• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.136-144
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• 2010

Since most domestic apartment, built in bearing wall system limiting variability of space, in spite of its good durability, cannot accept life style change and is being wasted, dumped scraps of which cause environmental pollution and waste of resources. As a response for this, researches on sustainable housing, that is, 'long-life housing' which has high durability, and variability responding life style change of the resident are in progress in and out of country. Therefore, this article aims, in suggesting the various status appearing on apartment and the interior plan responding the problem, to research on the house plan in the future which can be used continuously instead consuming type of apartment shortly used and discarded with understanding of long-life housing developed in foreign countries, and grasping the factors of application plan. Various reports from previous researches were comparatively analyzed and the studies on the characteristics, the real examples and the types of the surfaces were performed on the experimental model of long-life housing and similar residential surfaces to find the concept to be applied to Long-Life Housing and the introduction method of such concept. This article tries not only to prevent 'scarp and build', the serious cause of environmental pollution, but also to be basic materials for interior construction plan afterwards through 'long-life housing interior design plan' as the new conception which can accept life style and life cycle change.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.10 no.1
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• pp.57-68
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• 2002

The economical aspects should be evaluated to decide the LCC(Life Cycle Cost) of the long life facilities or equipments. Airplane operators evaluate the economical aspects to decide whether they maintain the existing airplane or substitute the new one. This paper presents economic life cycle and economic life cost for both Cessna 172R and Mooney 20J that are operated for flight training in 'H' University. The residual value that is used to calculate the capital recovery rate of the airplane is calculated based on the data from Blue Book published in USA. The annual equivalent on operation cost is calculated based on the 500 flight hours per year which is the annual flight hour for the airplane in 'H' university. This paper showed that economic life cycle of Cessna 172R is nine years since it was introduced in 2001, and Mooney 20J which was introduced in 1991 exceeds the economic life cycle in 2002.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.19-28
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• 2016

PURPOSES : Long-life asphalt pavements are used widely in developed countries. In order to be able to devise an effective maintenance strategy for such pavements, in this study, we evaluated the performance of the long-life asphalt pavements constructed along the national highways in South Korea. Further, an economic evaluation of the long-life asphalt pavements was performed based on a life-cycle cost analysis. We aimed to devise a model for evaluating the performance of long-life asphalt pavements using the national highway pavement management system (PMS) database as well as for analyzing the economic feasibility of such pavements, in order to promote their use in South Korea. METHODS : The maintenance history and pavement performance data were obtained from the national highway PMS database. The pavement performances for a total of 292 sections of 10 lanes (5 northbound lanes and 5 eastbound lanes) of national highways were used in this study. Models to predict the performances of hot mix asphalt (HMA) and long-life asphalt pavements under two distinct traffic conditions were developed using a simple regression method. Further, the economic feasibility of long-life asphalt pavements was evaluated using the Korea Pavement Management System (KoPMS). RESULTS : We developed service-life prediction models based on the traffic volume and the equivalent of single-axle load and found that long-life asphalt pavements have service lives 50% longer than those of HMA pavements. Further, the results of the economic analysis showed that long-life asphalt pavements are superior in terms of various economic indexes, including user cost, delay cost, total cost, and user benefits, even though their maintenance cost is higher than that of HMA pavements. A comparison of the economic feasibilities of the various groups showed that group A is superior to HMA pavements in all aspects except in terms of the maintenance criterion (crack 20% or higher) as per the NPV index. However, the long-life asphalt pavements in group B were superior in terms of the maintenance criterion (crack 25% or higher) regardless of the economic feasibility. CONCLUSIONS : The service life of long-life asphalt pavements was found to be approximately 50% longer than that of HMA pavements, regardless of the traffic volume characteristics. The economic feasibility of long-life asphalt pavements was evaluated based on the KoPMS. The results of the economic analysis were the following: long-life asphalt pavements are exceptional in terms of almost all factors, such as user cost, delay cost, total cost, and user benefit; however, the exception is the maintenance cost. Further, the economic feasibility of the long-life asphalt pavements in group B was found to be better than that of the HMA pavements (crack 25% or higher).

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.199-217
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• 1992

The purpose of this study was to examine changes in the household investment planning according to the family life cycle, to improve the household investment planning process, and to develop research model. The results were as follows : Household investment planning varied with stages of the family life cycle because the stock of resources shifted and financial goals changed as the family life cycle stage changed. The main financial goals of family in each stage of the life cycle were the purchasing of house in the establishing stage, children's education and marriage in the extending stage, and the elderly's economic welfare in the diminishing stage. Also, in the Ⅰ & Ⅱ stage the most important investment goals were the purchasing of house, children's education in the Ⅲ stage, children's marriage in the Ⅳ stage, and the elderly's economic welfare in the Ⅴ stage. Therefore, the financial goals were recognized as the important goals underlain the investment-planning goals, and alternatives for the accomplishment of investment-planning goals were determined. The results of this study can contribute to establish the long-run investment planning process and improve the level of household's financial well-being.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.1
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• pp.131-139
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• 1993

Low cycle fatigue characteristics of cast aluminum alloy A356 with a yield strength and ultimate strength of 229 and 283 MPa respectively was evaluated using smooth axial specimen under strain controlled condition. Reversals to failure ranged from 16 to 107. The cast aluminum alloy exhibited cyclically strain-gardening behavior. The results of low cycle fatigue tests indicated that the conventional low cycle fatigue tests indicated that the conventional low cycle fatigue life model was not a satisfactory representation of the data. This occurred because the elastic strain-life curve was not-log-log linear and this phenomena caused a nonconservative and unsafe fatigue life prediction at both extremes of long and short lives. A linear log-log total strain-life model and a bilinear log-log elastic strain-life model were proposed in order to improve the representation of data compared to the conventional low cycle fatigue life model. Both proposed fatigue life models were statistically analyzed using F tests and successfully satisfied. However, the low cycle fatigue life model generated by the bilinear log-log elastic strain-life equation yielded a discontinuous curve with nonconservatism in the region of discontinuity. Among the models examined, the linear log-log total strain-life model provided the best representation of the low cycle fatigue data. Low cycle fatigue life prediction method based on the local strain approach could conveniently incorporated both proposed fatigue life models.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.249-256
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• 1999

