• 한국공작기계학회논문집
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• 제12권1호
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• pp.32-37
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• 2003

Evaluation of fatigue strength on the spot welded part is very important for strength design of spot welded steel structures. In this paper, we could get the life cycle of the spot welded part using the lethargy coefficient obtained through the quasi-static tensile shear test for the specimen welded by current 10kA. The reliability evaluation of the life cycle is completed by comparing the life cycle calculated under the constant loading rate with the life cycle obtained by dynamic fatigue test. And then the result calculated by the lethargy coefficient is verified through the lift cycle calculated using the dynamic final tensile stress formula under the increased loading speed. This way can make save the time and cost in processing of predicting the life cycle of a structure.

• 가족자원경영과 정책
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• 제11권1호
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• pp.65-81
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• 2007

The purpose of this study is to analyze income and consumption expenditure patterns over the family life cycle. The data used in this study is the 2004 Survey data from the Annual Report on the Family Income and Expenditure Survey data which are included salary and wage earners' households living in urban areas. The income and expenditure data of 20,383 households are analyzed. The family life cycle is classified into six stages and the items of expenditure are classified into 12 categories. The data are analyzed by descriptive statistics, $X^2$ test, F-test, and Duncan's multiple range test using SAS 8.0 package program. The major findings of this study are as fellows: First, the average monthly family income of the total sample is 3,480,000 won. The proportion of regular and irregular income among the total family income is 95.5% and 4.5% respectively. Second, the amount and ratio of monthly regular income fur each category are significantly different over the family life cycle. Third, the average monthly family expenditure of the total sample is 2,250,000 won. The amount and ratio of monthly expenditure of all items are significantly different over the family life cycle. The highest expenditure item is the traffic expanse and phone charge.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2004년도 춘계학술대회
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• pp.61-65
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• 2004

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권3호
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• pp.208-215
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• 2016

Purpose: ASRP for the domestic development guided missiles requires not only for the reliability evaluation of the products in storage but also for the life cycle management of the products including development prototypes and initial production items. Methods: For this purpose, it should be performed to build a performance database before and after the accelerated aging test with shelf life items including development prototypes and initial production items, based on which the lifetime prediction should also be carried out. In addition, HILS must be applied for the acceptance test with the initial and follow-up production items, and also for ASRP for the long-term storage products in order to secure systematic quality assurance. Results: The results for the life cycle reliability Improving of domestic development of guided missiles are DB building of prescription Item performance, active application of HILS, Management associated with guided missiles life cycle and to Secure technology data about the introduction of foreign guided missiles. Conclusion: Furthermore, it is demanded that DTaQ, the managing agency of ASRP, actively take part in the process to maintain reliability engagement consistency over the life cycle of guided missiles.

• Korean Chemical Engineering Research
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• 제59권3호
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• pp.393-398
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• 2021

리튬이온전지의 성능을 최적화하기 위해서는 여러 열화 요소들을 고려한 성능 예측 모델링 기술이 필요하다. 본 연구에서는 리튬이온전지의 사이클 노화로 인한 방전 거동 및 사이클 수명 변화를 수학적으로 모델링하였다. 모델링의 신뢰성을 검증하기 위해 0.25C로 사이클 시험을 진행했으며, 30 사이클 간격으로 진행한 RPT (Reference performance test)를 통해 전기적 거동을 파악하였다. 기존의 리튬이온전지의 사이클 수명 예측 모델에 BOL (Beginning of life)에서 일어나는 현상 중 하나인 Break-in 메커니즘을 반영하여 수명예측 정확도를 개선시켰다. 모델에 근거하여 예측된 사이클 수명 변화는 실제 시험 결과와 잘 일치하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제40권7호
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• pp.593-598
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• 2016

