• 대한지역사회영양학회지
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• 제15권4호
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• pp.536-549
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• 2010

The purpose of this study was to investigate food intake, dietary diversity and dietary pattern during the summer in middle aged and older adults living in Gugoksundam (Gurye, Goksung, Sunchang and Damyang counties), Jeonla Province located in southern part of Korea and known as one of the representative Korean longevity areas. Food intake and dietary diversity were assessed by using the data from 2 day-24 hour recall of 1,051 subjects (394 males and 711 females) aged 45 years and older (45-93 years in male, 45-105 years in female). The average ages of males and females were 70.7 years and 71.1 years, respectively. Average total daily food intake was significantly decreased with aging in both genders, and the average animal food intake ratio to total food intake was ranged 10~14% in 3 different age groups, 45~64 years, 65~74 years and 75 years and older. The contribution of each food group, in weight, to total food intake showed the descending order of grains, fruits, vegetables and alcohols in males, and grains, fruits, potatoes and meats in females. On daily intake amount of each food item, rice, watermelon, soju, kimchi, and potato were ranked on top 5 in descending order in males, and rice, watermelon, potato, kimchi and ylmukimchi in females. On intake frequency, rice, kimchi, onion, green pepper and potato were ranked on top 5 in descending order in both genders. Dietary variety score (DVS) and dietary diversity score (DDS) for the assessment of dietary diversity and balance were significantly decreased with aging in both genders. In food group intake pattern (DMGFV), 01101 type without consumption of dairy and fruits was the most prevalent, and only 3.6% of male and 3.9% of female subjects showed 11111 type, consumed all the 5 food groups a day. Dietary pattern of subjects was analyzed by cluster analysis with 18 food groups intake. Overall dietary pattern was classified into two clusters, one was more desirable and the other was less desirable. The percentage of subjects with more desirable dietary pattern was about 15% in male and 32% in female. In conclusion, most of our subjects living in Gugoksundam area were taking very simple diet with low amount of dairy products and fruits. These results indicate that nutrition intervention and education for older people living in rural areas should be focused on various food intake including dairy products and fruits.

• Journal of Electrical Engineering and Technology
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• 제11권5호
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• pp.1377-1382
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• 2016

• Elastomers and Composites
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• 제40권3호
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• pp.166-173
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• 2005

본 논문에서는 세가지 종류의 경화제 (D-230, G-5022 및 HN-2200)를 사용하여 열화가 에폭시 접착제의 질량변화 및 흡수량에 미치는 영향을 고찰하였다. 경화된 시편의 열적 및 기계적 특성은 유리전이온도와 전단강도 측정을 통하여 알아보았다. 실험 결과, D-230와 HN-2200를 경화제로 사용하였을 경우 열화 시간이 시스템의 질량 변화에 영향을 주지 않았으며, G-5022를 경화제로 사용하였을 경우 시스템의 질량은 열화 시간에 따라 현저하게 감소하였다. 열화 이전의 DGEBA/G-5022 시편을 제외하고 모든 시편의 흡수량은 시간에 따라 점차 증가하였다. 또한, DGEBA/HN-2200 시스템이 제일 높은 $T_g$ 값을 나타내었으며, 이는 경화된 시스템이 지방족 고리를 함유한 3차원 네트워크 구조를 형성한 것으로 판단된다. 에폭시 수지의 접착강토는 열화 시간에 따라 점차 증가하였으며, 이는 에폭시 수지의 경화도 증가와 보다 발달된 3차원 네트워크 구조의 형성에 기인한다. 또한, 내수 실험 후 열화 전후의 모든 시편의 유리전 이온도와 전단접착강도는 흡수시간에 따라 감소하였다.

• 전기학회논문지
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• 제56권9호
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• pp.1561-1565
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• 2007

According to thermal degradation on power transformers, it is known that electrical, mechanical and chemical characteristics for power transformer's oil-paper are changed. In the chemical property, especially, when the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. Also the paper breakdown is accompanied by an increase in the content of various furanic compounds within the dielectric liquid. It is known that furanic components in transformer oil come only from the decomposition of insulating paper rather than from the oil itself. Therefore the analysis of furanic degradation products provides a complementary technique to dissolved gas analysis for monitoring transformers when we evaluate the aging of insulating paper by the total concentration of carbon monoxide and carbon dioxide dissolved in oil only. Recently, the analysis of furanic compounds by high performance liquid chromatography(HPLC) using IEC 61198 method for estimating degradation of paper insulation in power transformers has been used more conveniently for assessment of oil-paper. It is know that the main products which is produced by aging are 2-furfuryl alcohol, 2-furaldehyde(furfural), 2-furoic acid, 2-acetylfuran, 5-methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde. For investigating the accelerated aging process of oil-paper samples we manufactured accelerating aging equipment and we estimated variation of insulations at $140^{\circ}C$ temp. during 500 hours. Typical transformer proportions of copper, silicon steel and iron have been added to oil-paper insulation during the aging process. The oil-paper insulation samples have been measured at intervals of 100 hours. Finally we have analyzed that 2-furoic acid and 2-acetylfuran products of furanic compounds were detected by HPLC, and their concentrations were increased with accelerated aging time.

• 조명전기설비학회논문지
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• 제23권6호
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• pp.104-108
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• 2009

본 논문에서는 지중전력케이블을 대상으로 케이블의 절연열화특성 분석시험을 통해 케이블의 절연열화와 절연 진단결과 및 파괴강도와의 상관관계에 대한 실증연구를 수행하였다. 시험대상 선로의 제조결함 여부를 확인하기 위해 가교도분석, 핫오일테스트 등을 실시한 결과 제조결함은 없는 것으로 확인되었다. 진단대상 선로는 3상 모두 장기간 사용에 의해 열화가 많이 진전되었고, 특히 B상이 수트리 길이 및 화학구조결함 농도 면에서 가장 열화된 케이블인 것으로 판단되며, C상, A상의 순으로 열화정도가 다소 감소함을 확인하였다. 상기 결과는 진단시험 및 파괴 강도시험 결과와 일치하며, 따라서 열화시정수법을 이용한 진단장치가 열화상태가 심각한 케이블의 선별에 효과적인 진단법임을 확인하였다.

