• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.607-612
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• 2007

Early cost estimation promote efficient budget plan by comparing alternatives and presenting cost information However it is hard to predict accurate cost because of vague cost standard and lack of available information in the early stage. The precious cost model has limitations in the accuracy because they are simple linear model which uses the unit cost per kilometer. This study presents the framework of early cost estimation for road construction projects to overcome the limitation of previous cost model. This study analyzed domestic and foreign cost model and cost data of previous road construction project to present method of cost model framework.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.445-448
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• 2008

This study attempts to estimate approximate cost on construction of PSC BEAM Bridge using Case-Based Reasoning and suggests approximate estimation model at the planning and design stage. This paper suggests phased influence factors on construction cost and approximate estimation model for integrated project cost management.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.212-215
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• 2008

When managers predict exact construction cost at early stage and design phase, they can reduce construction cost in a more efficient way than to predict at construction stage. But present of public construction cost estimation and management almost after the construction documents design phase. Therefore, construction cost management in the early stage and schematic design phase to generally use approximate estimating is not correct. Accordingly, this study analyze problem of current cost estimating method and a concrete cost plans make using case information of actual cost to analyze in schematic design phase. Possible to check going on the suitable design, this study conducts the preliminary research for the development of cost estimating model.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.585-588
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• 2007

This study attempts to analyze estimating process and the level of information performing literature review and questionnaire and identify phased influence factors on construction cost using phased information of project and suggests framework of approximate estimation model at the planning and design stage. This paper suggests phased influence factors on construction cost and framework of approximate estimation model for integrated project cost management.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.42-52
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• 2021

The cost of remodeling parking lots of apartment houses accounts for about 20 percent of the total cost of remodeling. This means that when the remodeling cost of the underground parking lot is known, it becomes possible to estimate the total construction cost. The standard of estimation referenced when calculating the construction cost is difficult to apply to calculating the remodeling cost. Thus, a construction cost estimation model that reflects the characteristics of remodeling construction is necessary. This study developed a basic construction cost estimation model for expansion remodeling of underground parking lots of apartment houses that calculates the approximate cost of construction by reflecting the characteristics and design elements of remodeling. Based on literature review and consultation with experts, 37 activities of underground parking lot remodeling construction were derived. In order to enable calculation of approximate construction cost before the remodeling design drawing is finalized, the quantity calculation formula and unit price for each activity were presented. Based on expert advice, 13 factors that affect the increase in construction cost and weights of each factor were determined. As a result of applying three cases of remodeling complexes to the basic cost estimation model, the accuracy was confirmed to be 93 percent on average.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.87-100
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• 2009

The quality of early cost estimates is critical to the feasibility analysis and budget allocation decisions for public capital projects. Various researches have been attempted to develop cost prediction models in the early stage of a construction project. However, existing studies are limited on its applicability to actual projects because they focus primarily on a specific phase as well as utilize restricted information while the amount of information collectable differs from one another along with the project stages. This research aims to develop two-staged cost estimation model for the schematic planning and preliminary design process of a construction projects, considering the available information of each phase. In the schematic planning stage where outlined information of a project is only available, the Case-Based Reasoning model is used for easy and rapid elicitation of a project cost based on the extensive database of more than 90 actual highway construction projects. Then, the representing quantity-based model is proposed for the preliminary design stage where more information on the quantities and unit costs are collectable based on the alternative routes and cross-sections of a highway project. Real case studies are used to demonstrate and validate the benefits of the proposed approach. Through the two-stage cost estimation system, users are able to hold a timely prospect to presume the final cost within the budge such that feasibility study as well as budget allocation decisions are made on effectively and competitively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.781-790
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• 2013

This research focuses on development of the conceptual cost estimation models for I.L.M box girder bridge. The current conceptual cost estimation for public construction projects is dependent on governmental average unit price references which has been regarded as inaccurate and unreliable by many experts. Therefore, there have been strong demands for developing a better way of conceptual cost estimating methods. This research has proposed three different conceptual cost estimating method for a P.S.C. girder bridge built with the I.L.M method. Model (I) attempts to seek the proper breakdown of standard works that are accountable for more than 95 percentage in total cost and calculates the amount of standard work's materials from the standard section and volume of I.L.M box girder bridge. Model (II) utilizes a correlation analysis (coefficient over 0.6 or more) between breakdown of standard works and input data that would be considered available information in preliminary design phase. Model(III) obtains conceptual estimating through multiple-regression analysis between the breakdown of standard works and all of input data related to them. In order to validate the clustering of coverage in the preliminary design phase, the variation of I.L.M cost coverage from multiple-regression analysis[model(III)] has been investigated which result in between -3.76% and 11.79%, comparing with AACE(Association for the Advancement of Cost Engineering) which informs its variation between -5% and +15% in the design phase. The model proposed from this research are envisioned to be improved to a great distinct if reliable cost date for P.S.C. girder bridges can be continually collected with reasonable accuracies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.829-837
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• 2011

Construction cost estimation in planning phase which calculates the cost for performing construction tasks is used for various ways. Meanwhile, in the case of road construction, the existing cost estimating method in early phase based on numerical mean value of the past is not accurate to be used. This paper propose neural network model for estimating road construction cost in planning phase to solve the limit of current cost estimating method. The model was designed using past road construction bidding records, and variables of model were optimized through trial and error. The estimation result of the model was compared with regression analysis and government's standard and it was verified that the model is better in accuracy. It is expected that the proposed model will be used for road cost estimation in planning phase.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3D
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• pp.373-379
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• 2009

Cost estimation in the early phase enables government to plan public budgeting more efficiently by providing information about construction cost. However, cost estimation in the early phase is difficult to predict because only a little information can be utilized. The cost estimation method now being used by the government is calculated by length of the road multiplied by unit cost per length and shows high error rate because it cannot reflect the unique characteristics of each project. As the project is being proceeded, level of available information also changed. So, reflecting available information of a project is important. This paper divided early phase into two parts : planning phase and early design phase, and developed cost estimation model considering level of available information of each phase. Total 143 cases are utilized to find influencing variables and develop cost estimation model and model validation is done by adopting required accuracy level. This cost estimation model reflecting level of available information can be applied to public budgeting, feasibility test, and comparison between routes.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.95-103
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• 2009

The case of rivers facilities works, expense the standard unit cost for the quality and a rough public corporation expense estimating of the rivers public corporation which is fixed form with the information available which it follows basic design phase absently and possibility of fluctuation. It exists many difficulties in rough public corporation expense estimating. The rivers public corporation expense rough estimating method of existing produces does not exist the amount of material of representative section of the rivers dike and the rough public corporation expense estimating method which is systematic with the method which multiples the seniority (M). The research sees the rough public corporation expense predictive model from the planning stage which is not basic design to consider the quality of the rivers facility public corporation. From this study, it can prevent the waste of national budget from the general public corporation and is more accurate and public corporation expense production possibly.