LNG 선박용 성형 벨로우즈의 성형방법에 따른 특성을 파악하기 위하여 정적시험과 저주기 피로시험을 실시하였다. 벨로우즈의 규정된 수명 사이클인 8,000회를 실시하여 시험전후의 벨로우즈의 각 산에 걸리는 변형률과 응력을 측정하여 성형방법에 따른 벨로우즈간의 차이를 분석하고 산 별 응력분포를 살펴보았다. 본 저주기 피로시험은 x-y방향의 변위가 가능한 유압시스템의 구조시험장비에 성형 벨로우즈를 장착하고 벨로우즈의 각 산에는 스트레인게이지를 장착하고 멀티레코더를 통하여 데이터를 처리하였다. 이를 통하여 벨로우즈가 성형방법에 따른 수명의 차이가 있는지 살펴보았고, 성형방법에 따른 수명의 차이를 주는 원인을 분석하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.20-24
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• 2006

In this paper we investigated the method of examining the accelerated life test on LED traffic signal module by the temperature. The longevity presumption of the LED type signal light by a general heat cycle test used and executed cycle when it was done to longevity by the heat cycle test number and the acceleration factor of a real system requirements of this heat cycle test. Therefore, it reports on the introduction of the acceleration type from which the LED traffic signal module is done here to clarify the above-mentioned acceleration factor with the object and the acceleration factor is requested the test atmosphere actually in the system requirements.

• Journal of Sport and Applied Science
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• 제2권1호
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• pp.1-10
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• 2018

Today, the population of cycle participants is consistently increasing. Cycling is becoming not only a form of physical exercise but also a form of tourism in which cycle activities are related to visiting a particular destination. With the perspective of participation sport tourism, the purpose of this study is to investigate how the level of cycle tourists' participation affects their quality of life. An online survey link was sent to cycle participants to collect data. Out of the total 337 respondents, a total of 226 samples were used for the final analysis, disregarding those that were found to be inadequate or unreliable. For data analysis, frequency analysis, reliability test, validity, correlations, and regressions were employed with SPSS 22.0. For our first result, we found that the level of cycle participation did not significantly affect the quality of physical life. Second, the level of cycle participation did not have significant effect on the quality of mental life. Third, the level of cycle participation behavior did not have a significant effect on the quality of social life. Fourth, the level of cycle participation behavior did not have a significant effect on the quality of environmental life. Conclusions and political implications are discussed.

• 가족자원경영과 정책
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• 제1권1호
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• pp.27-42
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• 1997

The purpose of this study is to analyze consumption expenditure patterns over family life cycle. The data used in the study is the 1994 Survey data from Annual Report on the Family Income and Expenditure Survey. The study sample included 26,980 salary and wage earners’ households living in cities. The family life cycle was classified into six stages and items of expenditure were classified into 12 categories. Frequency distribution, mean, one-way ANOVA, Scheff test, and regression analysis were used to analyze the data. The major findings of this study are as follows : First, the average consumption propensity differs among family life cycle. Second, the amount and budget share of consumption expenditure for each expenditure category differ significantly among family life cycle in all expenditure categories. Third, family life cycle is found to be a significant factor on expenditure of food and education, and also on budget share of education.

• 유통과학연구
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• 제11권2호
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• pp.5-10
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• 2013

Purpose - The current research examines the effect of life cycle stages on capital structure of listed companies in Tehran Stock Exchange. Research design, data, methodology - By aid of 685 year-company data, which collected from financial statements of companies during 2006-2012, first, the companies, are classified into three groups including companies in growth, maturity and decline stages. After removing the companies, which were not in accordance with life cycle model, 86 companies were selected to test two main hypotheses of the research. Results - The results show that the capital structure of the sample companies is different in various life cycle stages. More investigation by LSD test also revealed that the total debt to total assets ratio means of the companies in growth stages were significantly different from those companies in maturity stages and those in growth stages had high level of debt to assets ratio. Conclusions - The result showed the average amount of the working capital for companies in three stages are significantly different and due to high level of operation of the companies in maturity and decline stages, these companies held high amount of working capital than those in the growth stages.