• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.387-396
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• 2012

Bridge is an indispensable facility as a social overhead capital. This study suggests and examines the ways of Economic valuation on maintenance alternatives for Bridge. In order to evaluate each alterative on the basis of the same time, the concepts of the basic year and the valuation year are introduced and applied. Interest rates and discount rates are also applied according to the time when each cost is incurred. This study also suggests the ways that the objects of the valuation on maintenance alternatives are not limited to construction cost, but the valuation period is fixed and so maintenance cost and remaining value incurred by maintenance alternatives are valuated. Furthermore, this study shows the way to estimate and evaluate maintenance cost through direct construction cost and annuity present value coefficient and the way to estimate remaining value based on the basic year. In addition, this study suggests economic valuation system, cost methods and analyses of the result through verification. The proposed system is considered to be applied to practical business.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.503-508
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• 2007

The Equipment Expenses section of the Poom-Saem, that is used for Construction Cost Estimation on public sectors in Korea, has been rarely revised, and so does not reflect changes of construction equipment technology and construction methods, since it was established based on data from Japan and the U.S in the early 1960s. In order to make reasonable estimation of maintenance costs(Interest, Storage, Insurance, Tax), the equipment expenses section of the Poom-Saem and the domestic and overseas documentary records were investigated. Further, 16 construction sites were visited, and 20 Construction Equipment leasing services were surveyed. Based on results from analysing figures related with the estimation of maintenance costs, the maintenance cost is redefined. Then, construction equipment was classified into 6 exclusive construction equipment and general one, and realistic figures of the maintenance cost, which consists of interest, storage, insurance, tax, are suggested respectively. The optimum level of each item which consists of equipment costs was revealed based on the result of the analysis on the figures of equipment costs calculation from the Poom-Saem and the collected data. The research will be the foundation that helps to estimate appropriate construction costs and the ground work of related studies.

• Journal of Korean Society of Steel Construction
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• v.18 no.6
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• pp.677-686
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• 2006

In this paper, a more practical and realistic method is proposed to establish the lifetime optimum maintenance strategies of the deteriorating bridges considering the life-cycle performance as well as life-cycle cost. The genetic algorithm is applied to generate the set of maintenance scenarios that is the multi-objective combinatorial optimization problem related to lifetime performance and cost as separate objective functions, and the technique to select optimum tradeoff maintenance scenario is presented. Optimum maintenance scenarios could be generated not only at the individual member level but also at the system level of the bridge. Through the analytical results of applying the proposed methodology to the existing bridge, it is expected that the methodology will be effectively used to determine the optimum maintenance strategy for introducing a real preventive maintenance system and overcoming the limits of existing maintenance methods.

• Journal of the Korea Institute of Building Construction
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• v.5 no.1 s.15
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• pp.97-103
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• 2005

Building costs means capital costs which include cost of land, costs of acquiring and preparing the site, construction costs, professional fees, furnishings, cost of financing the project. and cost of management required to run and maintenance the building for use. There are several phases that determine the building costs : design phase, construction phase, and operation & maintenance phase. So, the cost of work could be set against the examining the full range of complexities that a building program might contain. To solve this problem, it needs to compute building cost systematically. This is still in the development stage, awaiting the organization of rational cost data base. The method of cost saving by cost control could be constituted by detailed knowledge of building costs for all possible combinations of components and subsystems that can be assembled into integration model of cost factor on each phase of project development. The model of cost saving in each building phase is available for procedures of cost control of building systems.

• Journal of Applied Reliability
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• v.18 no.2
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• pp.184-191
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• 2018

Purpose: The purpose of this study is to propose a method to calculate the optimal preventive maintenance cycle of radar used in the aviation weapon system of ROKAF. Methods: A hybrid model is used to estimate the optimal preventive maintenance cycle in a system that can perform condition based predictive maintenance (CBPM) through continuous diagnosis. The failure data of the radars operating in the military were used to calculate the reliability. Results: According to the research results, the reliability threshold of the radar began to decrease after 5 flights, and decreased rapidly after 12 flights. Since the second check, costs have continued to decline. Conclusion: A method is proposed to determine the cycle of optimal preventive maintenance of radar within operational budget through modeling results between reliability limit and cost for radar. The results can be used to determine the optimal preventive maintenance cycle and frequency of various avionics equipment.

