• Journal of Korean Public Health Nursing
• /
• v.34 no.2
• /
• pp.198-210
• /
• 2020

Purpose: This study was undertaken to identify the effect of current health conditions and preparation for old age of university students on the awareness of successful aging. Methods: Totally, 273 university students, based across several cities in South Korea, were enrolled for the study. Data collected were analyzed by applying descriptive statistics, independent t-test, one-way ANOVA, Pearson correlation coefficients, and hierarchical multiple regression, using the SPSS Statistics 23.0. Results: There were three types of hierarchical regression model for awareness of successful aging in university students. Its explanatory power of each model was adjusted R² of .04, 07, and .31 respectively. Major (β=.14, p=.007), health condition (β=.13, p=.028), preparation for old age (β=.52, p<.001) were significant predictors of awareness of successful aging. Conclusion: Our study results indicate that for university students, diverse interventions to promote the awareness of successful aging must focus on improving the health condition and enhancing preparation for old age.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.8
• /
• pp.1148-1152
• /
• 2012

The vegetable-based insulating oils are substitutes for mineral oils in oil-filled transformer. The important properties of vegetable insulating oil is their higher flash/fire point and biodegradability than conventional mineral oils. The large oil-filled transformer eliminate the risk of explosion and fire should the transformer fail and oil ignite owing to high flash/fire point of vegetable insulating oil. In addition, higher biodegradability of vegetable insulating oils can let the oil spill damage reduced. In this experiment, the real oil-filled transformers using mineral oil and vegetable oil have accelerated aging. After working on the 100% accelerated aging experiment were conducted comparing the transformer. The hottest-spot temperature using thermal coefficients were calculated to determin the degree of accelerated aging. As a result, apply mineral oil transformer in accordance with the accelerated aging life come to an end. In contrast, vegetable insulating oils showed the opposite characteristics. Vegetable insulating oil compared to the mineral oil are found to be an long life. As a result, the vegetable oil has a long-term stability.

• Journal of agricultural medicine and community health
• /
• v.46 no.2
• /
• pp.89-97
• /
• 2021

Objectives: The purpose of this study is to identify the relationship among psychosocial stress, memory, and successful aging of the community-residing elderly. Methods: 152 people over 65 years old living in D area were interviewed, from August 1st, 2020 to October 30th, 2020. The outcomes were measured by Psychosocial Well-being Index (PWI), Mini-Memory Test (MiMeT) and successful aging. Data were analyzed using Pearson correlation coefficients and stepwise multiple regression. Results: There was a positive correlation between successful aging and memory. There was a negative correlation between psychosocial stress and successful aging, and between psychosocial stress and memory. Psychosocial stress was identified as a predictor of successful aging, which explained 26.4% of total variance of successful aging. Conclusions: When we prepare intervention programs which improve successful aging for community-residing older adults, we need to consider psychosocial stress. In addition, stress management programs for successful aging should be developed to improve current successful aging.

• Journal of the Korean Society of Tobacco Science
• /
• v.26 no.1
• /
• pp.27-34
• /
• 2004

This study was carried out to examinate the effect of aging period on chromatic, chemical and organoleptic characteristics, and to evaluate of optimum aging period for each grade in flue-cured leaf tobacco. The leaf tobaccos were produced in 2000, and threshed, redried and packed in carton box under the current methods. Four grades of processed leaf(A3O, B1O, C1L and D3L) were stored during 24 months(May 10, 2001 to April 31, 2003) in warehouse of Chungju Leaf Tobacco Processing Factory. The leaf tobaccos were sampled at three month intervals for analysis of chromatic, chemical and organoleptic properties. Yellow(b), pH values and total sugar contents of four grades were significantly decreased during the aging. Filling values, tar, nicotine and CO contents of tobacco smoke, and puff number of cigarettes were not significantly changed during the aging. Positive correlation coefficients were significantly observed between taste and irritation of the calculated attributes from contents of volatile oil components in leaf tobacco and those of the panel sensory attributes. The ratio of maximum change in taste attribute was larger than that in irritation attribute during aging. The optimum aging periods estimated by taste for A3O, B1O, C1L and D3L were 17.8, 14.9, 10.8, and 9.8 months, respectively. The thin leaf(Primings and Cutters) undergo satisfactory aging earlier as compared to bodied leaf(Leaf and Tips). The results suggest that decrease of aging period for thin leaf from 18～21 to 9～12 months may be beneficial to save storage cost in flue-cured tobacco.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.3
• /
• pp.855-864
• /
• 2013

