• Journal of the KSME
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• 제33권4호
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• pp.343-355
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• 1993

각종 기기 구조물이나 인간은 세월이 흐를수록 원래 그들이 가지고 있는 최적의 상태에서 점차로 열화 및 노화되어 간다. 이와 더불어 가혹한 주변환경이나 무리한 작동 및 활동으로 인한 피로, 관리 및 유지의 소홀함등과 같은 이유가 열화 및 노화현상을 더욱 가속화시키고 있다. 그림 8에 서로간의 연관성을 정리하여 나타내고 있다. 특히 막대한 자금으로 여러 가지 목적으로 설비된 기계구조물이 노후화되어감에 따라 유지, 검사 및 보수의 허로 인한 대형사고의 결과는 국가경 제뿐만 아니라 수많은 인명의 위험이 뒤따르므로 그것들의 방지책으로는 정확한 수명예측을 위한 기술적 터득과 더불어 데이터의 축적, 신뢰성 있는 평가방법들의 개발에 관한 투자와 연구가 시급한 실정이며, 인체의 노화에 대해서도 인적자원의 관리면에서 투자와 연구가 긴요하다는 것은 설명의 여지가 없다. 이러한 목적을 위해서는 각 전문분야의 학술적 교류와 더불어 산 . 학. 연의 공동연구를 통한 지속적 연구노력이 계속되어야 할 것이다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.915-922
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• 2017

The study on the thermal and oil resistance rubber composite, 2016. [6] predicted the lifetime of Fluorocarbon Rubber by accelerating aging at high temperature ($150^{\circ}C$, $175^{\circ}C$, $200^{\circ}C$). general rubber products are likely to exhibit different properties depending on the degradation factors such as temperature, humidity, ozone, light, emulsion, mechanical and electrical stress. To solve these problems, We compared the rate of change about tensile strength, elongation rate, volume change rate, weight change rate, thickness change rate, thermal conductivity in low temperature promoting aging on the basis of predictive lifetime of high temperature promoting aging. As a result of the review, the required life expectancy was satisfied, but there was a slight difference in the rate of change between the high-temperature promoted aging life result and the low temperature promoted aging life result. The cause was a reduction in "tensile strength / elongation" and an increase in "volume / weight / thickness" caused by the main chain decomposition of fluorine rubber due to aging at high temperature promoting aging. However, the low temperature promoting aging was caused by the curing reaction of fluorine rubber at $80^{\circ}C$. The tensile strength / elongation and volume / weight / thickness changes were small.

• Elastomers and Composites
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• 제44권3호
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• pp.269-273
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• 2009

A study on the life-time expectation of a CR-modified NR rubber composite through the change of thermal degradation characteristics was performed using both isothermal thermogravimetric analysis (TGA) and thermomechanical analysis (TMA). Master curves at reference temperature of $90^{\circ}C$ could be obtained with shift factor $a_T$, which was determined empirically using Time-Temperature Superposition Principle (TTSP). Activation energies could be calculated from the slope of Arrhenius plot of shift factor and showed similar values of $E_{a,TGA}$= 41.2 and $E_{a,TMA}$= 54.5 kJ/mol, respectively. It was considered from the results that chemical degradation resulting weight loss of the sample might be closely related to a physical degradation such as the dimensional change of the sample.

• Electric Engineers Magazine
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• 제267권11호
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• pp.30-34
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• 2004

최근에는 설비의 이상징후를 포착함으로써 사고를 예지하고 치명적인 상태로 진전되기 전에 보완하는 이른바 예측보전 기술을 중심으로 하는 사고예방 방향으로 변화되어 가고 있다. 이 예측보전기술은 기기의 상태를 정량적으로 파악하여 이상징후를 초기단계에서 검지하는 이상예지진단과 기기성능의 경녕적인 변화에 착안한 노화진단 등을 중심으로 하고 있다.

