• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.133-137
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• 2017

Nuclear power plants in Korea are usually built based on a duplicated model; so the project cost data of the preceding unit can be used as reference when estimating the project cost for the succeeding unit. However, since the contracting method is oriented towards the price, empirical factors such as making top-down estimations using the reverse calculation method based on the completion cost of the preceding unit is dominant. In order to develop a project cost database to resolve such problems, the detailed cost boundary of the project cost data must be categorized by project and by system. This study proposes a method to connect the code of account with the base quantities and the IAEA account, and proposes a database structure for the development of a project cost estimation system. The estimation system developed in the future is expected to utilize the proposed project cost data structure.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.196-202
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• 2009

Study from Yogyakarta earthquake reconstruction program, cast-in-place wall using fix-size formwork system (Old-CIP) has offered a good alternative for house construction. A simulation has also confirmed that this system using mortar as the main material can provide cheapest cost and lowest total man power compared to conventional wall construction technique: brick or mortar-block wall. This paper presents the new wall construction technique: full size cast-in-place wall (New-CIP). The detail of how this new technique implemented is described. In addition, considering that material and labor cost in one area is different to others, cost analysis for different resources prices and wages of three cities are taken into a simulation. The analysis is aimed to distinguish the implementation feasibility of New-CIP system compared to the four common wall systems. Finally, its implementation resistance is also discussed.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.808-813
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• 2005

Effective cost management requires reliable cost estimates at every stage of project development. The primary purpose of this research is to develop systematic modeling procedures and an automatic computing program for infrastructure estimating in the Texas Department of Transportation (TxDOT). The computing system toggles between project input information and segregated district unit prices for highway work item quantity estimates associated with earthwork and landscape, subgrade treatments and base, surface courses and pavement, structures, miscellaneous construction, and lighting, signing, markings and signals. This quantity-based approach was chosen because of the conventional approach lacking of quantity information until primary design is complete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.191-194
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• 2010

Construction companies are now trying a variety of cost-cutting strategies in the midst of recent slump of construction market. Notably, contract workers and local hires are accounting for increasing portion of management manpower as a part of their cost-reduction drive. However, construction site manpower researches to date have focused primarily on productivity analysis of site laborers, with little attention to the productivity of site management resources. This study aims to analyze the staffing status of office building construction site management manpower in reference to project size. Conclusions herein will provide basic inputs for subsequent attempts to build a model to enable efficient staffing of construction site management manpower.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.475-478
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• 2013

To carry out a one-off construction project successfully, effective and accurate early cost estimation is crucial, especially during the conceptual stage where very limited minimum information of construction project is given. As the level of accuracy of the early cost estimation has huge impacts on precise budgeting and cost management of a project, in other words, reducing the risk of a project, cost must be managed with special awareness. In an effort to improve the estimate accuracy of cost during the conceptual stage, this research introduces a Parameter Impact (PI) which can quantify weights of parameters and rank them; and PI development derived from the principle of impulse in physics is explicated. For a case study, 76 public apartment building cases in Korea are analyzed. To examine the validity of the proposed PI, a validation in terms of CBR applicability test and estimate accuracy comparisons using 10-nearest neighbor cases are carried out. The validation results support that the suggested PI can be applied in quantifying the weights of the parameters and CBR method for early cost estimation.

• Journal of Construction Engineering and Project Management
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• 제8권1호
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• pp.1-9
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• 2018

US transportation agencies are dealing with shrinking budgets, limited work forces, and deteriorating infrastructure. In order to cope with funding uncertainty, state highway agencies are now looking into their own organizations and identifying programs, practices, and processes that have potential for cost saving. A quality assurance (QA) program is an integral part of highway construction and ensures a project's contracted level of quality. The cost of quality (conforming and nonconforming) can constitute a sizable part of total construction cost. As the quality assurance programs evolved, various practices and processes were developed over time and later adopted by state highway agencies. These practices and processes include different QA standards and specifications, varying testing methods, central testing lab vs. on site testing, performance based vs. prescribed quality assurance practices, implementation of innovative quality assurance practices, etc. Therefore, there is an opportunity to assess different QA strategies and recommend those practices that are effective and cost efficient. A national survey was conducted by the authors, which provided a detailed mapping of various QA practices and processes used as part of QA programs and identified areas where agencies can focus on for cost savings. The survey found that QA sampling and testing plans, optimization of sampling plans, optimization of QA standards and specifications, and implementation of innovative test methods and processes are the main areas the agencies should focus to lean the current QA programs.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.417-424
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• 2009

