• KEPCO Journal on Electric Power and Energy
• /
• v.3 no.1
• /
• pp.23-28
• /
• 2017

The life management technology becomes important as the failure risk of the aged power transformers increases. Asset management technology, therefore, has been developed to evaluate the remaining life and build replacement strategies of power transformers, which enables an optimal investment decisions based on reliability and economic feasibility. The remaining life assessment technology uses data related to such as installation, operation, maintenance, refurbishment, and disposed history of power transformers. The optimal investment decision additionally uses data related to failure and social costs. To develop the asset management technology in power transformers, it is important to find deterioration parameters directly indicating degradation of power transformers. In this study, 110,000 DGA data during the past 35 years have been analyzed in order to find the deterioration parameters related to the degradation of power transformers. The alarm rates of combustible gases ($H_2$, $C_2H_2$, $C_2H_4$, $CH_4$, $C_2H_6$), TCG CO, and $CO_2$ were analyzed as deterioration parameters. The origin of the gas was discussed in connection with discharge, overheating and insulation aging.

• Journal of Nutrition and Health
• /
• v.39 no.3
• /
• pp.299-306
• /
• 2006

This study was done to investigate the use of nutritional supplements (NS) in Korean elite soccer players using an anonymous questionnaire. NS were classified into health supplements, manufactured health food supplements, chinese medicines & tonic foods, and nutrient supplements. Information was sought on the type of NS and factors that might influence supplement use including selected demographic parameters and health related variables. The data were collected from 241 athletes (aged $24.6{\pm}3.8$ years) in 9 professional soccer club. The prevalence of NS use among the subjects was 81.3%. Health supplements were used most frequently and nutrient supplement drug was the second one. Among the health supplements, weight/muscle gainer and calorie replacement product were most frequently used. Vitamin supplements were most frequently used among all nutrient supplement drugs. Users of NS were higher age (p<0.05) duration of exercise (p<0.05), and income (p<0.05) than non-users. The married (p<0.05) and a member of K-league (p<0.01) tended to have higher prevalence of NS use. The main adviser of NS were family (55.3%) and oneself (39%) instead of coach or sports nutritionist. Although NS use, only 26.2% certainly check up nutritional information on their used NS. Among the subjects, 84.5% of them felt that NS use were improved athletic performance, and 86.5% of them will to keep on taking supplement. These data suggest that a large number of elite soccer players use NS and these players may require education about healthy nutritional supplement practice and on the proper use of nutritional supplements.

• Steel and Composite Structures
• /
• v.12 no.5
• /
• pp.379-393
• /
• 2012

Many steel bridge infrastructures in the world are getting older, and a large number of these structures are in need of maintenance, rehabilitation or replacement. Most of them are subjected to corrosion due to exposure to aggressive environmental conditions and inadequate maintenance, causing reduction of their carrying capacities. In order to have an adequate bridge management, it is of paramount importance to develop an efficient, accurate and rapid condition assessment method which can be used to make reliable decisions affecting the cost and safety. Therefore, a simple and accurate method of calculating remaining yield and tensile strength by using a concept of representative effective thickness with correlation of initial thickness and maximum corroded depth is proposed in this study, based on the results of many tensile coupon tests of corroded plates obtained from a steel plate girder with severe corrosion, used for about 100 years. Furthermore, a strength reduction diagram which will be very useful for bridge inspection engineers to make rational decisions about the maintenance management of aged steel bridge infrastructures is presented.

• Journal of Korean Academy of Nursing
• /
• v.36 no.3
• /
• pp.449-456
• /
• 2006

Purpose: The purpose of this study was to investigate the influences of health perception, body image and sexual function on depression according to the menopausal stage in Korean middle aged women. Methods: Subjects were 182 perimenopausal and postmenopausal women who had not received hormonal replacement therapy. A five-item General HealthShort Form (SF-36) Health Survey Questionnaire (Ware & Sherbourne, 1992) was used to measure health perception. Body image was measured Semantic Differential scale, CES-D was used to measure the level of depression, and sexual function was measured by FSFI. Results: The subjects rated their health as 'moderate', their body image as 'moderate, and level of depression as 'high'. However, there were no significant differences in health perception, body image, and depression between perimenopasual and postmenopausal women. Postmenopausal women experienced lower levels of sexual function than perimenopausal women in sexual arousal, lubrication, orgasm, satisfaction, and pain. In stepwise regression analysis, 21.7% of variance in depression was shown to be perceived health and body image in postmenopausal women. However, in perimenopausal women, perceived health and sexual function explained 34.5% of variance in depression. Conclusion: These findings indicate that nurses must consider the menopasusal stage when counseling their patients.

