• International conference on construction engineering and project management
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• 2015.10a
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• pp.37-38
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• 2015

A number of documents containing important and useful knowledge have been generated over time in the construction industry. Such text-based knowledge plays an important role in the construction industry for decision-making and business strategy development by being used as best practice for upcoming projects, delivering lessons learned for better risk management and project control. Thus, practical and usable knowledge creation from construction documents is necessary to improve business efficiency. This study proposes a knowledge creating system from construction documents using text mining and the design comprises three main steps - text mining preprocessing, weight calculation of each term, and visualization. A system prototype was developed as a pilot study of the system design. This study is significant because it validates a knowledge creating system design based on text mining and visualization functionality through the developed system prototype. Automated visualization was found to significantly reduce unnecessary time consumption and energy for processing existing data and reading a range of documents to get to their core, and helped the system to provide an insight into the construction industry.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.60-62
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• 2015

The BIM-based architectural design can be the optimal method to improve all sectors of construction industry and reduce environmental impact through digital technologies. The goals and effects of BIM needs in LH to be newly planned based on the experience of public sectors, which will ultimately contribute to maximization of effectiveness. Referring the excellent case in the UK, the current BIM standards according to maturity level 2 handle the contents related to modeling, collaborative data production, data management and assure BIM data have to be used from building construction to operation and maintenance of buildings. Therefore the strategy for the utilization of BIM for construction projects in LH consisted of three steps; first, the minimization of defects via BIM: second, strengthening the competitiveness of construction and asset management: third, upgrading the system of building production and maintenance control. After this trial, LH can accumulate know-how for building construction to be more costeffective and competitive.

• Journal of Ocean Engineering and Technology
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• v.10 no.4
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• pp.149-159
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• 1996

Multipurpose development of the coast and ocean can be considered as multifunction construction combining the functions of coastal protection, waterfront amenity and creation or rehabilitation of habitats. Multfunction development of coastal and ocean spaces can be accomplished by applying the ecosystem control structure of artificial habitats which will cultivate fishing ground with ecological harmony to the coastal protection system. To evaluate the applicability of ecosystem control structures as as fundamental coastal protection structure, wave control function of the structure is studied by numerical and physical analyses. Dimensional analysis and hydraulic experiment point out the importance of width and crest depth of ecosystem control structure, construction water depth and wave steepness. Wave control efficiency is estimated by the attenuation coefficient $(K_H)$ according to wave steepness $(H_0/L_0)$, relative constructed water depth $(h_i/H_0)$, relative berm width $(B/L_0)$ and relative crest depth $(h_B/H_0)$ of eosystem control structure. Empirical fomulas are suggested based on the results of model test by applying the multiple model based on this experimental results and numerical wave shoaling-dissipation-breaking model appears to be valid for the analysis of wave transformation around ecosystem control structure in the coastal waters.

• Advances in concrete construction
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• v.14 no.1
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• pp.57-70
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• 2022

The spiral case concrete (SCC) used in the underground powerhouse of large hydropower stations is complex, difficult to pour, and has high requirements for temperature control and crack prevention. In this study, based on the closed-loop control theory of "multi-source sensing, real analysis, and intelligent control", a new intelligent cooling control system (ICCS) suitable for the SCC is developed and is further applied to the Wudongde large-scale underground powerhouse. By employing the site monitoring data, numerical simulation, and field investigation, the temperature control quality of the SCC is evaluated. The results show that the target temperature control curve can be accurately tracked, and the temperature control indicators such as the maximum temperature can meet the design requirements by adopting the ICCS. Moreover, the numerical results and site investigation indicate that a safety factor of the spiral case structure was sure, and no cracking was found in the concrete blocks, by which the effectiveness of the system for improving the quality of temperature control of the SCC is verified. Finally, an intelligent cooling control procedure suitable for the SCC is proposed, which can provide a reference for improving the design and construction level for similar projects.

• Safety and Health at Work
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• v.14 no.4
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• pp.406-414
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• 2023

