• Title, Summary, Keyword: 2-collinear

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Free Vibration Analysis of 4 Edges Clamped, Isotropic Square Plates with 2 Collinear Circular Holes (2개의 원형구멍이 있는 4변고정, 등방성 정사각형 판의 자유진동해석)

  • 이영신;이윤복
    • Journal of KSNVE
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    • v.4 no.3
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    • pp.283-295
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    • 1994
  • This work presents the experimental and finite element analysis results for the free vibration of 4 edges clamped, isotropic square plates with 2 collinear circular holes. Natural frequencies of finite element analysis are obtained for the complete square plate, the square plates with a central circular hole and the square plates with 2 collinear circulare holes. And natural frequencies are experimentally measured for the complete square plate, the square plate with a central circular hole(d = 150 mm) and the square plates with 2 collinear circular holes. Agreement between experimental and FEM results is excellent. Mode shapes in special case are presented. The conclusions of the study are as follows. There is little variation of nondimensional frequency parameters for the first six mode when the aspect ratio of circular hole is less than 1/6 in the isotropic square plates with 2 collinear circular holes. And the first nondimensional frequency parameter doesn't vary as the aspect ratio of circular hole increase.

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Design and Implementation of 2.4 ㎓ and 5 ㎓ Dual Band Antenna for Access Point of Wireless LAN (무선 LAN 엑세스 포인트용 2.4 GHz, 5 GHz 이중공진 안테나의 설계 및 구현)

  • 김창일;오종대;양운근;김성민
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.3
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    • pp.304-311
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    • 2003
  • In this paper, we present the 2.4 ㎓ and 5 ㎓ dual band antenna fur access point of WLAN(Wireless Local Area Network). The proposed antenna must have equal gains in both frequency bands to accept two services. We proposed using collinear array to compensate gain difference for two different frequency bands. Simulation results using 3D simulation program, CST MWS(Microwave Studio), for dual band antenna with collinear away show that the maximum gain is about 4.7 dBi at 2.4 ㎓, 5.2 dBi at 5.7 ㎓. We got additional gain of about 2.1 ㏈ with collinear array for 2.4 ㎓ in measurement. Measured results for the dual band antenna with collinear array show applicable performances for access point of wireless LAN.

A Collinear Dipole Array Antenna Operating at 2.4 GHz Band (2.4GHz 대역 코리니어 다이폴 배열 안테나)

  • 김진영;방재훈;안병철
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • pp.408-412
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    • 2000
  • In this paper, we present the design and measurement of a collinear dipole array (CDA) operating in the 2.4 GHz ISM band. The array is consisted of six collinear dipoles joined by phasing coils. A cmmercial software is used to design the antenna with an optimum performance. The designed array is fabricated and is measured to confirm the design.

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Crack-tip constraint analysis of two collinear cracks under creep condition

  • Jiao, Guang-Chen;Wang, Wei-Zhe;Jiang, Pu-Ning
    • Structural Engineering and Mechanics
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    • v.43 no.3
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    • pp.311-320
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    • 2012
  • The higher-order asymptotic C(t) - $A_2(t)$ approach was employed to investigate the crack-tip stress of two collinear cracks in a power-law creeping material under the plane strain conditions. A comprehensive calculation was made of the single crack, collinear crack model with S/a = 0.4 and 0.8, by using the C(t) - $A_2(t)$ approach, HRR-type field and the finite element analysis; the latter two methods were used to check the constraint significance and the calculation accuracy of the C(t) - $A_2(t)$ approach, respectively. With increasing the creep time, the constraint $A_2$ was exponentially increased in the small-scale creep stage, while no discernible dependency of the constraint $A_2$ on the creep time was found at the extensive creep state. In addition, the creep time and the mechanical loads have no distinct influence on accuracy of the results obtained from the higher-order asymptotic C(t) - $A_2(t)$ approach. In comparison with the HRR-type field, the higher-order asymptotic C(t) - $A_2(t)$ solution matches well with the finite element results for the collinear crack model.

