• Title/Summary/Keyword: Wall paper

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Numerical analysis for hydrodynamic interaction effects between vessel and semi-circle bank wall

  • Lee, Chun-Ki;Moon, Serng-Bae;Oh, Jin-Seok;Lee, Sang-Min
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.4
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    • pp.691-698
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    • 2015
  • The hydrodynamic interaction forces and moments induced by the vicinity of bank on a passing vessel are known as wall effects. In this paper, the characteristics of interaction acting on a passing vessel in the proximity of a semi-circle bank wall are described and illustrated, and the effects of ship velocity, water depth and the lateral distance between vessel and semi-circle bank wall are discussed. For spacing between ship and semi-circle bank wall (SP) less than about 0.2 L and depth to ship's draft ratio (h/d) less than around 2.0, the ship-bank interaction effects increase steeply as h/d decreases. However, for spacing between ship and semi-circle bank wall (SP) more than about 0.3 L, the ship-bank interaction effects increase slowly as h/d decreases, regardless of the water depth. Also, for spacing between ship and semi-circle bank wall (SP) less than about 0.2 L, the hydrodynamic interaction effects acting on large vessel increase largely as ship velocity increases. In the meantime, for spacing between ship and semi-circle bank wall ($S_P$) more than 0.3 L, the interaction effects increase slowly as ship velocity increases.

Characteristics of Insulation of Core Wall for Traditional Rural House (Earthen House) (전통 농촌주택(흙집) 심벽의 단열 특성)

  • 리신호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.5
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    • pp.126-132
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    • 2003
  • The insulation characteristics of earthen core wall were studied in this paper. The overall heat transfer coefficients(U) were obtained through experiment in accordance with Korea Industrial standards. The result of the experiment are compared with the Regional Overall Heat Transfer Coefficient(U) of Building. This results inform that core wall with soil can be used as building walls because the insulation characteristics agree to the rule of building standards.

Optimum Design of Retaining Wall with Seismic Constraints (내진제약조건(耐震制約條件)을 갖는 옹벽(擁壁)의 최적설계(最適設計))

  • Kim, Kee-Dae
    • Journal of the Korean Society of Industry Convergence
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    • v.6 no.2
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    • pp.95-102
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    • 2003
  • In this paper, optimum design is considered over the retaining wall with seismic constraints. The sequential linear programming method(SLP) is used as a rational approach to this optimum design. To make a comparison between the seismic design and the normal design, retaining wall with 4~7m height were adopted. It is shown that the seismic design is more expensive (over 30%) than the normal design for the construction cost.

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Nonlinear Analysis Model of RC Shear Wall Building (철근 콘크리트 벽식 구조물의 비선형 해석모델)

  • 정일영;이영욱
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.04a
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    • pp.141-148
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    • 1993
  • In this paper, TVLEM is selected for the shear wall model which was proposed by Kabeyasawa and the characteristics of spring models composing TVLEM was studied. In axial stiffness spring model, the horizontal displacements when Kabeyasawa model and simple axial stiffness hysteresis model were used, were closely similar. When the large shear-displacement was occured, stiffness degrading model was more adquate to the shear wall modelling than OOHM. Also for the purpose of modelling the horizontally continuous wall, the seperational method for TVLEM was used. The results of nonlinear analysis by this method were closely similar to experimental results .

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Wall Voltage Transfer Characteristics according to Address Bias Voltage

  • Lee, Y.M.;Jeong, D.C.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.601-604
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    • 2007
  • In this paper, we report the wall voltage transfer characteristic between sustain electrodes according to the address bias voltage in a 3-electrodes surface discharge type ac PDP by the VT close curve measurement technique. The result shows the change of wall voltage according to the gap voltage variation depends on the address bias voltage.

