• Steel and Composite Structures
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• v.46 no.2
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• pp.253-261
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• 2023

The goal of this paper is to investigate dynamic responses of simply-supported laminated micro beams under moving load. In the considered micro-scale problem, the modified coupled stress theory which includes the length scale parameter is used. The governing equations of problem are derived by using the Lagrange procedure. In the solution of the problem the Ritz method is used and algebraic polynomials are used with the trivial functions for the Ritz method. In the solution of the moving load problem, the Newmark average acceleration method is used in the time history. In the numerical examples, the effects of stacking sequence of laminas, fibre orientation angles and the length scale parameter on the dynamic responses of laminated micro beams are examined and discussed.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.27 no.2
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• pp.169-178
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• 2020

Purpose: This study examined the mediating effects of nursing professionalism on the relationship between the stress of clinical practice and compassion competence in nursing students. Methods: A correlational research design was used in this study. The participants were 120 nursing students recruited from three universities in South Korea. Data were collected using the self-reporting scales of stress of clinical practice, nursing professionalism, and compassion competence. Baron and Kenny's regression method and the Sobel test were used to analyze the mediating effects of nursing professionalism on the association between the stress of clinical practice and compassion competence. Results: The mean score for compassion competence was above average. Of the compassion competence domains, sensitivity and insights had the highest and lowest scores, respectively; there were significant mean differences in compassion competence scores according to their grade and level of satisfaction with nursing major. Compassion competence correlated negatively with the stress of clinical practice, whereas it correlated positively with nursing professionalism. In addition, nursing professionalism exerted full mediating effects on the relationship between the stress of clinical practice and compassion competence. Conclusion: The results suggested that enhancing nursing professionalism could help promote compassion competence among nursing students who experience stress in clinical practice.

• Journal of Korean Academy of Nursing Administration
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• v.17 no.3
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• pp.349-356
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• 2011

Purpose: In this study, differences and relationship between teaching style, personality, job stress, and job satisfaction among preceptors were examined. Method: The participants were 121 preceptors. Data were collected in November and December 2010 and analyzed using descriptive statistics, ANOVA, Scheffe's test, and Pearson correlation coefficients. Results: The most frequent teaching style was judgement-initiative, and personality scores were highest for conscientiousness. Job stress was average (3.05${\pm}$.59), and job satisfaction was below the mid-point level (2.76${\pm}$.39). Job stress and job satisfaction were significantly different according to teaching style. Significant correlations were found between personality and job stress, and personality and job satisfaction. Conclusion: These findings indicate that changes in perceived teaching style, and personality may be necessary to decrease job stress, and to promote job satisfaction among preceptors. The results of this study should be considered in the development of effective preceptor training programs.

• The Korean Journal of Food And Nutrition
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• v.32 no.3
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• pp.267-274
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• 2019

This study was performed to provide fundamental data on the dietary habits and food purchase types according to the stress patterns. The subject was 312 Chinese students in Gyeonggi region through a self-administered questionnaire. According to the results of the reliability analysis, the stress items showed an average of 2.91 and 0.846 for Cronbach alpha coefficient. The results of ANOVA analysis on the difference of dietary habits according to stress are as follows; There were significant differences for the meal frequency per day according to schoolwork, economic, general living, and dietary habits (p<0.05). Also, the general living pattern showed significant differences for the meal outside frequency and Chinese food intake (p<0.05). The results of ANOVA analysis on the difference of food purchase type according to stress are as follows; There was significant differences in degree of use of convenience foods according to interpersonal relationship, cooking method of convenience foods according to economics, the selection criteria of convenience foods according to schoolwork (p<0.05). The correlation coefficient of dietary habits and convenience food intake are 0.223, -0.147 in stress degree and dietary habits. In conclusion, I would like to provide the basic data necessary for the right choice of Chinese students' dietary habits and food purchases.

• Geomechanics and Engineering
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• v.6 no.2
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• pp.173-194
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• 2014

Laboratory and field data showed that deep mixed (DM) columns accelerated the rate of consolidation of the soft foundations. Most analyses of consolidation of DM column-improved foundations so far have been based on the elastic theory. In reality, the DM columns may yield due to the stress concentration from the soft soil and its limited strength. The influence of column yielding on the degree of consolidation of the soft foundation improved by DM columns has not been well investigated. A three-dimensional mechanically and hydraulically-coupled numerical method was adopted in this study to investigate the degree of consolidation of the DM column foundation considering column yielding. A unit cell model was used, in which the soil was modeled as a linearly elastic material. For a comparison purpose, the DM column was modeled as an elastic or elastic-plastic material. This study examined the aspects of stress transfer, settlement, and degree of consolidation of the foundations without or with the consideration of the yielding of the DM column. A parametric study was conducted to investigate the influence of the column yielding on the stress concentration ratio, settlement, and average degree of consolidation of the DM column foundation. The stress concentration ratio increased and then decreased to reach a constant value with the increase of the column modulus and time. A simplified method was proposed to calculate the maximum stress concentration ratios under undrained and drained conditions considering the column yielding. The simplified method based on a composite foundation concept could conservatively estimate the consolidation settlement. An increase of the column modulus, area replacement ratio, and/or column permeability increased the rate of consolidation.

