• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.118-126
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• 2006

There is a greater importance for underground work designed and built in the urban areas when it comes to considering the cost-effectiveness and the period of construction commensurate with an increasing trend of skyscrapers. At this stage of underground work, it's extremely necessary to choose a proper earth retaining method. Therefore, the study has suggested the rational retaining wall method by developing the support vector machine(SVM) model as a tool to choose a proper retaining wall method applied at the stage of selecting the earth retaining method. In order to develop the SVM model, the binary SVM classifier is expanded into a multi-class classifier. and to present the feasibility of our SVM model, we considered 129 projects. Applying the 'SVM Model' developed in the study to the designing and developing stages of the earth retaining work will contribute to the successful outcomes by decreasing any changes of design from implementing the earth retaining.

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.65-77
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• 2010

Our nation's housing construction is given much weight over 32% in 2007 and especially apartment is taking over 67%. If we put into construction environment consideration, we are having a trouble with price cap policy and the realestate recession due to the global economic crisis. So in order to get competitive power and supply of cheap apartment, the necessity of cost saving is increasing. This research collected the past constructed apartment project's cost saving examples which were influencing on the construction cost, quality and time. We analyzed collected cost saving datum and assorted these in compliance with classification system. By analysis of correlation among datum with exclusion and integration, we make a propose cost saving Checklist that will be a base data to give a chance to use in working level and other research.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.76-83
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• 2004

There is a greater importance for underground work designed and built in the urban areas when it comes to considering the cost-effectiveness and the period of construction commensurate with an increasing trend of skyscrapers. At this stage of underground work, it's extremely necessary to choose a proper earth retaining method. However, a frequent change order during construction happens in Korea where different performers design and construct separately, so there is a great possibility for the change order to affect the aspects of construction cost and period which normally define the outcome of construction work. Therefore, the study has suggested the rational retaining wall method by developing the case-based reasoning model as stool to choose a proper retaining wall method applied at the stage of selecting the earth retaining method. Applying the 'CBR Model' developed in the study to the designing and developing stages of the earth retaining work will contribute to the successful outcomes by decreasing any changes of design from implementing the earth retaining work.

• Korean Journal of Construction Engineering and Management
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• v.8 no.4
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• pp.155-166
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• 2007

The purpose of this research is to develop a conceptual model and prototype that establishes a new approach for building cost estimating in the schematic design phage. This research use the method that analyzes quantity and unit price separately to enhance schematic cost estimating through conducting literature review andi analyzing existing schematic cost estimating methods. In addition, this study proposes tile concept of cost breakdown structure including two more classifications: building element and floor compared to existing one only classified by trade. Thus, a Quantity Based Active Schematic cost Estimating(Q-BASE) model is developed founded on those two concepts. By applying proposed schematic cost estimating model, historical structure cost of residential complex building project is analyzed, and then, based on this analysis, prototype is implemented.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.448-452
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• 2006

Remodeling is deemedto be very important from the perspective of the recycling of resources, instead of scrapping the existing structure, and the creation of 'value added' which is equivalent to the 'value added' from the new construction. In addition, the selection of the appropriate construction method assures the saving of construction cost, the shortening of construction period, and the improvement of quality. Moreover, the selection of the construction method for the remodeling construction is far more important than the current new construction work, considering that the characteristicsof construction site and the structure have a great effect on the construction in case of the remodelingconstruction. Current selection of the construction method, however, does not reflect the construction information, but just adheres to the construction method which was commonly applied previously. Therefore, this study proposes the measure to embody the tool that assists the decision making in selecting the construction method.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.125-133
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• 2016

The Project Risk Management is intended to result in the effective management by identifying in advance and mitigating all significant risks including project risks and opportunities during the entire project life cycle - from project inception to completion of construction. It is impossible to predict an exact budget and construction duration before finishing a project. So, Washington Department of Transportation mandates that workshop-based risk management is conducted for projects over specific cost. However, the domestic construction sites have depended on numerical risk analysis without any workshop and efficient risk management have not made. Therefore, in this study, we propose the effective risk management using the RBES program which is very useful for workshop-based risk management and pre & post mitigation, by workshop-based risk management techniques. This proposed risk management approach is applied to a domestic 'A' river recovery project. It is concluded that we may expect the effect to mitigate the total cost overrun problem and the construction duration delay effect in the project by identifying significant risks and by preparing effective risk mitigation strategies.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.543-547
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• 2004

