• Earthquakes and Structures
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• 제14권5호
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• pp.437-447
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• 2018

Computational cost is one of the major obstacles for detailed risk analysis of structures. This paper puts forward a methodology for efficient probabilistic seismic loss assessment of structures using the Endurance Time (ET) analysis and the first-order reliability method (FORM). The ET analysis efficiently yields the structural responses for a continuous range of intensities through a single response-history analysis. Taking advantage of this property of ET, FORM is employed to estimate the annual rate of exceedance for the loss components. The proposed approach is an amalgamation of two analysis approaches, ET and FORM, that significantly lower the computational costs. This makes it possible to evaluate the seismic risk of complex systems. The probability distribution of losses due to the structural and non-structural damage as well as injuries and fatalities of a prototype structure are estimated using the proposed methodology. This methodology is an alternative to the prevalent risk analysis framework of the total probability theorem. Hence, the risk estimates of the proposed approach are compared with those from the total probability theorem as a benchmark. The results indicate a satisfactory agreement between the two methods while a significantly lower computational demand for the proposed approach.

• Journal of Korean Biological Nursing Science
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• 제10권1호
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• pp.11-18
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• 2008

Purpose: The purpose of this study was to identify the effect of the physical activity promotion program on physical function and quality of life in the elderly. Method: The research was designed with one single pre-post group. The study group of 295 elderlies were selected through the convenience sampling form in a senior citizen's center in Ulsan city. The subjects received the physical activity promotion program for 60 min three times a week for 3 months. To evaluation the effects of the physical activity promotion program, body mass index (BMI), physiological index, physical function (muscle endurance, agility, balance) and quality of life were measured at before and after the program. The data was analyzed through SPSS 10.0 program for descriptive statistics and paired t-test. Result: After performing the physical action promotion program for 3 months, the results were follows. 1) There were significantly increased in BMI (t=4.36, p=.000). 2) There were significantly decreased in diastolic pressure (t=.68, p=.009). 3) There were significantly improved in muscle endurance (t=6.50, p=.000), agility (t=4.74, p=.000) and Rt. leg balance (t=4.15, p=.000). 4) There were significantly improved in quality of life (t=7.28, p=.000). Conclusion: These findings showed that the physical activity promotion program was effective in improving physical function and quality of life in the elderly. Therefore, the physical activity promotion program could be applied as an effective nursing intervention program for the elderly to promote their health.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.47-54
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• 2014

선체 내구성은 기존 선급 규격에 의하여 구조 치수를 결정한 후 이러한 치수의 선체구조에 대하여 스펙트랄과 결정론적 및 간이 방법에 의하여 평가되고 있다. 이러한 방법은 선체재료를 선급 규격에서 제안하고 있는 재료로 구성하는 경우에는 적용할 수 있으나 선체 재료를 신소재로 구성하는 경우에는 적용할 수 없다. 따라서 본 연구에서는 폴리에틸렌 보트 선체에 대한 피로 손상을 평가하기 위하여 선체에 부하되는 단기간 선체 가속도를 직접 측정하고 이러한 데이터를 기초로 구조설계와 피로수명평가방법이 확립되지 못한 소형 선박의 선체 내구성을 선형누적손상 법칙으로 평가하는 방법을 제안하였다. 개발된 폴리에틸렌 보트의 경우 최대 가속도 상태에서 보트에 부하되는 최대 Von-Mises 응력은 1.8MPa로서 $1{\times}10^9$ 사이클 피로강도 5.9MPa 아래에 있고 유한피로수명개념을 적용한 폴리에틸렌 보트의 내구수명은 415년으로 평가되어져 거의 무한수명을 가지고 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.1165-1171
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• 2005

After 1974 an EMU, which is the first line opened, the car's term of endurance is introduced, End of life on the step, gradually the rate of cars out of service are increasing. In the country, we consider about recycled source, aspects of social economic of cars out of service and so on, treat efficiently and reasonable. According to research first we make investigations about the present situation and the actual condition of cars out of service then we should lay out schemes efficiently.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.28.1-28.1
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• 2008

• 한국가스학회지
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• 제16권6호
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• pp.67-72
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• 2012

