• Korean Journal of Occupational Health Nursing
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• v.11 no.1
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• pp.63-80
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• 2002

Objectives: The objective of this study is to evaluate the job characteristics of container terminal workers by applying the Job Strain model, and to assess the relationship among the general characteristics, job characteristics and psychosocial distress. Methods: A self-administrated questionnaire survey was performed to the container terminal workers in Pusan. Among the 200 male workers who answered the questionnaires, white-collar workers and blue-collar workers were 100, respectively. Karaseks Job Content Questionnaire was utilized to evaluate the job characteristics and Psychosocial well-being index (PWI) was applied to measure the extent of their psychosocial stress. Results: In white-collar workers, the skill discretion, created skill, decision-making authority, decision-making latitude, psychological job demand, and supervisor support of the job characteristics were significantly high, while in blue-collar workers physical exertion was significantly high. The result of Psychosocial well-being index (PWI) reveals that blue-collar workers were more stressed than white-collar workers, especially, the indices of depression (factor 2), sleeping disturbance and anxiety (factor 3), General well-being and vitality (factor 4) were significantly increased; whereas, in white-collar workers, only the index of social performance and self-confidence (factor 1) was significantly increased. And PWI scores were significantly increased in the lower social support and psychological job demand. By the multiple logistic regression analysis for PWI, blue-collar workers had increased odds ratio of 2.66(95% CI;1.11-6.41) compared with white-collar workers. The unmarried workers increased odds ratio of 3.54(95% CI;1.18-10.62) compared with married workers. And workers who have not own house increased odds ratio of 2.35(95% CI;1.15-4.79) compared with workers who have own house. Particularly, odds ratio of work-shift in blue-collar workers was 11.10(2.14-57.64). Conclusion: Skill discretion, created skill, decision-making authority, decision-making latitude, psychological job demand, and supervisor support were increased in white-collar workers. Decreased skill discretion and increased physical exertion were found in blue-collar workers, which is supported the Job Strain model. Job stress of blue-collar workers was comparatively higher than that of white-collar workers, especially, skill discretion, decision-making authority, decision-making latitude, job insecurity, physical exertion were noticeable factors. Especially, sleeping, smoking, and work shifting turned out to be a main cause that increases stress. Therefore, in order to decrease the job stress, a health promotion program to change the health behaviors should be activated and an organized job stress management program should be introduced. Especially, working condition for blue-collar such as physical exertion and work-shift should be improved.

• Journal of the Korean Geotechnical Society
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• v.18 no.6
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• pp.73-81
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• 2002

Various CPT-based prediction models far profiling stress history of marine clay at the southern part of the Korean peninsula were investigated by using both statistical analysis and case history study. Preconsolidation pressures($\sigma'$p) and overconsolidation ratio(OCR) estimated by empirical correlations and cone penetration tests were compared with those of laboratory odometer test results. Stress history of marine clay determined by odometer test results was in general overconsolidated at below 10m depth from the mudline, whereas marine clay at below l0m depth from the mudline which has an around 0.3 overconsolidation ratio showed variable stresses and unstable states. Preconsolidation pressures were computed by both empirical methods of the Chen and Mayne(1996) and theoretical method of Konrad and Law(1987). It is estimated that Chen and Mayne(1996)'s prediction method based on pore water pressure is more reliable than any other prediction methods, and their method proved to be the most reliable for overconsolidation ratio estimation. However, it is recommended that Mayne & Holtz(1988) and Mayne & Bachus(1988) methods are more suitable than any other methods for predicting the overconsolidation ratio at an underconsolidated (OCR<1) clay. For these reasons, rather than making use of existing prediction models, development of site specific empirical correlations which considers local characteristics and site conditions may be required due to different local stress history and variable soil properties.

