• Journal of Industrial Convergence
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• v.4 no.1
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• pp.3-15
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• 2006

Musculoskeletal Disorders are usually caused or aggravated by poor work processes and unsuitable working conditions - that involve or repetitive or forceful movements or the maintenance of constrained or awkward postures. The condition is characterized by discomfort and persistent pain. Case and Demographic Characteristics for Work-related Injuries and Illnesses Involving Days Away From Work, 2004. U.S" was examined. Causes of musculoskeletal disorders for assembly line workers were carpal tunnel syndrome(CTS), tendonitis, low back pain, and occupational stress. Recommendations of improvement for productivity are redesign of working conditions, exercise, prevent of musculoskeletal disorders and avoiding stress.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.476-486
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• 2007

This study was performed to investigate the dietary behaviors, perceived stress, and health-related factors along with their correlations in University students. The number of subjects was 150(64 males and 86 females), and the results of the study were as follows: Stress was felt by over 80% of the male and female students. The male students were more stressed than the females for economic value, gender difference, professor and drinking-related stress factors, and there was a significant difference between the genders. The female students had more clinical symptoms from stress than the male students in terms of dizziness, indigestion and constipation(p<0.01, p<0.001). The amount of food intake under stress was significantly different by gender. The female students preferred sweet tasting items, whereas the male students preferred hot tasting item when under stress. Also the intake of candy and chocolate when under stress in the male and female students was $2.00{\pm}0.74$ and $2.41{\pm}0.75$, respectively. The female students consumed candy and chocolate more than the male(p<0.01). Furthermore, 62.5% of the male students and 30.2% of the female students exercised to get rid of stress: the use of ball games as exercise in male and female students was $1.59{\pm}0.83$, $1.01{\pm}0.11$, respectively. Many students drank alcohol and smoked while under stress. In particular, the male students smoked more than normal as compared to the females, and there was a significant gender difference(p<0.001). The clinical symptoms positively correlated with the life stress level were degree of nervousness, sweaty, achy neck and shoulders, sore back, dizziness, eye fatigue, headache and indigestion. The amount of food intake under stress was positively correlated to the clinical symptom of headache. These results indicate the effects of life stress on dietary behaviors, food choice, and health status. Stress not only changed dietary behaviors, but was also related to health status. Therefore, education with regard to nutrition is necessary if college students are to practice food eating habits to correctly manage life stresses.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.2
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• pp.252-262
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• 2008

Purpose: This paper is aim to report that menopausal disorder can be effectively diagnosed and treated by referring to the life event stress of patient. Methods: Researchers got a grip on the life event stress of patient by using medical examinations by interview and compared the conditions of patient before and after treatment by using Kupperman's Index. The prescription of the Gamidangguisu-san hap samhap-tang( Jiaweidangguixu-san he sanhetang) and the Gamisoyo-san (Jiaweixiaoyao-san) and the acupuncture therapy and the moxibustion therapy were used for the treatment. Results: The serious musculoskeletal systemic pains, which includes back pain, lumbago, and myalgia, and other menopausal troubles were improved remarkably. Conclusion: The menopausal disorder could be caused by not only the change of hormone but also complex factors of environmental matters which includes social cultural surroundings, mentality etc. Therefore the life event stress could be one of critical factors of menopausal disorder. The diagnosis and treatment considering the life event stress could be effective method to relieve patient's menopausal disorder.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.100-113
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• 2016

Purpose: This study was performed to investigate the influence of children's hospital nurses' job characteristics and job stress on turnover intention. Method: The subjects were 148 nurses who have been working in 6 children's hospitals located in G city. Measurement tools used for this study included job characteristics were created by Lee, and modified by Hong, and job stress tool developed Kim & Ku and modified by Choi. And the tools used for assessing turnover intention were created by Mobley and Becker and modified by Kim. The collected data was analyzed using descriptive statistics, the independent t-test, one-way ANOVA, Pearson' Correlation and regression on SPSS 21.0 program. Result: Job challenge and job fitness among the sub-areas of job characteristics, job stress and salary were identified as factors influencing turnover intention. These factors explained 36.5% of variance of turnover intention. Conclusion: In conclusion, this results can be used to help the children's hospitals creates an environment where nurses can enhance Job challenge and job fitness also, reduce job stress which lead to turnover rate and turnover intention.

• Journal of Korean Academy of Nursing
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• v.30 no.2
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• pp.488-497
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• 2000

The purpose of this study was to explore the effect of a postpartum massage program on stress response in the Cesarean section mothers. The study focused on evaluating the effect of postpartum massage program on mood, anxiety, skin temperature and concentration of saliva and breast milk immunoglobulin A in the Cesarean section mothers. This study was designed as a nonequivalent control group pretest-posttest quasi-experimental study. Twenty-eight Cesarean section mothers were selected as experimental group, whereas twenty- seven were control group. The postpartum massage program consisted of 20 minutes of warm-up, massage and ending phases and used once a day. During each program, there were 4 minutes of warm-up, 14 minutes of massage on back, axillary and breasts, and 2 minutes of ending. Massage were used for the experimental group by the same investigator 20 times per minute. The massage technique used were efflurage, petrissage, accupressure, kneading and vibration. Skin temperature was monitored with YSI Tele-thermometer(Simpson electric Co., USA) before and after massage program. The concentration of immunoglobulin A in saliva and breast milk was analyzed by immunoturbididimeter assay(Cobas INTEGRA, Swiss) before and after massage program. Also at this time mood and anxiety were measured by self-report. The data were analyzed using SPSS version 7.5 and hypothesis was tested with ANCOVA analysis and Pearson coefficient correlation. The results were as follows : 1) Score of mood increased significantly after use of postpartum massage program. 2) Level of anxiety decreased significantly after use of postpartum massage program. 3) Skin temperature increased significantly after use of postpartum massage program. 4) Concentration of saliva immunoglobulin A increased significantly after use of postpartum massage program. 5) Concentration of breast milk immunoglobulin A did not change significantly after use of postpartum massage program. 6) After use of postpartum massage program, there was significant correlation between psychological stress response and physiological stress response.The results suggest that postpartum massage program can be effective nursing intervention to reduce stress response in the postpartum mothers under stress.

