• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.213-214
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• 2023

Positioning information of workers is important for safety management at construction sites. Among the various indoor positioning technologies, geomagnetic fields-based technology is more economical and has less error than other technologies. However, there is a problem that the installation and dismantling of materials such as formwork at construction sites can cause degradation in positioning performance. Therefore, in this study, the distortion of the geomagnetic field near euro-form was quantitatively measured and the application method of geomagnetic field-based indoor positioning technology on formwork stage was presented. The results showed that the distortion occurred within 10cm of the wall and column form, but positioning accuracy could be affected up to 60cm from the form due to the characteristic of geomagnetic field-collecting technology. Therefore, applying this technology to the formwork stage requires complementary measures, such as using other positioning techniques up to 60 cm near the formwork, or excluding distorted area when positioning. It is expected that this study can contribute to the efficient safety management of workers by suggesting ways to prevent an increase in positioning error when applying geomagnetic field sequence-based indoor positioning technology during the formwork stage.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.674-675
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• 2015

A 3D indoor model becomes an indiscernible component of BIM (Building Information Modeling) and GIS (Geographic Information System). However, a huge amount of time and human resources are inevitable for collecting spatial measurements and creating such a 3D indoor model. Also, a varied forms of 3D indoor models exist depending on their purpose of use. Thus, in this study, three different 3D indoor models are defined as 1) omnidirectional images, 2) a 3D realistic model, and 3) 3D indoor as-built model. A series of reconstruction methods is then introduced to construct each type of 3D indoor models: they are an omnidirectional image acquisition method, a hybrid surveying method, and a terrestrial LiDAR-based method. The reconstruction methods are applied to a large and complex atrium, and their 3D modeling results are compared and analyzed.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.869-875
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• 2009

Safety is a big issue in the construction sites. For safe and secure management, tracking locations of construction resources such as labors, materials, machineries, vehicles and so on is important. The materials, machineries and vehicles could be controlled by computer, whereas the movement of labors does not have fixed pattern. So, the location and movement of labors need to be monitored continuously for safety. In general, Global Positioning System(GPS) is an opt solution to obtain the location information in outside environments. But it cannot be used for indoor locations as it requires a clear Line-Of-Sight(LOS) to satellites Therefore, indoor location monitoring system could be a convenient alternative for environments such as tunnel and indoor building construction sites. This paper presents a case study to investigate feasibility of Wi-Fi based indoor location monitoring system in construction site. The system is developed by using fingerprint map of gathering Received Signal Strength Indication(RSSI) from each Access Point(AP). The signal information is gathered by Radio Frequency Identification (RFID) tags, which are attached on a helmet of labors to track their locations, and is sent to server computer. Experiments were conducted in a shield tunnel construction site at Guangzhou, China. This study consists of three phases as follows: First, we have a tracking test in entrance area of tunnel construction site. This experiment was performed to find the effective geometry of APs installation. The geometry of APs installation was changed for finding effective locations, and the experiment was performed using one and more tags. Second, APs were separated into two groups, and they were connected with LAN cable in tunnel construction site. The purpose of this experiment was to check the validity of group separating strategy. One group was installed around the entrance and the other one was installed inside the tunnel. Finally, we installed the system inner area of tunnel, boring machine area, and checked the performance with varying conditions (the presence of obstacles such as train, worker, and so on). Accuracy of this study was calculated from the data, which was collected at some known points. Experimental results showed that WiFi-based indoor location system has a level of accuracy of a few meters in tunnel construction site. From the results, it is inferred that the location tracking system can track the approximate location of labors in the construction site. It is able to alert the labors when they are closer to dangerous zones like poisonous region or cave-in..

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.29-30
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• 2018

The development of the industry has increased the indoor living time of modern people. Therefore, indoor pollution is attracting attention as a social issue. One of the indoor air pollution is formaldehyde. Formaldehyde has been classified as a first-level carcinogen by international cancer research organizations. Formaldehyde has been used to protect products such as construction materials and finish materials, and being diffused in the interior construction process. In this study, we used phytoncide with cement matrix to reduce formaldehyde, an indoor environmental contaminant. The strengths was increased slightly and formaldehyde showed a reduction effect over time.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.29-30
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• 2019

The indoor air quality of modern people who work indoors more than 80 percent a day has also become a very important factor in their lives. But most indoor air quality is highly polluted due to energy conservation and lack of ventilation. This can lead to pneumonia, asthma and even lung cancer, which can be fatal to children, the elderly and the elderly. Indoor pollutants are caused by boards, wallpaper, paint, etc. used in interior By producing indoor finishing materials using active alumina gel, which is used as dehumidifier, indoor pollutants will be reduced and the possibility of developing respiratory diseases and lung cancer will be reduced.

