• 한국전기전자재료학회논문지
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• 제11권11호
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• pp.1035-1042
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• 1998

After the 1990's, a computer-aided partial discharge(PD) measurement system was referred in part of aging diagnosis using digital signal processing as the new technology has been studied. The PD patterns and relevant information for pattern recognition are discussed in PD research area, because discharge quantity(q), the number of discharge pulse(n) and the applied boltage phase($\varphi$) was combined with the system information of the aging state. This paper investigates the discharge phase and quantity, as well as the number of discharge(n) with regard to discharge signals generated in power cable. therefore, according to characteristic analysis on the distribution of $\varphi$, q and n, it is able to apply in the aging analysis of power cable which visual observation is impossible and distribution change of discharge signals offers much information for risk degree on aging progress of insulation materials.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1726-1728
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• 2003

The aging diagnosis method using partial discharge measurement detects discharge signals that critical cause of failure in insulation material operated a long time and can diagnose aging state of insulation materials with an aging analysis algorithm. The HFPD measurement method is a technique to analyze aging state of high voltage insulation materials and detect higher frequency signals than conventional PD measurement method therefore it takes less noise effect and could execute active line measurement. It is possible to analyze main discharge phenomena and obtain access to aging progress occurred in insulation materials through accumulation of HFPD signals during determined interval and expression of fractal dimension using statistical process of accumulated signals. The HFPD signals that occurred in each applied voltages are measured during 180 cycles and accumulated to the same phase of one cycle. These patterns that made by previous method are normalized with logarithm function and than inputted to neural networks. The aging diagnosis of insulation material was possible and the recognition ratio of neural network appeared very high.

• 성인간호학회지
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• 제17권4호
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• pp.656-667
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• 2005

Purpose: This study examined the mood state, activities of daily living, and attitude toward aging in the elderly according to the existence of a spouse and investigated the relation between these factors. Method: The subjects consisted of 190 elderly people, who were classified into two groups: those with and without a spouse. The data was collected from March to December 2004 using a structured questionnaire that included general characteristics, mood states, instrumental activities of daily living (IADL), and an attitude toward aging scale. The collected data was analyzed using the program SPSS, including descriptive statistics, $x^2-test$, ANOVA, Scheff's test, and the Pearson correlation coefficient. Result: 1. There were significant differences between the two groups in mood state (t=-3.349, p=.001), anxiety-depression (t=-3.350, p=.001), and anger (t=p=.003) in the mood state subscales, and in attitude toward aging (t=2.514, p=.013). 2. There was a significant positive correlation between vigor and IADL (r=.253, p=.012) in the elderly with a spouse. 3. When there was a spouse, there was a significant difference according to gender (t=2.587, p=.012) in IADL. Without a spouse, there were significant differences in mood states according to education level (F=3.315, p=.023), in anxiety-depression according to the presence of illness (t=2.156, p=.033), in vigor according to age (F=3.439, p=.020) and education level (F=5.285, p=.002), and in IADL according to monthly income (F=3.322, p=.023) and the presence of illness (t=2.172, p=.032). Conclusion: An individualized approach is needed for elderly people that considers living arrangements and the existence of a spouse.

• 디지털융복합연구
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• 제10권1호
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• pp.185-194
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• 2012

한국에서의 고령화는 아직 걱정할 단계는 아니지만 고령화의 속도가 지나치게 빠르게 진행된다는데 문제가 있다. 인구의 절대규모는 2030년의 52,160 천명에서 정점을 이루다가 감소하여 2050년에는 2005년 수준인 48,121천명으로 감소하며, 핵심근로계층인 25-54세의 인구는 저출산과 고령화로 인하여 이미 2012년부터 감소하는 것으로 예측되었다. 고령화는 불가피하게 노동력의 부족을 초래하게 되며, 이는 한 번도 경험해보지 못한 상황에서 정책 수단들을 세워나가야 한다. 본 논문에서는 몇 가지의 대안을 제시하였다. 첫째, 인구규모 자체의 감소를 예방하기 위한 것으로 국가 지원의 보육체계를 포함하는 출산장려정책을 제시하였으며, 둘째, 노동력 절대규모의 감소라는 현실적 상황에서 고용률로 측정된 노동시장의 참여를 증대시킬 수 있는 방안을 제시하였다. 먼저 정년 연장형의 임금피크제를 포함하는 고령자 및 출산의 기회비용을 낮추어 여성의 노동시장 참여를 촉진하는 방안을 제시하였다. 결론적으로 고령화는 피할 수 없는 상황이며, 지속가능한 균형성장이라는 틀에서 문제해결에 접근해야 한다.

