• International conference on construction engineering and project management
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• 2015.10a
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• pp.310-312
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• 2015

Small Unmanned Aerial Systems (SUAS) have been gaining a special attention in the U.S. recently because it is capable of getting aerial footages conveniently and cost effectively, but also because of its potential threat to the safety of our society. Regarding the benefits, one can easily find successful cases. For example, remote controlled or pre-programmed unmanned aircraft help ranch owners monitor their livestocks or crop harvesting status cost-effectively without having to hire human pilots. The professionals in the construction industry also acknowledge the benefits they could gain from using SUAS. Some firms already use a small unmanned aircraft for monitoring their construction activities, which may help project managers figure out construction progress, resolve disputes in real time, and make proactive decisions for quality control. However, there are many technical challenges that my hinder the use of small unmanned aircraft in the construction industry. This paper explores opportunities and challenges in using unmanned aircraft to monitor concrete cracks on the surface of containment building in the nuclear power plant.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.2
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• pp.113-121
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• 2009

This research is for analyzing current situations related to u-City world market preoccupation and to suggest effective national strategies based on the analyzing result. It is predicted that u-City world market will grow fast and it is time to prepare effective strategies for u-City world market preoccupation. Therefore, this research reviewed current policies related to u-City world market, conducted a SWOT analysis based on reviewing results, and suggested four different strategies like followings: (1) grasping continuous current situations, (2) connection within/between internal and international network, (3) international development cooperation, and (4) core technology development. This research is conducted based on literature reviews and consultation with experts. And the research result can be used for the u-City comprehensive plan.

• Journal of the Korean Solar Energy Society
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• v.33 no.6
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• pp.54-61
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• 2013

This is study on the glazing performance of the apartment house to predict energy saving rate when the early design stage by calculating heating load. there are various factors of the window type in apartment building to save energy such as window's U-value, SC or SHGC, window wall ration, frame factor, sunshade coefficient and so on. In this study, we analyzed the heating load focused on the U-value, SC and window wall ration using variable heating degree days method for a small and middle size units $59m^2$, $84m^2$, respectively. Each cases were calculated heating load of the real models compared to standard model to predict energy saving rate. From those cases it was drew the conclusion that were window's U-value, SC and window wall ration for the small and middle size units to expect 10% energy saving rate at least.

• Journal of Information Processing Systems
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• v.18 no.2
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• pp.223-234
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• 2022

The evaluation of the print quality of 3D printing has traditionally relied on manual work using dimensional measurements. However, the dimensional measurement method has an error value that depends on the person who measures it. Therefore, we propose the design of a new print quality measurement method that can be automatically measured using the field-of-view (FOV) model and the intersection over union (IoU) technique. First, the height information of the modeling is acquired from a camera; the output is measured by a sensor; and the images of the top and isometric views are acquired from the FOV model. The height information calculates the height ratio by calculating the percentage of modeling and output, and compares the 2D contour of the object on the image using the FOV model. The contour of the object is obtained from the image for 2D contour comparison and the IoU is calculated by comparing the areas of the contour regions. The accuracy of the automated measurement technique for determining, which derives the print quality value was calculated by averaging the IoU value corrected by the measurement error and the height ratio value.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.492-499
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• 2022

A large number of employees shifted to Work from home (WFH) due to the COVID-19 pandemic, including the construction workforce. The changes in workload and productivity due to WFH impact the work performance and economic outputs of companies. However, there are mixed results about the impacts of WFH on workload and productivity. In particular, limited studies focused on specific types of work of different occupations in the construction workforce. This study aims to explore the impacts of WFH on workload and productivity considering different types of work for the construction workforce in the U.S. After identifying three main occupations and five types of work, an online survey (N = 69) was distributed. Descriptive analysis showed that participants had less workload (0.82 hours/week) and lower productivity (9.69%) during WFH. Three occupations had varied changes due to the different types of work. Analysis of Variance (ANOVA) indicated that there was no significant difference in workload, while productivity was decreased during WFH. In particular, the productivity of project-related work and communication and documentation decreased significantly. Overall, participants finished 2.85% less workload per week during WFH. The findings provide an insight into WFH in the construction workforce, which improves future remote or hybrid work arrangements in the construction industry.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.115-133
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• 2010

