• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7273-7284
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• 2015

The purpose of this study was to investigate the effect size of non-pharmacological intervention applied to patients with anxiety disorder and to provide information about evidence-based intervention. Twenty three studies were selected for meta-analysis through a systematic review of domestic studies. We searched journal articles published in Korea up to May, 2015 using the key words "Anxiety Disorders (MeSH)" and "Treatment or Intervention". Meta-analysis was performed using a random effects model, and the effect sizes on each of anxiety and depression were calculated. The effect size for anxiety of non-pharmacological intervention in this study was Hedges' g=1.693 (95% CI; 1.267-2.120), indicating a large effect size. The effect size for depression was Hedges's g=1.571 (95% CI; 0.481-2.661), indicating a large effect size. It is significant that this study systematically synthesized the study results for non-pharmacological intervention effects applied to patients with anxiety disorders in Korea. It also established a basis that can be applied to nursing intervention.

• Geomechanics and Engineering
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• v.18 no.4
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• pp.373-389
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• 2019

It is important to study the problem of durability for tunnel structures. As a main influence on the durability of tunnel structures, carbonation-induced corrosion is studied. For the complicated environment of tunnel structures, based on the data samples from real engineering examples, the intelligent method (genetic programming) is used to construct the service life prediction model of tunnel structures. Based on the model, the prediction of service life for tunnel structures in carbonation environments is studied. Using the data samples from some tunnel engineering examples in China under carbonation environment, the proposed method is verified. In addition, the performance of the proposed prediction model is compared with that of the artificial neural network method. Finally, the effect of two main controlling parameters, the population size and sample size, on the performance of the prediction model by genetic programming is analyzed in detail.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.1933-1943
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• 2001

A micromechanical model is presented for superplasticity in which heterogeneous microstructures are coupled with deformation behavior. The effects of initial distributions of grain size, and their evolutions on the mechanical properties can be predicted by the model. Alternative stress rate models such as Jaumann rate and rotation incremental rate have been employed to analyze uniaxial loading and simple shear problems and the appropriate modeling was studied on the basis of hypoelasticity and elasto-viscoplasticity. The model has been implemented into finite element software so that full process simulation can be carried out. Tests have been conducted on Ti-6Al-4V alloy and the microstructural features such as grain size, distributions of grain size, and volume fraction of each phase were examined for the materials that were tested at different strain rates. The experimentally observed stress-strain behavior on a range of initial grain size distributions has been shown to be correctly predicted. In addition, the effect of volume fraction of the phases and concurrent grain growth were analyzed. The dependence of failure strain on strain rate has been explained in terms of the change in mechanism of grain growth that occurs with changing strain rate.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.26-37
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• 2012

Multi-dimensional hydrodynamic and water quality models are widely used to simulate the physical and biogeochemical processes in the surface water systems such as reservoirs and estuaries. Most of the models have adopted the Eulerian grid modeling framework, mainly because it can reasonably simulate physical dynamics and chemical species concentrations throughout the entire model domain. Determining the optimum grid cell size is important when using the Eulerian grid-based three-dimensional water quality models because the characteristics of species are assumed uniform in each of the grid cells and chemical species are represented by concentration (mass per volume). The objective of this study was to examine the effect of grid-size of a three dimensional hydrodynamic and water quality model (EFDC) on hydrodynamics and mass transport in the Saemangeum Reservoir. Three grid resolutions, respectively representing coarse (CG), medium (MG), and fine (FG) grid cell sizes, were used for a sensitivity analysis. The simulation results of numerical tracer showed that the grid resolution affects on the flow path, mass transport, and mixing zone of upstream inflow, and results in a bias of temporal and spatial distribution of the tracer. With the CG, in particular, the model overestimates diffusion in the mixing zone, and fails to identify the gradient of concentrations between the inflow and the ambient water.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.624-635
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• 2024

In two-fluid simulations of flow boiling, the modeling of the mean bubble diameter is a key parameter in the closure relations governing the intefacial transfer of mass, momentum, and energy. Monodispersed approach proved to be insufficient to describe the significant variation in bubble size during flow boiling in a heated pipe. A population balance model (PBM) has been employed to address these shortcomings. During nucleate boiling, vapor bubbles of a certain size are formed on the heated wall, detach and migrate into the bulk flow. These bubbles then grow, shrink or disintegrate by evaporation, condensation, breakage and aggregation. In this study, a parametric analysis of the PBM aggregation and breakage models has been performed to investigate their effect on the radial distribution of the mean bubble diameter and vapor volume fraction. The simulation results are compared with the DEBORA experiments (Garnier et al., 2001). In addition, the influence of PBM parameters on the local distribution of individual bubble size groups was also studied. The results have shown that the modeling of aggregation process has the largest influence on the results and is mainly dictated by the collisions due to flow turbulence.