For a construction project to progress smoothly, effective cost estimation is vital, particularly in the conceptual and schematic design stages. In these early phases, despite the fact that initial estimates are highly sensitive to changes in project scope, owners require accurate forecasts which reflect their supplying information. Thus, cost estimators need effective estimation strategies. Practically, parametric cost estimates are the most commonly used method in these initial phases, which utilizes historical cost data (Karshenas 1984, Kirkham 2007). Hence, compilation of historical data regarding appropriate cost variance governing parameters is a prime requirement. However, precedent practice of data mining (data preprocessing) for denoising internal errors or abnormal values is needed before compilation. As an effort to deal with this issue, this research proposed a statistical methodology for data preprocessing and verified that data preprocessing has a positive impact on the enhancement of estimate accuracy and stability. Moreover, Statistically Preprocessed data Based Parametric (SPBP) cost models are developed based on multiple regression equations and verified their effectiveness compared with conventional cost models.

• 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.182-186
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• 2011

Early cost estimates are important to decision-making for a construction project. Moreover, the possibility of reducing the project cost is getting less as the project is progressed. Case-based reasoning (CBR), which can be viewed as an effective method for early cost estimating, is widely utilized recently. Early cost estimates using CBR have advantages over the traditional ones as they produce reasonable outputs and self-studying is possible by simply adding new cases. Case-based reasoning is composed of a cycle of retrieve, reuse, revise, and retain process. However, in the majority of research cases, they are focused on how to retrieve the similar cases, instead of revising the cases which is expected to increase accuracy results of cost estimation. This research suggests a method of revising retrieved similar cases in a GA-CBR cost model which is widely studied and utilized for early cost estimating recently. To validate the proposed method, case study is conducted based on Korean public apartment projects.

• 한국건설관리학회논문집
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• 제7권5호
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• pp.167-176
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• 2006

현재 재건축사업은 추진 의사결정과 관련한 확정된 지표나 기준이 없이 막연한 수익성에 대한 기대를 토대로 시행되고 있으며, 사업시행과정 에서 직면하게 되는 제반 위험 에 대해 경험 적으로 대응하고 있는 실정이다. 또한 재건축조합이나 시공예정 회사들이 제공하는 관리처분계획에 포함된 수익성에 관한 정보는 결정론적 분석을 통한 단순한 예측에 불과하여 재건축을 시행하는 과정에서 결과가 수정되는 것이 일반적이다. 즉 수익성에 대한 예측이 재건축시행 과정상의 유동적인 상황에서 변경됨에 따라 예측결과에 대한 신뢰도는 근본적으로 내 외적인 한계를 갖고 있다. 본 연구는 재건축사업의 수익성에 영향을 미치는 변수들을 확률적으로 평가하여 수익과 위험을 동시에 분석하는 수익성예측모델을 개발하고, 사례연구를 통해 개발모델의 적합성을 검증하여 기존의 결정론적 접근방식이 갖는 한계를 극복하고자 한다.

• Journal of Construction Engineering and Project Management
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• 제4권3호
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• pp.53-59
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• 2014

Project managers are responsible to conduct project on time with least amount of costs and the most possible quality with respect to shortage of resources and environmental certainties. They have to make the best decision to reach such conflicting objects. In this study the project scheduling with multi goals-multi modes was planned in fuzzy conditions under resource constraints and expanded by fuzzy goal programing (FGP). The project cost was calculated by the price of renewable resources and the quality criteria were evaluated by the quality function deployment method (QFD). Finally the model was verified by a construction case study with 22 activities along with solving by GAMS. The results showed that this model could provide a systematic framework to facilitate the decision making process and made the project managers to be able to schedule the project closer to reality.