This study is intended to propose a systematic procedure for the development of the reliability-based seismic safety and cost-effective Performance criteria for design and upgrading of long span PC bridges. In the paper, a set of cost function models for life cycle cost analysis of bridges is proposed. The total life cycle cost functions consist of initial cost and direct/indirect damage costs considering repair/replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses. The damage costs are successfully expressed in terms of Park-Ang median global damage indices and damage probabilities. The proposed approach is successfully applied to model bridges in both regions of a moderate seismicity area like Seoul, Korea and a high one like Tokyo, Japan. It may be expected that the proposed approach can be effectively utilized for the development of cost-effective performance criteria for design and upgrading of various types of bridges as well as long span PC bridges.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.257-264
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• 2002

This study presents a life-cycle cost (LCC) effectiveness of a concrete with lightweight aggregate. A number of researchers have made their efforts to develop a lightweight concrete, since it is difficult to apply conventional concrete using general aggregate to heavy self-weight structures such as long span bridges. In this study, an optimum design for minimizing the life-cycle cost of concrete slab bridges is performed to evaluate the life cycle cost effectiveness of the lightweight concrete relative to conventional one from the standpoint of the value engineering. The data of physical properties for new concrete can be obtained from basic experimental researches. The material properties of conventional one are acquired by various reports. This study presents a LCC effectiveness of newly developed concrete, which is made by artificial lightweight aggregate. A number of researchers have made their efforts to develop a lightweight concrete, since it is difficult to apply conventional concrete using general aggregate to heavy self-weight structures such as long span bridges. From the results of the numerical investigation, it may be positively stated that the new concrete lead to, the longer span length, the more economical slab bridges compared with structures using general concrete.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.551-562
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• 2022

The building production system has been analysed by the dichotomy "employer-contractor" relationship, which failed to take into account of the role and function of multiple stakeholders within the life-cycle supply chain. This is further observed in the current conflict resolution model, which, in my argument, struggles to contribute to industrialize the building production and achieve better efficiency and effectiveness as expected. The purpose of this paper is to critically assess the issues of current programme-based conflict resolution model, and discuss alternative models how they can be modelled and applied to the construction projects. The conclusions of findings are; First, the current model is framed around the contracts and dispute resolutions based on the legal concept of "claimant and respondent" where one party(s) advances a claim once and the other(s) objects, as such it fails to reflect the nature of construction projects where multiple stakeholders are involved concurrently and for a long period of life-cycle of buildings. Second, an alternative is "Six-stakeholders model" which represents the multiple stakeholders and clarifies the flow of obligation-liability-monetary relationships among participants for a long period of life-cycle of buildings. Further, with reference to both historical and recent cases, a reflection and insight into pros and cons of programming method is added, especially as to why this method is considered to have become a mandate of the modern construction management, and how academics and practitioners should deal with it more cautiously and prudently.

• Journal of the Korean Society of Costume
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• v.56 no.3 s.102
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• pp.81-90
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• 2006

The objective of the study is to review trends of clothing export in important countries of the world and thus to know the present stage of clothing export in Korea. For the purpose, changes of export amount, competitiveness and product life cycle were analysed in the countries from the 1960's to the 1990's. The results are as following: First, on the aspect of export amount, industrialized countries lost the lead to newly industrializing countries from the 1960's. Developing countries, as China, win the lead. Second, on the competitiveness aspect, industrialized countries lost competitiveness to newly industrializing countries before the 1960's. And newly industrializing countries were outpaced by China in the export competitiveness from the early 1990's. Third, on the aspect of product life cycle, industrialized countries go first through each period of product life cycle, introduction, growth, maturity and decline, and they all, excluding Japan, sustained period of Maturity for a long time. newly industrializing countries and developing countries go orderly through each period of product life cycle after industrialized countries. As to Korea, duration of each period was short. Specially characteristics of decline period appeared partly in the early 1990's. From the results, the theory of product life cycle, helping to explain changes in production and trade in new product lines, estimated to applicable to clothing export. The phenomena, Italy, Hong Kong and America sustain high competitiveness in the world clothing market for a long time, is needed to be studied carefully. The study about strong points in their clothing industries and competitiveness drive program be to influence Korean export policy in the future.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3517-3527
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• 2021

New 80-MW (electric) ultra-long-life sodium cooled fast reactor core having inherent safety characteristics is designed with heterogeneous fuel assemblies comprised of driver and blanket fuel rods. Several options using upper sodium plenum and SSFZ (Special Sodium Flowing Zone) for reducing sodium void reactivity are neutronically analyzed in this core concept in order to improve the inherent safety of the core. The SSFZ allowing the coolant flow from the peripheral fuel assemblies increases the neutron leakage under coolant expansion or voiding. The Monte Carlo calculations were used to design the cores and analyze their physics characteristics with heterogeneous models. The results of the design and analyses show that the final core design option has a small burnup reactivity swing of 618 pcm over ~54 EFPYs cycle length and a very small sodium void worth of ~35pcm at EOC (End of Cycle), which leads to the satisfaction of all the conditions for inherent safety with large margin based on the quasi-static reactivity balance analysis under ATWS (Anticipated Transient Without Scram).