• 제목/요약/키워드: ends

검색결과 2,229건 처리시간 0.027초

Optimization of Ti-indiffused LiNbO3Optical Waveguide for Fiber Coupling

  • Lee, Han-Young;Yang, Woo-Seok;Kim, Woo-Kyung
    • Journal of the Optical Society of Korea
    • /
    • 제8권2호
    • /
    • pp.90-95
    • /
    • 2004
  • The structure of Ti:LiNbO$_3$optical waveguide with a mode size far different from that of single mode optical fiber has been optimized by tapering the waveguide ends. This work was focused on determining the optimized sets of parameters for the fabrication of low-loss Ti indiffused optical waveguides in LiNbO$_3$. Numerical and analytical modeling were applied to simulate the guiding quality and to determine the mode sizes. Based on these modeling results, new waveguide structures with tapered ends have been defined, fabricated and characterized in the respect of the coupling of fiber to Ti-indiffused LiNbO$_3$waveguide.

강재 경계요소를 갖는 콘크리트 벽체의 내진 성능 (Seismic Response of Concrete Walls with Steel Boundary Elements)

  • 조순호
    • 한국지진공학회:학술대회논문집
    • /
    • 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
    • /
    • pp.290-297
    • /
    • 2000
  • A new form of construction utilizing structural steel as the boundary elements in ductile flexural concrete walls is proposed to solve the bar congestion problems associated with such a heavily reinforced region. Two wall specimens containing rectangular hollow structural sections(HSS) and channels at their ends respectively were constructed rectangular hollow structural sections(HSS) and channels ar their ends respectively were constructed and tested under reversed cyclic loading to evaluate the construction process as well as the structural performance. One companion standard reinforced concrete wall specimen was also tested for the comparison purpose At an Initial stage all three specimens were carefully detailed to have the approximately same flexural capacity. Analysis and comparison of test results indicated that the reversed cyclic responses of the three walls showed similar hysteretic properties but in those with steel boundaries local bucking of the corresponding steel elements following significant yielding of structural steel was prominent. Design procedures considering local instability of the structural steel elements and the interaction between steel chord and concrete web members in such composite walls are presented.

  • PDF

유압 액셜 피스톤 펌프의 실린더 포트 내부 비정상 압력특성에 관한 연구 (A study on the characteristics of dynamic pressure in cylinder pen of hydraulic axial piston pump)

  • 김종기;정재연
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 1999년도 제29회 춘계학술대회
    • /
    • pp.209-214
    • /
    • 1999
  • Dynamic pressure is one of the major sources on noise emission in hydraulic axial piston pump. This paper reports an experimental study of dynamic pressure characteristics in the cylinder port of hydraulic axial piston pump. We investigated dynamic pressure with not only the effect of delivery pressure, rotational speed and temperature but also V-notches at the ends of the kidney ports in the valve plate. We experimented three valve plates with three type V-notches at the ends of the kidney ports, because V-notches of the valve plate is known of noise reduction. Finally, we hope this paper help to design of the valve plate in hydraulic axial piston pump.

  • PDF

탄성받침의 철도교량 적용을 위한 최적화에 관한 연구 (A Study on the Optimization for Application of Elastomeric Bearing for Railway Bridge)

  • 김효원;김학군;손경욱;최동철;윤순종
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
    • /
    • pp.815-820
    • /
    • 2011
  • The railway bridge of the domestic still has been used steel base such as sperical bearing and pot bearing widely. However, the bearing of steel series is occured corrosion frequently, reduced durability and raised maintenance cost excessively due to the nature of the material. If the elastomeric bearing which is widely used in highway bridge is applied to the railway bridge, it will be able to compensate this defect a lot. In order to apply to the railway bridge used for highway bridge, is needed the control of the bridge ends deflection, lateral displacement and negative reaction. Therefore, the elastomeric bearing can be applied to the railway bridge enough, if installed negative reaction key for control of the bridge ends deflection, improved shear wedge performance for control of the lateral force, adjust the thickness of the elastomeric pad for the minimize deflection, in addition, can be economic design of sub-structures due to damping effect.

  • PDF

The Homotopy Perturbation Method for free vibration analysis of beam on elastic foundation

  • Ozturk, Baki;Coskun, Safa Bozkurt
    • Structural Engineering and Mechanics
    • /
    • 제37권4호
    • /
    • pp.415-425
    • /
    • 2011
  • In this study, the homotopy perturbation method (HPM) is applied to free vibration analysis of beam on elastic foundation. This numerical method is applied on three different axially loaded cases, namely: 1) one end fixed, the other end simply supported; 2) both ends fixed and 3) both ends simply supported cases. Analytical solutions and frequency factors are evaluated for different ratios of axial load N acting on the beam to Euler buckling load, $N_r$. The application of HPM for the particular problem in this study gives results which are in excellent agreement with both analytical solutions and the variational iteration method (VIM) solutions for all the cases considered in this study and the differential transform method (DTM) results available in the literature for the fixed-pinned case.

프로파일링한 테이퍼 로울러의 탄성유체윤활 해석 (An Elastohydrodynamic Lubrication Analysis of Tapered Roller with Profiled Ends)

  • 박태조
    • Tribology and Lubricants
    • /
    • 제28권4호
    • /
    • pp.153-159
    • /
    • 2012
  • Tapered roller bearings are widely used in high axial-load and radial-load applications. In this study, a numerical analysis is performed to study a finite line contacts EHL problem between a tapered roller and raceway in tapered roller bearings. Converged solutions are obtained for moderate load and material parameters using a finite difference method with non-uniform grids and the Newton-Raphson method. The contours and sectional plots of pressure distribution and film shape are compared. The pressure distribution and film shapes near both ends of the roller are very different from those in the central part and are transversely asymmetric. The maximum pressure and absolute minimum film thickness always occur at the small end of the roller.

전단변형이 양단고정 변단면 기둥의 좌굴하중에 미치는 영향 (Effects of Shear Deformations on Buckling Loads of Tapered Columns with Both Clamped Ends)

  • 이병구;이태은;안대순
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2000년도 봄 학술발표회논문집
    • /
    • pp.92-99
    • /
    • 2000
  • The nondimensional differential equations governing the buckling loads of tapered columns with both clamped ends and its boundary conditions are derived, in which the effects of shear deformations are included. These equations are solved numerically using a numerical integration technique and a bracketing method to obtain the buckling loads of columns. Four types of cross-sectional shape are considered in the numerical examples. The parametric studies of shear deformation effects on the buckling loads such as cross-sectional shape factor, shear coefficient, ratio of modulus of elasticity, slenderness ratio and section ratio are reported in tables and figures.

  • PDF