• Title/Summary/Keyword: Mixed method

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The local influence of LIU type estimator in linear mixed model

  • Zhang, Lili;Baek, Jangsun
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.2
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    • pp.465-474
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    • 2015
  • In this paper, we study the local influence analysis of LIU type estimator in the linear mixed models. Using the method proposed by Shi (1997), the local influence of LIU type estimator in three disturbance models are investigated respectively. Furthermore, we give the generalized Cook's distance to assess the influence, and illustrate the efficiency of the proposed method by example.

The mixed finite element for quasi-static and dynamic analysis of viscoelastic circular beams

  • Kadioglu, Fethi;Akoz, A. Yalcin
    • Structural Engineering and Mechanics
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    • v.15 no.6
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    • pp.735-752
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    • 2003
  • The quasi-static and dynamic responses of a linear viscoelastic circular beam on Winkler foundation are studied numerically by using the mixed finite element method in transformed Laplace-Carson space. This element VCR12 has 12 independent variables. The solution is obtained in transformed space and Schapery, Dubner, Durbin and Maximum Degree of Precision (MDOP) transform techniques are employed for numerical inversion. The performance of the method is presented by several quasi-static and dynamic example problems.

Mixed Effects Kernel Binomial Regression

  • Hwang, Chang-Ha
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.4
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    • pp.1327-1334
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    • 2008
  • Mixed effect binomial regression models are widely used for analysis of correlated count data in which the response is the result of a series of one of two possible disjoint outcomes. In this paper, we consider kernel extensions with nonparametric fixed effects and parametric random effects. The estimation is through the penalized likelihood method based on kernel trick, and our focus is on the efficient computation and the effective hyperparameter selection. For the selection of hyperparameters, cross-validation techniques are employed. Examples illustrating usage and features of the proposed method are provided.

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Heuristic Method for Sequencing Problem in Mixed Model Assembly Lines with Setup Time (준비시간이 있는 혼합모델 조립라인에서 투입순서문제를 위한 탐색적 방법)

  • Hyun, Chul-Ju
    • Proceedings of the Safety Management and Science Conference
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    • 2008.11a
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    • pp.35-39
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    • 2008
  • This paper considers the sequencing of products in mixed model assembly lines. The sequence which minimizes overall utility work in car assembly lines reduce the cycle time, the number of utility workers, and the risk of conveyor stopping. The sequencing problem is solved using Tabu Search. Tabu Search is a heuristic method which can provide a near optimal solution in real time. Various examples are presented and experimental results are reported to demonstrate the efficiency of the technique.

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The Mixed Finite Element Analysis for Porous Media using Domain Decomposition Method (영역 분할기법을 이용한 포화 다공질매체의 혼합유한요소해석)

  • Lee, Kyung-Jae;Tak, Moon-Ho;Kang, Yoon-Sik;Park, Tae-Hyo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.4
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    • pp.369-378
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    • 2010
  • The mixed finite element analysis is the most widely used method for saturated porous media. Generally, in this method, direct method and iterative method are proposed to obtain unknown variable, however, the iterative method is recommended because the method provide numerical stability and accuracy under the material properties for solid and fluid are different. In this paper, we introduce staggered method which has strong numerical stability, and FETI(Finite Element Tearing and Interconnecting) which is one of decomposition methods are applied into the method in order to obtain numerical efficiency. In which, Lagrange Multipliers and conjugated gradient method to solve decomposed domain are proposed, and then, the proposed method is verified numerical efficiency by point to point MPI(Message Passing Interface) library.

A Study on Image Evaluation consequent on Lighting Environment in time of reading in Learning Space (학습공간에서의 독서 행위 시 조명환경에 따른 이미지평가 연구)

  • Lee, Jin-Sook;Park, Ji-Young;Seo, Eun-Ji
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.9
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    • pp.1-9
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    • 2015
  • The aim of this study is to deduce color temperature and illuminance by conducting the preference & affective evaluation consequent on illuminance change of ambient light in case of the lighting method of ambient light mixed with task light in time of reading which is visual work action among the action in learning space. As a result of the prior survey on preferred lighting method in time of the act of reading targeting 20 experts before doing evaluation, the method of lighting mixed with ambient light and task light was found to be the highest. Such a result is analyzed to be attributable to the fact that the less the difference in illuminance of nearby space and work surface because of the mixed method of lighting, the less the glare, which makes a reader feels easy and concentrate on reading. On the basis of descriptive statistics of evaluation results and impact analysis by category, this study recommends the application of combinations of ambient light illuminance ranging from 40lx to 100lx with color temperature of 5500~6000K in case of the method of lighting mixed with general light and task light.

