• Title/Summary/Keyword: Mixed-effect modeling

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A study on structural relationship of receptivity to multiculturalism, communication and marital conflict: focused on mixed couples of FFWP (다문화 수용성, 의사소통, 부부갈등의 구조적 관계에 관한 연구: 국제 결혼한 세계평화통일가정연합 신도를 대상으로)

  • Park, Ok Ja;Yeo, Kyung Hwan
    • Journal of Family Relations
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    • v.21 no.2
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    • pp.149-167
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    • 2016
  • Objective: The purpose of this study is to verify the effect of receptivity to multiculturalism on marriage conflict of international marriage couples and mediation effect of communication between two variables. Method: The subjects are 205 individuals of mixed couples who are living in S. Korea. The mediation analysis was based on structural equation modeling followed by bootstrapping with the use of AMOS 22.0. The demographic variables are also controlled in the data analysis. Goodness-of-fit test using RMR, GFI, IFI, TLI, and CFI was conducted. Results: The study results were as follows: first, receptivity to multiculturalism had a direct effect on marital conflict and communication; second, communication had a direct effect on marital conflict; third, communication had a mediation effect between receptivity to multiculturalism and marital conflict. Conclusions: We could verify in this study that receptivity to multiculturalism and communication is the important factor for marital conflicts of mixed couples. More specifically, communication has a critical role for marriage life of mixed couples.

Centrifuge Modeling of Soft Clay with Vertical Drains Considering the Centrifuge Similarity (상사성을 고려한 배수재 설치 연약점토 지반의 원심모델링)

  • Yoo, Nam-Jae;Hong, Young-Kil;Jeong, Gil-Soo;Cho, Han-Ki
    • Journal of Industrial Technology
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    • v.27 no.A
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    • pp.111-120
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    • 2007
  • This paper is results of experimental research on the effect of application of similarity related to permeability of soil on the consolidation behavior as centrifuge modeling of consolidation is performed with the centrifuge model facility. In this research, the permeability of soil was controlled by changing the viscosity of porewater as the mixed water with glycerin was used during the centrifuge model experiments. The effect of drainage path on consolidation was investigated by installing the vertical drains. A serise of centrifuge model tests with conditions of single vertical and radial horizontal drainage were carried out. Kaolinite and Jumunjin standard sand were used as soft clay and surcharges respectively during tests. For testing condition of single vertical drainage considering similarity of permeability, it was found that consolidation with mixed porewater with glycerin was delayed in comparisons sons with test results with water only. For conditions of horizontal drainage with vertical drains, a low permeability by changing the viscosity of pore water resulted in delayed degree of consolidation at an initial stage of consolidation. But, it predicted not much differences in settlement as long as the consolidation time was sufficiently long enough to finish consolidation. Consequently, it was found that similarity in permeability should be considered to be critical for the case of centrifuge model experiments related to consolidation with long drainage path.

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Surface Treatment Effect on the Toilet by Numerical Modeling and High Speed CCD Camera (수치모델과 고속 CCD 카메라를 이용한 세변기 표면 처리 효과 특성 해석)

  • Roh, Ji-Hyun;Do, Woo-Ri;Yang, Won-Kyun;Joo, Jung-Hoon
    • Journal of the Korean institute of surface engineering
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    • v.44 no.1
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    • pp.32-37
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    • 2011
  • Numerical analysis is done to investigate the effect of surface treatment of a toilet on the cleanness. The surface treatment using plasma for the super-hydrophobic surface expects the self-cleaning effect of the toilet seat cover for preventing the droplets with a great quantity of bacteria during the toilet flushing after evacuation. In this study, the fluid analysis in the toilet during the flushing was performed by an ultrahigh-speed CCD camera with 1,000 frame/sec and the numerical modeling. And the spattering phenomenon from the toilet surface during urine was analyzed quantitatively by CFD-ACE+ with a free surface model and a mixed model of two fluids. If the surface tension of the toilet surface is weak, many urine droplets after collision bounded in spite of considering the gravity. The turbulence generated by the change of angle and velocity of urine and the variation of the collision phenomenon from toilet surface were modeled numerically.

Two Spool Mixed-Flow Turbofan Engine Performance Analysis Modeling (2 스풀 혼합흐름 배기방식 터보팬 엔진 성능해석 모델링)

  • Seungheon Lee;Hyoung Jin Lee;Sangjo Kim;Gyujin Na;Jung Hoe Kim
    • Journal of the Korean Society of Propulsion Engineers
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    • v.27 no.1
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    • pp.37-48
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    • 2023
  • In this study, performance analysis modeling of two spool mixed flow type turbofan engine according to steady-state and transient is performed. The target engine is selected as F100-PW-229 from Pratt & Whitney, and main engine components including fan, high pressure compressors, combustion, high pressure turbines, low pressure turbines, mixer, convergent-divergent nozzle are modeled. The cooling effect of turbine through secondary flow path are considered in engine simulation model. We develop in-house Matlab/Simulink-based engine performance analysis program capable of analyzing internal engine state and compare it with GASTURB which is generally used as a commercial engine analysis program.

