• Korean Journal of Construction Engineering and Management
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• v.10 no.3
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• pp.130-138
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• 2009

Bromilow's time-cost (BTC) relationship was examined for building projects in Vietnam using actual construction time and total construction cost. Data set was collected from 77 historical building construction projects completed between 1999 and 2005 which were adjusted by consumer price index (CPI) to 2000 price. Time-cost equations were specified respected to two sectors, public and private, in Vietnamese construction industry and all cases. It is shown that a public funded building project has the longer construction duration than a similar budget private funded project. The resulting models are statistically significant. The adjusted R-square coefficients of all cases, public and private projects models are respectively 0.403, 0.436 and 0.377 mean that the BTC regression lines moderately fit the data set.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.1
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• pp.9-16
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• 2003

In this paper, we propose a reliability evaluation method considering the momentary interruptions of power distribution systems. The results of research are concentrated on two parts. One is the analytic and probabilistic reliability evaluation of power distribution system considering the momentary interruptions and the other is the reliability cost evaluation that unifies the cost of sustained and momentary interruptions. This proposed reliability cost evaluation methodology is also divided into the analytic and probabilistic approach and the time sequential Monte Carlo method is used for the probabilistic method. The proposed methods are tested using the modified RBTS (Roy Billinton Test System) form and historical reliability data of KEPCO (Korea Electric Power Corporation) system. Through the case studies, it is verified that the proposed reliability evaluation and its cost/worth assessment methodologies can be applied to the actual reliability studies.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.935-940
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• 2005

This paper presents the results of a statistical analysis using historical data of cost contingency. As a result, a model that predicts and estimates an accurate cost contingency value using the least squares estimation method was developed. Data such as original contract amounts, estimated contingency amounts set by maximum funding limits, and actual contingency amounts, were collected and used for model development. The more effective prediction model was selected from the two developed models based on its prediction capability. The model would help guide project managers making financial decisions when the determination of the cost contingency amounts for multiple projects is necessary.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.131-139
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• 2011

In this Study, the Cost of Public Facility Construction in the VE Cost Model, and the Progress of the Construction Site Management, and Cost due to the Lack of Cpatial Information in Dispute Cost Work Type Recognize the limits of Historical Information, and to Overcome the Perception of Cost and Space Systems Unit In the Process of Transition that Began Seeking Ways to Improve Through this Study, Different Parts of the Proposed Area of Construction Work Unit System, the Core of Calculating Hourly and Detailed Engineering Information and Cost Information Generated Extension to Configure the Construction Unit in Every Space, Every Work Unit System, All Materials That Make Up Work Unit System, Unit Labor Costs, And All of the Configuration Items Enables Precise And Multidimensional Understanding is That.

• Journal of KIBIM
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• v.1 no.1
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• pp.18-25
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• 2011

Construction cost estimation in the early phase provides the opportunity to make reasonable decisions related to the project. For estimating this cost, various methods have been developed. But several problems have been recognized like accuracy, relation beteewn design and cost etc. In this study, we developed the method of cost estimating for building parts. The modified method has defferent ratio of space functions to calculate cost more correctly. Also historical cost data is used in this modified method for architects to estimate cost conveniently. By this modified method, we expects architects should easily design buildings based on cost.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.110-118
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• 2015

The standard production unit system is the most basic element in our country construction. However, this standard production unit system shows a large difference in the actual amount of labor input for works at the Apartment housing construction, Therefore, it may be a reasonable alternative to estimate the cost of construction by historical cost data, works will be calculated the cost of labor must determine the exact amount and It is necessary to determine the exact amount of labor input for the construction progress management. This study examines the results of comparing the standard production unit system and the actual amount of labor counting in apartment housing construction was completed in the metropolitan area since 2000, the following results were obtained. the actual amount of labor input are looked for 1.184person/1000 of masonary, $0.084persons/m^2$ of plaster, $0.039persons/m^2$ of Waterproofing, $0.059persons/m^2$ of tile at the Apartment housing construction. in the actual amount of labor counting Compared with standard production unit system, masonry ratio of 59.8%, plaster ratio of 41.3%, waterproofing ratio of 31.5%, tile ratio of 34.3% and The labor rate in the works was the lowest in the plaster. was relatively high in the masonary. Therefore, the amount of labor country apartment housing construction is preferably calculated on historical cost data. But it seems that the amount of labor necessary complement ongoing close enough to the actual standard production unit system a major variable in construction management.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.50-57
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• 2009

The Korea Standard of Estimate which has been used as the only basis of Cost estimate of public construction projects is failed to reflect the fluctuation of current construction cost. Therefore, the government decided to gradually introduce historical construction cost into cost estimate of public construction projects from 2004 and to reduce the use of Korean Standard of Estimate. This paper presents a series of process and the methodology for computing Actual Cost and analyzing the fluctuation patterns based on not only previous contract prices which made a successful bid but also all of the other bid prices. Also, this paper mainly handles a device for extracting strategic bid price such as low price bid for assuring reliable data and for predicting the construction cost which is built by Wavelet Analysis of Time series Analysis data and Neural Network. It is anticipated that the effective use of the proposed process for estimating actual unit cost would make the cost estimation more current and reasonable.

• Korean Journal of Construction Engineering and Management
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• v.7 no.3 s.31
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• pp.149-158
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• 2006

For construction projects, it is required to estimate the Environmental Management Cost(EMC) for pollution prevention, using the calculation standards prescribed in the Construction Technology Management Law(CTML). However, the EMC standards are difficult to utilize without definite site information. Therefore, it is needed a new calculation method reflecting project site information. According to the definition of EMC in the CTML, this study identifies the EMC items and classifies them into the pollution types such as air, water, noise, waste and others. With this EMC classification, the stud:』 analyzes using the SPSS the EMC for the 78 new multi-housing projects, which were executed during the past three years, 2000-2002. And then an EMC estimating matrix is developed with simple information such as site location and size of area from historical data. The proposed matrix can be effectively used to check and control budgeting and estimating the EMC of the multi-housing projects. In addition, the proposed EMC matrix are validated through a case study.

• Journal of the Korea Institute of Building Construction
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• v.11 no.5
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• pp.459-467
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• 2011

The work of constructing apartment housing involves various fields of industry that are linked to each other, and is based on a design document prepared by multiple technicians and architects. Consequently, design errors, material flaws or faulty construction works can cause defects, which sometimes overlap with each other. Construction companies should repair any defects found in a completed building within a specified period of time, and to do this, should establish a business plan by efficiently predicting the cost of defect repair. As it is very difficult for companies to accurately predict the occurrence of defects, historical performance data is used as a base. For domestic apartment housing units, data on the cost of defect repair is insufficient, so there are hardly any methods that can be used to make precise predictions. Therefore, the intent of this study is to develop a model that can predict the cost of defect repair by supply type and area, based on historical performance data with ten years worth of post-completion.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.107-110
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• 1996

Continuing advances in the formulation and solution of risk-sensitive control problems have reached a point at which this topic is becoming one of the more intriguing modern paradigms of feedback thought. Despite a prevailing atmosphere of close scrutiny of theoretical studies, the risk-sensitive body of knowledge is growing. Moreover, from the point of view of applications, the detailed properties of risk-sensitive design are only now beginning to be worked out. Accordingly, the time seems to be right for a survey of the historical underpinnings of the subject. This paper addresses the beginnings and the evolution, over the first quarter-century or so, and points out the close relationship of the topic with the notion of optimal cost cumulates, in particular the cost variance. It is to be expected that, in due course, some duality will appear between these notions and those in estimation and filtering. The purpose of this document is to help to lay a framework for that eventuality.