• 대한토목학회논문집
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• 제41권5호
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• pp.591-599
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• 2021

현재 국내 철도시설 운영기관은 노후 시설물 판단을 위한 명확한 정의와 시설물 보수/개량 우선순위 산정 방법이 정립되지 않아 성능중심 유지관리계획 수립에 어려움을 겪고 있다. 따라서, 본 연구는 선행연구에서 노후 시설물을 어떻게 정의하였는지 고찰하고, 국내 노후 철도시설물 관리제도와 미국 연방대중교통청(FTA)의 교통시설물 자산관리체계 비교분석을 통해 벤치마킹 포인트를 도출하였다. 노후 시설물 판단은 경과연수와 성능수준을 같이 고려해야 하며, 경과연수와 성능등급 간 관계를 통계적으로 분석하여 보수/개량 우선순위를 산정해야 한다. 또한, FTA와 같은 데이터 기반 철도시설 관리를 위해서는 표준 철도시설물 분류체계를 기반으로 시설물 분류 하위 수준에서 내용연수, 성능평가 결과, 유지관리비용 데이터베이스를 구축하는 것이 필요하다. 향후 데이터가 충분히 축적되면 성능중심 노후 철도시설 관리를 위한 효율적 예산집행계획 수립에 기여할 것으로 기대된다.

• 한국압력기기공학회 논문집
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• 제7권2호
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• pp.14-20
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• 2011

The end of design lifetime for Wolsong unit 1 will be reached on 20th November in 2012. So the license renewal documents for the continuous operation of Wolsong unit 1 is under reviewing now. Major components of primary system such as pressure tubes, feeder pipes including delayed neutron monitoring system tubing are being replaced and many components of secondary system are also being repaired. In this paper, the assessment on the wear degradation of delayed neutron monitoring system tubing(on the other hand, DN tube was called) was performed for the ageing management of the same component. The wear defects of this component was one of causes that resulted in heavy water leakage accidents. Therefore design specifications of Wolsong uint 1 and heavy water leakage accidents of pressurized heavy water reactors were reviewed and causes of wear defect for DN tubes were analyzed. Wear propagation equations based on the heavy water leakage history were made and the proper repairing time was possible to be expected if the continued operation was considered. Finally design change items of DN tubes that were conducted for the long term operation of Wolsong unit 1 are introduced.

• 한국의류산업학회지
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• 제14권6호
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• pp.1010-1017
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• 2012

This study examined the clothing wearing comfort of elderly women by electroencephalogram (EEG) and electrocardiogram (ECG) analyses. This study utilized 7 elderly individuals aged 65 or more. Two kinds of clothing ensemble (control and prototype) were used as experimental clothing. The control consisted of a general clothing ensemble and the prototype consisted of clothing that added an extra gap. Subjects wore the control or prototype from 9:00 to 21:30 and EEG and ECG signals were measured in the last 30 minutes. The EEG analysis showed that relative band power of a and ${\alpha}$/high ${\beta}$ were higher when they wore the prototype rather than the control. The ECG analysis showed that absolute band power of HF was higher; however, absolute band power of LF and LF/HF was lower when they wore the prototype rather than the control. Subjects felt less stressful and more comfortable when they wore the prototype. The results demonstrate the necessity to develop clothing in consideration of the body changes in elderly women. It is significant that the assessment of wearing comfort was aided by the use of EEG and ECG analysis in the field of clothing and textiles.

• Structural Engineering and Mechanics
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• 제65권6호
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• pp.751-760
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• 2018

Damages in concrete structures due to aging and other factors could be a serious and immense matter. Making the best selection of the most viable and practical repairing and strengthening techniques are relatively difficult tasks using traditional methods of structural analyses. This is due to the fact that the traditional methods used for assessing aging structure are not fully capable when considering the randomness in strength, loads and cost. This paper presents a reliability-based methodology for assessing reinforced concrete members. The methodology of this study is based on probabilistic analysis, using statistics of the random variables in the performance function equations. Principles of reliability updating are used in the assessment process, as new information is taken into account and combined with prior probabilistic models. The methodology can result in a reliability index ${\beta}$ that can be used to assess the structural component by comparing its value with a standard value. In addition, these methods result in partial safety factor values that can be used for the purpose of strengthening the R/C elements of the existing structure. Calculations and computations of the reliability indices and the partial safety factors values are conducted using the First-order Reliability Method and Monte Carlo simulation.

• 대한정형도수물리치료학회지
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• 제7권2호
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• pp.41-49
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• 2001

This study was undertaken to find out the effect analysis of conservative treatment in of lumbar intervertebral disc. The data was performed to evaluate the effect of conservative treatment in 50 patients aging from 20 to 67 with lumbar intervertebral disc patients. Changes in low back pain score were evaluated by age, occupation, duration of symptoms, marital status, education period, self assessment. Duration of symptoms in over 7 months was 62.0%. 8.6 scores of complete recovery was changes in low back pain score of self assessment patients. In the multiple regression of risk factors to changes in low back pain score were correlated with age, education period, marital status, duration of symptoms(p<0.05). All patients were assessed by the low back pain protocol which was composed of symptom, clinical sign and activities of daily living scales before and after the treatment. Poor result could be predicted after the nonoperative treatment in the patient groups of changes low back pain score decreased with aging, duration of symptom over 7 months.