and have low inherent damping, the significant floor vibration could be induced by residents' activities. These floor vibrations affect to safety and serviceability of building structures. So the vibration criteria are applied to the quality assessment of building structure. Therefore, the accurate vibration analysis should be performed for the correct assessment of deck floor slab. In this paper, practical analysis method with considering orthotropic rigidity of deck floor is proposed tot the accurate vibration analysis of dock floor slabs with form deck plates.

A Study on the Deformation Characteristics of the Roof Signboard Size in Wind Pressure Formation (풍압 형성에 따른 옥상광고판 크기별 특성에 관한 연구)

  • Hong, Ji-Wan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.401-408
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    • 2019
  • This study numerically examined the maximum wind pressure distribution of a billboard on the roof of a middle-rise building. The deformation caused by the maximum wind pressure was examined. For the numerical analysis, the signboard was assumed to be installed on $(b)20m{\times}(d)10m{\times}(h)$ buildings. The maximum wind pressure was measured using four models with the standard model and different sizes of the signboard. The numerical analysis showed that the horizontal deformation predominantly occurs as the shape of the signboard becomes closer to a rectangle, and high wind pressure and deformation occur at the corners of both ends. As the height of the signboard increases, vertical deformation predominantly occurs, and static pressure forms on the backside. When the height is lower than the width of the signboard, the wind pressure is concentrated on the center of the roof. Therefore, the distribution of the maximum wind pressure is stable, and the effect of the wind pressure is relatively low as the height-to-width ratio approaches 1.