• Journal of Life Science
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• v.9 no.5
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• pp.604-611
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• 1999

The effects of anti-stress chrysanthemum flower (ASCF) extract drink (ASCF-0.1% and ASCF-0.5% concentrations) were tested for the anti-stress action. ICR male mice (20$\pm$2 g) were fed with basic experimental diets and given free access to water containing these ingredients for 18 days. Psychological stress/sociopsychologcal stress exposed by foot-shock for 1 hour for 3 days. Both ASCF-0.1 and ASCF-0.5 groups in the sociopsychological stress resulted in a significant decrease of 28.1% and 27.3% in plasma corticosterone (CS) secretion compared with psychological stress (control group). Noradrenaline (NA) secretions in the brain were significantly increased 49.7% and 53.9%, respectively, in ASCF-0.1 and ASCF-0.5 groups compared with control group. MHPG-SO4 (3-Methoxy-4-hydroxyphenylethy-leneglycol sulfate) levels in the brain resulted in a marked decreases of 12.9% and 16.6%, respectively in ASCF-0.1 and ASCF-0.5 groups. NA/MHPG-SO4 ratios in the brain of ASCF-0.1 and ASCF-0.5 groups resulted in a significantly increase of 71.3% and 81.0%, respectively, compared with control group. These results suggest that anti-stress chrysanthemum flower (ASCF) drink can effectively ridded the sociopsychological stress.

• Journal of Life Science
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• v.9 no.5
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• pp.596-603
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• 1999

The effects of anti-stress mind tonic (ASMT) drink (ASMT-0.1% and ASMT-0.5% concentration) were tested for the anti-stress action. ICR male mice (20$\pm$2 g) were fed with basic experimental diets free access to water containing these ingredients for 18 days. Psychological stress/sociopsychological stress were exposed by foot-shock for 1 hour for 3 days. Both ASMT-0.1 and ASMT-0.5 groups in the sociopsychological stress resulted in a significant decrease of 19.1% and 41.9% in plasma corticosterone (CS) secretion compared with psychological stress (control group). Noradrenaline (NA) secretions in the brain were significantly increased 23.4% and 35.9%, respectively, in ASMT-0.1 and ASMT-0.5 groups compared with control group. MHPG-SO4 (3-Methoxy-4-hydroxyphenylethyleneglycol sulfate) levels in the brain resulted in a marked decreases of 27.1% and 19.6%, respectively in ASMT-0.1 and ASMT-0.5 groups. NA/MHPG-SO4 ratios in the brain of ASMT-0.1 and ASMT-0.5 groups resulted in a significantly increase of about 70% compared with control group. These suggest that mind tonic anti-stress drink can effectively ridded the sociopsychological stress.

• Journal of Life Science
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• v.9 no.5
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• pp.612-619
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• 1999

The effects of anti-stress rose fruit (ASRF) extract drink (ASRF-0.1% and ASRF-0.5% concentrations) were tested for the anti-stress action. ICR male mice (20$\pm$2 g) were fed with basic experimental diets and given free access to water containing these ingredients for 18 days. Psychological stress/sociopsychological stress exposed by foot-shock for 1 hour for 3 days. Both ASRF-0.1 and ASRF-0.5 groups in the sociopsychological stress resulted in a significant decrease of 24.3% and 38.0% in plasma corticosterone (CS) secretion compared with psychological stress (control group). Noradrenaline (NA) secretion in the brain were significantly increased 35.9% in ASRF-0.5 group, but NA secretion in ASRF-0.1 group could not be obtained significant result compared with control group. MHPG-SO4 (3-Methoxy-4-hydroxy-phenylethy leneglycol sulfate) levels in the brain resulted in a marked decreases of 16.5% and 18.9% respectively in ASRF-0.1 and ASRF-0.5 groups. NA/MHPG-SO4 ratios in the brain of ASRF-0.1 and ASRF-0.5 groups resulted in a significantly increase of 16.5% and 67.0%, respectively, compared with control group. These results suggest that anti-stress rose fruit (ASRF) drink also can effectively ridded the sociopsychological stress.

