• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.2
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• pp.58-62
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• 2004

The shape evolution of the interface void of copper metallization for intergrated circuits under electromigration stress is modeled. A 2-dimensional finite-difference numerical method is employed for computing time evolution of the void shape driven by surface diffusion, and the electrostatic problem is solved by boundary element method. When the diffusion coefficient is isotropic, the numerical results agree well with the known case of wedge-shape void evolution. The numerical results for the anisotropic diffusion coefficient show that the initially circular void evolves to become a fatal slitlike shape when the electron wind force is large, while the shape becomes non-fatal and circular as the electron wind force decreases. The results indicate that the open circuit failure caused by slit-like void shape is far less probable to be observed for copper metallization under a normal electromigration stress condition.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.16 no.3
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• pp.181-192
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• 2012

Here in this paper, the steady paint film flow on a vertical wall of a non-Newtonian pseudo plastic fluid for drainage problem has been investigated. The exact solution of the nonlinear problem is obtained for the velocity profile. Also the average velocity, volume flux, shear stress on the wall, force to hold the wall in position and normal stress difference have been derived. We retrieve Newtonian case, when material constant ${\mu}_1$ and relaxation time ${\lambda}_1$ equal zero. The results for co-rotational Maxwell fluid is also obtained by taking material constant ${\mu}_1$ = 0. The effect of the zero shear viscosity ${\eta}_0$, the material constant ${\mu}_1$, the relaxation time ${\lambda}_1$ and gravitational force on the velocity profile for drainage problem are discussed and plotted.

• Journal of Nutrition and Health
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• v.28 no.5
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• pp.375-386
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• 1995

This study was designed to investigate the changes in energy substrates, glucose and non-esterified fatty acid(NEFA), and fatty acid compositions in serum, following physiolgical stress in rats fed diets containing various fatty acids. Forty two Sprague-Dawley strain male rats, weighing 108$\pm$2.1g, were fed 3 different experimental diets for 4 weeks. The diets were composed of 105 fat(w/w) of either corn oil(CO;18:2 n6:57%), plant perilla oil(PO;18:3 n3:59%), or tuna fish oil(FO;20:5 n3:17%%, 22:6 n3:19%). After 4 weeks of feeding, each group wa subdiveided into (a) control, (b) 2 min swim in ice-cold water. Animals wer decapitated 20min after commencing the swim; trunk blood, brain, liver and epididymal fat pad were obtained. The levels of serum corticosterone, glucose, NEFA, triglyceride, fatty acid compositions, brain serotonin and 5-hydroxyindoleacetic acid were determined. Basal levels of corticosterone na NEFA of serum were significantly lower in fish oil fed animals than those of any other oil fed animals. Compared to either perilla oil-fed or corn oil-fed rats, cold swim stress in fish oil fed rats produced significantly smaller NEFA and larger corticosterone responses. However, there was no significant difference in basal levels of serum glucose. Stress increased serum glucose levels slightly, and the amount of increment was larger in fish oil rats than those of any other oil fed rats than those of any other oil fed rats, although all the values were normal level. Dietary fats and stress did not affect serotonin metabolism. In additions, the composition of fatty acids in serum was significantly affected by the dietary compostion of fatty acids and stress. Stress induced decreases in monounsaturated fatty acid and non-polyunsaturated fatty acid concentration in either perilla oil fed or fish group, but did not in corn oil fed group. Stress resulted in changes in fatty acid metabolism similar to that associated with essential fatty acid(EFA) dificiency, when feeding animals n-3 fatty acids in diet. In conclusion, feeding fish oil was more effective to decrease NEFA in serum than feeding perilla oil or corn oil and improved lipid metabolism, when the rats were maintained in normal or exposed to stressful environment. However, the fact that feeding diet containing n-3 fatty acids decreased EFA status under stress suggests that the requirement of n-6 PUFA should be increased in these groups.

• Sleep Medicine and Psychophysiology
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• v.25 no.1
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• pp.15-20
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• 2018

