• Korean Journal of Construction Engineering and Management
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• v.21 no.4
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• pp.82-89
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• 2020

Article 64 of the Enforcement Decree of the National Contract Act The requirement of the pre-amendment statute related to the adjustment of the contract price was 5% or more of the price fluctuation rate from the date of the contract. However, the meeting requirement was changed from 5% or more to 3% or more from the date of signing of the Presidential Decree No. 19035 to 2005. 9. 8. The method of adjusting the contract amount was also changed to determine the contractor's desired adjustment method at the time of contract. Alleviating these requirements and revising the empowerment of contract partners is intended to prevent difficulties in achieving smooth objectives by applying to public construction contractors without unfairly benefiting or unfavorable to contract partners. Even if the standards are relaxed and the rights are secured as described above, if the existing provisions for the adjustment of price fluctuation are applied, unlike the original purpose of the government system, the Korea Bank's price economic statistics classification method and the contract construction classification criteria applied in public construction work Due to the inconsistency, it can be seen that the amount of adjustment for price fluctuation by construction type is excessive and underestimated. Therefore, the purpose of this study is to analyze problems through cases and to make appropriate construction cost adjustment through improvement measures.

• Korean Journal of Construction Engineering and Management
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• v.7 no.6
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• pp.175-184
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• 2006

This study focused on developing Life Cycle Cost(LCC) analysis model for selecting sludge collectors in wastewater treatment system and applying the model to a case study. Cost items are examined through literature review and historical data of a facility. Analysis period, discount rate, energy cost escalation ratio are assumed to reasonable level. Monetary evaluation is performed using historical data and estimations from vendors. Sensitive analysis is executed using Monte Carlo Simulation for assumed factors. Interviews with operators, vendors, constructors, managers are conducted to define factors which indicates ease of maintenance, ease of delivery, technical performance, efficiency, environmental friendship. Factors are representing technical and social factors. Results from LCC analysis and qualitative analysis are evaluate together with Weighted Matrix Evaluation Methods for optimum alternative of sludge collectors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.702-708
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• 2018

3D printing technology is attracting increasing attention as a key technology of the fourth industrial revolution that can change the production paradigm of existing industries. The introduction of construction 3D printing technology has been slower than other industries because of the characteristics of the construction field. On the other hand construction automation using 3D printing is required to reduce the production population, as well as improve productivity and safety. In this study, a construction 3D printing work breakdown structure and link method to a standard estimation system were developed as a preliminary preparation for introducing 3D printing to construction. Based on expert consultation on construction and 3D printing, a hypothetical scenario was developed based on existing construction 3D printing technology. According to the scenario, 16 kinds of works required for 3D printing construction work were derived. The existing work breakdown structure and standard estimation system were analyzed, and the 3D printing work was linked. 3D printing works that were the same as the existing breakdown structure were found, and non-existent works were added to the similar breakdown structure. These results are expected to be helpful for future 3D printing construction management and cost estimation. The actual standard estimation system through 3D printing work will need to be calculated.

• The Magazine for Energy Service Companies
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• s.29
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• pp.48-61
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• 2004

최근 일본에서는 ESCO사업에 PFI법을 새로이 적용하고 있다. 성과배분제, 성과보증제에 이어 이 제도를 적용할 경우, 국가 및 공공기관을 대상으로 하는 ESCO사업의 확대 및 자금조달이 한층 유리해질 전망이다. 지난 99년 제정된 PFI(Private Finance Initiative)법(민간자금 등의 활용에 의한 공공시설 등의 정비 등의 촉진에 관한 법률)에 근거한 사업은 ''공공시설 등''에 있어서 건설, 유지관리 운영 등을 민간의 자금, 경영능력 및 기술적 능력을 활용하는 사업방법으로 사업 전체의 리스크관리가 효율적으로 행해지는 것과 설게$\cdot$시공$\cdot$유지관리$\cdot$운영의 전부 또는 일부를 일체적으로 취급하는 것에 의해 사업비용의 절감이 기대되며 질 높은 서비스의 제공이 가능한 제도이다. 이것과 매우 유사한 개념을 가지고 있는 것이 성과보증제에 의한 ESCO사업이다. 민간사업자인 ESCO사업자가 자금을 조달하고 에너지절약 개수공사에 따른 설계$\cdot$시공$\cdot$, 운전$\cdot$유지관리, 계측$\cdot$검증, 에너지절감 보증 등의 서비스를 제공하며, 광열수도비 및 운전$\cdot$유지관리비의 절감분으로 모든 투자와 ESCO사업자의 경비를 지불한다. 또 에너지절감 및 공공의 이익보증을 포함한 퍼포먼스계약이라고 하는 형태를 취하는 것으로 공공 이익의 최대화를 도모함과 동시에 금융기관의 투자 리스크에 관한 우려를 회피할 수도 있다. 또 PFI법 특유의 법제상, 재정상의 조치와 재정상 및 금융상의 지원이라는 배려에 있다. 예를 들면, 국고채무부담행위의 설정, 행정재산 사용료의 무상화 또는 감면, 프로젝트 파이낸싱 등에 의한 자금조달을 고려할 경우에 있어서 담보권의 설정 등에 관한 제도를 합리적으로 정비하는 것이 가능하게 된다. 그 내용의 대강을 살펴본다.

