• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1698-1700
• /
• 2002

Recently, the HFPD measurement methods that detect high frequency bandwidth of frequency components of partial discharge pulses are proposed and many studies are carried out. The HFPD measurement method is able to detect partial discharge signal in active line, therefore this method has a merit that can does condition monitoring of power equipments and measure growth state of partial discharge erosion with on-line and real time. In this study, the radiated HFPD signals are detected by antenna and aging diagnosis is executed with a neural network algorithm. As a result of this study, the aging diagnosis of insulation material using neural networks is possible.

• The Journal of the Korea Contents Association
• /
• v.21 no.12
• /
• pp.408-422
• /
• 2021

In this study, the relationship between trust and purchase intention, which is an outcome variable, was empirically verified by discovering the trust-forming factors of anti-aging products and developing measurement variables. In addition to the existing trust-forming factors such as perceived quality, perceived reputation, brand recognition, and customization, a newly discovered factor is 'accredited certification'. Since the anti-aging industry in Korea is an industry that directly affects consumer health, it was determined that the existing trust-forming factors had limitations in building consumer trust, and a new measure was discovered. This study conducted a survey on anti-aging product consumers and analyzed the solidity and relationship of the questions. As a result of the analysis, it was found that perceived quality, brand recognition, customization, and accredited certification among the anti-aging product trust-forming factors had a positive (+) effect on trust, and perceived reputation had a negative (-) effect on trust. appeared to affect It was found that there was a positive (+) effect between trust and purchase intention, which are the trailing variables. This study proved the meaningful relationship between trust-forming factors and trust by strategically developing and empirically and practically examining meaningful and effective trust-forming factors and measurement items. At the same time, this study is expected to significantly contribute to the establishment of marketing strategies related to anti-aging products in the future by discovering key factors for forming trust that are important for marketing in the anti-aging industry.

• Proceedings of the Korean Nutrition Society Conference
• /
• 2002.11b
• /
• pp.1154-1156
• /
• 2002

• Proceedings of the Korean Nutrition Society Conference
• /
• 2002.11a
• /
• pp.50-53
• /
• 2002

• The Transactions of the Korean Institute of Power Electronics
• /
• v.8 no.3
• /
• pp.247-252
• /
• 2003

Aging and failure of motor insulation depend on the stresses imposed on it. The insulation life time depends on the severity of the stresses. The electrical aging by transient surge is very important to traction motor in EMU(electric multiple unit). This paper presents the insulation characteristics of stator coil by transient surge from inverter. There are several nondestructive tests available for checking the condition of motor insulation, the probable extent of aging, and the rate of which aging is taking place. So the insulation characteristics of stator coil were each analyzed by measurement of leakage current, dielectric loss(tan $\delta$), capacitance, polarization index(PI) and partial discharge. The method of diagnosis is able to analyze the aging condition and predict the life of the traction motor in EMU.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.9
• /
• pp.783-789
• /
• 2003

The winding problems of traction motor are the major determinant of motor's life. The root cause of winding failure is gradual deterioration of the insulation due to thermal, electrical, mechanical and environmental stresses. The aging of the insulation reduces the electrical and mechanical strength of the insulation. At same point, a voltage surge or mechanical shock from a traction motor start will fracture or break down the insulation. To achieve the expected life usually requires extensive laboratory evaluation of the insulation systems and the use of accelerated aging tests. There are several nondestructive test available for checking, the condition of motor insulation, the probable extent of aging, and the rate of which aging is taking place. So the insulation characteristics of stator coil were each analyzed by measurement of dielectric loss(tan$\sigma$), capacitance and partial discharge. The method of diagnosis is able to analyze the insulation condition and evaluate the life of the traction motor.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.51 no.10
• /
• pp.465-472
• /
• 2002

This paper presents a study on the aging and recovery of HTV (high temperature vulcanized) silicone rubber used for outdoor insulators. UV irradiation, corona discharge and water immersion were employed as factors of the artificial aging. The effects of changes derived from these stresses on the tracking and arc resistance of silicone rubber were examined. We have investigated the aging phenomena of HTV silicone rubber by the above stresses using the surface energy calculation with contact angle measurement, solvent-extraction, and surface/volume resistivity and so on. These results showed that UV irradiation and corona discharge lead to nearly the same surface oxidation, but the percentage change of mobile low molecular weight by these stresses was different. Furthermore, the oxidized layer induced under UV irradiation restricted the recovery of hydrophobic surface. Water immersion little lowered hydrophobicity level and leaded to a loss of tracking and arc resistance. The degradation mechanism based on our results was discussed.

• Journal of Korean Academy of Nursing
• /
• v.49 no.1
• /
• pp.14-25
• /
• 2019

Purpose: This was a methodological study that aimed to develop a measurement scale for aging anxiety among middle-aged women. Methods: In this study, construct factors were extracted, and a conceptual framework was established through an extensive literature review and in-depth interviews with middle-aged women. Under the conceptual framework, 44 preliminary items were constructed, and a preliminary scale of 25 items was completed after two rounds of expert validation and item review. For this study, data were collected from 201 women aged 40~59 years, and the construct validity and reliability of the preliminary scale were verified. Results: To verify the construct validity, exploratory factor analysis was conducted. Four factors containing 19 items were extracted. Concurrent validity of the developed scale was verified with Pearson's correlation analysis. The final scale comprised 4 factors ("Social valueless", "Physical weakness", "Concern about changes in appearance", and "Expectations of old age") and 19 items. The Cronbach's ${\alpha}$ value was .91. Conclusion: The scale for measuring aging anxiety in middle-aged women developed in this study validly reflected the peculiarities of aging anxiety in middle-aged women, who experience many physical, emotional, and social changes. The scale can be said to reflect the cultural background, as it reflected real experiences gained through in-depth interviews with middle-aged women.

• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.2
• /
• pp.176-182
• /
• 2022

Since the various characteristics of the polymer electrolyte membrane are not clearly identified, it is difficult to predict and design applications for various conditions. In this study, as a previous study on the aging of the polymer electrolyte membrane, a study was conducted on the change of mechanical properties according to the aging of the polymer electrolyte membrane. Through the tensile test of Nafion 117, the mechanical properties change due to aging was confirmed. As a result of the tensile test, it was confirmed that the aged Nafion 117 had reduced tensile strength. Through DSC measurement, aged Nafion confirmed that the glass transition temperature and enthalpy change were low, which is thought to be the effect of molecular motion and transition due to the lapse of time. The effect is thought to cause a difference in the amount of change in enthalpy, resulting in a difference in mechanical properties during tension.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.2
• /
• pp.45-50
• /
• 2005

To improve mean-life and reliability of power cable, in this study, we have investigated electrical properties and stress-strain showing by changing the content of carbon black that is semiconductive additives for underground power transmission. Specimens were made of sheet form with the nine of specimens for measurement. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the pre-heated oven of both 25±1 [℃] and 90±1 [℃]. And stress-strain of specimens was measured by TENSOMETER 2000. A speed of measurement was 200[mm/min], ranges of stress and strain were 400[Kgf/㎠] and 600[%]. In addition tests of stress-strain were progressed by aging specimens in air oven. From this experimental results, volume resistivity was high according to increasing the content of carbon black. And yield stress was increased, while strain was decreased according to increasing the content of carbon black. And stress-strain were decreased some after aging because of oxidation reaction of chemical defect. We could know EEA was excellent more than other specimens from above experimental results.