• International conference on construction engineering and project management
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• 2009.05a
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• pp.203-211
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• 2009

Korean public owners who order public multi-family housing construction projects have yet to gain access to a model for predicting construction cost. For this reason, their construction cost prediction is mainly dependent upon historic data and experience. In this paper, a cost-prediction model based on Case-Based Reasoning (CBR) in the design phase of public multi-family housing construction projects was developed. The developed model can determine the total construction cost by estimating the different Building, Civil, Mechanical, Electronic and Telecommunication, and Landscaping work costs. Model validation showed an accuracy of 97.56%, confirming the model's excellent viability. The developed model can thus be used to predict the construction cost to be shouldered by public owners before the design is completed. Moreover, any change orders during the design phase can be immediately applied to the model, and various construction costs by design alternative can be verified using this model. Therefore, it is expected that public owners can exercise effective design management by using the developed cost prediction model. The use of such an effective cost prediction model can enable the owners to accurately determine in advance the construction cost and prevent increase or decrease in cost arising from the design changes in the design phase, such as change order. The model can also prevent the untoward increase in the duration of the design phase as it can effectively control unnecessary change orders.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.61
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• pp.89-98
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• 2000

For statistical process control, the process data are collected by the measurement system. But, the measurement system may have instrument error or/and operator error. In the measured values of products, the total observed variance consists of process variance and variance due to error of measurement system. In this paper, we design more practical T-s control chart considering estimated measurement error The effects of measurement error on the expected total cost and design parameters are investigated.

• Journal of the military operations research society of Korea
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• v.7 no.2
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• pp.100-113
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• 1981

A replacement policy for a finite time span is proposed for the cumulative process where an item can fail only when the total amount of deterioration exceeds a prespecified failure level. The optimal deterioration limit level is determined to minimize the total cost expected per unit for a given time span. An illustrative example in case of periodically inspected reformer tubes in ammonia plant is also presented.

• Korean Journal of Construction Engineering and Management
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• v.6 no.2 s.24
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• pp.111-119
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• 2005

Although the life-spans of most apartment buildings are over fifty years, they are often demolished and retrofitted only after twenty years, in spite of its remaining life expectancy, resulting in economical waste. The purpose of this paper is to estimate optimum remodeling period of apartment buildings using total cost. In this study it is seen that total sum of running cost of life-span on the buildings is about 4.69 times of initial cost till the fifty years of the life expectancy. The optimum remodeling period of the apartment building is thirty years applying the discount rate of $4.17\%$ and the discount rate should be $6.122\%$ to obtain the forty years of the optimum remodeling period. From the sensitivity analysis based on the change of the discount rates, it is seen that if discount rate decreases the optimum remodeling period can be extended, or vice versa. As a result, a time of the demolished and remodeling can be expected and the basic data can also be established for lengthening life-span of the apartment buildings.

• Journal of Integrative Natural Science
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• v.17 no.2
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• pp.43-51
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• 2024

Jung et al.(2015) suggest the two-phase warranty model, which is a general type of warranty model. Under the two-phase warranty, the warranty period is divided into two intervals, one of which is for renewing replacement warranty, and the other is for minimal repair warranty. And warranty policies play a very important role in product marketing. In this paper, we suggest the optimal warranty policy for free extended two-phase warranty. To determine the optimal warranty period, we adopt the expected profit per unit product. So, the expressions for the total expected cost, the sale price and the expected profit per unit product from the manufacturer's point of view are derived. Also, we discuss the optimal warranty period and the numerical examples are provided to illustrate the proposed the warranty policy.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.73-86
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• 2009

This paper discusses a method of determining the optimal design of a block. A horizontal layout of blocks is assumed in which transfer points are located at a side of the block. Each block has several transfer points (TPs) each of which is assigned to a group of adjacent bays and located at the center of the assigned group. The goal is to find the optimal size of a block and the optimal number of TPs while minimizing the total cost consisting of the fixed and operational cost of yard cranes (YCs), the operational cost of internal trucks, and the installation cost of TPs. Constraints on the maximum expected system time of trucks are imposed for the optimization. Formulas for estimating handling operation cycle times of a YC are derived analytically. Numerical experiments are conducted to illustrate optimal block designs for a given set of data.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.733-739
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• 2011

B2S(Ballasted track To Slab track) that is track system has been first developed in 2004 with foundation of rich experience and know-how of subway track upkeep and mending of facilities in 36 years to improve an existence pebble track at a concrete track. 'B2S' is admitted technology through patent registration in the domestic and Europe and it's made by a factory and put together at field, so it's able to construct precisely and to reduce a construction period. In addition, safety, the ecological balance and durability are excellent, and walking, cleaning, etc. has the advantage of easy maintenance. 'B2S' is currently laying 27.7km at Seoulmetro as of end of 2010 standard, but it'll be expected to be applied to a domestic Metro more from now on. It is possible to classify the total cost resolution structure of B2S system by R&D cost, test production and experiment cost, the initial facility cost, maintenance cost, disposal cost. In this research, it seems useful for selection evaluation which considered the life cycle cost or economics of the concrete track structure by analyzing an initial cost of facilities.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.400-405
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• 2011

The total length of Korean urban railways reaches 1,200km. Urban railway used to be installed with ballasted tracks by reason of low cost at the time of construction, slab tracks are now being installed due to the reasons of the improvement in safety, lengthening service life and more economical method in terms of maintenance. The length rate of slab tracks has exceeded 70% of the domestic urban railways with the methods ranging from STEDEF, LVT, ALT, Eidan-type, B2S to RHEDA. This study surveyed the share of domestic slab tracks, and compared and evaluated the input cost at the initial stage by the types of slab tracks. Construction processes have been standardized by the existing design documents and calculated the initial input cost for the length of 1km of a hypothetical straight line. Cost breakdown structure was evaluated as materials cost, construction cost, equipment cost, indirect cost, etc. It is expected that this study will be used in selection & evaluation which is considering the economic feasibility of slab tracks.

• Journal of Multimedia Information System
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• v.4 no.3
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• pp.157-162
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• 2017

The title of this project is "A Simple Interactive 3D Interior Design Application for Living Room - Cost Management", focusing on developing an application that enables costing and designing to be executed concurrently in interior design phases. This is because any changes made at costing phase after design phase is completed, it will potentially lead to unnecessary increase in cost and time. Therefore, the objective of this project is aimed to devise a cost management module to be included in the proposed application, allowing interior designer to make cost-based decision at the designing phase itself. This can be achieved through its proposed functions which include total cost update, budget management, cost estimator calculator and material list generation. The methodology being proposed in this project is Prototyping Development, categorized under Rapid Application Development (RAD), by starting off with planning, analysis, design and implementation phases are performed concurrently and repeatedly in a cycle to produce a prototype until the application is completed. In the end of this project, the developed prototype is expected to contribute a better solution towards cost management in interior design.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.82-87
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• 2007

This paper measures power quality of bus in case electric charges about customer are imposed by each bus, supposed that can calculate this cost. When reflected this in system planning, expected cost proposed following method through sample system. To calculate nodal cost operating condition of power equipment calculates nodal cost[$/MVAH] supposing by situation that is optimized by OPF(optimal power flow) in system. The damage cost that is shed by fault that happen during year of loads in system that is linked on each bus was produced. As a result, proposed method was very effective in case of calculating bus total cost including power quality cost.