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.269-269
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• 2001

Maintainability refers to the ease with which maintenance work can be done. It involves the process of ensuring that products can be easily and safely maintained and that the maintenance support requirement is minimized. When a product has a reasonably long life, the cost of operation and support during that life can greatly exceed the initial capital cost. The value to the customer of optimizing maintainability should be evident. Some effort and expense applied to achieving a product which can be easily and cheaply maintained will make very significant savings in the life cycle costs. In this paper, the International Standard IEC 60300-3-10, which is the application guide for maintainability, is considered. This standard can be used to implement a maintainability program covering the initiation, development and in-service phases of a product. It provides guidance on how the maintenance aspects of the tasks should be considered in order to achieve optimum maintainability. The elements of a maintainability program, which are maintenance policy and concept, maintainability studies, project management, design for maintainability, analysis and prediction methods, maintenance verification and validation, analysis of life cycle cost, maintenance support planning, and collection and analysis of maintenance data, are fully discussed in this paper.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.160-170
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• 2007

This study predicts Life Cycle Cost of RC Slab bridge case in maintenance and operation level and calculated economic efficiency by the avoidable costs of a bridge. This result of the study can be summarized as follow: (1) LCC analysis model on the bridge case is suggested. (2) Maintenance and operation level of a bridge have been divided, and LCC of the bridge case has been predicted at current maintenance and operation level and required maintenance and operation level. (3) Reduction costs is predicted by LCC of the bridge case, and its economic efficiency is calculated.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1528-1533
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• 2009

Infrastructure is provided to the user through long-term project period and large-scale working expenses. Existing facilities are getting old as time goes by. Accordingly, proper maintenance is required and generally more maintenance cost than initial invested cost is needed during life cycle. Therefore, a specific plan that just increases the value of facilities is required by evaluating performance of facilities and inputting minimum maintenance cost. Value engineering that increases the value of object by systemically analyzing Life Cycle Costs and function is actively promoted at the design phase of construction. These efforts can increase the performance of facilities at the maintenance phase of infrastructure. This study is to search how to evaluate the performance of Roadway by utilizing function analysis, as a core part of VE in the maintenance phase. In order to this a new evaluation criteria were proposed by adding an evaluation items to the existing criteria through the research of old documents, status of roadway maintenance and function analysis of VE. The results of this study may promote the effective performance evaluation to determine a resolution of roadway congestion in future. A succeeding study using the proposed evaluation criteria will be required.

• 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.

• Journal of the Korean housing association
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• v.13 no.5
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• pp.89-99
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• 2002

The multifamily housing has various advantages in construction cost, land-use intensity. KRIHS(1997) recommended the proper scale of th multifamily housing as 800 households in constructability, 1,000 households in facility compactability, 500 households in social aspect. At the early planning stage of project, the size of the multiftmily housing has, until now, been maximizingly considered under the regulation on which has been emphasized at the building volume ratio, land area, etc., except for the expenditure during the maintenance stage. This paper aimed at providing the proper size of multifamily housing in aspect of area and household number with maintenance cost at the early stage of project. For these, it took 곧 average cost function which is made from the 3-rd quardratic form and analyzes the unit increasing rate of the average cost. It surveyed in nationwide focused on the central heating system using diesel and kerosene. The number of samples is 88 and items of management cost is 11. The results are as follows ; first, 3rd-order quadratic function is proper at explaining the cost variation, considering the multicollinearity and statistics. Second, the proper size of multifamily housing is recommended with 83,000 $m^2$ on management area, 820 or over the 2,630 household number in aspect of total management cost.