본 연구에서는 압축천연가스 자동차용으로 사용하는 CNG 충전니플의 밀봉성과 밀봉내구 안전성에 관련된 접촉법선응력 및 등가진응력을 유한요소법으로 해석하였다. 기존의 원형 오링과 새로운 더블립 오링에 초기압축률 15%를 가한 상태에서 밀봉력을 해석한 결과에 의하면, 두 곳에서 밀봉작용을 하는 더블립 오링이 한곳에서 밀봉작용을 하는 기존의 원형 오링보다 41% 더 높게 나타남을 알 수 있다. 오링에 초기압축력 15%와 가스압축압력 8MPa을 작용한 상태에서 가스누출 차단 안전성을 비교하면, 기존의 원형 오링보다는 더블립 오링에서 5% 향상된 해석결과를 제시하고 있다. 또한, 오링의 밀봉내구 안전성을 비교한 FEM 해석결과에 의하면, 원형 오링보다는 더블립 오링에서 발생된 최대등가진응력이 10.2%나 더 높게 발생한 것으로 나타났다. 이것은 더블립 오링이 기존의 원형 오링보다는 장수명을 보장할 수 있다는 것이다.

• 한국가스학회지
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• 제17권1호
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• pp.73-80
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• 2013

본 연구에서는 유한요소해석법을 사용하여 V홈 오링의 밀봉거동과 내구 안전성에 관련된 변형률, 응력, 접촉법선응력 해석결과를 제시하고 있다. 밀봉거동과 내구 안전성에 관한 FEM 해석결과에 의하면, V홈 형상을 갖는 오링에 작용하는 최대변형률, 최대압축응력, 최대접촉법선응력은 기존의 오링에 비해 약 1.2배나 더 높게 나타났다. 이것은 오링이 두 개의 원형을 겹치도록 형성된 중간부에 V홈을 넣었기 때문에 가능한 것으로 판단되고, V홈 오링은 볼밸브, 압력용기, 가스기기의 밀봉을 하는데 매우 유용한 것으로 알려져 있다. 그리고, V홈 오링에서 가스압력을 높여도 압출에 의한 파손현상이 발생되지 않았는데, 이것은 V홈이 형성되어 있기 때문이다. 따라서, V홈 오링은 기존 오링에 비해 밀봉수명을 연장시킬 수 있다.

• 펄프종이기술
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• 제45권1호
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• pp.1-5
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• 2013

Printing papers published in between 1950's and 1990's were treated with three methods such as distilled water washing, $CaCO_3$ solution washing and methyl cellulose solution coating for improving their conservational properties. Accelerated aging with $80^{\circ}C$ and 80% RH for 14 days was applied to the testing papers. Results showed that distilled water and $CaCO_3$ washing kept increased pH even after accelerated aging, but did not improve folding endurances for 1950's-60's papers. Methyl cellulose treatment did not increased pH of the old papers, but increased folding endurances remarkably for 1950's-60's papers even after accelerated aging. It suggests that methyl cellulose treatment after $CaCO_3$ washing should give improvements both in pH and folding endurance.

• Journal of Life Science
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• 제11권2호
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• pp.87-91
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• 2001

We conducted this study to analyze the effectiveness of a treatment called 12-week therapeutic recreation dance movement (TRDM) to elderly people in terms of health care and recovery. Forty two elderly people were participated in this study and divided into two groups with healthy (twelve) and unhealthy (thirty). After TRDM treatment, the muscular power was increased in both groups without statistical significance within and between groups. The flexibility, agility and balance were slightly increased in both groups. Although the elevation of muscular endurance was not significant between groups, it was statistically meaningful within groups. The results of body composition comparison did not reveal meaningful difference within and between groups. However, the amount of fat in serum and fat distribution percentages ware decreased in both groups. Both group appeared to be increased muscle mass. The level of body water was decreased in healthy group and increased in unhealthy group. Unhealthy group appeared to be decreased level of T-C, TG and LDL-C. In contrast, the unhealthy group revealed the increased level of HDL-C. These results demonstrate the effect of TRDM to elderly people. This effectiveness can be adapted for the protection and treatment of geriatics-related adult diseases such as diabetes, hypertension and hyperlipidemia.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.239-245
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• 2005

Through the fatigue test of plastic gears using polyacetal polymer, this research aims at providing basic data for not only specifying operation conditions of plastic gears, but also designing dimensions of plastic gears with giving fatigue life and the estimated equation of fatigue life of plastic gears. That is, from the fatigue life curves, the estimated equation of fatigue life of plastic gears is taken out. For the estimated equation of fatigue life of plastic gears, this research provides two test methods; one is preserving non-limited temperature of tooth flank, the other is preserving limited temperature of tooth flank. As results, how the temperature of tooth flank affects the fatigue life is shown. In addition, based on the endurance limit, the essential factors of the unit load and K-factor are determined, which are needed in the design of gear by bending strength and surface durability.