Analysis of shallow footings rested on tensionless foundations using a mixed finite element model

  • Lezgy-Nazargah, M.;Mamazizi, A.;Khosravi, H.
    • Structural Engineering and Mechanics
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    • v.81 no.3
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    • pp.379-394
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    • 2022
  • Shallow footings usually belonged to the category of thick plate structures. For accurate analysis of thick plates, the contribution of out-of-plane components of the stress tensor should be considered in the formulation. Most of the available shallow footing models are based on the classical plate theories, which usually neglect the effects of the out-of-plane stresses. In this study, a mixed-field plate finite element model (FEM) is developed for the analysis of shallow footings rested on soil foundations. In addition to displacement field variables, the out-of-plane components of the stress tensor are also assumed as a priori unknown variables. For modeling the interaction effect of the soil under and outside of the shallow footings, the modified Vlasov theory is used. The tensionless nature of the supporting soil foundation is taken into account by adopting an incremental, iterative procedure. The equality requirement of displacements at the interface between the shallow footing and soil is fulfilled using the penalty approach. For validation of the present mixed FEM, the obtained results are compared with the results of 3D FEM and previous results published in the literature. The comparisons show the present mixed FEM is an efficient and accurate tool for solving the problems of shallow footings rested on subsoil.

Numerical Modeling of Soil-Cement based on Discrete Element Method (개별요소법을 이용한 시멘트 혼합토의 수치모델링)

  • Jeong, Sang-Guk
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.4
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    • pp.33-42
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    • 2016
  • Discrete Element Method was conducted for rock and coarse-grained materials in development of granular mechanics and related numerical model due to analyze and apply micromechanical property. And it was verified that the analysis to consider bonding effect was insufficient. In this study, to overcome limits of existing method, it was conducted to analyze difference between indoor test result and bonding effect using $PFC^{3D)}$. For indoor test of mixed soil, uniaxial compression tests by curing time and by cement content were performed. And, DEM to suitable for each condition of indoor test was conducted. In the result of this study, in terms of geotechnics, it was verified that DEM can be used for application as numerical laboratory as well as prediction of micro and macro behavior about bonding effect of mixed soil.

Effect of Microstructural Design on the Electrical Properties of Y2O3-Stabilized ZrO2 (미세구조 설계에 따른 이트리아 안정화 지르코니아의 전기적 성질 변화)

  • 김선재;김경호;오석진;강대갑;국일현
    • Journal of the Korean Ceramic Society
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    • v.30 no.9
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    • pp.717-722
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    • 1993
  • Effects of microstructures on the electrical properties of ZrO2 based ceramics were analyzed by modeling layer arrangements and mixed phase structures. Single layers and alternating multilayers were made from 3mol% and 8mol% Y2O3 doped ZrO2 powders, while mixed specimen was made by blending and compacting these raw powders. After sintering at 150$0^{\circ}C$ for 2hr in air, AC impedance characteristics were measured. Contributiion of bulk comonent to total resistivity and its temperature-dependence were larger in 8Y-ZrO2 single layer than in 3Y-ZrO2 single layer. The multilayered specimen connected in serial to electrodes showed partial characteristics of both 3Y-ZrO2 and 8Y-ZrO2 single layers. The multilayered specimen connected in parallel to electrodes and the mixed specimen exhibited characteristics mainly of 8Y-ZrO2 single layer. The multilayered specimen connected in parallel to electrodes revealed the highest electrical conductivity near the operating temperature of solid oxide fuel cell. However, it is expected that the mixed specimen is appropriate for the applications because of its relatively high electrical conductivity with high strength expected.

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Comparison of Absolute and Differential ECT Signals around Tube Support Plate in Steam Generator

  • Shin, Young-Kil;Lee, Yun-Tai;Song, Myung-Ho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.3
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    • pp.201-208
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    • 2005
  • In this paper, absolute and differential eddy current signals from various defects in the steam generator tube are numerically predicted and their signal slope characteristics are investigated. The signal changes due to frequency increase are also observed. After studying signal patterns from various defects and frequencies, the analysis of mixed defect signals affected by the presence of a ferromagnetic support plate is attempted. For the signal prediction, axisymmetric finite element modeling is used and this leads us to the slope angle analysis of the signal. Results show that differential signals are useful for locating the position of a defect under the support plate, while absolute signals are easy to presume and interpret even though the effect of support plate is mixed. Combined use of these two types of signals will help us accomplish a more reliable inspection.