• Journal of Korean Elementary Science Education
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• v.34 no.4
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• pp.447-457
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• 2015

This study has attempted to find the teaching methods for the elementary students with low science achievement by examining the differences of science learning motivation, academic stress and stress coping styles and the characteristics shown in the relationship between them. To achieve this, the differences of science learning motivation, academic stress and stress coping styles of the elementary students with low science achievement and their relationship was set up as a study problem. A science learning motivation using a science learning motivation questionnaire reconfigured with PALS along with underachievers diagnosis were measured targeting 660 elementary students located in Seoul. Using an academic stress questionnaire and stress coping style questionnaire, an academic stress and stress coping styles were measured. The results of analyzing the collected data are as follows. First, a science learning motivation of elementary students with low science achievement was lower than the general students but the academic stress was shown higher. Especially, the self-efficacy of science learning motivation was significantly lower and the school stress was highest. For stress coping styles, a tendency of passive and avoidment coping styles were shown higher than the general students. Second, among the science learning motivation of elementary students with low science achievement, the self-efficacy motivation and school stress have shown a negative correlation but had a positive correlation with the goal-oriented motivation centered on ability. In the correlation between the science learning motivation of elementary students with low science achievement and the stress coping styles, the pursuit of social support coping styles have shown a significant positive correlation with the science learning motivation and its subcategories. As a result of conducting a regression analysis on the influence of academic stress and stress copying styles on the science learning motivation of elementary students with low science achievement, among the academic stresses, the school stress was shown to have the biggest influence. Among the stress coping styles, the pursuit of social support coping styles had the biggest influence on the science learning motivation followed by active coping behaviors, passive and avoidment coping behaviors. Low science learning motivation as underachievement factors of elementary students with low science achievement was identified as having a relationship with high school stress and undesirable stress copying styles. Therefore, guidance and a program are required for the elementary student with low science achievement to have desirable stress coping methods on the stressful situations. In addition, for the improvement of science learning motivation, a learning environment is needed for the elementary students with low science achievement with seeking of relevant educational methods.

• Journal of muscle and joint health
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• v.14 no.1
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• pp.5-12
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• 2007

Purpose: The purpose of the study was to identify the relationship between low back pain and job stress in hospital nurses. Method: A descriptive correlation research design was employed. The participants were 355 nurses who worked in a general hospital in W city Kangwon-do and consented to participate in this study. The Visual Analog Scale and job stress scale were used in this study. Analysis included descriptive statistics, t-test, ANOVA, and partial correlation coefficients. Results: Experience of low back pain for nurse in the past was 86.5% and in the present was 67.5% for low back pain which measured an average of 4.4 points for the level of low back pain. The mean score for job stress was relatively low(M=47.2). Job demand, organization system, job instability and conflict in relationships contributed to high stress scores, instead inappropriate compensation, job culture, and job autonomy contributed to low stress. There was a significant relationship between low back pain and job stress. Conclusion: These results suggest that further research is needed to develop programs to prevention and management of low back pain for nurses.

• Journal of Korean Society for Quality Management
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• v.25 no.1
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• pp.80-99
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• 1997

This paper considers designing the simple (2-level) constant-and step-stress ALTs minimizing the asymptotic variance of the maximum likelihood estimator of the accelaeration factor, which is defined as the ratio of the 100qth percentile at use stress to that a specified stress, for items having lognormally-distributed lives. It is assumed that (i) the log-linear relationship exists between the stress and the mean log life, (ii) the standard deviation of the log life is constant, and (iii) the cumulative exposure model holds for the effect of changing stress. For the constant-stress ALT the low stress and the sample proportion allocated to low stress are determined and for two modes of stress loading of step-stress ALTs, the low-to-high and high-to-low, the low stress and the stress change time are determined. For selected values of the design parameters the optimum plans are figured, two modes of step-stress ALTs and the constant-stress ALT are compared to each other, and the effects of the incorrect pre-estimates of the design parameters are investigated.

• Women's Health Nursing
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• v.17 no.5
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• pp.484-490
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• 2011

Purpose: This study was aimed to investigate the impact of job stress on low back symptoms among Clinical nurses (CNs) in university hospital. Methods: A total of 322 CNs employed in a hospital in Seoul were interviewed by a well-trained interviewer using the structured questionnaire. Data collected for this study includes demographics, social and work characteristics, low back symptoms, and job stress. To test the impact of job stress on low back symptoms, we used multiple logistic regression analysis. Results: The prevalence of low back symptoms was 25.8% in this study. Low back symptoms differed significantly by factors, such as physical work burden, past history of injury and work duration. Also low back symptoms differed significantly by organizational system among independent variables of job stress. In a multiple logistic regression analysis, the odds ratio of organizational system to low back symptoms was 2.07 after an adjustment. Conclusion: This study showed that organizational system among job stress was a significant variable in explaining low back symptoms. We suggest the improvement of organizational system category as a preventive strategy for low back pain in CNs working in hospital.

• Geomechanics and Engineering
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• v.25 no.4
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• pp.341-345
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• 2021

1D sand compression response to ko-loading experiences volume contraction from low to high effective stress regimes. Previous study suggested compressibility model with physically correct asymptotic void ratios at low and high stress levels and examined only for both remolded clays and natural clays. This study extends the validity of Enhanced Terzaghi model for different sand types complied from 1D compression data. The model involved with four parameters can adequately fit 1D sand compression data for a wide stress range. The low stress obtained from fitting parameters helps to identify the initial fabric conditions. In addition, strong correlation between compressibility and the void ratio at low stress facilitates determination of self-consistent fitting parameters. The computed tangent constrained modulus can capture monotonic stiffening effect induced by an increase in effective stress. The magnitude of tangent stiffness during large strain test should not be associated with small strain stiffness values. The use of a single continuous function to capture 1D stress-strain sand response to ko-loading can improve numerical efficiency and systematically quantify the yield stress instead of ad hoc methods.