For assessment of U-Eco City technologies, more concrete definition of those technologies are required. However, almost researches defined technologies as conceptually and even cannot include all of them. In this sense, the purpose of this study is to deduct assessing items for specifying applying priority of U-Eco City technologies. We performed the research by 3 steps. Firstly, we deduct assessing items of the technologies by researching their advance process. After then, we compensate the defect of those items through documentary research and made a periodic table about core technologies that can be useful for deducting long-term items. The assessing items what are deducted as a result of this study can be applied to the selection of technology, and will be useful to construct more objective and systematized U-Eco City. Furthermore, if assessment frame about technologies and services is developed from this research, it gives to us probability that standardized process of U-Eco City construction can be established.

• The KIPS Transactions:PartA
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• v.14A no.3 s.107
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• pp.159-166
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• 2007

A arrival of u-teaming paradigm requires many u-teaming system and model that is varied and support to distance education, Accordingly, the distance education system in u-learning environment has attracted a fair amount of critical attention. However there remain many questions, as yet unresolved, such as it is difficult to maintain interaction between tutor and learner, the construction of system is a great expense to them, a tutor, who manages the system, lacks technologic background, in most current distance education system. To solve these problem, some preliminary observations have to be made first: to keep teaming process in situation that it is unconnected with tutor, to construct the system economically, and to make to be easy-to-use. Therefore, in this paper, we develop the 'Intelligent U-Learning System using Cyber Tutor', which includes the conception of u-learning such as mobility, immanency, supports to keep learning without real tutor by cyber tutor, and removes technological and economical costs, verify the validity.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.54-60
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• 1998

PSC box bridges by MSS construction method in high-speed railway may not be cast in place at one step. Web and bottom flange(U member) in the cross section are cast in place at first, then top flange will be cast in place later with some time lag. In this section, stress distributions of U member and top flange are different with those in generally complete cast in place cross section. In the composite section composed of two different aged members, the redistribution of stresses takes place. This results from time-dependent strain characteristics of concrete and the effects of forces applied at the various stages. For comparison in the present paper, two models, one with the composite cross section and the other with generally complete cast in place cross section, are analyzed. The longitudinal stress differences of two models on considering construction stages are compared. As the analysis results show the considerable differences in the stresses of cross section between two models, the composition of cross section is considered for rational design of PSC box girder bridge.

• Journal of the Korea Society of Computer and Information
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• v.23 no.12
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• pp.145-151
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• 2018

While commercialization of IoT technologies in the safety management sector is being promoted in terms of industrial safety of large indoor businesses, implementing a system for risk management of small outdoor work sites with frequent site movements is not actively implemented. In this paper, we propose an efficient dynamic workload balancing strategy which combined low-power, wide-bandwidth (LPWA) communication and low-power Bluetooth (BLE) communication technologies to support customized risk management alarm systems for each individual (driver/operator/manager). This study was designed to enable long-term low-power collection and transmission of traffic information in outdoor environment, as well as to implement an integrated real-time safety management system that notifies a whole field worker who does not carry a separate smart device in advance. Performance assessments of the system, including risk alerts to drivers and workers via Bluetooth communication, the speed at which critical text messages are received, and the operation of warning/lighting lamps are all well suited to field application.

• Journal of the Korea Safety Management & Science
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• v.24 no.3
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• pp.39-46
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• 2022

This study has found the socio-economic factors that affect occupational accidents and measured the influence quantitatively. We built the panel data of 4 countries (Japan, Germany, the U.S., and the U.K.) and the analysis model counted on the fixed effect model to reflect the countries' differences. The fatal occupational injury rates in the analyzed countries had a statistically significant relationship with the level of per capita GDP, the proportion of the construction industry, the rate of male workers, annual average working hours, the rate of workers in manufacturing and construction industries, etc. The annual average working hours have a positive correlation with the fatal occupational injury rate. To reduce occupational accidents effectively, we should be monitoring and researching various factors that can affect the occurrence of occupational accidents such as worker characteristics, changing industrial structure, and changes in working hours.