• Journal of Korean Public Health Nursing
• /
• v.31 no.1
• /
• pp.149-161
• /
• 2017

Purpose: This phenomenological study was conducted to describe and understand the experience of vulnerable elderly individuals with diabetes by identifying the meanings and structures of the experience. Methods: The data were collected through in-depth interviews of six vulnerable elderly individuals with diabetes aged over 65 years. The interview data were audio-recorded, transcribed verbatim and checked for accuracy. The Colaizzi's method of phenomenology was used to analyze the data. Results: Four theme clusters were extracted as follows: 'Life adversity', 'Adaptability to the life', 'Replacement of absence of family with social support', 'Difficulty of self-care'. Conclusion: The results provide an in-depth understanding of life experiences of vulnerable elderly individuals with diabetes. The findings will be useful to nurses caring for this population.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.11
• /
• pp.6839-6844
• /
• 2013

This study was conducted to analyze the prevalence of non-performance of mammography, and associated factors, among postmenopausal women. This analytical, exploratory, cross-sectional study, of a domicile population inquiry type, was performed in the municipality of Maringa, Parana, Brazil. A total of 456 women were interviewed, aged 45 to 69 years, who presented with natural menopause and cessation of menstruation for at least twelve months. Statistical associations were found between the non-performance of mammography and schooling of less than seven years, paid employment, sedentary lifestyle, smoking, the non-use of hormone replacement therapy, not having consulted a doctor in the previous year, not having consulted a gynecologist, lacking a family history of breast cancer, not having performed the Papanicolaou test, not having performed clinical breast examination, and not having difficult access to health services. After logistic regression analysis, not performing mammography was associated with reports of a fair or bad health status. The study data revealed factors "responsible" for the non-performance of mammography, and the results should contributing to improvement/enhancement of healthy behaviour of Brazilian women in the post-menopausal phase.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.352-364
• /
• 2007

It is essential to reduce track maintenance costs and to extend the periodic replacements of continuous welded rails based on accumulated passing tonnage. As recently train load decrease and rail joints wear down less, the periodic replacements of continuous welded rails can be extended. There are many kinds of rail damage like squat, head-check and corrugation. These can be taken nondestructive or naked eye test. So the periodic replacements of continuous welded rails based on accumulated passing tonnage were examine with focusing on a crack of rail bottom of continuous welded rail. Therefore, this study measure dynamic response of track by metro train load, it compute impact coefficient and track spring coefficient for estimating a condition of actual track system. Also, it is converted the measured stress waveform into stress frequency histogram by the rain-flow counting methods, and then the equivalence of stress is calculated. As apply s-n curve of a new welded rail, accumulated fatigue damage ratio of laid rail and remaining service lives is estimated. This study suggest a plan of the periodic replacements of continuous welded rails based on accumulated passing tonnage classified by the types of track system.

• International Journal of Highway Engineering
• /
• v.16 no.6
• /
• pp.19-25
• /
• 2014

PURPOSES : This study was performed to evaluate the possibility of Indirect Tensile Strength (ITS) as a testing method that can predict cracking on pavement. METHODS : Three asphalt binders and one kind of aggregate were used in this study, and all asphalt mixtures were produced using Gyratory Compactor followed asphalt mix design. The ITS test was performed for the mixture which are artificially short-term aged using the oven. The ITS properties were analyzed by air void, compaction temperature, asphalt content, and asphalt binder. RESULTS : The results of this study indicated that (1) the compaction temperature did not show relationship with the ITS test; (2) there was no specific trend between the asphalt content and the ITS test; (3) the ITS could reveal the property of kinds of asphalt binders; (4) the asphalt mixture that were produced at optimum temperature suggested by manufacturer did not exhibit optimum result for all asphalt binder. CONCLUSIONS : The possibility of ITS was confirmed from this study for replacement of the Marshall Stability method. However, it needs to perform in further studies of aggregate and compaction property to suggest a new ITS standard value.

• Journal of the Korean Home Economics Association
• /
• v.43 no.11 s.213
• /
• pp.165-183
• /
• 2005

Total fertility rate in South Korea is the lowest in the world. A fertility rate below replacement fertility level will result in serious social problems in the long term. Therefore, it is worthwhile to study a general understanding about the low fertility rate phenomenon and to investigate the effectiveness of fertility policies in order to ameliorate the resulting social problems due to the low fertility rate. This research was a descriptive examination into the low fertility rate phenomenon and an investigation of the needs for fertility potties and their effectiveness. The study subjects were consisted of 769 unmarried people aged from 18 to 40 years old. Data were collected from June to August 2004 and were analyzed by frequencies, mean, and standard deviation. The following results were revealed. First, unmarried people in general had positive perspectives about getting marriaged, giving birth, and being a parent. In addition, the primary cause of low fertility rate was economical difficulties for raising a child. Third, unmarried people thought that the low fertility rate phenomenon resoled in both positive and negative changes in a society. Fourth, policies for economical supports for raising children, establishing social atmosphere for gender equality, and trustful public educational systems were the political alternatives that people really wanted for having a child in the future. Effective alternatives for policies and strategies to address the low fertility rate problems are suggested in the discussion section.

• Journal of Korean Society of Water and Wastewater
• /
• v.31 no.3
• /
• pp.237-248
• /
• 2017

The estimation method of economical leakage management target utilized upon planning business for improvement of revenue water ratio in South Korea is presented and applicability of methods developed in this study is assessed through application on site. With a consideration of revenue water ratio in application target area, estimation method of long-term economical leakage management target is applied. Three leakage reduction methods such as replacement of residual aged pipe, leakage investigation and restoration and water pressure management are applied with a consideration of characteristics of site. Due to difficulty of obtaining data, analysis of cost/benefit by leakage reduction methods is performed by applying method of leakages estimation equation among statistical methods. As a result of application, revenue water ratio corresponding to long-term economical leakage management target is 91.6 %.