• 한국산업융합학회 논문집
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• 제25권6_3호
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• pp.1207-1219
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• 2022

「Act On Contracts To Which The State Is A Party」 stipulates that the "Construction Standard Production Rate" and "Construction Standard Unit Price" be used as the criteria for determining the estimated price of construction works performed by public institutions. In this regard, issues such as the application scope of the Construction Standard Unit Price, and the effect of budget reduction continue. However, due to the lack of quantitative data on the actual application of Construction Standard Unit Price, it is difficult to objectively evaluate various issues. In order to prepare data for objective evaluation of the Construction Standard Unit Price, this study analyzed the ripple effect of applying the Construction Standard Unit Price based on the bill of quantity. As a result of the analysis, the Construction Standard Unit Price ripple effect in the civil engineering part was 9.2%, and it was analyzed that there was a ripple effect of about 1.9% based on the civil engineering direct cost. In the construction part, the ripple effect was analyzed to be relatively high at 17%, but it was found to have a ripple effect of about 3% in the construction direct cost. Based on the total direct cost, the ripple effect was calculated as 2.2%. Based on the analysis results, it is possible to evaluate the effect of applying the Standard Market Unit Price, and it is expected to be used as basic data to solve issues. As a future study, it is necessary to additionally analyze the ripple effect by Standard Market Unit Price application range (over 10 billion, over 20 billion won, etc.) and delivery system type (comprehensive evaluation, qualification examination, technical bidding, etc.). In addition, it is necessary to study the appropriate ripple effect of the Standard Market Unit Price.

• Geomechanics and Engineering
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• 제34권3호
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• pp.303-316
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• 2023

With the development and utilization of urban underground space, the artificial ground freezing technology has been widely used in the construction of underground engineering in soft soil areas. The mechanical properties of soft clay changed greatly after freezing and thawing, which affected the seismic performance of underground structures. In this paper, a series of triaxial tests were carried out to study the dynamic response of the freezing-thawing clay under the seismic load considering different dynamic stress amplitudes and different confining pressures. The reduction factor of dynamic shear stress was determined to correct the amplitude of the seismic load. The deformation development mode, the stress-strain relationship and the energy dissipation behavior of the soft clay under the seismic load were analyzed. An empirical model for predicting accumulative plastic strain was proposed and validated considering the loading times, the confining pressures and the dynamic stress amplitudes. The relevant research results can provide a theoretical reference to the seismic design of underground structures in soft clay areas.

• 한국산업융합학회 논문집
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• 제23권5호
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• pp.735-746
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• 2020

Recently, in Korea, various technology developments have been made to utilize 3D space and facility data such as unmanned aerial vehicles (UAV) and laser scanners with the goal of improving productivity at construction sites. However, the lack of related regulations for 3D laser scanner surveying has been a barrier to using the technology across the surveying industry. As a result, owners, contractors, and construction supervisors are reluctant to introduce and apply technology to the site. In this study, the guidelines (drafting and inspection work to be supervised by construction supervisors when constructing earthworks using laser scanners) was developed and presented so that the earth surveying and quantity calculation technology using a laser scanner could be applied and diffused in a construction site. Through the development of this guideline (proposal), it is judged that the supervision and inspection of earthworks quantity using a laser scanner will be activated in the field.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.962-967
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• 2005

Construction management requires decision-making skills. Main approaches to training construction management students are: (1) analyzing sample situations involving decision-making; and (2) teaching logical decision-making procedures. The absence of 'pressure' factors in these approaches has significant impacts on the success of the training. The approaches also lack 'dynamic' effects that help create a spontaneous plan for construction projects where unforeseen changes and interruptions may occur. To minimize the adverse effects of the existing approaches, this paper proposes a framework for developing a web-based training system. The application is delivered as a game involving decision-making on the student's part in response to developments at the job-site, and where one student competes against another in an attempt to simulate a real-world scenario.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1100-1105
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• 2022

Denoising, registering, and detecting changes of 3D digital map are generally conducted by skilled technicians, which leads to inefficiency and the intervention of individual judgment. The manual post-processing for analyzing 3D point cloud data of construction sites requires a long time and sufficient resources. This study develops automation technology for analyzing 3D point cloud data for construction sites. Scanned data are automatically denoised, and the denoised data are stored in a specific storage. The stored data set is automatically registrated when the data set to be registrated is prepared. In addition, regions with non-homogeneous densities will be converted into homogeneous data. The change detection function is developed to automatically analyze the degree of terrain change occurred between time series data.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.830-835
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• 2005

4D models help construction planners to develop and evaluate construction plans. However, current analyses using 4D models are mainly visual and limit the quantitative comparison of construction alternatives. This paper explores the usefulness of extracting quantitative information from 4D models to support time-space analyses. We use two 4D models of an industry test case to illustrate how to analyze 4D content quantitatively (i.e., work space areas and distances between concurrent activities). This paper shows how these two types of 4D content can be extracted from 4D models to support 4D-based-analysis and novel presentation of construction planning information. We suggest further research to formalize the content of 4D models to enable comparative quantitative analyses of construction planning alternatives. Formalized 4D content will enable the development of reasoning mechanisms that automate 4D-model-based analyses and provide the information content for informative presentations of construction planning information.

