• Title/Summary/Keyword: Green function

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Unsteady Thermoelasic Deformation and Stress Analysis of a FGM Rectangular Plate (경사기능재료 사각 판의 비정상 열 탄생변형과 응력해석)

  • Kim, Kui-Seob
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.8
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    • pp.91-100
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    • 2004
  • A Green's function approach is adopted for analyzing the thermoelastic deformations and stresses of a plate made of functionally graded materials(FGMs). The solution to the 3-dimensional unsteady temperature is obtained by using the laminate theory. The fundamental equations for thermoelastic problems are derived in terms of out-plane deformation and in-plane force, separately. The thermoelastic deformation and the stress distributions due to the bending and in-plane forces are analyzed by using a Green's function based on the Galerkin method. The eigenfunctions of the Galerkin Green's function for the thermoelastic deformation and the stress distributions are approximated in terms of a series of admissible functions that satisfy the homogeneous boundary conditions of the rectangular plate. Numerical analysis for a simply supported plate is carried out and effects of material properties on unsteady thermoclastic behaviors are discussed.

Design and Planning Criteria for the Green Buffer Zone (환경친화적 완충녹지의 기준설정)

  • 박은영;유병림
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.2
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    • pp.25-35
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    • 2004
  • The purpose of the study is to analyze the existing situation of the green buffer zone in the large scale industrial site and other major residential apartment areas. In this study, it is specifically intended that the planning guideline be upgraded to adopt future landuse trends and thus to suggest design criteria for management of the buffer zone. The framework of the analysis is to review the current landuse, noise reduction, ecological implications and landscape in general. Although the major function of a green buffer zone is considered to protect the residential area from various hazards of industrial, traffic, and visual environment, the situation is that most of the zones are maintained at a minimum level of services by local government. The study carried out intensively almost every type of case studied throughout the country, which implies that the management of the green buffer zone should be expanded physically enough to function for its original objectives. The study recommends that ecological management of the green buffer zone be emphasized and therefore the criteria for this purpose as well as noise issue should be developed prior to the landuse aspects. The study suggests specific guidelines for planning and design for the green buffer zone development. This study should be verified positively through the sustainable monitoring and requires nationwide and overall examination so that it may be applied to whole green spaces.

A Comparative Study on Nonparametric Reliability Estimation for Koziol-Green Model with Random Censorship

  • Cha, Young-Joon;Lee, Jae-Man
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.231-237
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    • 1997
  • The Koziol-Green(KG) model has become an important topic in industrial life testing. In this paper we suggest MLE of the reliability function for the Weibull distribution under the KG model. Futhermore, we compare Kaplan-Meier estimator, Nelson estimator, Cheng & Chang estimator, and Ebrahimi estimator with proposed estimator for the reliability function under the KG model.

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A Study on Complex Image Method and hybrid CIM for Spatial Domain Green Function (공간영역 Green 함수의 복소영상법과 혼합 복소영상법에 관한 연구)

  • Kim, Sang-Jin;Kim, Young-Sik;Cheon, Chang-Yul
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1831-1833
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    • 1998
  • In this paper, A complex-image method(CIM) and efficient numerical integration algorithm is implemented to evaluate the spatial-domain Green's function through the Sommerfeld-type integral with a thick substrate. CIM is compared to numerical integration technique.

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Two-dimensional Unsteady Thermal Stresses in a partially heated infinite FGM Plate (부분 가열된 무한 경사기능재료 판의 2차원 비정상 열응력)

  • Kim, Kui-Seob
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.2
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    • pp.9-17
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    • 2007
  • A Green's function approach based on the laminate theory is adopted for solving the two-dimensional unsteady temperature field and the associated thermal stresses in an infinite plate made of functionally graded material (FGM). All material properties are assumed to depend only on the coordinate x (perpendicular to the surface). The unsteady heat conduction equation is formulated into an eigenvalue problem by making use of the eigenfunction expansion theory and the laminate theory. The eigenvalues and the corresponding eigenfunctions obtained by solving an eigenvalue problem for each layer constitute the Green's function solution for analyzing the two-dimensional unsteady temperature. The associated thermoelastic field is analyzed by making use of the thermal stress function. Numerical analysis for a FGM plate is carried out and effects of material properties on unsteady thermoelastic behaviors are discussed.

