• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.11a
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• pp.31-36
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• 1997

Strength test using strain rosette gage have been conducted to investigate safety of an auxiliary tank in a high-pressure air compressor. Thickness of auxiliary tanks in 6063-T5 aluminum at toy are 9mm and 17mm. The result of strength test make a comparison the design in strength of materials by nominal stress and the design in fracture mechanics with consideration of crack size. Summarizing the result: Comparing with the safe working pressure of the strength test and that of the design method in strength of materials by nominal stress with the experimental values, it makes difference 11% and 39% for 9mm and 17mm thickness of auxiliary tanks, respectively, and that of the design method by fracture mechanics, it makes difference 4％ and 5% for them, respectively. It is confirmed that the design by fracture mechanics is more economical and safe design than the design in strength of materials by nominal stress.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.225-233
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• 2019

The purpose of this study was to investigate state-anxiety, dyadic adjustment and pregnancy stress in pregnant women and to identify factors influencing pregnancy stress. Data were collected 158 pregnant women. Data were analyzed using t-test, ANOVA, Scheffe's test, Pearson's correlation coefficient, stepwise regression analysis. There was statistically significant difference in state-anxiety on variable such as age. There were statistically significant difference in dyadic adjustment on variables such as education, religion, income. There was not statistically significant difference in pregnancy stress on variables. Pregnancy stress was positively correlated with state-anxiety. Pregnancy stress was negatively correlated with dyadic adjustment. State-anxiety was negatively correlated with dyadic adjustment. Factor influencing pregnancy stress was state-anxiety, which explained 25.1%. Findings provide useful information for further studies in pregnancy stress of pregnant women. Therefore, to reduce pregnancy stress of pregnant women, it is necessary to standardized nursing intervention program.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.210-217
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• 1996

Under strong shock loads including earthquake or blast, structures may start to crack in stress concentrated members. The continuous behavior of the structure changes to the discontinuous. In this study, numerical method analyzing continuous and discontinuous behavior of a structure is developed using a modified distinct element method. Equations of motion of each distinct element are integrated using the central difference method, one of the finite difference methods. Interactions between he elements are considered by an element and pore spring. The forces acting in the center of an element include contact stress transferred by element spring; tensile stress by pore spring; and external traction such as earthquake or blast load. To verify the proposed method, the behavior of the cantilever beam subject to the quasi-static concentrated force at the end is investigated. The failure behavior of the simply supported beam subject to the strong shock at the center is studied. The proposed method can predict the failure behavior of the structure due to the shock loading and the post-failure discontinuous behavior of the structure.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1250-1264
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• 2023

This paper presents approximate in-depth residual stress and plastic strain profiles for laser-peened alloy 600 surface via FE analysis. In approximations, effects of the initial welding residual stress and the number of shots are quantified. Based on FE analysis results, residual stress profiles are quantified by two variables; the maximum difference in stress before and after LSP, and the depth up to which the compressive residual stress exists. Plastic strain profiles are quantified by one variable, the maximum equivalent plastic strain at the surface. The proposed profiles are validated by comparing with published LSP experimental results for welded plates. Effects of the initial welding residual stress and the number of shots on these variables are discussed. The proposed profile can be directly applied to predict the mitigation effect of LSP on PWSCC and to efficiently perform structural integrity assessment of laser peened nuclear components.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.4
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• pp.45-53
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• 2022

In this study, the loading test and structural analysis were performed on the snow load and the results were compared. The load plates were loaded on the roof surface of the model, and structural analysis was performed under the same conditions. The result of loading test, the maximum displacement was observed in the center of the top, and the maximum stress was observed near the bottom point. Displacement and stress were found to have a high linear relationship with the load. Comparing the structural analysis results with the loading test results, the maximum displacement difference is 4.5% and the maximum stress difference is 10.2%. It is expected that closer results can be derived if the boundary conditions for the longitudinal direction of the model are clarified during experiments and analysis.

• Journal of Korean Academy of Nursing
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• v.17 no.2
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• pp.153-161
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• 1987

This descriptive-correlational study was conducted to recognize the relational between the Perceived social support and stress in pregnant women. The subject were comprised of 154 patients who were at 24 weeks over, and data were collected by way of questionnairs at K-university hospital in Seoul during 23 days (November 21, 1986 to December 13, 1986). The result of this study may be summerized as follows. 1) The degrees of the support from situation perceived by pregnant women were: the minimal 20 feints, the maximal 61 points and the mean 40.42 feints. 2) The degrees of stress perceived by pregnant women were: the minimal 32 points, the maximal 109 points and the mean 65.49 points. 3) The results of hypotheses were: the first hypothesis was not supported that the higher the degree of social support from situation perceived by pregnant women, the lower that of stress(r= -0.01129, p=0.8895) the second was supported that the higher the degree if support perceived indirectly by pregnant women, the lower that of stress(r= -0.23832, p=0.0029). the third was supported that the higher the degree of support perceived directly by pregnant women, the lower that of stress. (r= -0.36019, p=0.0001) 4) The fourth shows that in the relationships between the characteristics of socio-popualtion and obstetrics and the degree of social support, there was significant difference; i) the support from situation differs in learning (t= -2.178, p<.05), and satisfaction of marriage (F=5.06, p<.01) ii) the support perceived indirectly differs in learning (t= -3.065, p<.01), month of pregnant(F= 2.78, p <.05), satisfaction of marriage (F=20.08, p<.001) and forms of family (t=2.11, p<.05) iii) the support perceived directly differs in satisfaction of marriage (F=21.00, p <.001) and forms of family (t=2.11, p<.05) 5) the fifth shows that in the relationship between the characteristics of sociopopulation and obstetrics and stress, the degree of satisfaction of marriage only shows the significant statistical difference(F= 0.40, p<.01) 6) The sixth shows that the factor affecting the stress of pregnant women was the support perceived directly and its explanatory power was 12.9%.

