• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.99-100
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• 2022

As the danger of exposure to the asbestos has been revealed, the importance of demolition asbestos in existing buildings has been raised. Extensive body of study has been conducted to evaluate the risk of demolition asbestos, but there were confined types of variables caused by not reflecting categorical information and limitations in collecting quantitative information. Thus, this study aims to derive a model that predicts the risk in workplace of demolition asbestos by collecting categorical and continuous variables. For this purpose, categorical and continuous variables were collected from asbestos demolition reports, and the risk assessment score was set as the dependent variable. In this study, the influence of each variable was identified using logistic regression, and the risk prediction model methodologies were compared through decision tree regression and artificial neural network. As a result, a conditional risk prediction model was derived to evaluate the risk of demolition asbestos, and this model is expected to be used to ensure the safety of asbestos demolition workers.

• Korean Journal of Construction Engineering and Management
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• v.15 no.2
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• pp.112-121
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• 2014

After IMF bailout crisis in Korea, project financing has been employed as a major funding vehicle for the housing development. In 2008, the recession of housing market due to the global financial crisis had an significant impact on the increasing insolvent site of PF based housing development project, resulting in serious impact to whole economy as a chain effect. In order to resolve this vicious circle of bankruptcy, the major construction companies were urged to take over the insolvent sites and invest to them for normal project exit, and finally play a critical role in normalization of market. Therefore, this study aims to define the core factors for decision making to invest to insolvent site and find out differences among constructors, developers, financial lenders. The results from AHP analysis, the profitability was the most important factor to constructors. Moreover, even though the location merit is little less, through competitive price, we can assure that stable profitability is most important factor to decide to invest in insolvent site. In conclusion, the price is cheap, is highly feasible, if the land secured, major construction company will participate in a PF business investment. These findings were verified by the investment case of major construction company.

• Journal of the Korea Institute of Building Construction
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• v.12 no.1
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• pp.122-132
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• 2012

Establishing a success model of a specific information system is critical to understanding the mechanism of IS success, the various dimensions of IS performance, and the factors and their causal relations in IS success. As one of the key IT applications, the project management information system (PMIS), particularly the web-based PMIS (Web-PMIS), has played a significant role in construction management processes in Korea. However, there have been few research attempts made to construct a Web-PMIS success model. This study primarily aims to propose a Web-PMIS success model based on DeLone and McLean's IS success model, and to discuss whether or not the D&M IS success model can be applied to the construction Web-PMIS. A questionnaire was sent out to Web-PMIS users (construction managers and constructors), and 253 completed questionnaires were received. Through multi-regression analysis, it was confirmed that it is statistically acceptable to apply the D&M IS success model to the Web-PMIS. However, the explanatory power of the model is not sufficient, and some of the model factors are not statistically significant enough. Relying on the statistical analysis results, this study also discusses the development direction for the Web-PMIS success model.

• Journal of the Korea Institute of Building Construction
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• v.20 no.6
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• pp.555-566
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• 2020

Recently, the aging of public facilities in Korea have accelerated, and the existing framework for facility management is shifting toward to facility asset management in terms of performance-based proactive control. Therefore, the operation of public facility involves both safety assurance from the deteriorated facilities and management capabilities for sustainable maintenance in the required valuation and level of service, such as valuation of facility assets, life-cycle management plans, financing, and so on. In this study, the Facility Asset Management Indicator(FAMI) has been developed for public facility asset management, and it provides the quantitative management grade, based on international standards, such as ISO 55000 series and International Infrastructure Management Manual(IIMM). The FMMI includes 10 key areas to apply a diagnosis model into management capabilities, 113 detailed elements, and 5 maturity grades. As the importance of public facility asset management is increasing constantly, this is expected to identify previously the strengths and weaknesses of public facility operating institutions. Eventually, they can obtain the effective ways to improve their own capabilities, minimize the public funds, establish the strategies for innovating the current management structures, and operate stably the facilities in the required performance.

• Journal of the Korea Institute of Building Construction
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• v.16 no.4
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• pp.297-303
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• 2016

Shrinkage Reducing Agent(SRA) was developed in order to control drying shrinkage cracks in concrete, and the use of SRA is increasing since it can control drying shrinkage cracks and improve the quality of concrete structures. Although there are many types of prediction equations of drying shrinkage strain, there is no prediction method which can consider the effect of SRA up to the present. Therefore, it is impossible to predict the tensile stress generated by drying shrinkage of SRA concrete, and to investigate the quantitative serviceability limit state of SRA concrete. In this study, the drying shrinkage of SRA concrete was investigated by experiment and analysis in order to suggest the predictability of drying shrinkage of SRA concrete. As a result, AIJ model, ACI model, GL2000 model showed there was a correlation between the predicted values and the experimental values within the error range of ${\pm}10%$. However, CEB-FIP model and B3 model underestimated the experimental values.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.619-630
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• 2022