Background: This study examined age-group differences in the rate, severity, and cost of injuries among construction workers to support evidence-based worker safety and health interventions in the construction industry. Methods: Ohio workers' compensation claims for construction workers were used to estimate claim rates and costs by age group. We analyzed claims data auto-coded into five event/exposure categories: transportation incidents; slips, trips, and falls (STFs); exposure to harmful substances and environments; contact with objects and equipment (COB); overexertion and bodily reaction. American Community Survey data were used to determine the percentage of workers in each age group. Results: From 2007-2017, among 72,416 accepted injury claims for ~166,000 construction full-time equivalent (FTE) per year, nearly half were caused by COB, followed by STFs (20%) and overexertion (20%). Claim rates related to COB and exposure to harmful substances and environments were highest among those 18-24 years old, with claim rates of 313.5 and 25.9 per 10,000 FTE, respectively. STFs increased with age, with the highest claim rates for those 55-64 years old (94.2 claims per 10,000 FTE). Overexertion claim rates increased and then declined with age, with the highest claim rate for those 35-44 years old (87.3 per 10,000 FTE). While younger workers had higher injury rates, older workers had higher proportions of lost-time claims and higher costs per claim. The total cost per FTE was highest for those 45-54 years old ($1,122 per FTE). Conclusion: The variation in rates of injury types by age suggests that age-specific prevention strategies may be useful.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.1-9
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• 2015

PURPOSES : The objective of this study is to propose a quality control and quality assurance method for use during asphalt pavement construction using non-destructive methods, such as ground penetrating radar (GPR) and an infrared (IR) camera. METHODS : A 1.0 GHz air-coupled GPR system was used to measure the thickness and in situ density of asphalt concrete overlay during the placement and compaction of the asphalt layer in two test construction sections. The in situ density of the asphalt layer was estimated based on the dielectric constant of the asphalt concrete, which was measured as the ratio of the amplitude of the surface reflection of the asphalt mat to that of a metal plate. In addition, an IR camera was used to monitor the surface temperature of the asphalt mat to ensure its uniformity, for both conventional asphalt concrete and fiber-reinforced asphalt (FRA) concrete. RESULTS : From the GPR test, the measured in situ air void of the asphalt concrete overlay gradually decreased from 12.6% at placement to 8.1% after five roller passes for conventional asphalt concrete, and from 10.7% to 5.9% for the FRA concrete. The thickness of the asphalt concrete overlay was reduced from 7.0 cm to 6.0 cm for the conventional material, and from 9.2 cm to 6.4 cm for the FRA concrete. From the IR camera measurements, the temperature differences in the asphalt mat ranged from $10^{\circ}C$ to $30^{\circ}C$ in the two test sections. CONCLUSIONS : During asphalt concrete construction, GPR and IR tests can be applicable for monitoring the changes in in situ density, thickness, and temperature differences of the overlay, which are the most important factors for quality control. For easier and more reliable quality control of asphalt overlay construction, it is better to use the thickness measurement from the GPR.

• Journal of the Korea Institute of Building Construction
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• v.10 no.3
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• pp.137-144
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• 2010

As mega-sized and complex building construction projects are on the rise, the importance of project scheduling and control is being highlighted. Project scheduling and control techniques are not yet widely used in Korea, but interest in these has progressively been increasing. Until now, most research projects have mainly focused on scheduling issues, but project progress management is of equal importance. In this research, the current state of project progress management in Korea is analyzed, and ways for improvement are suggested. We begin by analyzing previous research and practical studies in this field, and then survey experts about the current state of project progress management. This study suggests the Building Information Modeling (BIM)base project progress management method for quantitative and qualitative project progress analysis. Currently, BIM is applied to design, construction and maintenance for construction projects. BIM can also contribute to improving accuracy and understanding of the current project situation.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.145-153
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• 2000

This paper discusses the dynamic modeling and robust control development for a differentially steered mobile robot subject to wheel slip according to high load. Consideration of wheel slip is crucial for high load applications such as construction automation tasks because wheel slip acts as a severe disturbance to the system. It is shown that the uncertainty terms due to the wheel slip satisfy the matching condition for the sliding mode control design. From the full dynamic model of the mobile robot, a reduced ideal model is extracted to facilitate the control design. The sliding mode control method ensures the dynamic tracking performance for such a mobile robot. Numerical simulation shows the promise of the developed algorithm.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.184-185
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• 2017

In this study, the performance of low-priced ceramic panels developed to improve the poor interior residential environment of the underprivileged was evaluated by comparing them with the performance of I Company (Japan)'s Eco karat, a representative humidity control panel. Experimental results showed that the humidity control performance of the Ceramic panel was 53.33g/㎡, which was about 54% less effective than 98.88g/m2 of the Ecokarat. As a result, it is believed that the need to improve the quality of the Ceramic panels.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.97-98
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• 2017

These days the buildings are getting higher, bigger, and in a deep. According to that, it was the Large-Scale casuality by smoke from Daeyeongak Hotel fire in 1971 to Uijeongbu apartment fire in 2015, and the law of smoke control has consistently changed. but the analysis for improving the law isn't working. Therefore on this study, it conducts the analysis of historical comparative about smoke control and it will present the basic data for improving the law of smoke control and in-depth analysis.