Objectives: This study was designed to assess the change of heart rate variability (HRV) at resting, upright, and psychological stress states in depressive disorder patients. Methods: HRV was measured at resting, upright, and psychological stress states in 62 depressive disorder patients. We used visual analogue scale (VAS) score to assess tension and stress severity. Beck depression inventory (BDI) and state trait anxiety inventories I and II (STAI-I and II) were used to assess depression and anxiety severity, respectively. Differences between HRV indices and VAS score were evaluated using paired t-tests. Gender difference analysis was conducted with ANCOVA. Results: SDNN (standard deviation of normal to normal intervals), LF/HF (low frequency/high frequency), and VLF (very low frequency) were significantly increased, while NN50 and pNN50 were significantly decreased in the upright position compared to resting state. SDNN, RMSSD (root mean square of the differences of successive normal to normal intervals), and VLF were significantly increased, while pNN50 was significantly decreased in the psychological stress state compared to resting state. SDNN, NN50, and pNN50 were significantly lower in an upright position compared to a state of psychological stress, and LF, HF, and LF/HF showed no significant differences Conclusion: The LF/HF ratio was significantly increased after physical stress in depressive disorder. However, the LF/HF ratio was not significantly increased after psychological stress, and the change in LF/HF ratio after physical stress and psychological stress did not significantly differ from each other. Significant increase in SDNN, NN50, and pNN50 in an upright posture compared to psychological stress suggests that depressive patients react more sensitively to physical stress than psychological stress.

• Korean Journal of Human Ecology
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• v.12 no.4
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• pp.433-447
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• 2003

Since self-efficacy was suggested by Bandura(1977) as the most important factor that affects human behavior, preceding studies about self-efficacy are frequently related with children, and it is a main stream that only personal factors are chosen as related factors of these studies. Considering we don't have enough studies about family factors that reflect qualitative and relational factors of adolescents' home background, this study was aimed to seize the actual condition of self-efficacy meaning perceived and emotional faith about their own ability. These are our major concerns: 1. What kind of tendency does self-efficacy and appearance stress of adolescents, family functioning show? 2. How strong are relative influences of variables on self-efficacy of adolescents? This study was operated on July and August, 2002, aimed 378 middle school and high school students in Jeon-Nam, Mokpo area. 378 question sheets were used for analysis. Followings are results of this study. First, aimed students' average mark of self-efficacy was 2.09, which meant a normal level. And in low-ranked part, self-control-efficacy was the highest, and confidence task difficulty preference was following. Furthermore, whole self-efficacy showed a little difference from the demographic factor of adolescents. In low-ranked part, however, confidence and self-efficacy showed a somewhat difference. As students grew up, confidence decreased, and male students showed higher self-control-efficacy than female ones. Second, appearance stress and family functioning degree had a strong relation with self-efficacy. Family functioning, had important interrelation not only with whole self-efficacy but also with low-ranked part of self-efficacy. In low-ranked part, self-control-efficacy and task difficulty preference were proportional to the family functioning degree. From these results, we can find that the appearance stress was an actual factor that affected the self-efficacy of adolescents, and their self-efficacy was strongly related with family functioning degree. Accordingly, affirmative emotion in family, harmonic communication among family members and sharing housekeeping works had an immediate influence on elevation of self-efficacy.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.33 no.4
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• pp.44-54
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• 2020

Objectives : In the present study, we investigated whether or not an herb mixture including Lycii fructus(HML) has attenuation effects on light stress in rats. Methods : Light stress was induced by exposure to 300 lx of constant lifht for 24 h and 1mg/kg of caffeine was injected into the rat. Rats were orally treated with distilled water of HML for 21 days at 100mg/kg/d. The changes of mortality rate, clinical signs, body, blood chemistry, melatonin and IL-2 expression were analyzed after experiment. Results : Normal weight changes were observed in all treatment groups. In addition, no changes were observed in dead animals and general symptoms. At the time of autopsy, the appearance of all groups and gross examination of major organs were observed, and no gross findings were observed. Blood biochemical tests showed that total cholesterol and HDL cholesterol levels were statistically significantly decreased in the group treated with HML compared to the stress-induced group. Melatonin was measured in the blood, but there was no significant difference in the group treated with HML compared to the group with stress-induced group, but it tended to increase. IL-2 was measured in the blood, no significant change was observed in the group treated with HML compared to the stress-induced group. Conclusions : According to the above results, HML maybe help with hematological changes expressed by caffeine and light-induced stress.

• Journal of Nutrition and Health
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• v.40 no.4
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• pp.347-361
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• 2007

