• Title/Summary/Keyword: Life cycle

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An Analysis of Financial Statement Among Urban Households Based On a System Approach (체계론에 기초한 도시가계의 재정상태 분석)

  • 양정선
    • Journal of the Korean Home Economics Association
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    • v.30 no.1
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    • pp.237-255
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    • 1992
  • The purpose of this study was to investigate relations of resources and demands, family financial management and financial statement of urban households by applying a system approach. The results of this study were as follows; Saving rate had significant differences according to resources variables such as age, family life cycle, occupation of househead and housewife, ratio of employed to family member, and to demands variabels such as subjective prospect of business cycle, and value orientation, whereas total saving amount had significant differences according to resources vaiables such as age, family life cycle, educational level, percapita income, occupation of househead, type of income and to demand variable, perception of relative income. Also average monthly saving amount had significant differences according to resources vaiables such as educational level, per capita income, occupation of housewife, housing ownership, ratio of employed to family member, ratio of dependent to employed, and to demands variable, perception of relative income. The stocks had significant differences according to resources variables such as age, family life cycle, educational level, per capita income, occupation of househead, type of income, and housing ownership. Finally, real estate had significant differences according to resources variables such as age, family life cycle, educational level, percapita income, occupation of househead, type of income, housing ownership, and to demands variable, perception of relative income. Financial Statement among urban households according to family financial management had significant differences. And among all variables affecting financial statement among urban households, per capita income had the highest effect and perception of relative income was the second.

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The Study on Application of Fast Track Method for Dam Project Life Cycle′s Analysis (댐 공사에서의 Fast Track을 적용한 생애주기분석에 관한 연구)

  • Yoon, Jae-Ho;Moon, Young-Il
    • Journal of Korea Water Resources Association
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    • v.36 no.5
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    • pp.715-724
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    • 2003
  • It is true that SOC facilities, such as dams, need long life cycles since more time has to be invested for the phases of planning, examination, feasibility study, design, contract, construction, and maintenance. This longer life cycle is easily exposed to the risk. And thus, brings additional cost by the delayed project, convenient loss according to the additional run of use, and benefit lose of not to using the facilities. So, the purpose of this study is to try to find a solution to reduce these time consuming problems which could diminish the whole national competition. Hence, this study is to show efficient, systematical project performance and network model by using reciprocal analyses between the construction period and cost based on economical analysis of each phase of life cycles. In addition, on the basis of these outputs, the Fast Track Method is suggested as an alternative solution as a new Approach in Life Cycle's Analysis.

A Study on the Improvement of Public Facility Management System Using Life-cycle Management (Life-cycle Management를 활용한 공공시설 유지관리 시스템 개선방안)

  • Jeon Ick-Sung;Shon Jeong-Rak;Kim Kyung-Suk;Kim Jae-Jun
    • Korean Journal of Construction Engineering and Management
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    • v.5 no.2 s.18
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    • pp.55-63
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    • 2004
  • A building structures was used the facility management phase through $planing\cdotdesign\cdotconstruction$. phase. building's length of life was shorter than its physical length of life, because of the lack of law and institution, the lack of related agencies' preparation and owner's preparation. Also, considering the construction life-cycle, the facility phase accounted for $70\%$ of whole official lift, therefore, it needed to be opposed to systemic facility management. Current facility management system practically managed the defect of facility and almost never communicated between the other phase. In the side of policy, domestic law, institution, and policy related to building structure focused built-up market. and then the management of existing facilities was not consolidated efficiently. The purpose of this study was to suggest the direction of facility management construction for managing, utilizing, and operating public facilities, moreover, to study the direction of current facility management system improvement corresponding to total computer integrated construction system under government agencies.

Life Cycle Cost Optimization Considering Maintenance History of Bridge Beck and Girders (바닥판과 주형의 유지보수 이력을 고려한 LCC 최적설계)

  • Ahn Ye-Jun;Lee Hyun-Sub;Shin Yung-Seok;Park Jang-Ho
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.719-726
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    • 2005
  • The optimal design was performed for the bridge superstructure composed of steel box girders and concrete deck considering life cycle cost. The service life of the superstructure was estimated, after load carry capacity curves for steel girder and concrete deck were derived on the basis of condition grade curves and maintenance histories. The object function was determined as life cycle cost, including initial cost, total maintenance cost, disposal cost and user cost, for a period of the estimated service life. The optimal design of the superstructure was performed for the various service lifes. The annual costs were used to compare calculated results and to get the most economical design. Also this paper presents reasonable idea for the use of user cost with uncertainty.

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Low Cycle Fatigue Behavior of 12Cr Steel for Thermal Power Plant Steam Turbine (화력발전소 증기터빈용 12Cr 강의 저주기 피로거동)

  • Kang, Myeong-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.8
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    • pp.71-76
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    • 2002
  • In this study low cycle fatigue (LCF) behavior of 12Cr steel at high temperature are described. Secondly, comparisons between predicted lives and experimental lives are made for the several sample life prediction models. Two minute hold period in either tension or compression reduce the number of cycles to failure by about a factor of two. Twenty minute hold periods in compression lead to shorter lives than 2 minute hold periods in compression. Experiments showed that life predictions from classical phenomenological models have limitations. More LCF experiments should be pursued to gain understanding of the physical damage mechanisms and to allow the development of physically-based models which can enhance the accuracy of the predictions of components. From a design point-of-view, life prediction has been judged acceptable for these particular loading conditions but extrapolations to thermo-mechanical fatigue loading, for example, require more sophisticated models including physical damage mechanisms.