Visualization of construction process simulation and physical modeling were considered to overcome the limitations of current graphical simulation. The output of discrete-event simulation programs which are the most common mathematical statistical simulation tool for construction processes were analyzed for the visualization of earthmoving process that dealing with objects without fixed. Object-oriented models for equipment, material and work environments were devised to effectively visualize the numerical simulation results of the working time, the queuing time as well as the amount resources etc. The oscillation of the crane's cable and the lifted material that should be considered to rationally modeled and simulated by construction graphical simulation. The derived equation of motion was solved by numerical analysis procedure. Then obtained results was used for physical modeling.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.397-404
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• 2015

Construction equipment cost is critical to estimate the total construction costs, particularly in large and complicated projects. Public construction projects are typically estimated using the Poom-Saem which includes hourly rates for workers and equipments. Despite its importance, the construction equipment cost may not properly reflect the current market value because it is being updated every six years at most. To keep the data for construction equipment cost estimation up to date, it is highly recommended to use the standard market price that is reported each year by the Ministry of Security and Public Administration (MOSPA). However, there is still a wide gap to directly adopt the standard market price for updating the construction equipment prices. Therefore, this paper suggests an effective way to develop an ordinary management systems for updating construction equipment prices in the Poom-saem based on the standard market price.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.371-371
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• 2023

담양 및 화순 홍수조절지는 홍수 시 본류에 계획방류량만 흘러가도록 제수문을 운영하고, 계획방류량을 초과하는 홍수량은 하도 및 조절지 내에 저류하여 홍수를 지체시킨 후 저류된 홍수량은 첨두홍수가 지나간 이후 방류하는 방법으로 영산강 유역의 홍수를 방어하기 위해 '12년 건설되었다. 그러나 홍수조절지는 200년 빈도의 홍수량을 저감 시키도록 설계됨에 따라 준공 이후 10년간 '20년 8월 홍수 등 3회만 홍수방어용으로 활용되었다. 영산강은 오염부하량 대비 유출량 부족 등으로 수질관리에 취약하고 하천유지용수를 공급하는 다목적댐이 없는 등 수자원 확보가 어려우므로, 비홍수기 홍수조절지에 환경대응용수를 담수 및 방류하여 영산강의 유량확보 및 수질개선 등 활용 다변화 방안을 모색하고자 한다. 이와 관련하여 '16년 및 '19년에 시범담수를 실시하였으나, 담수 수질 관리의 어려움, 방류 전후 강우 등 제한적 여건으로 인해 하류 유량증가 및 수질 개선 효과의 확인은 어려웠으며, 제방 물비침 등을 발견하여 시설 안정성 확보가 필요한 것으로 확인되었다. '21년 안정성 확보를 위한 보강 그라우팅을 시행했으며, '19년부터 '21년 2월까지 「홍수조절지를 활용한 영산강 수질개선 방안」연구용역을 실시하여, 비홍수기 활용방안을 수립하였다. '21년 4/4분기 댐과 보 등의 연계운영협의회에 '시범담수 계획' 안건 상정 및 의결을 거쳤고, '22년 3월 25~26일까지 담양 74mm, 화순 61mm 비가 내려 담양 63만m³, 화순 151만m³를 담수하고 18~19일간 저류 후 담양은 평균 3.0m³/초로 25시간 동안, 화순은 평균 5.0m³/초로 32시간 동안 하류로 방류하였다. 방류 후 담양·화순 모두 가까운 하류 수위국 수위 상승을 확인했으며, 화순의 경우 하류 수질에 일부 영향이 있음을 확인하였다. 다만, 초기유출수 배제 등을 고려하지 않아 담수의 수질이 본류보다 좋지 않았으며, 이에 따라 수질 영향의 인과관계 확인이 어려웠다. 기존 연구용역에서 제시한 비홍수기 활용방안의 검증·보완을 위한 연구용역이 '22.5월부터 '23.12월까지 진행될 예정이며, 초기유출수 배제를 위한 조건 재수립, 수질 모니터링지점 확대 등 보완된 '시범담수 계획'을 '23.3월 댐과 보 등의 연계운영협의회에 보고하였다. 연말까지 연구용역과 연계한 시범담수·방류 시행 및 모니터링·효과분석을 통해 비홍수기 홍수조절지 최적운영방안을 마련할 계획이다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.463-466
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• 2008

Owing to the characteristics of the construction industry, large number of risk factors exist in construction projects compared to other industries. In the year 2007, due to industrial disaster, there was a loss of about 70 million number of working days and about 3 trillion won of the economic direct loss Economic loss is estimated up to 16trillion won including the indirect loss. Hence, a countermeasure is required to reduce the loss. However, the existing safety management is inefficient because it is based on experiential safety knowledge in the form of safety index, regulations. The purpose of this research is to improve this problem by proposing a quantitative risk assessment methodology. First, the limitation of existing hazard index is analyzed and subsequently variables for assessing degree of risk is established. Finally, these variables are then combined and a quantitative risk assessment methodology is proposed.