The purpose of this study was to analyze and evaluate dietary intake between with and without hypertension. Study subjects were more than 30 years old adults (n = 3,806) who participated in the 2001 Korea National Health and Nutrition Examination Survey. People who have 'self-recognition about hypertension' and 'having diet for hypertension' were excluded. Using the WHO standard, subjects were divided into the hypertensive group (SBP> 140, DBP> 90) and the normal group (SBP< 140, DBP< 90). The Body Mass Index (BMI) and the Waist-Hip Ratio (WHR) of a hypertensive group were higher than those of a normal group (p < 0.01). The distribution of the subjects for smoking, alcohol consumption, exercise, stress, preference of salty food were not significantly different between a normal group and a hypertensive group (p>0.05). Dietary intakes were investigated by the 24-hour recall method. When food and dish intakes analyzed by sociodemographic factors, normal group consumed more fruits than those of a hypertensive group. Statistical significant were shown at female group, residences in metropolitan area and having elementary school education (p<0.05). Hypertensive group consumed more alcoholic beverages than those of a normal group at 'age 39-39', 'aged 50-64', 'high economic status', 'low economic status' and 'residences in metropolitan' (p<0.05) The amount of intakes for fat, potassium, thiamin, vitamin C and alcohol were significantly different between the normal group and the hypertensive group (p<0.05). The highest score of the Dietary diversity score (DDS) was 4 in both normal group and hypertensive group. Normal group showed high Nutrition Density (ND) of vitamin C and hypertensive group showed high ND of sodium. In summary, these results showed that significant difference for people with hypertension were intakes of fruits, alcohol, thiamin, vitamin C. And these results differed by sociodemographic groups. Therefore, the differential approach in each group is demanded for prevention and control of the hypertension.

• Journal of Korean Biological Nursing Science
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• v.3 no.1
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• pp.11-28
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• 2001

This study was to identify the levels of perceived stress, immunity cells, physical health and depression, and their relationships among those variables in the elderly who institutionalized comparing home residents. The result of this study can be used as basic data when applying nursing interventions to increase quality of life in the elderly. The questionnaires to estimate stress, health status and depression were collected through direct interview from July to August in 1999 and immunity cells were measured by venous blood specimen collected from 9 to 10 A.M. during the same period. The collected data were analysed using SAS program. The results were as follows. The score of perceived stress of all subjects was 38.49 and perceived stress score of institutionalized elderly(42.62) was significantly higher than that in home resident elderly(34.52). All immune cells tested in this study such as total T cell, helper T cell, suppressor T cell, T4/T8 ration, total B cell, and NK cell, were all under the standard criteria of cells distributions. Most elderly who institutionalized and reside home replied that their health status was not good. However their physical health activity was mostly good even though institutionalized elderly had more disability than home residents. The highest rate was 67.3% as disability due to arthritis. The score of depression in all subjects was 8.2 that indicated having depressive symptom. There was no difference in the depression level between institutionalized elderly and home resided elderly. There was a significant correlationship between physical health and depression, however, the rest of varibles did not show any significant relationships. In summary, the immune cells in the elderly who replied perceiving low level stress, was under normal range. Their health status was perceived as 'not good' but physical health activity was perceived as 'good'. The relationships of stress, immunity, physical health and depression were partially significant but not had evidence as enough as theoretically the suggested relationship. We suggest that further studies using large sample size and more diverse variables should be performed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.71-79
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• 2018

The purposes of this study were to identify the stress level of nursing students prior to clinical training and to examine the effects of aromatherapy on stress, stress perception, and mood during clinical practice. This study was a randomized control trial using a pre-post test conducted from May-July 2016. A total of 41 junior nursing students were recruited. The experimental group (n=22) underwent aroma inhalation using a necklace containing lavender essential oil and a control group (n=19) used a normal saline necklace. There were significant improvements in stress (p=.023) and mood levels in the experimental group (p=.006). The difference in stress perception between the experimental and control groups was not statistically significant (p=.382). Aroma therapy might be useful for decreasing stress and improving their positive mood during clinical practice for nursing students.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.29-38
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• 2012

This study conducted a survey 185 adolescents in multi-cultural family to measure the level of their social capital and their acculturation stress and examined how it affects them to adapt to school. Followings are the main results of this study. First, after measuring the social capital level of those surveyed, their average was lower than the normal level, showing 2.24(SD=.32), and their acculturation stress showed 2.54(SD=.58), a bit higher than the normal level. Second, their level of adapting to school showed 2.26(SD=.39), which was lower than the normal level, and there was statistically a meaningful difference between the groups depending on their grade, academic level, economic level, parents' marital status, mother's Korean ability. Third, the factors that affected in adapting to school were in the order of their network of social capital(${\beta}$=.225), mother's Korean ability(${\beta}$=.195), acculturation stress(${\beta}$=-.175), interpersonal trust of social capital(${\beta}$=.171), norm of social capital(${\beta}$=.161), parents' marital status(${\beta}$=.156), academic level(${\beta}$=.151), economic level(${\beta}$=.145). Based on these results, this study suggest ways to promote trust building among people and network formation through active use of information communication, and to improve multi-cultural acceptability by developing and using various contents.