Hydrodynamic interactions and coupled dynamics between a container ship and multiple mobile harbors

  • Kang, H.Y.;Kim, M.H.
    • Ocean Systems Engineering
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    • v.2 no.3
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    • pp.217-228
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    • 2012
  • As the size of container ships continues to increase, not many existing harbors can host the super-container ship due to its increased draft and the corresponding dredging requires huge budget. In addition, the minimization of waiting and loading/offloading time is the most important factor in harbor competitiveness. In this regard, mobile-harbor concept has been developed in Korea to achieve much improved harbor capacity and efficiency. In developing the concept, one of the most important elements is the operability of crane between two or more floating bodies in side-by-side arrangement. The container ship is to be stationed through a hawser connection to an outside-harbor fixed-pile station with the depth allowing its large draft. The mobile harbors with smart cranes are berthed to the sides of its hull for loading/offloading containers and transportation. For successful operation, the relative motions between the two or more floating bodies with hawser/fender connections have to be within allowable range. Therefore, the reliable prediction of the relative motions of the multiple floating bodies with realistic mooring system is essential to find the best hull particulars, hawser/mooring/fender arrangement, and crane/docking-station design. Time-domain multi-hull-mooring coupled dynamic analysis program is used to assess the hydrodynamic interactions among the multiple floating bodies and the global performance of the system. Both collinear and non-collinear wind-wave-current environments are applied to the system. It is found that the non-collinear case can equally be functional in dynamics view compared to the collinear case but undesirable phenomena associated with vessel responses and hawser tensions can also happen at certain conditions, so more care needs to be taken.

THE ALEKSANDROV PROBLEM AND THE MAZUR-ULAM THEOREM ON LINEAR n-NORMED SPACES

  • Yumei, Ma
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.5
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    • pp.1631-1637
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    • 2013
  • This paper generalizes the Aleksandrov problem and Mazur Ulam theorem to the case of $n$-normed spaces. For real $n$-normed spaces X and Y, we will prove that $f$ is an affine isometry when the mapping satisfies the weaker assumptions that preserves unit distance, $n$-colinear and 2-colinear on same-order.

Omnidirectional Collinear Antenna Using for Multi-Layer PCB Structure (다층 PCB 구조를 이용한 전방향성 코리니어 안테나)

  • Jung, Huyk;Suh, Kyoung-Whoan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.11
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    • pp.1133-1136
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    • 2011
  • In this paper, we proposed a collinear antenna with a stripline structure for IEEE 802.11b/g applications in ISM (Industrial, Scientific, Medical) band of 2.4~2.5 GHz, which supplements disadvantages of COCO(Coaxial Collinear) antenna and OMA(Omnidirectional planar Microstrip Antenna). By using the proposed 4-layer substrate, we obtained improved performances and advantages in production compared with the existing antenna. In order to get antenna arrays, the same phase structure is designed by alternatively connecting outer conductor to inner conductor with ${\lambda}$/2 antenna element, and the substrate of FR4 epoxy (${\epsilon}_r$=4.4, tan${\delta}$=0.02) was used for the actual implementation. The maximum gain of about 4.93 dBi was measured, which leaded to a little improved gain of 0.33 dBi in comparison to the existing OMA structure.

Stress Analysis of Composite Laminated Plates with 2 Collinear Circular Cutouts (2개의 원형개구부가 있는 복합재료 적층판의 응력해석)

  • 이윤복;이영신
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.223-226
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    • 1999
  • This paper presents the theoretical analysis method to determine the stress concentrations around the circular cutouts with various geometrical parameters. The purposes of this study are to investigate on the stress distribution around the circular cutouts due to interaction between two circular cutouts and to develop the design method in composite plates. The composite laminated plate with 2 equal collinear circular cutouts under inplane loads is treated as an quasi-isotropic, symmetric, finite, square, multiply connected and thin plate. The effects of cutout sizes, distances between two circular cutouts and inplane load conditions on stress distribution are studied in detail.

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The Application of Delaunay Triangulation on RP (Delaunay 삼각형 분합법의 RP에의 응용)

  • 김대원
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • pp.129-134
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    • 1998
  • STL which is used in Rapid Prototyping is composed of a lot of triangular facets. The number of triangles and the shapes of these triangles determine the quality of STL. Therefore, proper algorithm is necessary to enhance the quality of triangular patch. In this paper we used the Delaunay triangulation method to apply to following processes. 1) On processing for reducing sharp triangles which cause errors on intersection. 2) On processing for connecting two or more collinear edges. 3) On processing for deleting unnecessarily inserted points in coplanar polygon.

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