• Journal of the Korea Institute of Building Construction
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• v.2 no.4
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• pp.105-112
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• 2002

The EVMS(Earned Value Management System) comes from C/SCSC which was first released by the United States Department of Defense in December 1967, and preyed very powerful and efficient project management tool from a lot of practices. Although it is an excellent tool, we can not be succeed appling foreign system due to the differences of construction culture and law between the Korean and US construction industries. EAC(Estimate at Completion) is one of the most important functions in the EVMS. The purpose of this study is to propose the improved EAC method according to the performance indices better than old that and to prove from examples. In advance, the improved EAC method is to estimate more exactly costs and to promote efficiency in construction projects.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.192-200
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• 2003

The object of this research is to develop a computerized algorithm of cost estimation method to forecast the total construction cost in the bidding stage by the historical and elemental work cost data. Traditional cost models to prepare Bill of Quantities in the korea construction industry since 1970 are not helpful to forecast the project total cost in the bidding stage because the BOQ is always constant data according to the design factors of a particular project. On the contrary, statistical models can provide cost quicker and more reliable than traditional ones if the collected cost data are sufficient enough to analyze the trends of the variables. The estimation system considers non-deterministic methods which referred to as the 'Monte Carlo simulation. The method interprets cost data to generate a probabilistic distribution for total costs from the deficient elemental experience cost distribution.

• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.75-80
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• 2010

With the intensifying of price competition and structural diversifications, the uncertainty of the domestic housing market has been increased. This highlights the importance of the planning stage of construction projects, and the increased need for a higher level of accuracy in approximate estimates. Currently, a number of research and development programs to calculate construction cost at the initial planning stage are being conducted. However, there are few cases in which local characteristics are considered in deriving the results. If local calibration can be conducted during estimates, more accurate cost estimates will be enabled. This could also play a major role in ensuring the success of a project. Therefore, the purpose of this research is to develop a calculation methodology and a model for a local index based on the historical data of public apartment buildings, and to derive a local index that supports accurate construction cost estimates.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.199-212
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• 2010

To establish an infrastructure for technology and information in the domestic construction industry, several construction regulations pertaining to construction information have been institutionalized. However, there are major problems with the domestic information classification system, earned value management (EVM) and project management information system (PMIS). In particular, the functions of the current PMIS have consisted of a builder-oriented system, and as EVM is not applied to PMIS, the functions of reporting, analysis and forecast for owners are lacking. Moreover, owners cannot confirm information on construction schedule and cost in real time due to the differences between the EVM and PMIS operation systems. The purpose of this study is to provide a framework that is capable of operating PMIS efficiently under an e-business environment, by providing a proposal on how to establish a work breakdown structure (WBS) and an EVM - PMIS integration model, so that PMIS may provide the function of EVM, and stakeholders may have all information in common. At the core of EVM - PMIS integration is the idea that EVM and PMIS have the same operation system, in order to be an activity-based system. The principle of the integration is data integration, in which the information field of an activity is connected with the field of a relational database table consisting of sub-modules for the schedule and cost management function of PMIS using a relational database management system. Therefore, the planned value (PV), cost value (CV), actual cost (AC), schedule variance (SV), schedule performance index (SPI), cost variance (CV) and cost performance index (CPI) of an activity are connected with the field of the relational database table for the schedule and cost sub-modules of PMIS.

• Korean Journal of Construction Engineering and Management
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• v.20 no.3
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• pp.3-11
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• 2019

The construction of a facility is an act whereby infrastructure such as roads and railways and other facilities such as housing and office spaces are constructed, and due to the characteristics of the relevant industry where such construction is carried out in a custom order method, it requires a long period of time mostly. While the construction is carried out over a long period of time, fluctuations in the price of raw materials required for the construction occur. Therefore, the cost of the construction also fluctuates inevitably. The fluctuation of the construction cost meshes closely with the profit of a constructor and the efficiency of government spending. Therefore, it is necessary to maintain the construction cost at a reasonable level by adjusting the construction cost rationally in order to secure the required construction quality and spend the budget efficiently. The buffer system for solving such problem is the contract amount adjustment system by fluctuations in prices (Escalation/De-Escalation). In this study, the method combining the escalation method based on the item adjustment method was suggested for an efficient contract amount adjustment method. In addition, it is proposed that there be an investigation and codification of matters not applied to government acts and regulations on contracts related to the adjustment of fluctuations in prices legally.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.349-352
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• 2003

Using EVMS can probably cause lots of confusion under the different systems and different circumstances of the construction industry between Korea and The United States, because The United States has wide experience in applying to EVMS during several decades but Korea has not. Therefore this research deals with the problem about Performance Indices in forecasting EAC(Estimate at Completion) among the problems of using EVMS. A target index of testing in this research is the Performance Indices used in the research at home and abroad in the past and those is applied to APT projects within the country with statistical method. Through this method, we can catch the tendency and the properties of the Performance Indices for applying to Korea.

