• The Journal of Sustainable Design and Educational Environment Research
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• v.9 no.2
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• pp.1-8
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• 2010

This study is to present an engineering solution for the repair frequency and repair rates of a building. The existing data for the repair frequency and repair rates are used to draw the probability distribution for the generalized repair frequency and repair rate in a building. The suggested methodology can be widely used for most buildings to estimate the legal repair frequency and repair rates. Also, the methodology can be applied to resolve the risks on the maintenance costs in LC (Life Cycle) plans or LCC (Life Cycle Cost) analysis. As the future studies, there are the multiple regression analysis including the parameters on incurred costs and the decision methods on efficient repair and replacement.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.574-580
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• 2005

Recently, the number of bridges and tunnels in railway is increasing due to the super high-speedy of train. Also, because of successively accidents of civil structures such as bridges and dams, the importance of maintenance become influential. The purpose of this study is to show the probabilistic life cycle cost analysis technique(PLCC) of the railroad bridge as pubic-infrastructures, and reasonably to indicate the economy in life cycle cost(LCC) through a case study. Rationally for life cycle cost analysis, the data gathered through many materials considered the uncertainty such as covariance. As a result, it is indicated that prestressed concrete bridge is pretty more cost-effective during life-cycle than preflex as well as steel box bridge. In future, if the construction of database and maintenance materials for railroad infrastructure is actualized, the life cycle cost analysis for railroad can be conducted easily and practically.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1424-1428
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• 2009

The performance of a heat pump using river water as a heat source was compared with that of a conventional air-conditioner for cooling and a boiler system for heating. The heat pump system using river water considered the 1-stage cycle for cooling and the 2-stage cycle for heating. The COPs of the river water source heat pump were $0.5{\sim}1.1$ higher than those of the conventional system in the cooling season. The LCC of the river water source heat pump system was lower 13.5% and 32.4% than that of the conventional system I and II. In addition, when the initial cost ratios of the river water source heat pump system to the conventional system I and II were less than 1.2 and 1.4, respectively, an acceptable payback was found to be less than 5 years.

• Journal for History of Mathematics
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• v.20 no.4
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• pp.175-190
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• 2007

In the nineteenth century was Augustus De Morgan, British mathematician, a great mathematics teacher. Although his name is well known to everybody who is interested in set theory, his major mathematical legacy would arise from his novel research in logic. In this article, we first investigate De Morgan's life briefly; we then consider his precious philosophy of mathematics education based on his students' remarks and his works. Finally, by considering his teaching style, we highlight some of the ingredients that go into making a great mathematics teacher.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.62-68
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• 2009

Life Cycle Cost(LCC) is adopted to decide the target of safety level in designing suspension bridges. The LCC are evaluated considering two types of uncertainty; aleatory and epistemic. The nine alternative designs of suspension bridge are simulated to decide the safety level which can minimize the LCC. The LCC is calculated through the probability of failure and safety index including the uncertainty. This method results in the useful tool deciding the optimum safety level with minimal LCC as the main design factor.

• Journal of Labour Economics
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• v.43 no.3
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• pp.123-148
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• 2020

This study empirically estimates the possible association between the college graduate Young Peoples' wages in the labor market and their internal migration through college education after high school education. Using the Graduate Occupation Mobility Survey(GOMS), we found out that the more likely young peoples find jobs in the location from different their hometown the higher they command wages in the labor market.

• Journal of Korean Medical classics
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• v.18 no.2 s.29
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• pp.145-153
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• 2005

통과궐증적고찰(通過厥證的考察), 득도료여하적결론(得到了如下的結論) 기일시(其一是), 한궐시인어양기부족이불능온통혈맥이발생적(寒厥是因於陽氣不足而不能溫通血脈而發生的), 기기혈불능온양사지이발생적궐냉증(其氣血不能溫養四肢而發生的厥冷症), 저취시한궐적주증상(這就是寒厥的主症狀). 기이시(其二是), ${\ulcorner}$소문(素問) 궐논(厥論)${\lrcorner}$지음허내열적열궐시인어주포입방이발생적(之陰虛內熱的熱厥是因於酒飽入房而發生的), 기특징취시수족열증(其特徵就是手足熱症). 기삼시(其三是), 양성격음적열궐시인어양기울체이발생적(陽盛格陰的熱厥是因於陽氣鬱滯而發生的), 기특징시유고열겸수족궐냉증(其特徵是有高熱兼手足厥冷症). 기사시(其四是), 사지궐냉적원인유삼(四肢厥冷的原因有三). 기일시인어양기부족(其一是因於陽氣不足), 한궐속어차(寒厥屬於此). 기이시곤어양기울체(其二是困於陽氣鬱滯), 양성격음적열궐화포궐속어차(陽盛格陰的熱厥和暴厥屬於此). 기삼시시궐(其三是尸厥), 기병기시인감어부정지기이기폐새야(其病機是因感於不正之氣而氣閉塞也). 기오시(其五是), 혼도발생적원인유이(昏倒發生的原因有二). 기일시인어기폐새(其一是因於氣閉塞), 시궐박궐화한궐속어차(尸厥薄厥和寒厥屬於此). 기이시인어화열치성(其二是因於火熱熾盛), 열궐전궐화포궐속어차(熱厥煎厥和暴厥屬於此).

• 월간 기계설비
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• s.306
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• pp.94-98
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• 2016

300억원 이상의 국가 및 공공기관 발주공사에 대해 최저가낙찰제를 대신하여 종합심사낙찰제 전면 실시 등의 내용을 담은 국가계약법 시행령이 개정되어 2016년 1월 1일부터 시행에 들어갔다. 종합심사낙찰제는 가격 뿐만 아니라 공사수행능력, 사회적책임을 종합 평가하여 낙찰자를 선정하는 제도로 기존의 최저가낙찰제에서 발생한 덤핑낙찰 및 이로 인한 잦은 계약변경, 부실시공, 저가하도급, 임금체불, 산업재해 증가 등의 문제점을 해소하기 위해 도입된 제도이다. 종합심사낙찰제 도입에 따라 공사 품질이 제고됨으로써 생애주기(lifecycle, 유지보수비용 등을 포함) 측면에서의 재정효율성 제고를 비롯하여 불공정 하도급 관행 개선 등 건설산업의 생태계 개선과 함께 시공결과에 책임짐으로써 기술경쟁 촉진 등 건설산업의 경쟁력 강화 효과도 기대된다. 또한 국가계약예규도 개정되어 주계약자관리방식에 의한 공동계약(주계약자 공동도급)이 최저가낙찰제에서 종합심사낙찰제로 전환됐다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.21-23
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• 2012

The process of building project for planning, designing, construction, maintenance, and waste disposal are related with each other. However, we have a difficulty for estimating building's LCC due not to be flexible each other. Therefore, we analyzed the boundary condition between the process of construction and maintenance, and analyzed the factor of segment. We also suggested the Link System for flexible relation.

• KIEAE Journal
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• v.11 no.6
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• pp.81-86
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• 2011

By strengthening the insulation performance of a building, a great deal of energy can be saved and a comfortable indoor environment can be offered to people. On the other hand, the climate, which has a great influence on the indoor environment, is changed by global warming. Therefore, in planning building envelope structure and design, climate change should be considered. In this paper, the optimal insulation thickness of exterior walls was calculated by an economic assessment method using heating degree-days. Additionally, how much influence climate change has on planning building insulation was investigated. The examination showed that heating degree-days have decreased by about 10% due to climate change in the past few decades. It was also shown that the optimal insulation thickness of exterior walls was thin, at about 6%, in three representative Korean cities (Seoul, Daejeon, Jeju).