• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.6
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• pp.93-101
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• 2007

In general, geotechnical properties have many uncertain aspects, thus probabilistic analysis have been used to consider these aspects. It is, however, quite difficult to select an appropriate target probability for a certain structure or construction process. In this study, minimum expected cost design method based on probabilistic analysis is suggested for design of vertical drains generally used to accelerate consolidation in soft clayey soils. A sensitivity analysis is performed to select the most important uncertain parameters for the design of vertical drains. Monte Carlo simulation is used in sensitivity analysis and probabilistic analysis. Total expected cost, defined as the sum of initial cost and expected additive cost, varies widely with variation of input parameters used in design of vertical drain systems. And probability of failure to get the minimum total expected cost varies under the different design conditions. A minimum value of total expected cost is suggested as a design value in this study. The proposed design concept is applicable to unit construction process because this approach is to consider the uncertainties using probabilistic analysis and uncertainties of geotechnical properties.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.2
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• pp.113-127
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• 2007

In this study, a model to calculate the expected total construction cost is developed that simultaneously considers the rehabilitation cost related to the sliding of the caisson, the economic damage cost due to harbor shutdown in the event of excessive caisson sliding, and the economic damage cost due to temporal operational stoppage by excessive wave overtopping. A discount rate is used to convert the damage costs occurred at different times to the present value. The optimal cross-section of a caisson is defined as the cross-section that requires a minimum expected total construction cost within the allowable limit for the expected sliding distance of the caisson during the lifetime of the breakwater. Two values are used for the allowable limit: 0.3 and 0.1 m. It was found that the economic damage cost due to harbor shutdown by excessive caisson sliding is more critical than the rehabilitation cost of the caisson or the economic damage cost by excessive wave overtopping in the decision of the optimal cross-section. In addition, the optimal cross-section of the caisson was shown to be determined by the allowable limit for the expected sliding distance rather than the minimum expected total construction cost as a larger value is used for the threshold sliding distance of the caisson for harbor shutdown.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.10a
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• pp.216-223
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• 1993

The safety factors of current standard code are considered to be not appropriate compared to design and construction practices, even this safety factors are not determined from probabilistic study but merely from experiences and practices. This study pripose the optimum safety indices based on expected total cost minimization using only three parameters, which are the level of the failure cost to the initial cost by improvement in safety, and the order of the initial cost function.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.4
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• pp.280-293
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• 2005

In this study, a model to calculate the expected total construction cost has been developed by combining a model to calculate the sliding distance of a caisson of a vertical breakwater and a model to calculate the rehabilitation cost of a caisson. The optimal cross-section of a caisson of a vertical breakwater is defined as the cross-section that requires a minimum expected total construction cost within the allowable limit of caisson sliding. Two allowable limits are considered: 0.1 m of the expected sliding distance during the lifetime of the breakwater and 0.1 of the probability that the cumulative sliding distance during the lifetime of the breakwater is greater than 0.3 m. A discount rate has also been introduced to convert the future rehabilitation cost to the present value. The introduction of the discount rate reduces the expected total construction cost for the caissons designed for shorter return periods due to frequent rehabilitations. The present design method requires a smaller cross-section than the conventional deterministic method in shallow water depths, enabling us to design a caisson more economically. On the other hand, the above-mentioned allowable limits of caisson sliding show similar results for smaller water depths, while, for larger depths, the former requires a larger cross-section than the latter.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.44-45
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• 2014

Recently the Korean government also has strictly restricted a law such as GBCC(Green Building Certification Criteria)and RPS(Renewable Portfolio Standard) on the construction. Especially the government announced a obligation of renewable energy consumption over 12% for all the public buildings of total area over 1,000㎡ since 2014. Regarding to the policy, this study presented the economics of energy analysis of the public office buildings that supplies 12% renewable energy output in the early stage of construction project. This paper calculated on CO₂ emission by the geothermal, solar heat, and solar photovoltaic system and estimated the saving cost. Reduced cost through the energy saving are predicted to influence on the total construction cost. As a result air pollution and energy saving cost are expected that renewable energy system would be saving total initial cost of construction on planning phase.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.151-158
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• 1998

This paper presents an optimal decision model for minimizing the life-cycle cost of steel box girder bridges. The point is that it takes into account service life process as a whole, and the life-cycle costs include initial (design, testing, and construction) costs, maintenance costs and expected failure costs. The problem is formulated as that of minimization of expected total life-cycle cost with respect to the design variables. The optimal solution identifies those values of the decision variables that result in minimum expected total cost. The performance constraints in the form of flexural failure and shear failure are those specified in the design code. Based on extensive numerical investigations, it may be positively stated that the optimum design of steel box girder bridges based on life-cycle cost approach proposed in this study provides a lot more rational and economical design, and thus the proposed approach will propose the development of new concepts and design methodologies that may have important implications in the next generation performance-based design codes and standards.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.228-229
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• 2019

This study performs analyzing a status of labor cost policy of public construction project and labor management information system in Korea for improving of labor cost survey in the construction market. The outcome of this study will be helpful to build a labor cost information system included the information of man-hour, regular pay and benefit, total wage. And if these result is integrated with the information of worker's career, qualification, skill level, it is confidently expected that the survey of labor cost is reliable.

• Journal of the Korea Institute of Building Construction
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• v.4 no.1
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• pp.105-110
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• 2004

Resource procurement is an important management area because cost of resource covers 40％ of total construction project cost and resource delivery has direct relationship with project performance. Integration of cost provides various potentials for effective and efficient project control. This study investigates the usefulness of time in resource procurement management focused on materials. These days, construction projects have characterized manufacture because of industrialization and component. Therefore, application of systematic resource planning has been requested in the construction. There are many companies conducting procurement of resource on the web by applying MRP, ERP etc. in the construction. However, in applying them in the construction yet, there is obstruction. MRP has the character doing its function under accurate cost prediction of resource. But prediction of resource is difficult in industry mechanism of the construction. If accurate cost prediction of resource is possible in the construction, it will be expected to reduce cost of procurement of resource substantially by applying successful resource planning model in the manufacture. On the basis of recent current, the purpose of study is to present procurement of resource system that period observance of construction and minimization of stock is possible by reflecting accurate lead-time to apply proactive thought to be able to cope with alteration of construction schedule efficiently in analyzing resource planning of the construction site.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.109-114
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• 2000

In this paper, an optimum design model for minimizing the life-cycle cost (LCC) of high-speed railway steel bridges is proposed The point is that it takes into account service life process as a whole, and thus the life-cycle costs include initial (design, testing, and construction) costs, maintenance costs, expected strength failure costs and expected serviceability failure costs. The problem is formulated as that of minimization of expected total life-cycle cost with respect to the design variables. By processing the optimum LCC design the effective and rational basis is proposed for calculating the total LCC and the sensitivity analysis of LCC is peformed. Based on a numerical example, it may be positively stated that the optimum LCC design of high-speed railway steel bridges proposed in this study provides a lot more rational and economical design, and thus the proposed approach will expedite the development of new concepts and design methodologies that may have important implications in the next generation performance-based design codes and standards.