Mixed-Mode Stress intensity Factors for Elliptical Corner Cracks in Mechanical Joints by Weight Function Method (가중함수법에 의한 기계적 체결부에 존재하는 타원형 모서리균열의 혼합모드 응력확대계수)

  • Heo, Sung-Pil;Yang, Won-Ho;Kim, Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.4
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    • pp.703-713
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    • 2001
  • Mechanical joints such as bolted or riveted joints are widely used in structural components and the reliable determination of the stress intensity factors for corner cracks in mechanical joints is needed to evaluate the safety and fatigue life. This paper analyzes the mixed-mode stress intensity factors of surface and deepest points for quarter elliptical corner cracks in mechanical joints by weight function method and the coefficients included in weight function are determined by finite element analyses for reference loadings. The extended form of the weight function method for two-dimensional mixed-mode to three-dimensional is presented and the number of terms in weight function is determined by comparing the results for the different number of terms. The amount of clearance is an important factor in evaluating the severity of elliptical corner cracks in mechanical joints and even horizontal crack normal to the applied load is under mixed-mode in the case that clearance exists.

Numerical analysis for the development of a Mixed-flow In-line duct fan with a high performance (고성능 사류식 In-line duct fan의 개발을 위한 전산해석)

  • Kim, Sung-Kon;Cho, Lee-Sang;Cho, Jin-Soo;Won, Eu-Pil
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.604-609
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    • 2001
  • This numerical analysis uses the lifting surface method and frequency-domain panel method based on the linear compressible aerodynamic theory. Increased knowledge of flow conditions within mixed-flow fan should indicates means of improving performance of these turbomachines. Thus, only an approximate solution is obtained whose prime intent is to recognize the most significant characteristics of the "ideal" geometry. For a given set of operating condition, the flow conditions within mixed-flow fan depend on the geometry of the machine (three-dimensional flow effects) and on the properties of the fluid. But most treatments of the problem have been concerned with the two-dimensional flow effects for incompressible, non-viscous fluids. Interest in the field of mixed-flow fan resulted in the undertaking of a program to develop reliable design procedures that would avoid the need for lengthy development work.

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A Study on the Modified Adaptive MMSE Filtering for Mixed-Noise Elimination in Image Signals (영상신호에서의 복합 잡음 제거를 위한 수정된 적응 MMSE 필터링에 관한 연구)

  • Lee, Je-Il;Kim, Sung-Hwan
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.4
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    • pp.70-76
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    • 1996
  • In the case of an image corrupted with mixed noise, conventional MMSE filter can not remove such a mixed noise properly, because the impulse moise cause a certain bias of the minimum mean-square error estimate at regions close to outliers. In this paper, we proposed the new method or removal of mixed noise by combining MMSE filtering structure with local multi-windowing method according to directions and with ranked-order method. As a result, the improvement of the image quality with the proposed was obtained between about 9.7 and 35.2 times in the sense of NMSE(normalized mean square errors) evaluation than that of MMSE filter. Also, we could obtain the enhanced image in the mixed noisy image from visual and quantitative aspect.

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NUMERICAL SIMULATION ON THE FLOW PHENOMENON OF SEDIMENT INHALATION BY DIFFERENCE OF WATER HEAD (수두차를 이용한 해저퇴적물 흡입현상의 수치시뮬레이션)

  • Jeong K.-L.;Lee Y.-G.;Jeong Uh-Cheul;Son Choong-Yul
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.213-217
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    • 2005
  • In this study the water including sediment is assumed that the density is different from fresh water. And the phenomenon inhaled by low pressure around the pipe is numerically simulated in two dimension. The simulation is done using finite difference method in rectangular staggered mesh system and Navier-Stokes equations and continuty equation are employed as governing equations. The method of Irregular leg lengths and stars are adopted to satisfy boundary condition of body boundary. Marker-Density method is used to calculate the density of mixed flow. Also SGS turbulence model is applied to consider vortex smaller then grid at high Renolds number. This study is to analyze inhalation phenomenon of mixed flow with sediment and to verify the numerical method for mixed flow. To verify the numerical results are compared with experimental results

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