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Analysis for the Stability of a Haptic System with the Computational Time-varying Delay (가변적인 계산시간지연에 의한 햅틱 시스템에서의 안정성 영향 분석)

  • Lee, Kyungno
    • Journal of Institute of Convergence Technology
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    • v.5 no.2
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    • pp.37-42
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    • 2015
  • This paper presents the effects of the computational time-varying delay on the stability of the haptic system that includes a virtual wall and a first-order-hold method. The model of a haptic system includes a haptic device model with a mass and a damper, a virtual wall model, a first-order-hold model and a computational time-varying delay model. In this paper, the maximum of the computational time-varying delay is assumed to be as much as the sampling time. Using the simulation, it is analyzed how the sample-hold methods and the computational time-varying delay affect the maximum available stiffness. As the maximum of computational time-varying delay increases, the maximal available stiffness of a virtual wall model is reduced.

Point Number Algorithm for Position Identification of Mobile Robots (로봇의 위치계산을 위한 포인트 개수 알고리즘)

  • Liu, Jiang;Son, Young-Ik;Kim, Kab-Il
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.427-429
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    • 2005
  • This paper presents the use of Point Number Algorithm (PNA) for real-time image processing for position identification of mobile robot. PNA can get how many points in the image gotten from the robot vision and can calculate the distance between the robot and the wall by the number of the points. The algorithm can be applied to a robot vision system enable to identify where it is in the workspace. In the workspace, the walls are made up by white background with many black points on them evenly. The angle of the vision is set invariable. So the more black points in the vision, the longer the distance is from the robot to the wall. But when the robot does not face the wall directly, the number of the black points is different. When the robot faces the wall, the least number of the black points can be gotten. The simulation results are presented at the end of this paper.

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A Study on the Hydrodynamic Interaction Forces between Ship and Bank Wall in the Proximity of Bank (측벽부근을 항해하는 선박과 측벽간의 상호 간섭력에 관한 연구)

  • Lee, Chun-Ki;Kang, Il-Kwon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.1
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    • pp.73-77
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    • 2004
  • It is well known that the hydrodynamic interaction forces between ship and bank wall affect ship manoeuvring motions. In this paper, the calculation method based on the slender body theory for estimation of the hydrodynamic interaction forces between ship and bank wall is investigated. The numerical simulations on hydrodynamic interaction force acting on a ship in the proximity of bank wall are carried out by using this theoretical method. The theoretical method used in this paper will be useful for practical prediction of ship manoeuvrability at the initial stage of design, for discussion of marine traffic control system and for automatic control system of ship in confined waterways.

Low Attenuation Waveguide for Structural Health Monitoring with Leaky Surface Waves

  • Bezdek, M.;Joseph, K.;Tittmann, B.R.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.3
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    • pp.241-262
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    • 2012
  • Some applications require structural health monitoring in inaccessible components. This paper presents a technique useful for Structural Health Monitoring of double wall structures, such as double wall steam pipes and double wall pressure vessels separated from an ultrasonic transducer by three layers. Detection has been demonstrated at distances in excess of one meter for a fixed transducer. The case presented here is for one of the layers, the middle layer, being a fluid. For certain transducer configurations the wave propagating in the fluid is a wave with low velocity and attenuation. The paper presents a model based on wave theory and finite element simulation; the experimental set-up and observations, and comparison between theory and experiment. The results provide a description of the technique, understanding of the phenomenon and its possible applications in Structural Health Monitoring.

Design Considerations for Tied Back Soil Landslide Suppressor Walls (사면붕괴 억제 타이백 벽체 설계에 대한 고찰)

  • Bae, Yoon-Shin
    • Journal of the Korean Geosynthetics Society
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    • v.8 no.1
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    • pp.41-51
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    • 2009
  • This paper reviews many of the design considerations surrounding the topic of tiedback landslide suppressor walls primarily for soils app1ications. The design requires combining knowledge of many aspects of soil mechanics and geology to obtain a design a wall that fits site specific conditions. Many of the aspects necessary to complete the design are stil1 not comprehensively studied or understood. This paper provides an overview of the more traditional aspects of tieback wall design and a discussion of newer issues such as suppressor wall earth pressures and rotation of stresses due to tiebacks. An overview is also provided regarding the effect of seismic forces.

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