• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.162-171
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• 2004

Crack sealing is a maintenance procedure that is commonly used to reduce pavement degradation. If cracks in pavements are not sealed, surface water penetration can reduce the strength of the sub-base layers, which can result in increased deflections of the pavement. Reduced strength of the sub-base also accelerates the deterioration of the surface, due to development of greater cracking and potholes. Crack sealing is performed to reduce water and debris penetration, thereby helping to maintain pavement structural capacity and limiting future degradation. The process of sealing cracks in pavements is however dangerous, costly, and labor-intensive operation. Labor turnover and training are increasing problems related to crack sealing crews, and as traffic volumes increase. Automating crack sealing can reduce labor and road user costs, improve work quality, and decrease worker exposure to roadway hazards. The main objective of this research is to develop an automated system for sealing cracks in pavement. Extension of the algorithms and tools presented in this research is also recommended for future study.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.12-21
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• 2015

Reconstruction and remodeling have been introduced as a part of renewal (redevelopment) projects for old apartments built after the mid-1970's and government policies for revitalizing each project has been changed continually. However, the frequent changes of the policies have caused conflicts among business entities in selecting business methods. The conflicts from their early stages have made serious problems in the entire business process. Therefore, this study deduced factors of business selection by applying comparison analysis between the two business projects on how certain factors have an influence on selecting reconstruction and remodeling business projects. Based on the analysis, four categories and 26 factors were finally selected. After then, the priority of each selection factor was deduced through the AHP method used for analysis of relative importance and impact values regarding to the business selection. It is expected to resolve conflicts among owners and select rational directions for reconstruction and remodeling business, based on the conclusion through analysis of influence on selection factors.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.67-75
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• 2009

While the trend of all industries recently lies in combination, construction industry is much interested in enhancing efficiency and competitiveness in the aspect of site control by adopting RFID. Though RFID has been applied to diverse areas thus far, it cannot be easily applied to construction industry due to diverse physical, chemical and use-environmental properties of construction materials. Furthermore, it is rarely applied to the site because of many problems in its application. It is required to prepare RFID code issuance and system that can systematically control the code as well as to research the standardization of frequency, specification, protocol, package method, recognition method, etc in order to apply RFID to construction industry. In this research, RFID code issuance and management program are proposed as a part of program research to apply RFID. Furthermore, the restricted matters of existing RFID tag are drawn to produce pilot product of RFID tag that can solve it so as to perform site application test. According to the experiment, effective recognition distance varies depending on material/environmental property and control efficiency changes depending on attachment method and application method. Thus, preparing diverse restrictive factors and solutions by systematically analyzing control method(medium, process) of current architecture materials and applying it to construction site can be the way to successfully apply RFID.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.123-134
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• 2009

Since 1970s, urethane waterproofing method is broadly used in rooftops, underground spaces, and sports stadium for its outstanding ultraviolet blockage, watertightness, and elasticity. However, development of slippage-resistance and endurance, improvement of function considering convenience and visually pleasing of users, urethane waterproofing method is necessary, since rooftops and underground spaces have slippage and external force risks. Therefore, many improved waterproofing methods are being developed and, recently, embo-thane waterproofing method, which applies embo-spray coating system, has been developed. This paper explains exposure, nonexposure, and floor-material of embo-thane waterproofing method, and then perform experimental study for comparison with urethane waterproofing method about tensile strength, coefficient of expansion, performance of bond, anti-abrasion, and slippage-resistance. In addition, the performance index was presented for the superiority of embo-thane waterproofing method compared to urethane by setting up evaluation criteria considering not only physical performance but also design side of embo-thane waterproofing method, and Value Analysis applying AHP. Also for an assessment considering uncertain result, Monte Carlo Simulation Method was used to operate reliability analysis through statistic approach method.

• Korean Journal of Construction Engineering and Management
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• v.8 no.4
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• pp.110-118
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• 2007

For deciding the owner's budget of the building construction in the predesign stage, the probabilistic methodologies for estimating the cost are often studied, however these parameter-based conceptual estimating methodology has limitation of applying it to the practical business because it hardly can link the design decision-making and the cost estimating and control. Besides if the result of detail estimating after detail design is over the budget, locally and arbitrarily control the level of interior design and fix the design. This research proposed the prototype-based cost estimating model for building interior construction which leads to estimate the interior cost easily linking with design decision-making and supports to evaluate the design alternatives in the schematic design and the design development stage for office buildings. The model divides the building on the design process by Element Breakdown Structure and presents the design alternative by selecting the elements of each room from the database accumulated the historical office buildings' prototypes and estimates the cost. The 2 case studies presented to validate the effectiveness of as the linking tool integrating the design and construction data and applicability to the practical design on the presented prototype-based model.