A Study on Computational Method for Fatigue Life Prediction of Vehicle Structures (차체 구조물의 피로수명 예측을 위한 컴퓨터 시뮬레이션 방법에 관한 연구)

  • 이상범;박태원;임홍재
    • Journal of KSNVE
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    • v.10 no.4
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    • pp.686-691
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    • 2000
  • In this paper a computer aided analysis method is proposed for durability assessment in the early design stages using dynamic analysis, stress analysis and fatigue life prediction method. From dynamic analysis of a vehicle suspension system, dynamic load time histories of a suspension component are calculated. From the dynamic load time histories and the stress of the suspension component, a dynamic stress time history at the critical location is produced using the superposition principle. Using linear damage law and cycle counting method, fatigue life cycle is calculated. The predicted fatigue life cycle is verified by experimental durability tests.

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A Study on Scuffing Life by the Plastic Strain on Sliding Surfaces under Miscellaneous Lubricated Conditions (윤활조건에 따른 미끄럼표면의 소성변형량에 의한 스커핑수명 연구)

  • 김병주;이영제
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.10a
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    • pp.91-99
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    • 1998
  • A correlation between the low-cycle fatigue life and the scuffing-failure life is demonstrated using the plastic strain in boundary lubricated sliding. Loadings proportional to hardness with three different lubricated conditions were used to evaluate the plastic strain. As the results of scuffing tests using vacuum pump oils in nitrogen gas, plastic strain shows 0.0062, and In the mineral oils and commercial engine oils in air, plastic strain show 0.0042 and 0.00092. Those are very useful to describe quantitatively the real lubricated sliding conditions, and are very effective to find the relation between the low-cycle fatigue life and the scuffing life.

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A Life Cycle Cost Analysis in Design and Manufacturing of Production System (생산시스템의 설계/제조에서의 생애비용(LCC)에 관한 연구)

  • 함효준
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.18 no.34
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    • pp.173-183
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    • 1995
  • Life cycle cost has been one of the key criteria in design or purchasing of systems, particularly in the flying weapon system. Unexpected cost increase or system breakdown during the system life can be reduced by controlling maintenance cost A system should be designed for maintainability in early stage of product life cycle. The design should be insensitive to its environmental, organizational, and human factors in the stage of customer's utilization. This paper presents LCC as a controllable variable and also suggests a new control model for LCC analysis. The estimation of maintenance cost based upon maintenance scenario, design of maintainability followed by minimizing maintainability loss function in the beginning stage of design, and increase of useful life of systems are among the factors to control LCC.

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Health behaviors and quality of life by life cycle of hypertensive patients (고혈압환자의 생애주기별 건강행태와 삶의 질)

  • Kim, Hyun-Ji;Min, Eun-Sil
    • Journal of Convergence for Information Technology
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    • v.10 no.7
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    • pp.58-66
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    • 2020
  • The purpose of this study was to identify the relation of health behaviors and the quality of life by life cycle of hypertensive patients. This study was conducted by analyzing secondary data with data from the 2017 Community Health Survey. The subjects were total of 62,056 who were diagnosed with hypertension and analyzed using the SPSS WIN 20.0 program. As a result of the study, As a result of the study, first, hypertension treatment and drug compliance were significantly lower in adulthood than in middle-aged and older adults. Second, it was confirmed that the quality of life score by life cycle was the highest in adulthood and decreased as age increased. Third, the quality of life according to health behaviors differed according to drinking, exercise, and low-salt diet throughout the life cycle. Considering the results presented in this study, it is suggested that health education by life cycle is essential for lifelong health management of hypertensive patients. In particular, it is considered that a convergence approach such as education and medical approaches will be needed to develop measures to increase drug compliance in adult hypertensive patients and to have healthy health behaviors to improve quality of life.

Low Cycle Fatigue Behavior of Cobalt-Base Superalloy ECY768 at Elevated Temperature (코발트기 초내열합금 ECY768의 고온 저주기피로 거동)

  • Yang, Ho-Young;Kim, Jae-Hoon;Ha, Jae-Suk;Yoo, Keun-Bong;Lee, Gi-Chun
    • Journal of the Korean Society of Safety
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    • v.28 no.3
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    • pp.18-22
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    • 2013
  • The Co-base super heat resisting alloy ECY768 is employed in gas turbine because of its high temperature strength and oxidation resistance. The prediction of fatigue life for superalloy is important for improving the efficiency. In this paper, low cycle fatigue tests are performed as variables of total strain range and temperature. The relations between strain energy density and number of cycle to failure are examined in order to predict the low cycle fatigue life of ECY768 super alloy. The lives predicted by strain energy methods are found to coincide with experimental data and results obtained from the Coffin-Manson method. The fatigue lives is evaluated using predicted by Coffin-Manson method and strain energy methods is compared with the measured fatigue lives at different temperatures. The microstructure observing was performed for how affect able to low-cycle fatigue life by increasing the temperature.