• Elastomers and Composites
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• 제54권4호
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• pp.351-358
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• 2019

To evaluate the aging of a rubber pad in power window switch which is the part of a vehicle, the accelerated thermal aging test of rubber pad material is performed. Finite element analysis was performed using the nonlinear material constants of the rubber pad to calculate the operating force, and the Arrhenius relationship was derived from the aging temperature and time. The aging test was performed at 150, 180, 210, or 240 ℃ for 1 to 60 days. When the operating force of the rubber pad is changed by 10% from the initial value, the service life is expected to be 113 years, which is much longer than the life of the vehicle. This indicates that the aging life of the rubber pad is sufficiently safe and the operating force of the rubber pad during the life of the vehicle (20 years) was decreased by approximately 8.4%. By examining the correlation between the shear elastic modulus and operating force calculated from finite element analysis under each aging test condition, the changes in the operating force of the rubber pad and the shear elastic modulus showed good linear relationship. The aging life could be predicted by the change in shear elastic modulus and a process for predicting the aging life of automotive power window switch rubber pad parts is described herein.

• 한국건설안전학회 논문집
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• 제2권1호
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• pp.1-8
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• 2019

현재 건축물의 높이가 높아지고 우리나라 가구 형태가 개인 주택에서 아파트로 변화함에 따라 타워크레인의 사용 횟수는 계속해서 증가하고 있다. 그러나 이처럼 증가하는 타워크레인 사용 횟수에 반해 우리나라 타워크레인 관련 정책은 매우 미비한 실정이다. 특히 타워크레인과 관련된 사고의 원인 중 가장 큰 비중을 차지하는 타워크레인 연식에 대한 기준은 그 설정 근거가 부족하다. 따라서 본 연구에서는 이와 같은 문제점에 주목하여 타워크레인의 보다 신뢰성 있는 타워크레인의 연식을 설정하는 연구를 진행한다. 이를 위해 본 연구에서는 기존 연구에서 사용했던 사례와 영국 타워크레인 기준을 바탕으로 사용 연식을 설정한다.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.23-30
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• 2011

International cooperation to reduce greenhouse gas emissions is expected to provide a big crisis and a great opportunity at the same time for our industry that heavily consumes energy. To cope actively with the international environmental regulation, such as the Framework Convention on Climate Change, quantitative measurement of the volume of greenhouse gases emitted by various industries and quantitative prediction of the greenhouse gas emissions of the future are becoming more important than anything else at the national level. This study aims to propose the calculation process of carbon dioxide($CO_2$) emission for building in life cycle. This paper describes and compares 9 different tool for environmental load estimation with LCA. This study proposed the calculation process for quantitatively predicting and assessing $CO_2$ emissions during the life cycle of buildings based on the life cycle assessment(LCA). The life cycle steps of buildings were divided into the design/supervision, new construction, repair, renovation, use of operating energy in buildings, maintenance, and reconstruction stage in the life cycle inventory analysis and the method of assessing the environmental load in each stage was proposed.

• 사물인터넷융복합논문지
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• 제3권1호
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• pp.1-8
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• 2017

현대인들에게는 정보와 시간이 매우 중요하며, 각 개인에 맞는 특화된 정보를 제공하고 알려주는 비서시스템에 대한 연구가 폭넓게 진행되고 있다. 본 연구에서는 날씨나 기온, 뉴스, 교통 정보 등의 사용자가 원하는 정보를 시간과 함께 제공하는 개인 비서 시스템 (Personal Secretary System) 일명 지니(Genie) 시스템을 개발한다. 지니 시스템에서는 뉴스, 날씨와 온도, 버스 도착 시간을 포함한 교통 정보, 그리고 메모 등의 정보를 시간과 함께 알려주어 사용자의 삶의 여유를 찾고, 안락한 생활을 영위할 수 있도록 도움을 줄 것으로 예상된다.

• International Journal of Reliability and Applications
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• 제4권1호
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• pp.27-40
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• 2003

Maintenance models involving minimal imperfect repair frequently appear in the literature of reliability and operations research. Most of the literatures concerning the stochastic behavior of repairable systems assume that it takes negligible time to repair a failed system and so the length of repair time does not affect the maintenance strategy. It is more realistic to consider the length of repair times in developing maintenance model, however. In this paper, we consider an imperfect repair model with random repair time and investigate some stochastic properties of the number of perfect repairs and the number of minimal repairs. Also we derive the expressions for evaluating the expected numbers of perfect and minimal repairs in general and apply these formulas for certain parametric life distributions.

