• 대한토목학회논문집
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• 제26권4C호
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• pp.229-238
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• 2006

수직배수재가 설치된 연약지반의 압밀거동을 해석하기 위하여 아무리 정교한 수치해석기법을 사용하더라도 비균질 다층지반의 대표지반정수의 추정, 압밀거동에 대한 수치모델링 및 계측시스템 오차 등과 관련된 불확실성 때문에 실제 현장에서 관측되는 거동은 설계단계에서 예측된 거동과 종종 다르게 발생된다. 본 연구에서는 다층지반으로 구성된 복잡한 압밀물성특성을 갖는 연약지반에 대하여 압밀물성특성을 정확히 예측하기 위해 유전자 알고리즘에 근거한 역해석 기법을 제안하였다. 다층 연약지반의 압밀과정 초기단계에서 계측된 거동을 바탕으로 본 프로그램에 적용된 역해석기법을 이용하여 압밀거동과 관련된 주요 설계변수를 최적화함으로써 장래의 압밀거동을 비교적 정확히 예측하는 것이 가능하다. 국내 배수재가 설치된 다층지반에 대한 예제해석을 수행하여 제안된 역해석 기법의 적용성을 검토하였다.

• 대한간호학회지
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• 제54권1호
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• pp.73-92
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• 2024

Purpose: This study developed and tested a hypothetical model of health promotion behavior on migrant workers based on the Health Promotion Model and the Health Literacy Skills Framework. Methods: Data were collected from 298 migrant workers in 9 regions across the country from December 2020 to March 2021. The exogenous variables were e-health literacy, occupational stress, acculturation, and social support. The endogenous variables were perceived benefits of action, self-efficacy, and health promotion behavior. Data were analyzed using SPSS/WIN 25.0, AMOS 20.0, and R-4.0.3 program. Results: The model fit was appropriate. Social support had the most significant direct impact on the health promotion behavior of migrant workers. Perceived benefits of action and self-efficacy played a mediating role in the relationship among e-health literacy, social support, and health promotion behavior. Based on multi-group analysis, the migrant worker group with less than 5 years of residency had a more statistically significant effect on the relationship between perceived benefits of action and health promotion behavior than those with over 5 years. Conclusion: Providing social support as a critical administrative strategy to enhance the health promotion behavior of migrant workers is necessary. Furthermore, when developing an intervention program utilizing the internal mechanism between social support and health promotion behavior, a self-efficacy-enhancing strategy is considered to be more effective. Additionally, educating migrant workers with short-term residence of less than 5 years about the benefits of health behaviors is essential.

• Ocean Systems Engineering
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• 제13권4호
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• pp.349-365
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• 2023

Targeting a floating wave and offshore wind hybrid power generation system (FWWHybrid) designed in the Republic of Korea, this study examines the impact of the interaction, with multiple wave energy converters (WECs) placed on the platform, on platform motion. To investigate how the motion of WECs affects the behavior of the FWWHybrid platform, it was numerically compared with a scenario involving a 'single-body' system, where multiple WECs are constrained to the platform. In the case of FWWHybrid, because the platform and multiple WECs move in response to waves simultaneously as a 'multi-body' system, hydrodynamic interactions between these entities come into play. Additionally, the power take-off (PTO) mechanism between the platform and individual WECs is introduced for power production. First, the hydrostatic/dynamic coefficients required for numerical analysis were calculated in the frequency domain and then used in the time domain analysis. These simulations are performed using the extended HARP/CHARM3D code developed from previous studies. By conducting regular wave simulations, the response amplitude operator (RAO) for the platform of both single-body and multi-body scenarios was derived and subsequently compared. Next, to ascertain the difference in response in the real sea environment, this study also includes an analysis of irregular waves. As the floating body maintains its position through connection to a catenary mooring line, the impact of the slowly varying wave drift load cannot be disregarded. To assess the influence of the 2^nd-order wave exciting load, irregular wave simulations were conducted, dividing them into cases where it was not considered and cases where it was included. The analysis of multi-degree-of-freedom behavior confirmed that the action of multiple WECs had a substantial impact on the platform's response.

• 한국실내디자인학회논문집
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• 제2호
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• pp.17-21
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• 1994

The purpose of this study was to compare the spatial structures for household activities according to the house size. multi-Dimentional Scaling analysis was done, using questinonaire data from 349 middle income housewives living in apartment in the area of Captital region. This was an extended article of previous one. In case of house whose size was less than 20 Pyung, washing cloth and bathing behavior took place in the same place whereas in other house size, bathing behavior was incoperated into various behaviors usually shown in the bedroom. The ideal structure in the house of 20 Pyung's showed home office space closer to the bedroom area whereas in others it appeared independently.