The concrete mix design and compressive strength evaluation are used as basic data for the durability of sustainable structures. However, the recent diversification of mixing factors has created difficulties in calculating the correct mixing factor or setting the reference value concrete mixing design. The purpose of this study is to design a predictive model of bidirectional analysis that calculates the mixing elements of ternary concrete using deep learning, one of the artificial intelligence techniques. For the DNN-based predictive model for calculating the concrete mixing factor, performance evaluation and comparison were performed using a total of 8 models with the number of layers and the number of hidden neurons as variables. The combination calculation result was output. As a result of the model's performance evaluation, an average error rate of about 1.423% for the concrete compressive strength factor was achieved. and an average MAPE error of 8.22% for the prediction of the ternary concrete mixing factor was satisfied. Through comparing the performance evaluation for each structure of the DNN model, the DNN5L-2048 model showed the highest performance for all compounding factors. Using the learned DNN model, the prediction of the ternary concrete formulation table with the required compressive strength of 30 and 50 MPa was carried out. The verification process through the expansion of the data set for learning and a comparison between the actual concrete mix table and the DNN model output concrete mix table is necessary.

• Journal of Korean Tunnelling and Underground Space Association
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• v.2 no.3
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• pp.25-36
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• 2000

The purpose of this research work is to propose an analytical method of tunnel design based on reasonable site data. Therefore the proposed design method consists of monitoring data and Modified In Situ Rock Model. Also the Rock Mass Rating for very poor quality rock is very difficult to estimate, the balances between the ratings may no longer gives a reliable basis for the rock mass strength. But in reality Rock Mass Rating is only the property which can be obtained from face mapping records of the exposed tunnel face during construction stage. Evaluation of rock parameters for the actual design prior to tunnel construction should be corrected during tunnelling process in particularly complex ground conditions. This study intends to investigate application of in-situ rock model to soft rock tunnelling (weathered rock) by face mapping results and site measurement data that are obtained at the costraction site of Seoul Subway Tunnel. For the preparation of more reliable ground parameters, the Rock Mass Rating values for the weathered rocks were modified and readjusted in accordance with the measurement data. The modified input parameters obtained by the proposed method are used for the prediction of the tunnel behavior at subsequent construction stages. The results of this study revealed that more reasonable feed back tunnel analysis can be possible as suggested. Ample measurement data would be able to confirm the new proposed technique in this research work.

• Land and Housing Review
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• v.2 no.4
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• pp.397-406
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• 2011

This research aims to develop various infill-systems for practically applying to long-life housing with 100-year durability and flexibility as a strategy for realizing sustainable residential environment. Especially, the developed infill-systems & technologies were concentrated to the mock-up house applied with the standard model of long-life housing, and their in-situ applicability by a phase, experts' consultation, and questionnaire survey were also evaluated. This research was executed to divide by 3 phases. In the First phase infill-systems for a housing unit of $84m^2$ exclusive use area as well as a support of whole structure and infill-systems including dry wall, and windows were constructed, and their in-situ applicability were evaluated. In the Second phase vertical integration of upper and lower housing units of $50m^2$ and $40m^2$ exclusive use area was investigated the first in domestic for 3 housing units of $50m^2$ exclusive use area. In addition, various infill-systems including the horizontal expansion of $50m^2$ and $10m^2$ exclusive use areas were also constructed and evaluated on their in-situ applicability. In the third phase diverse performance tests and field investigation for in-situ verifying of dry Ondol, developed this research, were executed to improve their practicability. Inner dry walls were taken apart, moved and re-constructed for verifying their practicability to investigate 3R-Reduce, Reuse and Recycle-realization too.

• The Transactions of the Korea Information Processing Society
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• v.2 no.2
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• pp.137-147
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• 1995

In the construction project, the design and the construction have been divided strictly. Because the design files of CAD library cannot be used directly in project quantity survey, we depend on manual handling.. It's because there has no interface between the system of the design and that of the construction. In this paper, by using the sizes and quantites of project design, we construct database model for automation of project quantity survey, and analyze the interface among the structure design files stored in design library of CAD system and the information of quantity survey, build a system which can survey the project quantity efficiently and evalulate the performance of this system.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.38-49
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• 2009

In public project market, design-build projects have been increased because of market trend change which enables technical competition. In this condition, its importance is also getting important. Generally, life cycle of design-build project consists of planning, preliminary design, procurement, contract, detail design, start of construction, construction, end of construction, and evaluation. From contractor's viewpoint, it has problems such as difficulties in project management and information sharing because of frequent change of charged division. To solve these problems, it is desirable to change from function-based management system to process-based management system. The purpose of this study is to develop management process model for design-build project by progress phases. This study analyzed main conflicts and decision making factors of each stage in design-build projects, then systemized management subjects' responsibilities and management points' change. And also this study defined the key information that is the key point by project characteristics and progress phases. Based on this analysis, this study did business process modeling from planning stage to construction design check stage. At last, we proposed the way to manage business process by design-build project progress.