• Title/Summary/Keyword: Layered method

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A Study on the Effect of the Thickness of Bond Coating on the Thermal Stresses of a Sprayed Thermal Barrier Coating (접착층의 두께가 용사 열차폐 코팅의 열응력에 미치는 영향에 관한 연구)

  • 김형남
    • Journal of Welding and Joining
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    • v.19 no.2
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    • pp.221-227
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    • 2001
  • Based on the principle of complementary energy, an analytical method is developed which focuses on the end effects for determining thermal stress distributions in a three-layered beam. This method gives the stress distributions which completely satisfy the stress-free boundary conditions. A numerical example is given in order to verify this method. The results show that the present analytical solutions have the values of stress in excellent agreement with the solutions derived by other investigators. Using this method, the effects of the thickness of bond coat on the thermal stresses of a typical sprayed thermal barrier coating, which consists of IN738LC substrate, MCrAIY bond coat and ZrO$_2$-8wt%Y$_2$O$_3$top coat, were investigated.

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New Approach for Nonlinear Analysis of Reinforced Cconcrete Fames (철근 콘크리트 골조 비선형 해석의 새로운 기법)

  • 김진근;이태규
    • Computational Structural Engineering
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    • v.5 no.2
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    • pp.119-127
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    • 1992
  • The entire nonlinear behavior of reinforced concrete frames up to collapse, is analyzed by the displacement control method and the combined layered and nonlayered method. All of the rigidities of section are calculated approximately by a sum over all the layers for the layered method, are used the integral values over the cross section area for the nonlayered method. The spurious sensitivity to the chosen element size in the result of analysis by finite element method for the materials with strain-softening can be overcome by modifying the strain distribution based on the concept of fracture energy at plastic hinge considering the applied axial load.

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Flexural Modeling of Strengthened Reinforced Concrete Beam with Nonlinear Layered Finite Element Method

  • Kim, Min-Kyung;Lee, Cha-Don
    • KCI Concrete Journal
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    • v.11 no.3
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    • pp.115-126
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    • 1999
  • An analytical method based on the nonlinear layered finite element method is developed to simulate an overall load-deflection behavior of strengthened beams. The developed model distinguishes itself by its capability to trace residual flexural behavior of a beam after the fracture of brittle strengthening materials at peak load. The model. which uses a rather advanced numerical technique for iterative convergence to equilibrium, can be regarded as superior to the two models based on load control and displacement control The model predictions were compared with the experimental results and it was observed that there was good agreement between them.

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Infiltration Analysis for Surficial Stability Evaluation of Two-layered Slopes (2층 지반의 표면파괴에 대한 안정성 평가를 위한 침투거동 해석)

  • Cho Sung-Eun
    • Journal of the Korean Geotechnical Society
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    • v.21 no.8
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    • pp.45-53
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    • 2005
  • Shallow slope failures in residual soil during periods of prolonged infiltration are common over the world. Therefore, this study examines an approximate method to estimate the influence of infiltration on surficial stability of slopes by one-dimensional infiltration model. Modified GAML model based on the Green-Ampt model was extended to predict the infiltration behavior of two-layered slope. Then, the model has been considered to evaluate the likelihood of shallow slope failure which is induced by a particular rainfall event that accounts for the rainfall intensity and duration for various return periods in two-layered soil profile. The results obtained from the approximate method were compared with those obtained from numerical analyses. According to the results, with the use of properly estimated input parameters, the proposed method was found to give good results that agree reasonably well to those of the more rigorous finite element analyses.

LDI (Layered Depth Image) Representation Method using 3D GIS Implementation (LDI 표현방법을 이용한 3D GIS 구현)

  • Song Sang-Hun;Jung Young-Kee
    • KSCI Review
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    • v.14 no.1
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    • pp.231-239
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    • 2006
  • Geographic information system (GIS) geography reference it talks the software system which is possible. When like this geographic information system in key feature trying to observe the problem which is an expression of geography information in the center, the research and development with 3 dimension expressions is active from 2 dimension expressions of existing and it is advanced. double meaning geography information which is huge to be quick, the place where it controls efficiently there is a many problem, the ring from the dissertation which it sees and 3 dimensions and efficient scene of the GIS rendering compared to the ring from hazard image base modeling and rendering compared to hazard proposal LDI (Layered Depth Images) it uses GIS rendering compared to the ring to sleep it does. It acquired the terrain data of 3 dimensions from thread side base method. terrain data of 3 dimensions which are acquired like this the place where it has depth information like this depth information in base and the LDI, it did it created. Also it was a traditional modeling method and 3DS-Max it used and it created the LDI. It used LDI information which is acquired like this and the GIS of more efficient 3 dimensions rendering compared to the possibility of ring it was.