• 한국콘텐츠학회논문지
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• 제9권5호
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• pp.277-283
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• 2009

국제결혼이 문제가 되는 경우는 대부분 2세들이 사화와의 충돌이나 갈등을 야기 시키기 때문이므로 이 문제가 부각되기 전에 이에 대한 연구와 준비가 필요하다. 이에 본 연구는 다문화(국제결혼) 가정 자녀들의 보육시설에서의 행동특성을 분석하여 언어, 정서, 또래관계, 집중력 등의 발달 수준이 일반 가정의 어린이들과 어떤 차이가 있는지를 분석하였으며, 그 결과에 의하여 다문화가정 자녀의 보육지도를 위한 교수 전략을 개발하였다.

• Interaction and multiscale mechanics
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• 제4권3호
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• pp.239-245
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• 2011

The dynamic mechanical behavior of silicone rubber reinforced with multi-walled carbon nanotubes (MWCNTs) has been investigated in this study. The MWCNT-reinforced nanocomposites are tested in compression mode through dynamic mechanical analysis (DMA). Multiple effects including MWCNT loading, testing frequency, dynamic strain amplitude, and pre-strain level are taken into consideration. Results show that, by adding 5 wt% of MWCNTs, the dynamic stiffness and damping coefficient of the silicone rubber are significantly enhanced. It is further observed that the dynamic mechanical properties of the nanocomposites are sensitive to dynamic strain amplitude but only slightly affected by pre-strains.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.592-595
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• 2011

A numerical investigation on a suction vortices, free vortices and subsurface vortices behavior in the model sump system with multi-intakes is performed A test model sump and piping system were designed based on Froude similitude for the prototype of the recommended structure layout by HI-9.B Standard for Pump Intake Design of the Hydraulic Institute. A numerical analysis of three dimensional multiphase flows through the model sump is performed by using the finite volume method of the CFX code with multi-block structured grid systems. A ${\kappa}-{\omega]$ ShearStressTransportturbulencemodelandthe Rayleigh-Plesset cavitation model are used for solving turbulence cavitating flow. From the numerical analysis, several types of vortices are reproduced and their formation, growing shedding and detailed vortex structures are investigated. To reduce abnormal vortices, an anti-vortex device is considered and its effect is investigated and discussed.

• Structural Engineering and Mechanics
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• 제91권4호
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• pp.349-355
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• 2024

This paper investigates the influence of the torsional component of earthquake on the nonlinear structural behavior of reinforced concrete (RC) buildings. It also estimates the equivalent additional eccentricity that results from this component. For this purpose, we generate torsional accelerograms from translational ones and conduct nonlinear seismic analysis on both regular and irregular structures. The results show that the torsional component has a significant impact on the structural response, especially for irregular structures. The equivalent additional eccentricity of the cases studied was higher than 5% which is the value of accidental eccentricity suggested by many seismic codes.

• 대한기계학회논문집A
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• 제32권8호
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• pp.642-653
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• 2008

In this paper, we propose a 3-D finite element (FE) analysis model with combined physical behavior and kinematical impact factors for evaluation of residual stress in multi-impact shot peening. The FE model considers both physical behavior of material and characteristics of kinematical impact. The physical parameters include elastic-plastic FE modeling of shot ball, material damping coefficient, dynamic friction coefficient. The kinematical parameters include impact velocity and diameter of shot ball. Multi-impact FE model consists of 3-D symmetry-cell. We can describe a certain repeated area of peened specimen under equibiaxial residual stress by the cell. With the cell model, we investigate the FE peening coverage, dependency on the impact sequence, effect of repeated cycle. The proposed FE model provides converged and unique solution of surface stress, maximum compressive residual stress and deformation depth at four impact positions. Further, in contrast to the rigid and elastic shots, plastically deformable shot produces residual stresses closer to experimental solutions by X-ray diffraction. Consequently, it is confirmed that the FE model with peening factors and plastic shot is valid for multi-shot peening analyses.

• Journal of Welding and Joining
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• 제8권3호
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• pp.79-88
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• 1990

Welded joint often contains soft or softened regions such as the HAZ of TMCP steel welded with high heat input. In this study, the equivalent yield strength of plate structure containing softened region was predicted by FEM analysis, and its incremental behavior was explained with the results of the analysis. The calculated results of yield strength indicated the following for the plate structures. 1) As the softened region starts to yield, shear stress begins to build up along the boundary between base metal and softened region. This results in multi-axial stress condition which gives restraint on the softened region. 2) Restraint effect has a significant influence on the distribution of the shear stress, the nominal stress, and the strain. 3) The yielding behavior of softened region becomes the same as that of base metal when both ratios of length to width and thickness to width of softened region are larger than 30 and 13 respectively.