• Journal of Sensor Science and Technology
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• v.29 no.5
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• pp.342-347
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• 2020

In this study, a portable total-phosphorus (TP) monitoring system utilizing a photocatalytic-reaction-based pretreatment method is proposed, fabricated, and characterized. Commercial TP monitoring systems are only used in laboratories because of their complex monitoring procedure, bulk-size, and high-cost. In particular, pretreatment in commercial TP monitoring systems is performed at high temperatures (> 120 ℃) and pressure (> 1.1 kg cm^-2) making it difficult to minimize the scale of the systems. The proposed TP monitoring system employs a pretreatment method with a photocatalytic reaction; thus, its size can be reduced, as photocatalytic reactions occur at room temperature and atmospheric pressure. Analytes with various TP concentrations are pretreated using the proposed portable TP monitoring system and are quantitatively measured with an LED and a photodiode.

• Journal of the Korean Institute of Educational Facilities
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• v.27 no.1
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• pp.3-10
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• 2020

Due to the frequent occurrence of large-scale disasters such as recent earthquakes, the problem of the safety of old school buildings has emerged. The need to secure safety management technology through constant monitoring is increasing in an attempt to supplement old school buildings with weak disaster response capabilities. Traditional research is approaching the development of an existing sensor-based risk precursor information monitoring system. However, unlike this, in this study, we will focus on the development of a data analysis platform as part of the development of a continuous monitoring system that can be prepared for earthquakes, collapses, and fires, based on constantly measured data. For this reason, the development of a safety diagnostic algorithm based on the optimal sensor-attached points and sensor data reflecting the fragile characteristics of old school buildings was derived. Utilizing this, a message and action manual system for each management / use entity of school buildings after retirement was constructed.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.909-916
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• 2024

The emergence of Building Information Modelling (BIM), reality data, Virtual Reality (VR), and Augmented Reality (AR) has significantly enhanced the collaboration between stakeholders in construction management. The utilization of VR/AR devices holds considerable potential for monitoring safety in complex and constrained working environments on the construction site. On the other hand, near-miss incidents remain an important early sign of struck-by accidents. However, research on early warning and prevention methods for this risk is still limited. This paper, therefore, presents a framework for on-site and off-site collaborative safety monitoring framework using augmented and virtual reality for near-miss incidents. In the proposed framework, three phases to develop a VR/AR-based safety monitoring system include (1) construction safety simulation environment, (2) localization-based interaction system, and (3) safety monitoring system. The system can undertake the processing of data and enables communication among disparate VR/AR devices. VR clients are observational tools and offer guidance, while the AR client stays onsite for construction tasks. All clients connect to a processing computer, which also works as a host. The system embedded in the AR device can trigger an alarm or receive signals from the VR client when a near-miss issue happens. Additionally, all device clients possess the capability to share data acquired from onsite monitoring cameras, thereby fostering effective discussions and decision-making. The efficacy of this cross-platform system has been validated through the implementation of an outdoor coordination case study.

• Journal of the Korean Society of Safety
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• v.21 no.1 s.73
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• pp.41-47
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• 2006

This paper introduces stress monitoring system for buried gas pipeline in poor ground. During the six months of improvement construction of poor ground, maximum settlement of gas pipeline is about 40 cm. This value represents relative small compared to the initial settlement estimation of ground improvement construction plan, 90 cm. Also, this paper includes the result of finite element analysis of gas pipeline to confirm safety of pipelines in poor ground. The stress monitoring system for gas pipeline was developed to guarantee the safety of buried gas pipeline in poor ground. Eventually, the ground improvement workings are ended safely and it is proved that the pipeline has no safety problem.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.842-850
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• 2021