• Nuclear Engineering and Technology
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• 제47권6호
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• pp.712-718
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• 2015

Cast duplex stainless steels are susceptible to thermal aging during long-term service at temperatures ranging from $280^{\circ}C$ to $450^{\circ}C$. To analyze the effect of thermal aging on leak-before-break (LBB) behavior, three-dimensional finite element analysis models were built for circumferentially cracked pipes. Based on the elasticeplastic fracture mechanics theory, the detectable leakage crack length calculation and J-integral stability assessment diagram approach were carried out under different bending moments. The LBB curves and LBB assessment diagrams for unaged and thermally aged pipes were constructed. The results show that the detectable leakage crack length for thermally aged pipes increases with increasing bending moments, whereas the critical crack length decreases. The ligament instability line and critical crack length line for thermally aged pipes move downward and to the left, respectively, and unsafe LBB assessment results will be produced if thermal aging is not considered. If the applied bending moment is increased, the degree of safety decreases in the LBB assessment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1880-1884
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• 2000

The discrete wavelet transform is utilized as preprocessing of Neural Network(NN) to identify aging state of internal partial discharge in transformer. The discrete traveler transform is used to produce wavelet coefficients which are used for Classification. The statistical parameters (maximum of wavelet coefficients, average value, dispersion, skewness, kurtosis) using the wavelet coefficients are input into an back-propagation neural network. The neurons whose weights have obtained through Result of Cross-Validation. The Neural Network learning stops either when the error rate achieves an appropriate minimum or when the learning time overcomes a constant value. The networks, after training, can decide if the test signal is Early Aging State or Last Aging State or normal state.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 추계학술대회 논문집
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• pp.200-201
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• 2013

This paper investigates a new approach for Li-Ion battery state-of-charge (SOC) estimation using sliding mode observer (SMO) technique including parameters aging compensation via recursive least squares (RLS). The main advantages of this approach would be low computational load, easiness of implementation along with the robustness of the method for internal battery model parameters estimation. The proposed algorithm was first tested on a set of acquired battery data using implementation in Simulink and later developed as C-code module for firmware application.

• Preventive Nutrition and Food Science
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• 제22권1호
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• pp.30-36
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• 2017

Physicochemical properties of Fujian Yongchun aged vinegar (FYAV) and Shanxi mature vinegar (SMV) were compared in terms of the fermentation methods applied and aging periods (3, 5, 8, and 10 years), and combined E-nose/E-tongue analyses were performed to assess their flavors. Compared with submerged fermentation-derived FYAV, solid-state fermentation-derived SMV showed higher values of pH, brix, soluble solids, total phenolic content, and antioxidant activity, but not total acidity or total organic acids. Aging period resulted in an increase in pH, total phenolic content, and antioxidant activity. Principal component analysis based on E-tongue/E-nose analyses was performed to distinguish between the vinegars produced by different fermentation methods and under aging periods. Solid-state fermentation and an aging process were considered good techniques for vinegar brewing, considering the various organic acids and high levels of total phenolics and antioxidant activity.

• The Korean Journal of Physiology
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• 제26권1호
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• pp.89-97
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• 1992

In hypoxic tissue conditions, pyruvate can not enter the Krebs cycle and lactic acid, produced from pyruvate, accumulates to induce lactic acidosis. Pyruvate, However, can also be converted to alanine by glutamate pyruvate transaminase, that could be enhanced by glutamate. Therefore, it would be a fundamental measure to treat the lactic acidosis in tissue hypoxic conditions when one can convert the accumulated lactic acid, through pyruvate, to alanine. To test the above hypothesis, we induced a lactic acidosis in cats and the effect of glutamate on recovery of acid base state and removal of the lactic acid from blood were assessed and the results were compared with those of bicarbonate administration, which is one of the most frequently used conventional measure for correction of the acid base state during lactic acidosis. The results were that glutamate and combined glutamate bicarbonate solutions not only restored the acid base status completely from the lactic acidosis in an hour or two, but also restored the blood level of lactate partially. We concluded that administration of glutamate solution to convert pyruvate into alanine is effective in preventing lactic acid accumulation and treating lactic acidosis.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.86-94
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• 1997

Quick aging of catalysts has done with IAE(Institute for advanced engineering) AGING MODE suggested by IAE. To estimate the effects of number of aging cycle, temperature and $H_2O$, characteristics of surfaces, mechanical properties and weibull modulus were estimated. Also, the conversion efficiency of aged catalysts was evaluated with model gas bench test. The area of surface and pore volume were decreased according to the number of aging cycle. The precious metal which is well dispersed in fresh state was sintered and agglomerated with aging. The mechanical of deactivation and sintering of catalysts are discussed on the basis of mechanical tests. The conversion efficiency was decreased with the repeats of aging. Especially, the existence of $H_2O$ in supply gas had a main role in catalyst deactivation withy high temperature.