The purpose of this study is to confirm the structural relationship between parental support, relationships with teachers, and stress variables on adolescents' mental health. Among the panel of 7,324 third-year high school students in the 8th survey in 2020 of the ‘Korean Education Longitudinal Study 2013’ conducted by the Korea Educational Development Institute, 6,054 people who participated in the survey were selected as research subjects. Frequency analysis, descriptive statistics, correlation analysis, and Bayesian structural equation model path analysis were performed using SPSS 26.0 and Amos 24.0. First, adolescents' parental support had a statistically significant positive effect on their mental health. Second, the relationship with teachers had a negative effect on stress and a positive effect on mental health. Third, it was confirmed that stress has a negative effect on the mental health of adolescents. Fourth, relationships with teachers had a positive effect on mental health with stress as a mediating variable. This study identified predictors that affect mental health at the point when adolescents' mental health problems become serious, and the research results can serve as data related to policy establishment and program operation in educational settings to improve mental health.

An elliptic blending Reynolds stress transport equation model for Newtonian fluids has been extended to predict polymer-induced drag reduction FENE-P fluids. The conformation tensor equation which is related to the polymer stress is adopted from the model form of Resende et al., and the models of redistribution and dissipation rate terms for the Reynolds stress transport equation are considered by the elliptic blending equation. Also, the new model terms for viscoelastic turbulent transport and viscoelastic dissipation in the Reynolds stress transport equation are introduced to consider the polymer additives effect. The prediction results are directly compared to the DNS data to assess the performance of the present model predictions.

An algebraic model for turbulent heat fluxes is proposed on the basis of the elliptic blending equation. The algebraic model satisfies the temperature-pressure gradient correlation characteristics of near-wall region and the flow center region far away from the wall. That is, the turbulent heat flux conditions for both regions are connected by the solution of the elliptic blending equation. The predictions of turbulent heat transfer in a plane channel flow have been carried out with constant wall heat flux and constant wall temperature difference boundary conditions respectively. Also, the rotating channel flow with constant wall temperature difference is considered to test the applicability of the model. The prediction results show that the distributions of the turbulent heat fluxes and mean temperature are well captured by the present algebraic heat flux model.

The Notched Ring Test(NRT) has proven to be very useful in determining the slow crack growth behavior of polyethylene pressure pipes. In particular, the test is simple and an order of magnitude shorter in experimental times as compared to the currently used Notched Pipe Test(NPT), which makes this method attractive for use as the accelerated slow crack growth test. In addition, since the NRT specimen is taken directly from the pipe, having maintained the cross-section, processing induced artifacts that would affect the slow crack growth behavior are not altered. This makes the direct comparison to the slow crack growth specimen in pipe from more meaningful. In this study, for comparison with other available slow crack growth methods, including the NPT, the stress intensity factor equation for NRT specimen was developed and demonstrated of its accuracy within 3% of that obtained from the finite element analysis. The equation was derived using a flexure formula of curved beam bending along with numerically determined geometric factors. The accuracy of the equation was successfully tested on 63, 110, 140, 160, 250, and 400 mm nominal pipe diameters, with crack depth ranging from 15 % to 45 % of the pipe wall thickness, and for standard dimensional ratio(SDR) of 9, 11, and 13.6. Using this equation the slow crack results from 110SDR11 NRT specimen were compared to that from the NPT specimen, which demonstrated that the NRT specimen was equivalent to the NPT specimen in creating the slow crack, however in much shorter experimental times.

본 연구는 국내 외국인유학생의 문화성향이 대학생활적응에 미치는 영향을 파악하기 위하여 Chun, Moos, and Cronkite(2006)가 제시한 스트레스-대처 맥락적 모형을 근거로 문화성향이 문화적응스트레 스, 자기효능감, 대처방식 및 대학생활적응에 영향을 미치는 경로에 대한 구조모형을 설정하고 검증 하였다. 자료 수집은 서울 소재 일 개 4년제 대학에 재학 중인 외국인유학생 363명을 대상으로 2013 년 6월 1일부터 7월 15일까지 실시하였다. 연구 결과 외국인유학생의 대학생활적응에는 개인주의성 향이 직접적인 영향을 미쳤고, 집단주의성향은 대학생활적응에 직접적인 영향을 미치진 않았으나 자 기효능감을 완전매개로 한 간접효과와 자기효능감이 적극적대처를 불완전매개로 한 간접효과 및 적 극적대처를 완전매개로 한 간접효과가 있었다. 또한 외국인유학생의 대학생활적응력을 향상시키고, 대학생활적응에 부정적 영향을 미치는 문화적응스트레스를 낮추기 위해서는 자기효능감이 중요한 중재방안이 될 수 있음도 확인되었다.