• Tunnel and Underground Space
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• v.30 no.3
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• pp.256-269
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• 2020

The objective of this study is to evaluate the stress thresholds in crack development and the corrected fracture toughness of KURT granite under dry and saturated conditions. The stress thresholds were identified by calculation of inelastic volumetric strain from an uniaxial compression test. The corrected fracture toughness was estimated by using the Level II method (Chevron Bend specimen), suggested by ISRM (1988), in which non-linear behaviors of rock was taken into account. Average crack initiation stress(σ_ci) and crack damage stress(σ_cd) under a dry condition were 91.1 MPa and 128.7 MPa. While, average crack initiation stress(σ_ci) and crack damage stress(σ_cd) under a saturated condition were 58.2 MPa and 68.2 MPa. The crack initiation stress and crack damage stress of saturated ones decreased 36% and 47% respectively compared to those of dry specimens. A decrease in crack damage stress is relatively larger than that of crack initiation stress under a saturated condition. This indicates that the unstable crack growth can be more easily generated because of the saturation effect of water compared to the dry condition. The average corrected fracture toughness of KURT granite was 0.811 MPa·m^0.5. While, the fracture toughness of saturated KURT granite(K_CB) was 0.620 MPa·m^0.5. The corrected fracture toughness of rock in saturated condition decreases by 23.5% compared to that in dry condition. It is found that the resistance to crack propagation decreases under the saturated geological condition.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.1
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• pp.1-8
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• 2003

Topology optimization has been evolved into a very efficient conceptual design tool and has been utilized into design engineering processes. Traditional topology optimization has been using homogenization method and optimality criteria method. homogenization method provides relationship equation between structure which includes many holes and stiffness matrix in FEM. Optimality criteria method is used to update design variables while maintaining that volume fraction is uniform. Traditional topology optimization has advantage of good convergence but has disadvantage of too much convergency time. In one way to solve this problem, element removal method using the criterion of an average stress is presented. As the result of examples, it is certified that convergency time is very reduced.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.297-307
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• 2009

Korean household debt is one of the main sources of the current financial crisis. This paper studies the impact of household members' attributes such as a type of housing(self-own or rent), education, age, average monthly income of the head of household, and the area of residence, on the stress level of the household members due to household debt. We analyze a real data set collected by KB Kookmin Bank in 2004. We consider low and high stress level as a binary response variable and use a logistic regression model with the attributes of household members as explanatory variables. A simple but well-fitting model is selected by backward elimination method based on the likelihood statistic for goodness-of-fit test, and the impact of the attributes on the stress level is studied from parameter estimates of the selected model. We also perform the similar analysis on a binary response variable which distinguishes households with no debt from the rest. From the analysis, the stress level tends to be low for households with self-own houses, high average monthly income, low education level, and young members.

• Korean Journal of Health Education and Promotion
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• v.25 no.3
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• pp.153-165
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• 2008

Objectives: The purpose of this study was to understand health-promotion behaviors and to find factors associated with the behaviors among Korean-Chinese workers who live in Korea. Methods: The number of Korean-Chinese workers participated in this study was 187, and the sample was chosen using a convenient sampling method. To understand general characteristics, frequencies and percentages were utilized. To examine the seven categories of health-promotion behavior, their average scores were calculated. To explore factors related to health-promotion behaviors, a multiple stepwise regression analysis was performed. Independent variables used for the analysis were self-concept, social support, stress, perceived health status, and demographics. Results: The average score of the seven health-promotion behaviors was 2.35. Of the seven subcategories of health-promotion behaviors, the scores of rest/sleep and self-actualization were relatively higher; the scores of exercise and stress management were relatively lower. Of demographics and four factors of main interest (i.e., self-concept, social support, stress, perceived health status), education level, types of residence, social support, and perceived health status remained statistically significant. Among the four factors, social support had the greatest impact on health-promotion behaviors. Conclusions: This study has two suggestions. First, it is needed to develop strategies, which can help Korean-Chinese workers enhance levels of health-promotion behaviors regarding stress management and exercise. Second, considering the greatest effect of social support on health-promotion behavior, it is necessary to strengthen social support among Korean-Chinese workers.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.6
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• pp.302-308
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• 2001

SVD(Singular Value Decomposition) filter for the suppression of EMG in multi-lead stress ECG is studied. SVD filter consists of two parts. In the first part, the basis vectors were chosen from the averaged singular vectors obtained from the decomposed noise-free ECG. The singular vector is computed from the stress ECG and is compared itself with basis vectors to know whether the noise exist in stress ECG. In the second part, the existing elimination method is used, when one(or two) channels is(or are) contaminated by noise. But the proposed enhanced SVD filter is used in case of having the noise in the many channels. During signal decomposition and reconstruction, the noise-free channel or the least noisy channel have the weight of 1, the next less noisy channel has the weight of 0.8. In this way, every channel was weighted by decreased of 0.2 in proportion to the amount of the added noise. For the evaluation of the proposed enhanced SVD filter, we compared the SNR computed by the enhanced SVD filter with the standard average filter for the noise-free signal added with artificial noise and the patient data. The proposed SVD filter showed better in the SNR than the standard average filter. In conclusion, we could find that the enhanced SVD filter is more proper in processing multi-lead stress ECG.