• Korean Journal of Construction Engineering and Management
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• v.8 no.4
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• pp.128-136
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• 2007

As the international-level concern has been focused on the environmental sustainability in recent years, many researches emphasized the needs for methods and techniques that would facilitate sustainability assessment at the various project level interfaces. As part of methods and techniques to facilitate sustainability assessment, this paper provides 'Computerized Waste Management Performance Evaluation Tool' for the purpose of assessing the level of management system in dealing with the onsite construction wastes. This tool applies twenty-three waste management performance factors for the purpose of evaluating the level of waste management performance by scoring those factors which were identified in the previous research. These twenty-three factors are classified into four categories: manpower, material, method, and management based on their characteristics. In order to quantitatively evaluate the effectiveness of waste management performance, the levels of actions executed in a site by each waste management performance factor were identified and their weight were analyzed throughout the expert interview and survey. Furthermore, an excel-based computerized tool was developed in order to facilitate the evaluation process. If this tool can be developed in more detail and be used as the method to control waste management at a project level for the future, it is expected that this tool can play an important role in the body of knowledge of environmental management in construction industry.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.38-46
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• 2014

The Global's top five Design Firms selected from BauNetz a German architectural magazine in 2007 designed free form building design which was 25% of the overall design by 2006-2010. Free form building is a landmark of the city and the country so its social and economic impacts are very large. In case of Korea, free form buildings such as Tribowl in Incheon, KINTEX Exhibition hall 2 and Dongdaemun Design Plaza have increased. However, those the increase in design trends and, the needs due to the lack of free form building design and construction management experience, free form building projects can't be expected to profitability and have a number of problems after completion. Especially, there are many excessive quality problems and the rising cost due to design changes frequently and lack of experience and data. Thus an initial plan regardless of considering of free form building's characteristics can be a huge risk because of the difference with the plan and actual projects, yet there aren't free form building project's performance data and case studies related to productivity. In this study, through selection of low-construction productivity works and an analysis of the work process and productivity data, hope to propose an actual field productivity of free form building and the ways to improve productivity.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.68-76
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• 2014

The accurate estimation of construction cost is important to a successful development in construction projects. In previous studies, the construction cost are estimated by statistical methods. Among the statistical methods, support vector regression (SVR) has attracted a lot of attentions because of the generalization ability in the field of cost estimation. However, despite the simplicity of the parameter to be adjusted, it is not easy to find optimal parameters. Therefore, to build an effective SVR model, SVR's parameters must be set properly without additional data handling loads. So this study proposes a novel approach, known as genetic algorithm (GA), which searches SVR's optimal parameters, then adopt the parameters to the SVR model for estimating cost in the early stage of apartment housing projects. The aim of this study is to propose a GA-SVR model and examine the feasibility in cost estimation by comparing with multiple regression analysis (MRA). The experimental results demonstrate the estimating performance based on the percentage of estimations within 25% and find it can effectively do the accurate estimation without through the trial and error process.

• Korean Journal of Construction Engineering and Management
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• v.15 no.4
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• pp.150-158
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• 2014

A bunch of asphalt roads have been damaged frequently in relation to the rapid climate change. To solve and prevent this type of problems, many nationalities in the world have performed various researches. In this regard, the objective of this study is to develop prediction model as to the number of potholes occurred in seoul. At the same time, we have utilized empirical and statistical approaches in order for us to identify factors which is affecting the actual occurrence. The predictive model was determinded by using BHS (Basic Harmony Search) algorithm. Prediction was based on the weather and traffic data as well as data occurrence data of porthole. To assess the influences which are PAR(Pitch Adjusting Rate) and HMCR(Harmony Memory Considering Rate), we determined suitability by changing the values. In the process of the determining a predictive model, the predictive model composed Training data (2011, 2012 and 2013yrs data). To determine the suitability of the model, we have utilized Testing Set (2009 and 2010 yrs data). The suitability of the basic prediction model has been from RMSE(Root Mean Squared Error), MAE(Mean Absolute Error) and Coefficient of determination.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.1019-1022
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• 2007

Recent construction projects are becoming larger, more complex and higher rising. Accordingly, necessity of the VE is emphasized as more suitable for expense, function and quality. However, the VE is not functional because of difficulty of application process or of the methods in use in the field of construction. One of the alternative is to introduce the incentive system to activate the VE in the field of construction. By using the incentive system, employers can reduce the relevant project's prime cost and builders will maximize profit creation. In domestic case, they presented the systematic support policy 'Technical development compensation system' which is similar to the 1992 American's VE incentive system about builder's technical development effort but the result was not positive. This study investigates both domestic and other country's construction VE incentive system and reported problems in the construction VE incentive system to executives and construction VE experts. From this survey, conclusions were drawn about problems in the domestic construction VE incentive system's similarity system: 'Insufficiency of the construction VE incentive's article and standards', 'Insufficiency of the appraiser of the construction VE and of the full charge department' etc. I had interviews with the experts of the construction VE which were based on the above-mentioned problems and then presented 'Improvement of the construction VE's incentive system relevant law and system', 'Construction VE experts and construction formation' etc. for ways to bring acceptance of the construction VE in the construction industry.