• Korean Journal of Construction Engineering and Management
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• v.12 no.2
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• pp.3-11
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• 2011

There are several causes to recalculate the contract amount in public construction projects. Among them, the escalation clause was introduced in 1969 and now the condition to recalculate the cost is effective after 90 days from the date of contract and the rate of fluctuation should be more than 3% from the date of bidding. The two calculation methods for the rate of fluctuation are item-adjustment and index-adjustment. According to the results of investigation into 4 public institutions and 163 projects, all of them have used the method of index-adjustment and the rate of projects that spend over 6 months obtaining the approval of contract amount adjustment is more than 90%. The reason for spending lots of time is caused by problems of the calculation method on the price fluctuation rate. Therefore, it is necessary that the calculation method should be diversified to cope with the problems and a option of the builder should be expanded as well. Furthermore, if the way to apply correction factors to construction price index and average index based on the producer and consumer price index made by the bank of Korea is added, then the duration will be reduced without additional expenses. This study proposed the diversification of the calculation method using price fluctuation rate and builders' expanded options as improvement on the managerial method of Price Fluctuation System for the prompt and efficient contract amount adjustment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.111-112
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• 2012

Korean government is planning to supply a half million public and permanent rental houses from 2013 to 2018 for settlement of non-homeowners. It is requested an objective criterion to appropriate the budget for the rental houses construction project cost. In this study, construction cost indices, which reflect the inflation trend of construction resources, were explorated to suggest a effective methodology for the construction cost estimation of therental houses. We figured out the future construction cost indices using several scientific methods, and seven estimated indices values were shown. It is required an additional research to select the proper value among the analyzed indices.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.96-96
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• 2021

수문기상인자 중 하나인 증발산량은 수자원 계획 및 관리 시 고려되며, 특히 물수지 모형 등의 입력자료로 활용된다. 우리나라를 포함한 각국 기상청 및 국제기구에서는 직접 관측이 아닌 FAO56 Penman-Monteith(PM)을 통해 증발산량을 산출하고 있다. FAO56 PM 방법은 복사(radiation), 대기온도(air temperature), 습도(humidity), 풍속(wind speed) 등의 기상인자로부터 기준증발산량(reference evapotransipiration)을 추정하며, 상대적으로 높은 정확성을 보여준다. 그러나 FAO56 PM 방법은 많은 기상인자를 요구하므로 미계측 유역을 포함한 일부지역에 대한 증발산량 자료 구축이 어려운 실정이다. 또한, 기준증발산량의 특성이 시간에 따라 변화하므로 비정상성(nonstationary)을 고려한 분석이 요구된다. 본 연구에서는 온도인자 기반의 대체모형(surrogate model)을 개발하여 기준증발산량의 비정상성을 고려하고자 한다. 한강유역에 위치한 관측소를 대상으로 모형을 개발하였으며, 시간에 따라 변동하는 기준증발산량의 특성을 고려하기 위해 Bayesian 추론기법을 통해 매개변수를 시간에 따라 추정하였다. 또한, 본 연구에서는 대체모형으로 산정된 증발산량을 활용해 가뭄지수인 EDDI(evaporative demand drought index)를 제시하였다. 가뭄 모니터링 및 조기 경보 안내를 위해 개발된 EDDI를 활용하여 기존 가뭄보다 빠르게 진행되는 초단기 가뭄(flash drought)를 평가하였다. 본 연구에서 개발된 모형은 미계측 지역에서도 적용이 가능하므로 수자원분야에서 활용성이 높을 것으로 사료된다.

• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.366-372
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• 2012

In most of construction work, especially mat foundation construction, it is very important that accidents be prevented at early aged construction stage. To reduce the risk of accidents, it is necessary to choose the curing method to provide instructions for safety forming work by proper curing of concrete after placing. Therefore, this paper has proposed a designation algorithm of curing method for representing curing type and period by analyzing the transient hydration heat solution, focusing on mat foundation construction. This has been implemented, moreover, using an object oriented programming language to develop structural analysis system taking account crack index. In addition, we present in this paper a safety curing management system developed to assess risk during forming work.