• Journal of Korean Academy of Nursing
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• v.48 no.2
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• pp.154-166
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• 2018

Purpose: This study aimed to identify the actor and partner effects of health status, marital satisfaction, and self efficacy on retirement preparation in middle aged couples using the Actor-Partner Interdependence Model. Methods: Participants were 121 middle aged couples living in Seoul, Gyeonggi-do and Daegu City, Korea. All measures were self-administered. The collected data were analyzed using SPSS 20.0 and AMOS 20.0. Results: 1) Wife's self efficacy and marital satisfaction showed direct actor and partner effects on retirement preparation in middle aged couples. Wife's health status showed an indirect actor effect through wife's self efficacy and marital satisfaction on wife's retirement preparation, and showed an indirect partner effect through husband's self efficacy on husband's retirement preparation. 2) Husband's self efficacy and marital satisfaction showed only direct actor effect on retirement preparation. Health status among the husbands showed an indirect actor effect on husband's retirement preparation through their self efficacy and marital satisfaction, and an indirect partner effect through wife's marital satisfaction on wife's retirement preparation. 3) The actor effect size of health status on self efficacy and marital satisfaction was larger among husband's than wife's. Additionally, the partner effect size of health status on self efficacy and marital satisfaction was different between the two groups; however, the actor and partner effect size of self efficacy and marital satisfaction on retirement preparation was the same for husband and wife. Conclusion: The results of this study indicate that nursing intervention strategies for improving self efficacy and marital satisfaction are strongly needed to enhance retirement preparation of middle aged couples in Korean community.

• Computers and Concrete
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• v.12 no.5
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• pp.585-612
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• 2013

The paper presents quasi-static numerical simulations of the behaviour of short reinforced concrete beams without shear reinforcement under mixed shear-tension failure using the FEM and four various constitutive continuum models for concrete. First, an isotropic elasto-plastic model with a Drucker-Prager criterion defined in compression and with a Rankine criterion defined in tension was used. Next, an anisotropic smeared crack and isotropic damage model were applied. Finally, an elasto-plastic-damage model was used. To ensure mesh-independent FE results, to describe strain localization in concrete and to capture a deterministic size effect, all models were enhanced in a softening regime by a characteristic length of micro-structure by means of a non-local theory. Bond-slip between concrete and reinforcement was considered. The numerical results were directly compared with the corresponding laboratory tests performed by Walraven and Lehwalter (1994). The advantages and disadvantages of enhanced models to model the reinforced concrete behaviour were outlined.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.848-854
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• 2014

A Meta-analysis refers to a statistical literature synthesis method from the quantitative results of many known empirical studies. We conducted a meta-analysis and review of external factors based on the technology acceptance model for Smartphone-related researches. This study surveyed 106 research papers that established causal relationships in the technology acceptance model published in Korean academic journals during 2008 and 2013. The result of the meta-analysis might be summarized that the playfulness has the highest effect size in the path from external factors to the perceived usefulness, with the effect size(0.536). Also the self efficacy showed the highest effect size(0.626) in the path from external factors to the perceived ease of use. Based on these findings, several theoretical and practical implications were suggested and discussed with the difference from previous researches.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.655-666
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• 2021

Objectives: A systematic review and a meta-analysis were performed investigate the factors related to turnover intention of dental hygienists in Korea. Methods: Literature between 2000 and January 2021 were used to support the meta-analysis, which focused on 21 factors extracted from 50 articles using a random effects model. The correlation coefficient, r, in the effect size was calculated. Results: Substantial literature was published after 2011 (76%); in academic journals (74%); and targeted nonmetropolitan areas (40%). Lawler's turnover intention tool was used in several studies. The effect size for each ecosystem was in the order of microsystem (r=0.325), mesosystem (r=0.307), macrosystem (r=0.259), exosystem (r=0.176), and individuals (r=0.171). The random-effects model indicated an overall average of r=0.311. The factor that showed a large effect size in relation to turnover intention was organizational commitment of the microsystem (r=-0.594). Furthermore, mesosystem reward (r=- 0.416), microsystem burnout (r=0.464), job stress (r=0.408), and job satisfaction (r=-0.405) were identified as other major factors. Conclusions: To lower the turnover rate of dental hygienists, it is important to focus on factors belonging to the microsystem, and mesosystem reward.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.47-53
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• 2007

The laminar combustion characteristics of interacting coal particles in a convective flow are numerically investigated at particle arrangement and size difference. The numerical simulations, which use the two-step global reaction model to account for the surrounding gas effect, show the detailed interaction among the inter-space particles, undergoing devolatilization and subsequent char burning. Several parametric studies, which include the effect of the gas temperature (1700 K), high pressure(10 atm) and variation in geometrical arrangement of the particle diameter on the volatile release rate and the char combustion rate, have been carried out. The comparison indicates that the shift to the multiple particle arrangement resulted in the substantial change of the combustion characteristics and that the volatile release rate of the interacting coal particles exhibits a strong dependency on the particle spacing and size difference.