• Journal of the Korea Institute of Building Construction
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• v.12 no.4
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• pp.401-414
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• 2012

The adoption of Green Frame is expected to provide economic benefits, since construction costs are reduced by the in-situ production of precast concrete column and beam. The cost reduction can ultimately be realized by saving transportation costs and the overhead and profit of PC plants. The cost structure of Green Frame, which is built up using composite precast concrete members, is similar to that of a bearing-wall structure, but the difference in construction process has resulted in some cost differences for a few items. In particular, production and installation is the principal work involved in Green Frame made by precast concrete members, while form and concrete work is the principal work for a bearing-wall structure. As such, the rental time and fee for a tower crane should be compared through time analysis. To verify reliability, this study focused on developed residential projects to estimate the construction costs. Through this analysis, it was found that the costs of Green Frame were 1.57% lower than the costs of bearing-wall structure. The results of this study will help in the development of a management plan for the structural work of Green Frame.

• Journal of the Korea Institute of Building Construction
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• v.10 no.4
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• pp.123-132
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• 2010

Rebar work accounts for approximately 30% of the total construction costs for rebars and concrete. Recently, the high rising prices of rebars have become one of the principle factors of rising construction costs. Therefore, construction companies are putting much effort into loss reduction of rebars. Consequently, in this study, we wished to present loss reduction methods of rebars before the preparation of the placing drawings. To devise such methods, we collected previous case studies and analyzed methods that were applied for loss reduction. As a result of the analysis, we were able to find the following methods for loss reduction of rebars: method of reducing the number of splices at the mat foundation, method of reducing splice length at the internal columns or walls of the underground parking lot, method of reducing cap-ties of internal beams of basement floors excluding perimeter beams, and method of reducing anchorage length at the internal column or wall of the underground parking lot. Based on those analysis results, we presented our own loss reduction methods of rebars. Applying our methods resulted in considerable loss reduction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.66-67
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• 2016

Modular construction is attracting attention as the solution of recent problems in construction site. Such as lack of construction workforce, increasing labor costs, work delay due to extreme weather events and strengthening government regulations. However, despite the many advantages, Modular construction has not been activated dueto high construction costs compared to other construction methods. Accordingly, the object of this study is priority derivation of prefabricated house cost reduction factors and use as basic research data. For research performance, we have analyzed the blueprint and bill of quantities of a modular construction based public dormitory which was built in 2013. In result, the proportion of modular construction and on-site construction is 66% and 34%, and the construction cost proportion by activity was devided in to construction(79%), machinery(7%), electricity(5%) and civil(9%). Among these results in order to reduce costs, interior finishing(19.4) steel-frame(16.9%), metal works(13.5%), RC(11.8%), joinery(7.3%) is the order requires focused management.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.368-375
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• 2011

Along with the growing interest in greenhouse gas reduction, the effect of energy reduction from green buildings is gaining interest as well. However, green buildings may have difficulties in financing due to their high initial construction costs. With this in mind, the objective of this study is to suggest a financing model for green building projects with a governmental guarantee based on CER (Certified Emission Reduction). In other words, in the financing model, the government provides a guarantee for the increased costs of a green building project in return for CER. The suggested financing model was tested and found feasible for implementing green building projects. In addition, the model in this study is applicable to private projects because guarantee has its return. To utilize CER as a return for a financial guarantee, however, certification of CDMs (Clean Development Mechanism) for green buildings must be vitalized.

• Korean Journal of Construction Engineering and Management
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• v.7 no.6
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• pp.202-211
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• 2006

Rework in the construction industry can adversely affect project cost and schedule performance. Based on direct rework costs recorded on 359 construction projects, this paper presents an assessment of the magnitude of rework by various types of projects and sources of rework. The results from this paper establish that on average 4.5% and 2.5% of actual construction costs were spent on rework for owner and contractor projects, respectively. Furthermore, this paper determines that the direct rework costs differ by project types and sources of rework. Finally, it permits the development of rework reduction initiatives. By quantifying and recognizing the different magnitude of rework, the industry can be aware of the waste from rework and develop effective plans for managing rework, ultimately improving project cost performance.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.46-53
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• 2020

