• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.475-486
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• 2017

This paper estimates the health life expectancies for Korean people based on a sample cohort database collected through objective measurements by the National Health Insurance Service. Health life expectancy is estimated using the single-state approach of Sullivan (1971). The 9-order correction factor method of Greville (1945) and Brass-logit model of Brass (1971) are also adopted for unobserved or incompletely observed age-specific morbidity and mortality. Based on the mortality and morbidity estimated from sample cohort DB, men and women in Korea are expected to live a 'healthy life' for 61 and 60 years in 2013, respectively, whereas life expectancies of men and women are 80 and 87, respectively. We also estimate certain disease-free life expectancies for each of genders, income levels, and types of insurance from 2003 to 2013 in Korea. We found that there exists an inequality of healthy life expectancy in Korea for different genders, income levels, and types of insurance.

• Korea journal of population studies
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• v.35 no.2
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• pp.209-232
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• 2012

The purposes of this study is to calculate the gender-based Life Expectancy and Disability Free Life Expectancy of 65-year-olds in accordance with the regions of 16 in Korea based on the years 2005 and 2010 by using the Sullivan method. We used the Census in 2005, 2010, the Korea National Statistical Office(10% sample). We also reviewed examining the changes in LE and DFLE and understanding the relevance between the DFLE of 65-year-olds of the year 2010 and related factors. As a result of this study, it was shown that the LE of the group of all 65-year-old in Korea increased from 18.15 years in 2005 to 19.75 years in 2010 and DFLE increased from 11.41 years in 2005 to 11.64 years in 2010. Regionally, the highest LE for total of 65-year-olds was found to be the entire Jeju area and DFLE was the highest in the city of Seoul. And the highest LE and the highest DFLE for 65-year-old male were found to be in the city of Seoul. Regarding the regional LE of 65-year-old female, both in 2005 and 2010 Jeju area was seen to be the highest. The results of a correlation analysis showed that the DFLE of 65-year-olds in 2010 was found to be increasing with high LE and high population density and in regions with low average temperatures, low number of beds and low age standardized death rates of malignant neoplasms and circulatory disease.

• Korea journal of population studies
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• v.34 no.3
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• pp.157-177
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• 2011

This paper examines the performance of the coherent Lee-Carter method for the mortality forecasting for the Republic of Korea combined with Japan and the Taiwan Province of China as a group by comparing it with the separately applied Lee-Carter method. It narrowed the gap of life expectancies between three countries from 6.8 years to 3.0 years in 2050, with higher life expectancy forecasts for the Taiwan Province of China and lower ones for Japan than with the separate forecast. This method did not affect the sex-combined life expectancy forecast for the Republic of Korea, but it accelerated the mortality decline for ages 65 and over and decelerated it for the younger age groups, diminishing sex differentials of life expectancy at a slower speed. It suggests that the integration of regional mortality information into mortality forecasting of one country gives several advantages in terms of short run fit within each country as well as long run convergence between countries, a modification of the age pattern of mortality decline, and a consistent application of the forecasting of subgroups within a country.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.417-428
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• 2021

Since future maintenance cost estimation of infrastructure involves uncertainty, it is important to make use of a failure prediction model. However, it is difficult for local governments to develop accurate failure prediction models applicable to infrastructure due to a lack of budget and expertise. Therefore, this study estimated the life expectancy of asphalt road pavement of national highways using the Bayesian Markov Mixture Hazard model. In addition, in order to accurately estimate life expectancy, environmental variables such as traffic volume, ESAL (Equivalent Single Axle Loads), SNP (Structural Number of Pavement), meteorological conditions, and de-icing material usage were applied to retain reliability of the estimation results. As a result, life expectancy was estimated from at least 13.09 to 19.61 years by region. By using this approach, it is expected that it will be possible to estimate future maintenance cost considering local failure characteristics.

