• Journal of the Korean Geotechnical Society
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• v.16 no.6
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• pp.127-139
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• 2000

In the study, an expert system was developed to predict the safety of tunnel and select proper tunnel reinforcement system using fuzzy quantification theory and fuzzy inference rule based on tunnel information database, For this development, many tunnelling sites were investigated and the applied countermeasures were studied after building tunnel database. There will be benefit for the deciding tunnel reinforcement method in the case of poor ground condition. The expert system developed in the study has two main parts, pre-module and post-module. Pre-module is used to decide input items of tunnel information based on the tunnel face mapping information which can be easily obtained in in-situ site. Then, using fuzzy quantification theory II, fuzzy membership function is composed and tunnel safety level is inferred through this membership function. Post-module is used to infer the applicability of each reinforcement methods according to the face level. The result of the predicted reinforcement system level was similar to measured ones. In-situ data were obtained in three tunnel sites including subway tunnel under Han River. Therefore, this system will be helpful to make the mose of in-situ data available and suggest proper applicability of tunnel reinforcement system to development more resonable tunnel support method without dependance of some experienced experts opinions.

• Korean Journal of Computational Design and Engineering
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• v.19 no.1
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• pp.80-90
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• 2014

In architecture projects, BIM library has widely been using for prefabrication of products and design process. However, since the shape of structures is different by each project in civil engineering projects and a shape representation system is complicated, it is not easy to develop a standardized BIM library. To solve these issues, this study develops BIM library based on standardized 2D shop drawings for civil structures. The standardized shop drawings, which are the targets of the BIM library model, should be first selected. Besides, in order to define modeling scope with the level of general and shop drawings for each structure, LOD(Level of Detail) and breakdown structure are determined, and development methods of families of 3D object type including 2D profile and rebar through commercial software are established. With these, properties of BIM library are configured, and a utilization model of the BIM libraries is constructed for 3D modeling and a simulation using the BIM library. Therefore, this study can identify properties that are necessary when IFC schema is configured for civil engineering projects. For future, it is expected that easiness of BIM design for the civil engineering projects and generation, management, and analysis system of BIM library for road projects will be secured.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.581-590
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• 2008

A SWP method is a revolutionary dewatering method. The conventional dewatering method, deep-well method, had ever occurred a civil appeal caused by the well depletion in compliance with the reduction of the groundwater level over a wider area considerably by the deep-well pumping from homogeneous sand-layer ground for a dry-work, while pump groung excavation working in Sendai city, Japan 10 years ago. it'd developed with the problematic proposal to find the new method which can lower the groundwater level only within the sheet pile without any reduction of groundwater outside of the sheet pile and until currently steady improvement came. It's been confirmed with plenty of executional results that there was almost no decreasing of water-level from surroundings, over so many construction-sites including vertical shafts which completely does not enter into non-water permeable layer and pumping ground etc. The SWP method in this time has been introducing initially and carried into a the execution tentatively at a construction-site and made a various result get through the execution.

• Journal of the Korea Institute of Building Construction
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• v.8 no.5
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• pp.35-42
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• 2008

In this study, a sample was fabricated according to the recycled aggregate replacement level(0%, 30%, 60%), and the steel fiber mixing status in order to use recycled aggregate as a concrete alternative coarse aggregate, and then the materials and structural characteristics of recycled aggregate and steel fiber which impacted the reinforced concrete were analyzed. A conclusion was derived as follows. After considering the results of various material experiments and mock-up test, when a flexural strength and a ductility factor is increased and the replacement level is increased through mixing the steel fiber with the recycled aggregate concrete, the ductility and flexural strength reduction seems to be inhibited by adding the steel fiber. Also, it is indicated that the recycled aggregate has almost-similar compressive strength, tensile strength flexural strength and ductility capacity to the concrete which using the general gone even though the steel fiber is used and the replacement level is increased to 30%. Accordingly, the reinforced concrete frame using the steel fiber mixture and recycled aggregate seems to apply to the actual structure.

• Earthquakes and Structures
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• v.13 no.6
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• pp.531-538
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• 2017

In this paper, the seismic behavior of BRBF structures is studied and compared with special concentric braced frames (SCBF). To this purpose, three BRBF and three SCBF structures with 3, 5 and 10 stories are designed based on AISC360-5 and modelled using OpenSees. These structures are loaded in accordance with ASCE/SEI 7-10. Incremental nonlinear dynamic analysis (IDA) are performed on these structures for 28 different accelerograms and the median IDA curves are used to compare seismic capacity of these two systems. Results obtained, indicates that BRBF systems provide higher capacity for the target performance level in comparison with SCBF systems. And structures with high altitude (in this study, 5 and 10 stories) with the possibility of exceeding the collapse prevention performance level, further than lower altitude (here 3 floors) structures.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.353-358
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• 2020

