• Journal of Korean Academy of Nursing
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• v.35 no.2
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• pp.239-251
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• 2005

Purpose: This study was designed to construct a structural model for explaining mental health status in middle - aged women. Methods: The data was collected by self - reported questionnaires from 206 middle - aged women in Seoul. Data analysis was done with the SAS pc program for descriptive statistics and a PC - LISREL Program for finding the best fit model which assumes causal relationships among variables. Results: The overall fit of the hypothetical model to the data was good, but paths and variables of the model were modified by considering theoretical implications and statistical significances of parameter estimates. Thus it was modified by excluding 3 paths, The modified model showed was good fit to the data($x^2=177.55$, p=.00), GFI=0.908, AGFI=0.860, RMR=0.013, NFI=0.972, NNFI=0.982). Perceived stress, anger expression method, and self -esteem were found to have direct effects on mental health status in middle - aged women. These predictive variables of mental health status explained $66.6\%$ of the model. Conclusion: Programs to enhance mental health status in middle - aged women should include stress management skill, anger expression skill, and self -esteem enhancement skills to be effective.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.69-75
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• 2009

This paper examines the evolving role of ijang(village representative) and his job stress during Pyeongchang floods in 2006. Results based on telephone survey and interviews reveal that ijang played a crucial role in evacuating residents, allocating resources and commanding the recovery, although official job description considered him as only a mediator between local officers and villagers. Moreover, unexpected enormous burden created severe job stress to many ijangs; while 60 percent felt like quitting the job, about three fourth felt fretful whenever the telephone rang and lost some weights. Chi-square analysis also indicated that previous job training, villagers' abuse, and disaster damages were significantly related with job stress. These results suggest that the emergent human resources model rather than the command and control model can be an effective approach for a disaster management plan in rural Korea.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.1
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• pp.54-62
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• 2019

In this paper, a stress-strain model for high-strength confined concrete is proposed using compressive fracture energy. In the compression test performed by author in Reference [6], an acrylic bar with strain gauges was embedded in the center of the specimen to measure the local strain distribution. It was found from the test that the local strain measurement by this acrylic rod is very effective. The local fracture zone length was defined based on the local strain distribution measured by the acrylic rod. Specifically, it was defined as the length where the local strain increases more than twice of the strain corresponding to maximum stress. In addition, the stress-strain relationship of confined concrete with compressive fracture energy is proposed on the assumption that the amount of energy absorbed by the compressive members subjected to the given lateral confining pressure is constant regardless of the aspect ratio and size. The proposed model predicts even results from other researchers accurately.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1404-1414
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• 2008

In the mechanistic-empirical trackbed design of railways, the resilient modulus is the key input parameter. This study focused on the resilient modulus prediction model, which is the functions of mean effective principal stress and axial strain, for three types of railroad trackbed materials such as crushed stone, weathered soil, and crushed-rock soil mixture. The model is composed with the maximum Young's modulus and nonlinear values for higher strain in parallel with dynamic shear modulus. The maximum values is modeled by model parameters, $A_E$ and the power of mean effective principal stress, $n_E$. The nonlinear portion is represented by modified hyperbolic model, with the model parameters of reference strain, ${\varepsilon}_r$ and curvature coefficient, a. To assess the performance of the prediction models proposed herein, the elastic response of a test trackbed near PyeongTaek, Korea was evaluated using a 3-D nonlinear elastic computer program (GEOTRACK) and compared with measured elastic vertical displacement during the passages of freight and passenger trains. The material types of sub-ballasts are crushed stone and weathered granite soil, respectively. The calculated vertical displacements within the sub-ballasts are within the order of 0.6mm, and agree well with measured values with the reasonable margin. The prediction models are thus concluded to work properly in the preliminary investigation.

• The Journal of Korean Academic Society of Nursing Education
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• v.22 no.4
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• pp.452-461
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• 2016

Purpose: This study was conducted to investigate the relationships among communication competence, professional self-concept, and stress in clinical practice of nursing students. Methods: The study participants were 308 senior year nursing students in D city and K province. Collected data were analyzed using t-tests, analysis of variance, Pearson's correlation coefficient, and stepwise multiple regression with the SPSS Version 20.0. Results: There were significant differences in participants' stress of clinical practice based on their level of satisfaction on clinical practice, self-confidence of nursing and difficulty with relationships in clinical practice. A negative correlation was detected between stress in clinical practice and the professional self-concept of nursing students. Significant predictors of the perceived stress of clinical practice were satisfaction in clinical practice and pride in nursing. These accounted for 18% of the perceived stress of clinical practice in a regression model. Conclusion: The results may serve as basic data in support of the need to the develop effective systematic stress management programs and clinical training courses in order to attenuate the stress experienced during clinical practice of nursing students.

• Structural Engineering and Mechanics
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• v.18 no.2
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• pp.263-276
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• 2004

The purpose of this paper is to determine the subsoil depth affected from the load on the plate resting on elastic foundation using stress distribution within the subsoil that will be occurred depending on the loading and dimension of the plate. An iterative method is developed in order to determine the effective depth of the subsoil under the plate. Numerical examples from the technical literature are solved by means of the method suggested herein and displacements, bending moments and shear forces are presented in graphical and tabular forms to evaluate the effects of the limit depth considered in the study. Results showed the efficiency and simplicity of the present approach for the plate resting on an elastic foundation.