• Journal of Technologic Dentistry
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• v.31 no.3
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• pp.67-85
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• 2009

This study aims to provide the research for dental technician's stress prevention and management with basic materials by understanding dental technician's psychosocial stress level and examining relevant factors. The subject of this study is 255 dental technologists who work mainly in Seoul Gyeonggi district for a month of April of 2009 and I conducted cross-sectional study through self administered survey. The contents of survey include general feature, occupational feature, health behavior feature. I used Karasek's Job Content Questionnaire, JCQ and Psychosocial well-being index, PWI-SF as means of measurement. To compare the level of dental technician's psychosocial stress, I conducted t-test and ANOVA and I measured the factors that are related with psychosocial stress symptom with step by step multiple regressive analysis. According to the result of Cronbach's a value which is yielded to verify the reliability of means of measurement, the reliability of concept is sufficient. The detailed result of this study is as follows. 1. According to the result of analyzing the stress symptom in accordance with general feature and occupational feature, those dental technologists who are older and not married, graduate from junior college, have lower position, work at university hospital or general hospital show lower stress(p<0.05). There is no difference in the level of psychosocial stress with regard to duty related feature, period of service, daily average working hours, monthly average pay. 2. With regard to health behavior feature, those dental technologists who control weight better and have meal more regularly show lower stress(p<0.05). Those dental technicians who smoke, drink liquid and take a suitable sleep show low stress but the difference does not have significance statistically. 3. With regard to the factors of stress in the workplace, those dental technicians who have lower duty related requirement, have higher duty related control ability, have higher social support, have less instability of employment and have less workload and physical burden show lower stress(p<0.05). 4. According to the result of analyzing the factors that influence dental technologist's stress symptom, social support has the most enormous influence on stress symptom. Unstable employment, regular exercise, regular eating, daily average sleeping hours and technological capacity are also important in this order. According to the result of this study, those dental technicians who have higher social support, less instability of employment, do exercise more regularly, take enough sleep more soundly and have higher technological capacity show lower psychosocial stress symptom. Therefore, to adjust appropriately the dental technician's stress and properly maintain and improve the dental technician's mental health, effective management plan that enables dental technicians to maintain smooth human relationships for dental technicians should be sought. In addition, heath education and health management for dental technicians should be given more thoroughly so that they can establish desirable health behavior in daily life.

• Korean Journal of Plant Resources
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• v.20 no.6
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• pp.544-547
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• 2007

The effects of hwangryun(Coptidis Rhizoma) on lowering lipid and oxidative stress in the induced obesity rat was observed. The concentration of plasma triglyceride in hwangryun treatment groups showed the low values compared to the control group, and as the increased hwangryun, the concentration of triglyceride decreased. The concentration of plasma total cholesterol decreased in all hwangryun treatment groups. However the concentration of plasma HDL-cholesterol and LDL-cholesterol showed no significantly difference in all the treatment groups. Thiobarbituric acid reactive substance(TBARS) concentration in plasma and liver showed low values in all hwangryun treatment groups compared to the control group. Glutathione peroxidase(GSH-Px) and superoxide dismutase(SOD) activities showed no significantly difference in all the treatment groups. However catalase(CAT) activity showed a tendence to increase in hwangryun groups, and in 200mg/kg hwangryun treatment group showed significantly a high value than the control group. Summarizing the results above, hwangryun has the functional materials that lowering lipid and works with oxidative stress.

• Journal of Welding and Joining
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• v.15 no.4
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• pp.187-193
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• 1997

In the weldmentsm the crack propagation rate is changed due to the residual stress. The crack propagation rate is high in the region with the residual stress. However it shows rhw same behavior with the base metal in the region that does not include the residual stress. The fatigue crack growth rate for the material with residual stresses can be predicted more precisely by using the effective stress ratio. The difference between experimental results and prediction results in the initial stage seems to be due to the redistribution of residual stresses and microstructural change.

• Health Communication
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• v.13 no.2
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• pp.223-231
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• 2018

Background: Many nursing university students were stressed during clinical practice. The purpose of this study was to identify the difference between stress of clinical practice and mental health according to behavioral styles in nursing university students. Methods: The participants of this study were 233 junior and senior nursing students who had experienced clinical practice. Data were collected by self-report questionnaires in online from November 2017 to March 2018. Collected data were analyzed with SPSS/WIN 25.0 using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients. Results: The most frequent DISC behavior style of the subjects was conscientiousness (43.8%), follewed by steadiness (19.7%), influence (18.9%), and dominance (17.6%). The participants'scores for stress of clinical practice and mental health were $3.35{\pm}0.55$ and $1.13{\pm}0.65$. The stress of clinical practice of the subjects was different according to DISC behavior styles(F=2.86, p=.038). The results show that the higher the score of stress of clinical practice was the higher the score of mental health(r=.51, p<.001). Conclusion: This study found that the difference of DISC behavioral styles can be attributed to stress of clinical practice. Therefore, nursing intervention program considering with the subjects'DISC behavior styles needs to be developed to reduce their stress of clinical practice.