• 대한치과의사협회지
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• 제58권10호
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• pp.649-655
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• 2020

As a dentist, we should be prepared for emergencies that can occur at any time in dental practice. In addition, we must be able to provide first aid to patients with the latest knowledge when an emergency actually occurs. It has been revised every five years since the American Heart Association published advanced cardiovascular life support (ACLS) guidelines. The current final guideline is the 2015 version. It is expected that the 2020 version will be released around the winter of 2020. Therefore, at this point, the latest version (2015 ver.) will be important. Many changes were made from 1995 to 2015. I would like to summarize the parts of the revised parts that remain important.

• International Journal of Reliability and Applications
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• 제17권1호
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• pp.85-105
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• 2016

In this paper accelerated life testing is incorporated in quality control technique of acceptance sampling plan to induce early failures in high reliability products.Stress under accelerated condition can be applied in constant-stress, step-stress and progressive-stress or combination of such loadings. A ramp-stress results when stress is increased linearly (from zero) with time. In this paper optimum failure-censored ramp-stress accelerated life test sampling plan for log-logistic distribution has been formulated with cost considerations. The log-logistic distribution has been found appropriate for insulating materials. The optimal plans consist in finding optimum sample size, sample proportion allocated to each stress, and stress rate factor such that producer's and consumer's interests are safeguarded. Variance optimality criterion is used when expected cost per lot is not taken into consideration, and bilevel programming approach is used in cost optimization problems. The methods developed have been illustrated using some numerical examples, and sensitivity analyses carried out in the context of ramp-stress ALTSP based on variable SSP for proportion nonconforming.

• 대한가정학회지
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• 제37권12호
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• pp.13-28
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• 1999

This study aimed to analyze the process of courtship form having date and marriage toward women who had job before marriage. The objects were 27.36 years old and had 9.59 months marital life at average. This study conducted structured questionnaires using the reflection of spouse selection procedure. By using collected data through questionnaires, it conducted descriptive statistics, cluster analysis and t-test. The type of marriage would be divided into the emotional marriage group and the implemental marriage group The emotional marriage group had longer dating time and more satisfaction of spouse selection than the implemental group. On value variable, the emotional marriage group had more subjective selection standard and more expectation social and emotional benefit than the latter group. On search variable, the emotional marriage group estimated the relation stability and satisfied the relation with spouse more than the implemental marriage group and expected the less possibility to meet new partner.

• 한국학교보건학회지
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• 제6권1호
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• pp.78-92
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• 1993

The purpose of this study is to find out the stress causes of the primary students in Korea, through the three major methods, life event score, multiple regression about stress causes and G.H.Q. path-diagram. A survey was made of 889 students who were selected among students of six primary schools in seoul and Ka-pyeng, from Sep. 28 to Oct. 2. 1992. The results of this study are summarized as follows : 1. Life event score Among the children's life events, (deaths of family) (degrade of school record) (the increase of absence days) (divorce of parents) (trouble with relationship) are high ranking in life event score. Besides, (scolded by teacher and parents) (beginning of extracurricular work) are spread stress causes. In conclusion, these stress causes are shown by two aspects, home, school, and so children are under stress circumstance in both places. These stress causes vary with area and sex. 2. Multiple regression about stress causes and G.H.Q. This study analysed how a stress caused by home life affects the children's health of mind and body. The most influential factors are , and these factors vary with area and sex. 3. Path-diagram This study proved that socio-psychological school environment raises children to secede from school, and this secession that operates as a stress cause affects children's health of mind and body. This serial process is analysed by path analysis, and made out a path-diagram. In conclusion, as expected socio-psychological,school environment affects the children's health of mind and body. This is shown by two aspects : positive, negative. This stress causes vary with area and sex.

• 한국양봉학회지
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• 제32권2호
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• pp.99-109
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• 2017

DWV, IAPV, KBV, SBV, BQCV, kSBV, SBPV and Paenibacillus larvae, Mellisococcus plutonius, Lysinibacillus fusiformis, Klebsiella oxytoca의 뒤영벌 병원체들에 대한 다중 실시간 중합효소 연쇄반응법(PCR)을 개발하였다. 하나의 시료에서 추출된 핵산은 11종 PCR들에 같은 시간 및 조건으로 사용될 수 있으며, 각 병원체 특이 표적 DNA가 PCR 기질로 1000분자가 존재한다면, 해당 특이 PCR 증폭산물들은 정성적, 정량적으로 20분안에 성공적으로 증폭되었다. 우리가 제안하는 이 다중 PCR 검출법이 뒤영벌의 국제교역을 위한 검역검사에 사용되기를 기대한다.