Recent efforts to develop a common standard for nuclear power plants (NPPs) with the aim of creating (1) a digital environment for a better understanding of NPPs life-cycle management aspect and (2) engineering data interoperability by using existing standards among different unspecified project participants (e.g., owners/operators, engineers, contractors, equipment suppliers) during plants' life cycle process (EPC, O&M, and decommissioning). In order to meet this goal, there is a need for formulating a standardized high-level physical breakdown structure (PBS) for NPPs project management office (PMO). However, high-level PBS must be comprehensive enough and able to represent the different types of plants and the new trends of technologies in the industry. This has triggered the need for addressing the issues of the recent operational NPPs and future technologies' ramification for evaluating the changes in the NPPs physical components in terms of structure, system, and component (SSC) configuration. In this context, this ongoing study examines the recent conventional NPPs and technological trends in the development of future NPPs facilities. New reactor models regarding the overlap of variant issues of nuclear technology were explored. Finally, issues on PBS for project management are explored by the examination of the configuration of NPPs primary system. The primary systems' configuration of different reactor models is assessed in order to clarify the need for analyzing the new trends in nuclear technology and to formulate a common high-level PBS. Findings and implications are discussed for further studies.

• Korean Journal of Construction Engineering and Management
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• v.9 no.1
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• pp.155-166
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• 2008

The Equipment Expenses section of the Poom-Saem that is used for Construction Cost Estimation of public sectors in Korea has been rarely revised, and so does not reflect changes of Construction Equipment technology and construction methods, since it was established based on data from Japan and the U.S in the early 1960s. In order to make reasonable estimation of equipment expenses for a bulldozer and a loader, the domestic and overseas documentary records were investigated. Further, 16 construction sites were visited, and 20 Construction Equipment leasing services were surveyed. The optimum level of each item which consists of equipment costs was revealed based on the result of the analysis on the figures of equipment costs calculation from the Poom-Saem and the collected data. The research will be the foundation for applying the rapid development of Construction Equipment and technology to the appropriate cost estimations and the ground work of related studies.

• Korean Journal of Construction Engineering and Management
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• v.13 no.6
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• pp.45-53
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• 2012

Recently, with achieved US$ 500 Billion international cumulative construction order, the Korean government presented overseas construction industry visions for international orders of US$ 100 Billion and entering the top five countries in global construction market. Also, Korean companies are developing strategies for expansion of international markets. However, ODA loan projects are low risk for the Korea Construction companies trying to advance their overseas business. This study provides data-based advice on securing competence for Korean construction companies entering the global market through the ODA loan projects. To analysis construction firm's competitiveness for ODA loan project, FGD was utilized and BSA model was applied to the valuable analysis. Competencies highly assessed were construction quality control, relationship building through high-level diplomatic activities, and project management. Competencies requiring urgent improvement were handling risks of local countries, financing projects, and developing know-how within participating companies.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.45-52
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• 2020

Construction industry has a relatively higher industrial accident rate than other domestic industries. Thus, to reduce the accident rate, researches on the methodology of worker's safety education combined with new technologies like IT technology have increased. In the light of workers' safety information provision, this study develops a VR(Virtual Reality)-based construction site using the BIM(Building Information Modeling) data. The target structures and geographical features are included in the VR-based construction site where the construction machinery model and worker model are also created using a game engine. For highly effective provision of safety information, video clips with suitable captions corresponding to working processes were made with proper screen directing. They should be appropriately connected to correct worker's operations to improve the work commitment level, sense of reality and inducement of interest. From this scenario, the 3D VR-based construction site, which can be experienced through a VR equipment, was created and in the same platform, the safety information was provided by the video clip combined with the suitable captions. Although the real construction site involves various requirements depending on field situation and the expertness and experience of workers are not consistent, the developed safety information provision based on the VR construction site is expected to effectively reduce the incomplete factors leading to construction accidents by improving the worker's perception of workplace safety.

• Journal of Environmental Health Sciences
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• v.41 no.3
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• pp.163-170
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• 2015

Objectives: This study evaluated the effect of construction on ambient PM-10 in the surrounding area. Methods: Four study sites were selected from total AAQMN 11 points in Daegu city. All the four study sites were located near under or completed construction. Mean monthly PM-10 in 2007 to 2013 were analyzed. Results: Impact of residential construction on PM-10 was more obvious than industrial area. PM-10 was positively associated with number of construction near the study site. When there were 2 or 3 construction sites, PM-10 level was higher. Wind direction and the surrounding terrain affected PM-10. Conclusions: Construction has a strong influence on PM-10 in the surrounding Area. Reduce PM-10 there is the need for special construction site management. Proper management is required to minimize fugitive dust in construction sites.