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$L^{\infty}$-CONVERGENCE OF MIXED FINITE ELEMENT METHOD FOR LAPLACIAN OPERATOR

  • Chen, Huan-Zhen;Jiang, Zi-Wen
    • Journal of applied mathematics & informatics
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    • v.7 no.1
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    • pp.61-82
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    • 2000
  • In this paper two so-called regularized Green's functions are introduced to derive the optimal maximum norm error estimates for the unknown function and the adjoint vector-valued function for mixed finite element methods of Laplacian operator. One contribution of the paper is a demonstration of how the boundedness of $L^1$-norm estimate for the second Green's function ${\lambda}_2$ and the optimal maximum norm error estimate for the adjoint vector-valued function are proved. These results are seemed to be to be new in the literature of the mixed finite element methods.

An Integrated Assessment of Green Environment on Urban Space (도시공간의 통합적 녹지환경 평가)

  • Lee, Woo-Sung;Jung, Sung-Gwan;Park, Kyung-Hun;You, Ju-Han
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.2
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    • pp.15-31
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    • 2014
  • The purpose of this study is to assess the green environment on urban space and to suggest the sustainable green space planning. The study area is Dalseo-gu which has the biggest spatial imbalance of green space among 7 districts of Daegu. Three functions such as nature-ecological, environment-control, and usage function were established for assessing the green environment. For the assessment step of nature-ecological function, 'green connectivity' and 'animal movement' were used. Also,'thermal environment' and 'temperature decrease' were utilized in terms of environment-control function and 'green space's service supply' were utilized in terms of usage function. According to the results of integrated assessment, the green rich zone(Grade I) was 44.8% of total area in Dalseo and this zone was distributed along the southern forest of Mt. Ap and Mt. Biseul and the northern forest of Mt. Gung and Mt. Waryong. On the other hand, the green broken zone(Grade IV) was located in the residential areas of Gamsam and Jukjeon and the residential and industrial areas of Wolseong 1 and Jincheon and this zone was 5.5% of total area. The findings from this study can be used as the plan criteria for construction and distribution of green space in urban master plan.

Approximation of Green Warranty Function by Radon Radial Basis Function Network (Radon RBF Network에 의해 그린 보증 함수의 근사화)

  • Lee, Sang-Hyun;Lim, Jong-Han;Moon, Kyung-Li
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.123-131
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    • 2012
  • As the price of traditional fuels soar, the alternatives are becoming more viable. And manufacturers are promoting the growing viability of electric and biofuel-powered vehicles through longer warranties. Now, these longer green environment (emission)warranties, sometimes called extended warranties or "super warranties," have been adapted. The main result of this paper is to present a new method to approximate a bivariate warranty function by using Radial Basis Function Network with application of Radon Transform and its inverse which is used to reduce the dimension of the warranty space. This method consist of the following stages: First, by using the Radon Transform, the bivariate warranty function can be reduced to one dimensional function. Second, each of the one dimensional functions is approximated by using neural network technique into neural sub-networks. Third, these neural sub-networks are combined together to form the final approximation neural network. Four, by using the inverse of radon transform to this final approximation neural network we get the approximation to the given function. Also, we apply the above method to some green warranty data of automotive vehicle company.

Development of a CPInterface (COMSOL-PyLith Interface) for Finite Source Inversion using the Physics-based Green's Function Matrix (물리 기반 유한 단층 미끌림 역산을 위한 CPInterface (COMSOL-PyLith Interface) 개발)

  • Minsu Kim;Byung-Dal So
    • Geophysics and Geophysical Exploration
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    • v.26 no.4
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    • pp.268-274
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    • 2023
  • Finite source inversion is performed with a Green's function matrix and geodetic coseismic displacement. Conventionally, the Green's function matrix is constructed using the Okada model (Okada, 1985). However, for more realistic earthquake simulations, recent research has widely adopted the physics-based model, which can consider various material properties such as elasticity, viscoelasticity, and elastoplasticity. We used the physics-based software PyLith, which is suitable for earthquake modeling. However, the PyLith does not provide a mesh generator, which makes it difficult to perform finite source inversions that require numerous subfaults and observation points within the model. Therefore, in this study, we developed CPInterface (COMSOL-PyLith Interface) to improve the convenience of finite source inversion by combining the processes of creating a numerical model including sub-faults and observation points, simulating earthquake modeling, and constructing a Green's function matrix. CPInterface combines the grid generator of COMSOL with PyLith to generate the Green's function matrix automatically. CPInterface controls model and fault information with simple parameters. In addition, elastic subsurface anomalies and GPS observations can be placed flexibly in the model. CPInterface is expected to enhance the accessibility of physics-based finite source inversions by automatically generating the Green's function matrix.