• 한국건설관리학회논문집
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• 제16권2호
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• pp.77-85
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• 2015

현재 건설공사 사후평가시스템 입력과정에서 자료가 오류 및 누락이 발생되는 경우가 많아 데이터의 신뢰성이 떨어지는 경우가 많다. 이에 따라 본 연구에서는 사후평가 결과분석의 신뢰성 확보를 위해 건설공사 사후평가시스템의 입력누락 및 입력오류에 대한 세부적인 분석을 실시하였다. 분석결과, 건설사업 초기 단계일수록 자료의 미입력된 자료의 비중이 높게 나타났다. 그리고 분석된 등록오류로는 참고자료의 부정확, "원" 단위 오류, 입력항목에 대한 이해부족 등으로 나타났다.

• 상하수도학회지
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• 제30권4호
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• pp.401-408
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• 2016

Desalination is getting more attention as an alternative to solve a global water shortage problem in the future. Especially, a desalination technology is being expected as a new growth engine of Korea's overseas plant business besides one of the solutions of domestic water shortage problem. In the past, a thermal evaporation technology was a predominant method in desalination market, but more than 75% of the current market is hold by a membrane-based reverse osmosis technology because of its lower energy consumption rate for desalination. In the future, it is expected to have more energy efficient desalination process. Accordingly, various processes are being developed to further enhance the desalination energy efficiency. One of the promising technologies is a desalination process combined with Pressure Retarded Osmosis (PRO) process. The PRO technology is able to generate energy by using osmotic pressure of seawater or desalination brine. And the other benefits are that it has no emission of $CO_2$ and the limited impact of external environmental factors. However, it is not commercialized yet because a high-performance PRO membrane and module, and a PRO system optimization technology is not sufficiently developed. In this paper, the recent research direction and progress of the SWRO-PRO hybrid desalination was discussed regarding a PRO membrane and module, an energy recovery system, pre-treatment and system optimization technologies, and so on.

• 한국산업융합학회 논문집
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• 제25권4_2호
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• pp.549-563
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• 2022

Continuous global warming is causing ecosystem destruction and direct damage to human life. The main cause of global warming is greenhouse gases, which account for more than 90 % of carbon dioxide. The leaders of each country signed the Paris Agreement at the United Nations Convention on Climate Change (UNFCCC) to reduce greenhouse gas emissions. Currently, the total amount of CO₂ emitted from South Korea is 664.7 million tons as of 2018, ranking eighth in the world. 37 % of South Korea's total CO₂ emissions come from the construction & building field, especially the cement production, which is a construction material. Carbon reduction technologies can be largely divided into four types: carbon reduction (CC), carbon reduction and storage technology (CCS), carbon reduction and utilization technology (CCU), and carbon reduction, storage and utilization technology (CCUS). Overseas, CCUS technology is mainly applied to reduce and store CO₂ emitted from construction and construction field. A technology for permanently storing CO₂ through mineralization by capturing CO₂ and utilizing CO₂ into a cement production process was developed, and this technology is applied to the entire cement industry. However, the development of CCUS technology applicable to the cement industry is still insignificant in South Korea. In this study, carbon dioxide reduction technology and methods for reducing carbon dioxide emitted during the cement manufacturing process, which is the main component of concrete mainly used in civil engineering construction, were investigated. Overseas, it has reached the commercialization stage beyond the demonstration stage as a way to reduce carbon dioxide by vomiting carbonation reactions. Accordingly, if carbon dioxide reduction plan technology generated during cement manufacturing is developed based on domestic technology differentiated from foreign technology, it is expected to contribute one more step to the carbon neutrality policy.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.754-757
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• 2005

Construction firms attempt to improve project performance by adopting technology. However, the advantages gained from technology utilization are still not clear. Lack of information regarding technology benefits has resulted in industry reluctance to implement new technology. Therefore, there are needs for studies that quantify the impacts of technology utilization on project performance. An industry-wide survey was used to collect project data from 70 capital facility projects on the issue of technology usage and project owner satisfaction parameter. This paper reports on integration/automation technology usage in the Taiwanese construction industry and associated impacts on project owner satisfaction. In addition, integration and automation technology findings are presented by project phase. The analyses indicate that projects with owner satisfaction have, on average, higher levels of technology utilization than projects with owner dissatisfaction for all technology usage metrics analyzed.