• Journal of Families and Better Life
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• 제23권3호
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• pp.1-16
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• 2005

This study explored the elements, types, and determining factors of successful aging for the Korean elderly. In order to examine the expectations of the Korean elderly, a sample of 377 elderly aged 65 and over living in Seoul and Kyunggi areas was selected and interviewed. The elements of successful aging that the Korean elderly pointed out in the interviews were: 'peaceful and comfortable life', 'self-maintenance,' 'secure social support,' and 'ostentation.' The expected elements of successful aging were further classified into three types of successful aging: 'idealized expectation.' 'self-centered expectation,' 'balanced self-other expectation.' The elderly groups sorted by the types exhibited significant differences in terms of demographic characteristics, self-evaluated economic status, and self-evaluated health status. The variables that affected the expectations were age, level of education, marital status, gender, and self-evaluated health condition. However, further analysis revealed that the factors that affected the expectation for successful aging were different for male and female elderly. The results suggest that the successful aging of Korean elderly should be understood in the context of Korean society and culture. The results could be used to better understand varied and unique life of Korean elderly, as well as in establishing a basis of intervention that meets the specific demands of the Korean elderly.

• Journal of the Korean Society of Propulsion Engineers
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• 제22권4호
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• pp.55-60
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• 2018

The thermal property is one of the most important characteristics in the field of energetic materials. Because energy materials release decomposition heat, differential scanning calorimetry (DSC) is frequently used for thermal analysis. However, thermodynamic events, such as melting can interfere with DSC kinetic analysis. In this study, we use isothermal mode for DSC measurement to avoid thermodynamic issues. We also merge accelerating rate calorimetry(ARC) data with DSC data to obtain a robust prediction results for small scale samples and for large scale samples as well. For the thermal property prediction, advanced kinetics and technology solutions(AKTS) programs are used.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.148-153
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• 2017

During natural ageing of HTPB propellant undergoes a series of slow physico-chemical degradation reactions. By using accelerated ageing conditions it is possible to simulate the material behaviour at different time-temperature conditions especially focused on the in-service conditions. Ageing behaviour of HTPB propellant were investigated using HFC(Micro-Heat Flow Calorimeter) is universal technique for measuring the rate of slow chemical and physical processes in long-term storage.

• Journal of the Korean Society of Propulsion Engineers
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• 제20권4호
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• pp.34-39
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• 2016

Arrhenius kinetic constants, the activation energy and the pre-exponential factor, of energetic material $BKNO_3$ are estimated using Differential Scanning Calorimetry (DSC). Different from the conventional way, the activation energy was estimated more precisely through DSC aging trial, and the consumed fraction by heat was calculated by comparing the integration of heat flow. We suggested the condition of accelerated aging test for the energetic material $BKNO_3$ and reconsidered the meaning of the thermal accelerated aging.

• Journal of the Korean Society of Propulsion Engineers
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• 제22권5호
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• pp.59-65
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• 2018

During natural aging, hydroxyl-terminated polybutadiene(HTPB) propellant undergoes a series of slow physico-chemical degradation reactions. By using accelerated ageing conditions it is possible to simulate the material behavior at different time-temperatures focusing on in-service conditions. Aging behaviors of HTPB propellant are investigated using HFC(heat flow calorimeter), a universal technique for measuring the rate of slow chemical and physical processes in long-term storage.

• Convergence Security Journal
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• 제24권3호
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• pp.59-65
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• 2024

This research proposes an accelerated aging test procedure for Static Random Access Memory Physically Unclonable Functions (SRAM PUFs). PUFs utilize semiconductor process variations to serve as a hardware security feature, akin to semiconductor device fingerprints. Thus, the proposed accelerated aging test simulates a semiconductor's 10-year lifecycle, enabling the prediction of PUF characteristics after a decade of use, which is crucial for verifying the safety and stability of SRAM PUFs. This research introduces test procedures that simulate 10 years of aging in approximately 9 days by setting temperature and voltage higher than operational environments. These procedures allow for the quantitative evaluation of SRAM PUF characteristics. This research is expected to contribute to the advancement of design and maintenance testing techniques for systems based on SRAM PUFs.