The domestic construction industry is becoming larger, high-rise and specialized. However, safety consciousness is still staying in low levels and falling accidents are apt to rise compared to other industries. So, the new way of safety management is required for reducing of the construction falling accidents. In this paper, we evaluate appropriateness of safety management on construction sites utilizing USN using smart safery equipment. Thus, we calculate loss costs of falling accidents considering accident rates and costs of the USN using smart safery equipment installation then compare both calculated costs. This research aims to propose the method for reduction of construction accidents in addition to conventional safety control methods by analyzing the propriety of applying USN using smart safery equipment on construction sites.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.413-423
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• 2015

Exterior Insulation and Finishing System(EIFS) is recognized as a promising alternative for energy reduction as energy reduction ratio of apartment is to be increased from 40% to 60% in 2017. However, EIFS is not actively applied to apartment because additional construction costs and duration are required for the current existing construction method of EIFS. Therefore, this study proposes a conceptual framework for concurrent construction method of EIFS which can reduce construction costs and duration by working sequentially from frame work to exterior insulation finishing work, and then verify the method's feasibility by analyzing a case study. It has been proven from the analysis that concurrent construction method of EIFS reduces 6.7% of construction duration and 13% of construction costs compared with the conventional exiting method. The proposed method is expected to contribute to invigorated application of EIFS to apartment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.10-22
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• 2010

The first full-scale u-City operation has started in Dongtan u-City. As local cities take over and operate the u-City, unexpected issues arise such as securing the budget of operating costs and self-providing the costs with business models utilizing the u-City assets. The paper presents a strategy for solving these issues. The strategy provides a foundation(infrastructure) for long-term operation models which may reduce the long-term operating costs. In order to establish the economic operating framework of u-City, suggested are some cost-reduction models based on the operating costs structure. For each model, a base framework with comparative analysis of operating costs is provided. With these models, each u-City may select a relevant model according to the characteristics of it. We hope that the framework provides the foundation for efficient and sustainable u-City operations.

• Structural Engineering and Mechanics
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• v.43 no.1
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• pp.31-51
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• 2012

This paper presents a computational study that explores the design of rigid steel frames by considering construction related costs. More specifically, two different aspects are investigated in this study focusing on the effects of (a) reducing the number of labor intensive rigid connections within a frame of given geometric layout, and (b) reducing the number of different member section types used in the frame. A genetic algorithm based optimization framework searches design space for these objectives. Unlike some studies that express connection cost as a factor of the entire frame weight, here connections and their associated cost factors are explicitly represented at the member level to evaluate the cost of connections associated with each beam. In addition, because variety in member section types can drive up construction related costs, its effects are evaluated implicitly by generating curves that show the trade off between cost and different numbers of section types used within the frame. Our results show that designs in which all connections are considered to be rigid can be excessively conservative: rigid connections can often be eliminated without any appreciable increase in frame weight, resulting in a reduction in overall cost. Eliminating additional rigid connections leads to further reductions in cost, even as frame weight increases, up to a certain point. These complex relationships between overall cost, rigid connections, and member section types are presented for a representative five-story steel frame.

• International Journal of Railway
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• v.2 no.1
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• pp.1-7
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• 2009

The development of structural solutions for high-speed or very high-speed tracks that minimize total life cycle costs of the system is a key issue to improve the operational profitability of new investments. In opposition to conventional ballasted tracks, slab track solutions can be a cost-effective solution, but only in the cases where the benefits due to the increase in track availability and the reduction of track maintenance offsets its much higher construction costs. In the cases where such investment is not feasible, it is worth to evaluate possible structural improvements to ballasted track that allow reducing its maintenance needs without increasing too much its construction costs. This paper evaluates the design requirements and the impact of improving conventional high-speed ballasted tracks by using a bituminous subballast layer. It is divided into two main parts: first the design requirements of the structural solutions with bituminous subballast and its possible benefits on high-speed track deterioration, and secondly the evaluation of the economic impact, in terms of construction costs, of using this structural solution material in future Spanish high-speed lines.