• Geomechanics and Engineering
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• v.28 no.5
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• pp.505-520
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• 2022

In recent years, geotextile-encased gravel columns (usually called stone columns) have become a popular method to increasing soil shear strength, decreasing the settlement, acceleration of the rate of consolidation, reducing the liquefaction potential and increasing the bearing capacity of foundations. The behavior of improved loose base-soil with gravel columns under shear loading and the shear stress-horizontal displacement curves got from large scale direct shear test are of great importance in understanding the performance of this method. In the present study, by performing 36 large-scale direct shear tests on sandy base-soil with different fine-content of zero to 30% in both not improved and improved with gravel columns, the effect of the presence of gravel columns in the loose soils were investigated. The results were used to predict the shear stress-horizontal displacement curve of these samples using support vector machines (SVM). Variables such as the non-plastic fine content of base-soil (FC), the area replacement ratio of the gravel column (Arr), the geotextile encasement and the normal stress on the sample were effective factors in the shear stress-horizontal displacement curve of the samples. The training and testing data of the model showed higher power of SVM compared to multilayer perceptron (MLP) neural network in predicting shear stress-horizontal displacement curve. After ensuring the accuracy of the model evaluation, by introducing different samples to the model, the effect of different variables on the maximum shear stress of the samples was investigated. The results showed that by adding a gravel column and increasing the Arr, the friction angle (ϕ) and cohesion (c) of the samples increase. This increase is less in base-soil with more FC, and in a proportion of the same Arr, with increasing FC, internal friction angle and cohesion decreases.

• Smart Media Journal
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• v.12 no.11
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• pp.1-9
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• 2023

Stress is a significant issue in modern society, often triggered by external or internal factors that are difficult to manage. When high stress persists over a long term, it can develop into a chronic condition, negatively impacting health and overall well-being. However, it is challenging for individuals experiencing chronic stress to recognize their condition, making early detection and management crucial. Using biosignals measured from wearable devices to detect stress could lead to more effective management. However, there are two main problems with using biosignals: first, manually extracting features from these signals can introduce bias, and second, the performance of classification models can vary greatly depending on the subject of the experiment. This paper proposes a model that reduces bias using convo utional autoencoders, which can represent the key features of data, and enhances generalizability by employing soft voting, a method of ensemble learning, to minimize performance variability. To verify the generalization performance of the model, we evaluate it using LOSO cross-validation method. The model proposed in this paper has demonstrated superior accuracy compared to previous studies using the WESAD dataset.

• Child Health Nursing Research
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• v.26 no.2
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• pp.238-253
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• 2020

Purpose: The purpose of this study was to explore the structure of variables in studies related to unmarried mothers (UMs) based on Neuman's systems model, and the stressors and stress responses of UMs. Methods: Whittemore and Knafl's methodology for integrative reviews was applied. The literature was searched using five electronic databases (KISS, KMbase, KoreaMed, NDSL, and RISS) and a total of 99 variables were collected from 15 studies published between 2009 and 2019. Results: The main stressors for UMs were a sense of loss and burden caused by childbirth and childrearing. The main stress responses were parenting stress and depression, respectively. Within the basic structure of variables related to UMs, self-esteem played a crucial role by helping UMs adapt to their situation. Meanwhile, social support of UMs was significantly correlated with parenting stress, depression, and self-esteem. Conclusion: In order to understand UMs' stress, is necessary to explore their sense of loss, burden, and self-esteem. Furthermore, it is important to assess the level of parenting stress and depression of UMs and to provide effective interventions to alleviate these stressors. The results of this study provide useful knowledge that can be applied to nursing assessment and interventions for stress management in UMs.

• Computers and Concrete
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• v.14 no.2
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• pp.109-125
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• 2014

The force transfer mechanism in positive moment continuity details for prestressed concrete girder bridges is investigated in this paper using a three-dimensional detailed finite element model. Positive moment reinforcement in the form of hairpin bars as recommended by the National Cooperative Highway Research Program Report No 519 is incorporated in the model. The cold construction joint that develops at the interface between girder ends and continuity diaphragms is also simulated via contact elements. The model is then subjected to the positive moment and corresponding shear forces that would develop over the service life of the bridge. The stress distribution in the continuity diaphragm and the axial force distribution in the hairpin bars are presented. It was found that due to the asymmetric configuration of the hairpin bars, asymmetric stress distribution develops at the continuity diaphragm, which can be exacerbated by other asymmetric factors such as skewed bridge configurations. It was also observed that when the joint is subjected to a positive moment, the tensile force is transferred from the girder end to the continuity diaphragm only through the hairpin bars due to the lack of contact between the both members at the construction joint. As a result, the stress distribution at girder ends was found to be concentrated around the hairpin bars influence area, rather than be resisted by the entire girder composite section. Finally, the results are used to develop an approach for estimating the cracking moment capacity at girder ends based on a proposed effective moment of inertia.