• The Korean Journal of Applied Statistics
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• v.31 no.4
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• pp.427-446
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• 2018

Korea will have a super-aged society within only 30 years according to the United Nations' definition of an aging society and the statistics on Korea's Population projections (2016), indicates that Korea has the fastest ageing speed in the world. There is a lack of data on long-term time-series data on death as related to pension and welfare policies compared to the rapid rate of aging. This paper estimates life expectancy over 245 years (from 1955 to 2200) through past and future forecasts as well as compares the expected life expectancy of the synthetic cohort and the real cohort. In addition, an international comparisons were made to understand the level of aging in Korea. Estimates of the back-projection period were compared with previous studies and the LC model to improve accuracy and objectivity. In addition, the predictions after 2016 reflected the declined mortality rate effect of Korea using the LC-ER model. The results showed an increase in life expectancy of about 30 years over 60 years (1955-2015) with an expected life expectancy of the real cohort over the second century (1955-2155) higher than the synthetic cohort. The comparative advantage of life expectancy of real cohorts was confirmed to be a common trend among comparative countries. In addition, Japan and Korea have a higher life expectancy and starting from 85 to 90 years old, all comparative countries show that the growth rate for the life expectancy of synthetic and real cohorts is less than previous years.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.503-503
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• 2007

본 논문에서는 지중배전(22.9kV) 선로에 사용되는 지상변압기를 대상으로 수행한 방열해석 및 개선과 변압기수명연장에 관한 검토 결과를 수록하였다. 변압기의 열화메커니즘에 대한 문헌 조사를 통해 변압기 온도와 수명간의 관계를 작도하였는바, 수명 평가를 위한 핵심 인자로 열에 의한 절연지의 열화에 초점을 맞추었다. 기존 외함에 설치된 방열구중 상부 위치를 상부판에도 변경하는 경우 약25%의 통풍량 증가 효과를 기대할 수 있을 것으로 평가 되었으며 상부판과 내함 사이에 형성되던 고온 영역에서의 온도를 약$15^{\circ}C$정도 낮출 수 있는 것으로 나타났다. 절연지의 인장강도 변화로 평가한 수명예측 곡선에 따르면 약$10^{\circ}C$의 은도 저감은 약10배의 수명 연장 효과를 가져오는 것으로 나타난바, 본 연구에서 확인한 방열구의 위치 변경에 따른 지상기기 내부의 온도 저하는 변압기 수명을 연장하는데 일조할 것으로 기대된다. 기존 지상변압기에서의 방열구조를 통해 변압기 온도와 수명간의 관계를 작도하였는바, 수명 평가를 위한 핵심인자로 효과적으로 방열할 수 있는 새로운 외함의 구조 및 디자인을 제시하고 시뮬레이션을 통해 개선효과를 예측하였다. 또한, 개선된 모델을 가지고 실제 변압기를 제작한 후 부하를 인가하여 개선전과 후에 대한 방열효과를 실증시험을 통해 확인하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.3
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• pp.30-36
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• 2013

This paper presents a method to estimate a storage life for loss of stabilizer content as storage periods using accelerated life test data. The estimate of storage life based on deterministic accelerated life test and degradation data cannot describe a condition distribution and storage life distribution. Previously, the method to show the condition distribution and storage life distribution by using gamma process has been studied. But it has limitation because it is impossible to collect the deterioration data at initial production phase. The estimated storage life presented by this study shows the similar value to previous studies and the method can describe the condition distribution and storage life distribution. So, the estimation method studied in this paper can be used for a life cycle management about deterioration of propellant for propulsion unit or components of missile, too.

• The Korean Journal of Applied Statistics
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• v.9 no.1
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• pp.53-73
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• 1996

This paper compares two accelerated life for Weibull distribution. One is the optimum constant stress accelerated life test which minimizes the asymptotic variance of maximum likelihood estimator of a specified quantile at design stress, and the other is corresponding simple step stress test. The models and optimum designs of constant stress and step stress tests are reviewed. Behaviors of asymptotic variances, effects of design parameters to optimum tests, and expected numbers of failures and expected test times of the two tests are investigated. The efficiency of step stress test relative to constant stress test is studied in terms of variance ratio, and robustness to preestimates of design parameters are investigated.

• 대한예방의학회:학술대회논문집
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• 1995.10a
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• pp.109-110
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• 1995

• Nuclear industry
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• v.35 no.4
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• pp.65-70
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• 2015

통합된 형상 관리 정보 시스템은 원전의 허가에서부터 설계, 조달, 건설, 시험 가동, 운영, 유지보수와 원자로의 폐기까지 원전 수명의 전 과정을 아우르는 모든 데이터와 정보들을 총괄하여 관리하는 것이다. 최신 형상 정보 관리 시스템을 도입하면 원전 수명의 전 단계에 걸쳐 운영상의 이점과 경제적인 수익을 기대할 수 있다.