• Journal of the Korean GEO-environmental Society
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• v.10 no.3
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• pp.53-62
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• 2009

This study was conducted to investigate characteristics of the non-point source pollution under construction and evaluate available pollution control methods. Suspended solid loading is high when soil disturbs by rainfall and this phenomenon is much more severe at the initial stage of construction than at the final one. There are three methods available for erosion and sediment control, which are check dam, silt fence, and geotextile. Check dam and silt fence are for control of suspense solids and geotextile is for preventing soil erosion during rainfall. They can be installed as temporary control facilities at construction sites. From the comparison of those methods, it was found that geotextile method was the most efficient for the runoff control of non-point source pollution. Check dam and silt fence can remove suspense solids by pore spaces to some degree, but the removal of pollutants mainly occurs through sedimentation. Because the temporary control facilities have limited removal efficiency of pollutant, they often cause civil claims and contamination of water environment. Hence, using a pressurized filtration system along with temporary control facilities, highly enhanced treatment efficiency was anticipated. In addition, the loading capacity of these techniques depends on filtration velocity and input loading. And their pre-treatments are necessary for efficient operation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.1
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• pp.127-134
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• 2022

Recently, policies and research to prevent increasing construction accidents have been actively conducted in the domestic construction industry. In previous studies, the prediction model developed to prevent construction accidents mainly used only structured data, so various characteristics of construction sites are not sufficiently considered. Therefore, in this study, we developed a machine learning-based construction accident prediction model that enables the characteristics of construction sites to be considered sufficiently by using both structured and text-type unstructured data. In this study, 6,826 cases of construction accident data were collected from the Construction Safety Management Integrated Information (CSI) for machine learning. The Decision forest algorithm and the BERT language model were used to train structured and unstructured data respectively. As a result of analysis using both types of data, it was confirmed that the prediction accuracy was 95.41 %, which is improved by about 20 % compared to the case of using only structured data. Conclusively, the performance of the predictive model was effectively improved by using the unstructured data together, and construction accidents can be expected to be reduced through more accurate prediction.

• Korean Journal of Construction Engineering and Management
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• v.22 no.4
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• pp.29-40
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• 2021

Recently, interest in Building Information Modeling (BIM) has increased globally, and 3D modeling is a start for the application of BIM at construction sites. However, while many studies have been conducted on the efficiency of 3D modeling focused on civil facilities, there is a lack of research on the earthwork BIM. In particular, since 3D slope often has complex shapes depending on the ground models, the efficiency method for 3D slope are needed. This study analyzed the interfaces and procedures of other software to find out what functions users need. Then the functions to enter intervals between 3D faces, select multiple ground models, and improve the interface are reflected on the developed system and is able to efficiently perform modeling with only five steps, and reduce the number of clicks and inputs. As a result of conducting the test to verify the efficiency, using the developed system made skilled users complete modeling at least 1.8 times faster and unskilled people at least 2.4 times faster than using other software. This is expected to perform 3D slope modeling more efficiently, as well as to contribute to the activation of future BIM adoption for housing construction projects.

• Korean Journal of Construction Engineering and Management
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• v.3 no.3 s.11
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• pp.66-74
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• 2002

The Cost of Engineering is composed of the $3{\~}5{\%}$ of total cost of construction. It is important the role of engineering in the first stage of the business. But, it was not more the technical level of domestic design stage than advanced state. Expecially, it was because of the cognition lack and unreliable results about technical development. The result of that, it was lacking to the draw results of foreign countries. And it was to waste national budget through overlapped adopting of similar technologies from abroad that few projects are performed as their original plan. Therefore, the research is proposed to the intensification plan of technical competitive strength in domestic construction engineering company to cope with the change of economic environment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.210-211
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• 2022

Pruning is the most important work for the growth and aesthetics of street trees. It is also the most actively conducted maintenance work. However, the specifications, application methods, and cost criteria for pruning have not been systematically established. This has recently caused a lot of confusion in the practice of street tree pruning, such as indiscriminate pruning and lack of construction costs. Therefore, this study clarified the contents of work according to the form of pruning. It added 'aesthetic pruning,' which takes into account design. In addition, It revised equipment not in conformity with the law and excluded personnel necessary for on-site traffic control so that they could be reflected separately. As a result, this study is expected to contribute a lot to securing appropriate construction costs for maintaining street trees.

• Korean Journal of Construction Engineering and Management
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• v.13 no.5
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• pp.12-24
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• 2012

The Risks in undertaking a construction project comes from many sources and often involves many participants in the project. This study has identified various kinds of risks, assessed the risk factors quantitatively and suggested risk management method for response pertinent in Design Build(Turn Key)type of projects in Korean context. A questionnaire was designed comprising of 145 possible risks in all types of construction projects. The population from owner, consultant and contractor groups was asked to indicate the risks applicable in DB projects. 25 numbers of critical risks in DB projects were identified and further analyzed for reveling inherent relationship between them through factor analysis. Factor analysis revealed 8 risk factors in DB projects. Construction site related, contract related and design related risk factor consisted about 72% of total risk weight. It has been found out about 6%, while considering the mutual dependency, it is about 10% of total cost of DB project. Therefore, It is suggested that 6% to 10% of construction amount as contingency has to be made provision for risk responses in the DB projects.