The dynamic characteristics of natural rubber bearings, which are used as isolator, are dependent on the main rubber's dynamic behaviors and nonlinear properties. Rubber materials tend to undergo an aging process under the influence of mechanical or environmental factors, so they inevitably end up facing damage. A main cause of aging like this is known to be oxidization, which occurs through the heat of reaction at high temperatures. Accordingly, in this study an accelerated thermal aging test was carried out in order to compare the characteristic values of the bearings before and after thermal aging occurs. As a result of this experiment, it was found that a thermal aging phenomenon could have some effects on shear stiffness, energy absorption, and equivalent damping coefficients of the bearings. Furthermore, a deterioration in the dynamic properties of the natural rubber bearings caused by the thermal aging was applied to an actual bridge and then the effects of such thermal aging on the seismic performance of the bridge were also compared and analyzed based on numerical analysis. As a result of this analysis, it was found that the changes in the basic properties of the natural rubber bearings caused by the thermal aging bring only a minor effect on the seismic performance of bridges.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.2A
• /
• pp.109-116
• /
• 2012

The dynamic properties of lead rubber bearings, which are used as isolator, are dependent on the main rubber's dynamic behaviors and nonlinear qualities. Rubber materials tend to undergo an aging process under the influence of mechanical or environmental factors, so they can end up inevitably facing damage. A main cause of such aging is known to be oxidization, which occurs through the heat of reaction at high temperatures. Accordingly, in this study an accelerated thermal aging test was carried out in order to compare the characteristic values of the bearings with each other before and after thermal aging occurs. As a result of this experiment, it was found that a thermal aging phenomenon could have an effect on shear stiffness, energy absorption, and equivalent damping coefficients. Furthermore, a decline in the dynamic properties of the lead rubber bearings by means of the thermal aging process was applied to an actual bridge and the effects of such thermal aging on the seismic performance of the bridge were also compared and analyzed based on numerical analysis. As a result of this analysis, it was found that the changes in the basic properties of the lead rubber bearings have a minor effect on the seismic performance of bridges.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.3
• /
• pp.51-57
• /
• 2019

Post curing effects are estimated by specimen tests. Propellant specimen accelerated aging tests are performed when post curing is estimated to be complete and the coefficients of Arrhenius aging equations are acquired. Simulated motors with cylindrical grain are designed and fabricated to confirm the application. Accelerated aging tests are conducted, and aged properties are measured and estimated for the inner bore, center and bond parts of the grain. The measured aging ratios of the modulus are compared with the ones predicted by the equations. As the results, the accelerated aging equations predict well the propellant aging trends; however, some differences are observed at the bond part. Therefore, the specimen extraction part must be carefully chosen to suit the test purpose when a rocket motor grain is used for the aging test.

• Elastomers and Composites
• /
• v.42 no.1
• /
• pp.32-46
• /
• 2007

Mechanical properties of rubber material are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the material test and accelerated heat aging test were carried out. In order to investigate the effects of heat-aging on the material properties, hardness, elongation, stress-strain curves and dynamic characteristics were obtained from various test conditions. Also, rubber material coefficients were determined by both the uniaxical and equi-biaxial tensile tests.

• The Journal of the Korea Contents Association
• /
• v.16 no.4
• /
• pp.582-593
• /
• 2016

The purpose of this study was to identify predictive factors of successful aging and to determine mediating effect of transcendence between successful aging and influencing factors of community-dwelling elders in Korea. 162 elders were participated in this study who visited seniors welfare center and senior citizen center. Data were analyzed by PASW 18.0 for t-test, Pearson's correlation coefficients and hierarchical regression analysis. Transcendence, parent-child relationship, depression, spirituality and perceived economic status were statistically significant influencing factors, explained 77% of successful aging in community-dwelling elderly. The mediating role of transcendence was identified about parent-child relationship, depression, spirituality and perceived economic condition. The study findings demonstrated that transcendence was significant variable affecting successful aging. The variables affecting successful aging such as transcendence, parent-child relationship, depression, spirituality, perceived economic status can be utilized for nursing strategies to successful aging in community-dwelling elders.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.02a
• /
• pp.93-112
• /
• 2000

The permeability of converter slag, replacing material of sand mat on improving soft clay foundation, was evaluated in the laboratory. The effects of grain size, flow water time and aging were investigated using sea and fresh water. Converter slag being submerged with fresh water, the coefficients of permeability in A and B samples less than 10mm grain sizes were measured as 6.52${\times}$10$\^$-2/cm/sec and 5.99${\times}$10$\^$-1/cm/sec, while changed as 1.88${\times}$10$\^$-2/cm/sec, 3.86${\times}$10$\^$-1/cm/sec under sea water condition. Also, the condition of turbulent flow may exit and was experimentally identified from the relationship between hydraulic gradient and seepage velocity. After 180 days on using sea water, the coefficients of permeability of sample A and B samples decreased ten times smaller than those initial values. And after that time continually decreased as for till 360 days. The reduction of permeability coefficient was considered to influence filled with voids in high-calcium quicklime(CaO). However, in-situ coefficient of permeability was practically satisfactory.