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Calculating transmission loss of cylindrical silencers lined with multi-layered poroelastic sound absorbing materials using mode matching method (모드 매칭법을 이용한 다층 다공성 탄성 흠음재가 채워진 원통형 소음기의 음향투과손실 계산)

  • Lee, Jongmoo;Yang, Haesang;Seong, Woojae
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.4
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    • pp.375-388
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    • 2022
  • This paper deals with the process of obtaining sound transmission loss of a cylindrical silencer lined with multi-layered poroelastic sound absorbing materials. The Biot model and the Johnson-Champoux-Allard-Lafarge (JCAL) model were used to deal with waves propagating in multi-layered poroelastic materials. The boundary conditions required for analysis of the silencer were obtained and the numerical process of finding modes was explained. A numerical experiment was conducted on the 2-layered silencer using the modes and the transmission loss converged with the first 12 modes. Finally, the mode matching method proposed in this research was validated by being compared with the results calculated from Finite Element Method (FEM) about different kinds of sound absorbing materials.

Influence of Bubble Sheet Applying Methods on Temperature of Exposed Joint Rebar at Wall Surface of Load-Bearing Wall Structure Building During Winter (동절기 벽식구조 건축물 벽부분의 버블시트 포설방법 변화가 이음부 노출철근의 온도에 미치는 영향)

  • Han, Cheon-Goo;Lee, Jea-Hyeon;Kim, Min-Sang
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.2
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    • pp.149-155
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    • 2017
  • In this research, the surface covered curing method using the double-layered bubble sheet was evaluated. This double-layered bubble sheet has outstanding insulating performance with its low heat conductivity and high economic feasibility with its high durability. However, in the case of wall-typed building construction, the area of exposed rebar is curious on curing performance with the double-layered bubble sheet in spite of the double-layered bubble sheet showed favorable performance for slab. Therefore, in this research, regarding the actually constructed wall-typed apartment building, the most efficient curing method was suggested based on the evaluation of curing performance depending on temperature distribution depending on various location of covered or exposed rebar. As a result, the D method was determined as the most efficient curing method without any concern of early-age frost damage. However, by considering easiness of construction, the B method of covering the pieced double-layered bubble sheet on gap between rebars can be another option of desired result.

Relationship between Structural Stability and Crystallinity in Layered Manganese Oxide (층상구조 망간산화물에서의 구조적 안정도와 결정성과의 관계)

  • Hwang, Seong-Ju
    • Journal of the Korean Chemical Society
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    • v.48 no.1
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    • pp.46-52
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    • 2004
  • The effect of crystallinity on the structural stability of layered manganese oxide has been systematically investigated. While well-crystalline manganate was prepared by solid-state reaction-ion exchange method, nanocrystalline one was obtained by Chimie-Douce reaction at room temperature. According to micro-Raman and Mn K-edge X-ray absorption spectroscopic results, manganese ions in both the manganese oxides are stabilized in the octahedral sites of the layered lattice consisting of edge-shared MnO6 octahedra. The differential potential plot clarifies that the layered structure of nanocrystalline material is well maintained during electrochemical cycling, in contrast to the well-crystalline homologue. From the micro-Raman results, it was found that delithiation-relithiation process for well-crystalline material gives rise to the structural transition from layered to spinel-type structure. On the basis of the present experimental findings, it can be concluded that nanocrystalline nature plays an important role in enhancing the structural stability of layered manganese oxides.

Efficient Flooding Algorithm for Mobile P2P Systems using Super Peer (슈퍼피어를 이용한 모바일 P2P시스템을 위한 효율적인 플러딩 알고리즘)

  • Kang, So-Young;Lee, Kwang-Jo;Yang, Sung-Bong
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.2
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    • pp.217-221
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    • 2010
  • As the appearances of various new mobile devices and the explosive growth of mobile device users, many researches related to mobile P2P systems have been proceeded actively. In this paper, we propose a new search algorithm for the double-layered super peer system in the mobile environment. For the proposed search algorithm, we divide the entire experiment region into a grid of cells, each of which has the same size. The grid is configured properly by considering the communication range of a mobile device and the number of peers in the system. The proposed search algorithm is a partial flooding search method based on the directions of cells involved with the search. It reduces successfully the network traffic, but shows a low search hit ratio. To enhance the search hit ratio, we introduce a bridge-peer table for a super peer and utilize an n-way search. The experimental results show that the proposed algorithm made an average of 20~30% reduction in the number of message packets over the double-layered system. The success ratio was also improved about 2~5% over the double-layered system.

Validity of Two-layered Ocean Bottom Model for Ray Model (음선 모델에 적용된 이층 해저 바닥 모델의 유효성)

  • Lee, Keunhwa;Seong, Woojae
    • The Journal of the Acoustical Society of Korea
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    • v.34 no.6
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    • pp.470-478
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    • 2015
  • A heuristic method treating a layered ocean bottom in a ray modeling is to use the plane wave reflection coefficient for multiple-layered structure, named an one-layer assumption in this paper. We examine the validity of one-layer assumption in the case of two-layered ocean bottom, and obtain a simple inequality condition depending on the sound speed ratio, the ratio of layer thickness to source-receiver range, and the grazing angle of first reflected ray. From this inequality condition, it is shown that an one-layer assumption can be applicable to ray propagation problems at mid frequencies. Finally, numerical experiments are performed in the ocean environment similar to the East Sea in Korea. Incoherent transmission loss is calculated by the geometrical beam model with the plane wave reflection coefficient for multiple-layered ocean bottom and compared with the result of SNUPE 2.0, which is a parabolic equation package developed in Seoul National University.