• Journal of the Korean Society for Heat Treatment
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• v.31 no.6
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• pp.307-314
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• 2018

Simple tensile tests and microstructural investigations have been performed on extrudates of high strength aluminum alloys such as 7075, 7021 and 7xxx(Sc) to understand correlation between extruding conditions and extruded properties. Tensile specimens which were taken from different locations at the same cross section of an extrudate were tested at room temperature and with a strain rate of $8.9{\times}10^{-5}/s$. The microstructures according to the locations at the cross section have been observed using optical microscopy and electron back-scattered diffraction (EBSD) mapping to characterize the effect on stress-strain curve. The results could be classified in three types independent of alloying contents and extusion methods. The fine differences in the stress-strain curves were resulted from inhomogenity in the microstructures according to locations of an extrudate which were performed through instantaneous extruding conditions such as temperature, strain rate and strain.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1518-1520
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• 2001

Bi-layer Mo films were deposited on sodalime glass substrates using DC magnetron sputtering. As the gas pressure and power density, the resistivity varied from $1.5{\times}10^{-5}$ to $4.97{\times}10^{-4}{\Omega}{\cdot}cm$. Furthermore, stress direction yielded compressive-to-tensile transition stress curves. The microstructure of the compressive stress films which had poor adhesion consists of tightly packed columns, but of the tensile-stressed films had less dense structure. Under all gas pressure conditions, Mo films exhibited distinctly increasing optical reflection with decreasing gas pressure. The expansion of (110) peak width with the gas pressure meant the worse crystalline growth. Also, The highest efficiency was 15.2% on 0.2 $cm^2$. The fill factor, open circuit voltage and short circuit current were 63 %, 570 mV and 42.6 mA/$cm^2$ respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.3
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• pp.440-449
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• 2003

Residual strength of fiber metal laminates after impact was studied. 3/4 lay up FML was fabricated using 4 ply prepreg, 2 ply aluminum sheets, and 1 ply steel sheet. Quasi isotropic ([0/45/90/-45]s) and orthotropic ([0/90/0/90]s) FRP were also fabricated to compare with FML. Impact test were conducted by using instrumented drop weight impact machine (Dynatup, Model 8250). Penetration load and absorbed energy of FML were superior to those of FRPs. Tensile tests were conducted to evaluate the residual strength after impact. Strength degradation of FML was less than that of FRP. This means that the damage tolerance of FML is excellent than that of FRP. Residual strength of each specimen was predicted by using Whitney and Nuismer(WN) Model. Impact damage area is assumed as a circular notch in WN model. Damage width is defined as the average of back face and top face damage width of each specimen. Average stress and point stress criterions were used to calculate the characteristic length. It is supposing that a characteristic length is a constant. The distribution of characteristic length shows that the assumption is reasonable. Prediction was well matched with experiment under both stress criterions.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.231-234
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• 2005

The high temperature deformation behavior of AZ 31 Mg alloy was investigated by designing a back propagation neural network that uses a gradient descent-learning algorithm. A neural network modeling is an intelligent technique that can solve non-linear and complex problems by learning from the samples. Therefore, some experimental data have been firstly obtained from continuous compression tests performed on a thermo-mechanical simulator over a range of temperatures $(250-500^{\circ}C)$ with strain rates of $0.0001-100s^{-1}$ and true strains of 0.1 to 0.6. The inputs for neural network model are strain, strain rate, and temperature and the output is flow stress. It was found that the trained model could well predict the flow stress for some experimental data that have not been used in the training. Workability of a material can be evaluated by means of power dissipation map with respect to strain, strain rate and temperature. Power dissipation map was constructed using the flow stress predicted from the neural network model at finer Intervals of strain, strain rates and subsequently processing maps were developed for hot working processes for AZ 31 Mg alloy. The safe domains of hot working of AZ 31 Mg alloy were identified and validated through microstructural investigations.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.11
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• pp.996-1000
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• 2005

Experimental results are presented for the degradation of 3 nm-thick gate oxide $(SiO_2)$ under both Negative-bias Temperature Instability (NBTI) and Hot-carrier-induced (HCI) stresses using P and NMOSFETS, The devices are annealed with hydrogen or deuterium gas at high-pressure $(1\~5\;atm.)$ to introduce higher concentration in the gate oxide. Both interface trap and oxide bulk trap are found to dominate the reliability of gate oxide during electrical stress. The degradation mechanism depends on the condition of electrical stress that could change the location of damage area in the gate oxide. It was found the trap generation in the gate oxide film is mainly related to the breakage of Si-H bonds in the interface or the bulk area. We suggest that deuterium bonds in $SiO_2$ film are effective in suppressing the generation of traps related to the energetic hot carriers.