• Journal of Families and Better Life
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• v.14 no.2
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• pp.127-138
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• 1996

The purpose of this study is to show farm women's stress under productive activity role multiple overload through family characteristic (pattern and number) and characteristic(type working time and involvement proportion) of productive activity. The outline of the study is as follow; 1. Stress by pattern and number of a family is highest in a four generation family and increases according as the number of the family increases. 2. The characteristic of productive activity : 1) Stress based on type of productive activity is highest in Type III of the most multiple overload roles. 2) in light of stress based working time area of household task activity is in inverse proportion to working time but area of farming and wage earning activity are approximately in direct proportion to it. The two-way ANOVA analysis show that stress in Type I of area of household task increases but in Type IV it decreases as working time increases 3) In stress based on involvement proportion to it. The wo-way ANOVA analysis show that stress in Type I of area of household task increases but in Type IV it decreases as working time increases. 3) In stress based on involvement proportion in three as working time increases 3). In stress based on involvement proportion in three activity areas the more the involvement proportion the less of the stress : an inverse ratio.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.723-736
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• 1992

Most degeneating diseases and back pains in the orthopaedic disease are originated from the unbalance of stress distribution in the low-lumbar spine. Therefore the stress analysis of lowerback is indispensible to the clinical diagnosis for the developing reason and the developing process of diseases. Therefore the same model materials as following are eveloped to analyze the stress distributions of lower-back by photoelastic experiment. The verterbral body and the process are molded from epoxy resin(the weight ratio of Araldite and hardner is 10 to 3), models are geometrically identical to them in vivo respectively and the ratio of their elastic modulus to that of model material is 1 to 10. It is assured that KE-1300 Silicon(E=0.8MPa), TSE-3562 Silicon(0.5MPa) and the composite silicon(3MPa) (the weight ratio of KE-1300 silicon and Jioreal : 10 to 4) are respectively effective as the model materials of ligament, musles and intervertevral disc which is essential to the movement of low-lumbar spine. All the elements associated with the movement of the low-lumbar spine are molded through the molding method developed in this research and assembled with the angles between the verterbra and the disc in the normal human lumbosacral spine. The stress distributions of the assembled model are analyzed by photoelastic experiment. It is certified by comparing the results of photoelastic experimebt with the clinical situations that the loading dveice and the loading conceptions used in this paper are effective.

• Structural Engineering and Mechanics
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• v.30 no.3
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• pp.317-330
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• 2008

Stress intensity factors for a planar crack parallel to a bimaterial interface are considered. The formulation leads to a system of hypersingular integral equations whose unknowns are three modes of crack opening displacements. In the numerical analysis, the unknown displacement discontinuities are approximated by the products of the fundamental density functions and polynomials. The numerical results show that the present method yields smooth variations of stress intensity factors along the crack front accurately. The mixed mode stress intensity factors are indicated in tables and figures with varying the shape of crack, distance from the interface, and elastic constants. It is found that the maximum stress intensity factors normalized by root area are always insensitive to the crack aspect ratio. They are given in a form of formula useful for engineering applications.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.4
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• pp.1041-1050
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• 1995

The deformed shape of rod specimen of copper alloys was measured after the high-velocity impact against a rigid anvil and analyzed with one-dimensional theory to determine dynamic yield stress and strain-rate sensitivity which is defined as the ratio of dynamic yield stress to static flow stress. The evvect of two-dimensional deformation on the determination of dynamic yield stress by the one-dimensional theory, was investigated through comparison with the analysis by hydrocode. It showed that the one-dimensional theory is relatively consistent with two-dimensional hydrocode in spite of its simplicity in analysis.

• Journal of Ocean Engineering and Technology
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• v.8 no.1
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• pp.41-49
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• 1994

The leak-before-break(LBB) design on the large structures such as ship's hull, tank structure, pressure vessels etc. is one of the most inportant subjects for the evaluation and the assurance of safety. In these structures, various loads are acting. In some structural members, therefore, out-of-plane stress due to bending often may become with in-plane stress due to stretching. In the present report, the characteristics of fatigue life and peneration behaviour from a surface cracked plate under combined tension and bending have been studied experimentally and analytically by using eccentricity. Estimation of fatigue crack growth was done with the Newman-Raju formula before penetration, and with the stress intensity factor after penetration proposed by the author. Calculated aspect ratio showed the good agreement with the experimental result. It was also found that particular crack growth behaviour and crack shape after penetration can be satisfactorily evaluated using the K solution proposed.