• Journal of the Korea Institute of Building Construction
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• v.11 no.6
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• pp.576-586
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• 2011

In recent years, pollution in residential spaces has been a significant area of concern. In particular, the indoor air quality (IAQ) of an apartment building before occupancy, which is related to the interior material, is a serious problem. Unlike previous research, which has mainly focused on pollution control after construction, this study has derived influencing factors and priority of management with a controlling schedule for IAQ. The objectives of this research are 1) control of schedule or improvement of management for IAQ, 2) distribution of responsibility to the parties concerned (factory, material company, construction company, design and engineering, occupancy). The results show the relative priority of the four major items in wall?based apartment buildings and in column?based apartment buildings. An analysis of the parties responsible for improvement based on the IAQ results shows more efforts to improve IAQ are needed in material factories and engineering/design companies.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.143-148
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• 2007

Recently indoor air pollution caused by exposing hazardous chemicals (VOCs, formaldehyde) due to undiscriminated use of new construction materials and air-tightness to save energy is becoming a big issue. We have developed technologies to estimate the amounts of contaminants from constructions materials and method. We have further developed construction technologies to reduce and characterize these contaminants. The developed technologies were then refined to eliminate defects through considering field applicability.

• Journal of Construction Engineering and Project Management
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• v.6 no.2
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• pp.30-39
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• 2016

This research presents the development of a self-governing mobile robot navigation system for indoor construction applications. This self-governing robot navigation system integrated robot control units, various positioning techniques including a dead-reckoning system, a UWB platform and motion sensors, with a BIM path planner solution. Various algorithms and error correction methods have been tested for all the employed sensors and other components to improve the positioning and navigation capability of the system. The research demonstrated that the path planner utilizing a BIM model as a navigation site map could effectively extract an efficient path for the robot, and could be executed in a real-time application for construction environments. Several navigation strategies with a mobile robot were tested with various combinations of localization sensors including wheel encoders, sonar/infrared/thermal proximity sensors, motion sensors, a digital compass, and UWB. The system successfully demonstrated the ability to plan an efficient path for robot's movement and properly navigate through the planned path to reach the specified destination in a complex indoor construction site. The findings can be adopted to several potential construction or manufacturing applications such as robotic material delivery, inspection, and onsite security.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1170-1178
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• 2022

Indoor POI data, an essential component of indoor spatial data, has attribute information of a specific place in the room and is the most critical information necessary for the user. Currently, indoor POI data is manually updated by direct investigation, which is expensive and time-consuming. Recently, research on updating POI using the attribute information of indoor photographs has been advanced to overcome these problems. However, the range of use, such as using only photographs with text information, is limited. Therefore, in this study, and to improvement this, I proposed a new method to update indoor POI data using a smartphone camera. In the proposed method, the POI name is obtained by classifying the indoor scene's photograph into artificial intelligence technology CNN and matching the location criteria to indoor spatial data through AR technology. As a result of creating and experimenting with a prototype application to evaluate the proposed method, it was possible to update POI data that reflects the real world with high accuracy. Therefore, the results of this study can be used as a complement or substitute for the existing methodologies that have been advanced mainly by direct research.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.11
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• pp.982-986
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• 2013

The noise emitted from construction machinery has long been a cause of environmental disputes, especially to the nearby residents. In 2008, the Ministry of Environment adopted the construction machinery noise labeling system to encourage the development of the low noise construction machinery. After the implementation of the noise labeling system of the construction machinery, the noise emitted from the construction machinery has been decreased over the six years. But, as the quality of life improves, a growing number of people desire more comfortable and quite living environment. Under the situation, new systems like the low noise labeling system are considered to encourage the development of the low noise construction machinery. In accordance with the low noise labeling system, the construction machinery satisfying the standard of low noise are qualified to attach the low noise label in front of the products. Thus, the product qualified the low noise certification will be incentivized by the choice of the consumer. In this paper, we have studied the necessity of the low noise labeling system for the construction machinery and the considerations to adopt the low noise labeling system of construction machinery. And we have studied appropriate criterion to judge the low noise construction machinery. The considerations studied in this paper will be helpful to adopt the low noise labeling system of construction machinery in the future.