Real Time Simulation (RTS) has long been used in the nuclear power industry for operator training and engineering purposes. And, Online Simulation (OLS) is based on RTS and with connection to the plant information system to acquire the measurement data in real time for calibrating the simulation models and following plant operation, for the purposes of analyzing plant events and providing indicative signs of malfunctioning. An OLS system has been developed to support PWR operations for CPR1000 plants. The OLS system provides graphical user interface (GUI) for operators to monitor critical plant operations for preventing faulty operation or analyzing plant events. Functionalities of the OLS system are depicted through the maneuvering of the GUI for various OLS functional modules in the system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.731-736
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• 2011

On this paper, we propose how to apply the vision system for monitoring a platform safety. The vision system is tested in real platform in a deagu subway station. According to the result of field test, we propose how to use vision system for monitoring a platform safety. The result showed that it had a high performance to detecting ratio.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.6
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• pp.33-43
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• 2009

This study analyzed data on the pore water pressure, the ground water level, the horizontal displacement and the resistivity monitoring from instrument system, which is established to evaluate the safety in reservoirs. The pore water pressure in the embankment ranged from $0.035{\sim}1.116kg/cm^2$. The seepage that piping showed, as well as the leakage from the reservoirs are acceptable for the safety management of the reservoir. The maximum horizontal displacement and direction analyzed from the measured inclinometer data gives us very effective information to evaluate the safety in reservoirs. The resistivity monitoring technique, which is obtained on the reservoir crest, is an efficient tool to detect leakage zone. The safety index (SI) was predicted by the resistivity monitoring, and was evaluated to have a safety level of 0.8-1.0 at all reservoirs. Safety evaluations of reservoir through instrument systems are effective when studying the embankment, when the results of the instrument system have been analyzed compositively.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.840-851
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• 2010

This study analyzed data on the pore water pressure, the ground water level, the horizontal displacement and the resistivity monitoring from instrument system, which is established to evaluate the safety in reservoirs. The pore water pressure in the embankment ranged from $0.035{\sim}1.116kg/cm^2$. The seepage that piping showed, as well as the leakage from the reservoirs are acceptable for the safety management of the reservoir. The maximum horizontal displacement and direction analyzed from the measured inclinometer data gives us very effective information to evaluate the safety in reservoirs. The resistivity monitoring technique, which is obtained on the reservoir crest, is an efficient tool to detect leakage zone. The safety index(SI) was predicted by the resistivity monitoring, and was evaluated to have a safety level of 0.8-1.0 at all reservoirs. Safety evaluations of reservoir through instrument systems are effective when studying the embankment, when the results of the instrument system have been analyzed compositively.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.186-192
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• 2022

Flow accelerated corrosion (FAC) is a type of pipe corrosion in which the pipe thickness decreases depending on the fluid flow conditions. In nuclear power plants, FAC mainly occurs in the carbon steel pipes of a secondary system. However, because the temperature of a secondary system pipe is over 150 ℃, in situ monitoring using a conventional ultrasonic non-destructive testing method is difficult. In our previous study, we developed a waveguide ultrasonic thickness measurement system. In this study, we applied a waveguide ultrasonic thickness measurement system to monitor the thinning of the pipe according to the change in pH. The Korea Atomic Energy Research Institute installed FAC-proof facilities, enabling the monitoring of internal fluid flow conditions, which were fixed for ~1000 h to analyze the effect of the pH. The measurement system operated without failure for ~3000 h and the pipe thickness was found to be reduced by ~10% at pH 9 compared to that at pH 7. The thickness of the pipe was measured using a microscope after the experiment, and the reliability of the system was confirmed with less than 1% error. This technology is expected to also be applicable to the thickness-reduction monitoring of other high-temperature materials.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.813-818
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• 1999

The construction of large scale civil and building structures which form the base of social economy has been grown greatly. As the increasing of aged and deteriorated structures, it is necessary to evaluate the safety of those structures. The deterioration, safety evaluation, repair and rehabilitation are important problems in the construction area that every country faces. This paper presents the general information on how to conduct a data analysis of long-term monitoring system and evaluate the characteristics of surveying methods.