• 한국건축시공학회지
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• 제12권4호
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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.

• 한국건축시공학회지
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• 제10권4호
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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.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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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.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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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.

• 한국건설관리학회논문집
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• 제7권6호
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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.

• 한국안전학회지
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• 제35권6호
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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.

• 한국건축시공학회지
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• 제15권4호
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• pp.413-423
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• 2015

공동주택의 에너지 의무 절감률이 현재 40%에서 2017년에는 60%까지 단계적으로 상향 조정되면서 에너지 절감을 위해 외단열 공법이 주목받고 있다. 그러나 기존 외단열 공법은 내단열 공법에 비해 추가되는 공사비와 공사기간으로 인해 활성화가 미흡한 실정이다. 따라서 본 연구는 외단열공사와 골조공사를 연속적으로 시공함으로서 공사기간을 단축하고 공사비를 절감할 수 있는 외단열 적층시공 공법의 개념모델을 개발하고 사례적용을 통해 공법의 타당성을 검증하였다. 연구결과 외단열 적층시공 공법은 기존의 외단열 공법에 비해 6.7%의 공기절감 효과와 13%의 외단열 공사비 절감효과가 있는 것으로 나타났다. 본 연구의 결과인 적층시공 공법은 외단열 공법적용의 저해요소를 해결하여 향후 외단열 공법 활성화에 기여할 것으로 기대된다.

• 산업경영시스템학회지
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• 제33권4호
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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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• 제43권1호
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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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• 제2권1호
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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.