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.4
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• pp.135-148
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• 2009

Purpose: The purpose of this study is to recognize correlation between stress and menstrual pattern among low-income women. Methods: From 5th October to 24th October 2009 we researched 14 low-income mothers by questionnaires to investigate their stress and menstrual patterns. Results: The mean level of their stress was $6.71{\pm}2.92$. The less the income was, the higher the stress was. Among the women, the stress of those who do not had husbands was also high. Most of the women's menarche came late and their menstrual cycle was long. The menstrual color was a little dark and they had blood clots and pain during menstruation. Their mental states also often changed over the period and they had pattern of blood stasis. The study observed that the higher the stress was, the worse the menstrual pain was. Conclusion: Low-income women are under stress by their socioeconomic status and their menstrual patterns often change. Stress has correlation with menstruation.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.519-525
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• 2015

Positive bias stress-induced instability in amorphous indium-gallium-zinc-oxide (a-IGZO) bottom-gate thin-film transistors (TFTs) was investigated under high $V_{GS}$/low $V_{DS}$ and low $V_{GS}$/high $V_{DS}$ stress conditions through incorporating a forward/reverse $V_{GS}$ sweep and a low/high $V_{DS}$ read-out conditions. Our results showed that the electron trapping into the gate insulator dominantly occurs when high $V_{GS}$/low $V_{DS}$ stress is applied. On the other hand, when low $V_{GS}$/high $V_{DS}$ stress is applied, it was found that holes are uniformly trapped into the etch stopper and electrons are locally trapped into the gate insulator simultaneously. During a recovery after the high $V_{GS}$/low $V_{DS}$ stress, the trapped electrons were detrapped from the gate insulator. In the case of recovery after the low $V_{GS}$/high $V_{DS}$ stress, it was observed that the electrons in the gate insulator diffuse to a direction toward the source electrode and the holes were detrapped to out of the etch stopper. Also, we found that the potential profile in the a-IGZO bottom-gate TFT becomes complicatedly modulated during the positive $V_{GS}/V_{DS}$ stress and the recovery causing various threshold voltages and subthreshold swings under various read-out conditions, and this modulation needs to be fully considered in the design of oxide TFT-based active matrix organic light emitting diode display backplane.

• Journal of muscle and joint health
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• v.20 no.2
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• pp.141-150
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• 2013

Purpose: This study was conducted to identify relationships among nursing activities, the use of body mechanics, and job stress in nurses with low back pain. Methods: Participants were 225 nurses with low back pain working at an university hospital. The data were collected with self-reported questionnaires at March, 2012 and analyzed by descriptive statistics, t test, ANOVA, Scheff$\acute{e}$e test and multiple regression analyses. Results: There was significantly a higher degree of pain in subjects who working at special units including intensive care units and emergency room than at general wards. Low back pain was negatively correlated with the use of body mechanical principles while it was positively associated with the degree of job stress. According to results of multiple regression analyses, low back pain was significantly associated with the use of body mechanics and job stress in nurses working at general ward and special units including intensive care units and emergency room. Conclusion: The use of the principles of body mechanics and reducing job stress are important to prevent low back pain in nurses. It is necessary to develop and apply stress management and education program about the use of the principles of body mechanics.

• Journal of Mechanical Science and Technology
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• v.18 no.10
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• pp.1782-1798
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• 2004

A numerical study of a natural convection in a rectangular cavity with the low-Reynolds-number differential stress and flux model is presented. The primary emphasis of the study is placed on the investigation of the accuracy and numerical stability of the low-Reynolds-number differential stress and flux model for a natural convection problem. The turbulence model considered in the study is that developed by Peeters and Henkes (1992) and further refined by Dol and Hanjalic (2001), and this model is applied to the prediction of a natural convection in a rectangular cavity together with the two-layer model, the shear stress transport model and the time-scale bound ν$^2$- f model, all with an algebraic heat flux model. The computed results are compared with the experimental data commonly used for the validation of the turbulence models. It is shown that the low-Reynolds-number differential stress and flux model predicts well the mean velocity and temperature, the vertical velocity fluctuation, the Reynolds shear stress, the horizontal turbulent heat flux, the local Nusselt number and the wall shear stress, but slightly under-predicts the vertical turbulent heat flux. The performance of the ν$^2$- f model is comparable to that of the low-Reynolds-number differential stress and flux model except for the over-prediction of the horizontal turbulent heat flux. The two-layer model predicts poorly the mean vertical velocity component and under-predicts the wall shear stress and the local Nusselt number. The shear stress transport model predicts well the mean velocity, but the general performance of the shear stress transport model is nearly the same as that of the two-layer model, under-predicting the local Nusselt number and the turbulent quantities.

• Journal of computational fluids engineering
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• v.6 no.4
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• pp.35-42
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• 2001

In this study, numerical calculations are carried out in order to evaluate the performance of low-Re Reynolds stress model based on SSG model for a swirling turbulent flow in a pipe. The results are compared with those of k-ε model, GL model and the experimental data. The results show that low-Re Reynolds stress model and GL model give better results than k-ε model. In the region near the wall, low-Re Reynolds stress model improves the predictions. However, there is no large difference between the predictions with two Reynolds stress models.