• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.40-44
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• 2010

North Korea's discharge of water from a dam into the Imjin River that flows through the inter-Korean border swept away a riverside camping site early Sunday morning, killing six people. This tragic incident might have been prevented if the North had given prior notice of the release from its Hwanggang Dam to the South. Investigations are under way to determine the reasons behind the unexpected act. This incident was a man-made disaster not least death of six people. A water level monitoring system(WLMS) of the Imjin River was installed the bridge of Pilseung that operate three public institutions. The WLMS of the A institution set up warning siren and broadcasting as the water level has been rising the bridge of Pilseung in the Imjin River. But the A institution's system was already out of side before discharged of water a dam into the Imjin River and the operators were culpable negligence. The B institution's office employee on charges of negligence that might have contributed to the tragedy and one of the A institution's employees ignored 26 warning messages on the WLMS. This tragic incident was a man-made disaster not least death of six people and might have been prevented if the WLMS was normally operated and the system operators must be worked a tight.

• Journal of Radiation Protection and Research
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• v.19 no.2
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• pp.147-156
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• 1994

On-line gamma monitoring system around KAERI-site was set up to monitor the radiation fluctuations in environment. Data on gamma exposure rates measured by the ionication chamber in the monitoring posts are transmitted to a computer of central control station with. radio telemetry transmission modem and monitored in real time. Radio telemetry transmission system is economical and reliable on handling and storing of data. This monitroing system can triger an early warning system in the event of abnormal radiation levels.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.91-97
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• 2017

This study contains research on a bio-monitoring system (BMS) capable of detecting abnormal high water temperatures, the shell valve movements (SVMs) of Pacific oysters (Crassostrea gigas), which were measured at four different temperature (5, 10, 20 and $30^{\circ}C$) under laboratory conditions. All the Pacific oysters were kept under fasting conditions for 3 days to prevent the influence of food and excretions before the onset of the experiments. SVMs did not detect at $5^{\circ}C$. However, SVMs increased with an increase in temperature (at $10^{\circ}C$ : $6.31{\pm}2.18times/hr$ and at $20^{\circ}C$: $22.0{\pm}10.0times/hr$). At $30^{\circ}C$, SVMs were divided into two groups: those with no SVMs as at $5^{\circ}C$ and those with SVMs similar to conditions at $20^{\circ}C$($23.9{\pm}9.35times/hr$). This indicates oyster shells maintain a closed condition due to a decrease in metabolism at $30^{\circ}C$, although some Pacific oysters had active SVMs due to an increase in metabolism. If a BMS using the SVM status of Pacific oysters was installed to monitor abnormal high water around oyster farms, early warning levels and serious alerts might be made available more rapidly for SVMs of more than ca. 30 times/hr and closing conditions in a matter of hours, respectively. Therefore, a BMS using the SVMs of Pacific oysters might be an effective early warning system for abnormal high water temperatures.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.117-129
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• 2009

This paper studied the safety management network system of infrastructure which constructed smart sensors, closed-circuit television(CCTV) and monitoring system. This safety management of infrastructure applied to bridge, cut slop and tunnel, embankment etc. The system applied to technologies of standardization guidelines, data acquirement technologies, data analysis and judgment technologies, system integration setup technology, and IT technologies. It was constructed safety management network system of various infrastructure to improve efficient management and operation for many infrastructure. Integrated safety management network system of infrastructure consisted of the real-time structural health monitoring system of each infrastructure, integrated control center, measured data transmission using i of tet web-based, collecting data using sf ver, early alarm system which the dangerous event of infrastructure occurred. Integrated control center consisted of conference room, control room to manage and analysis the data, server room to present the measured data and to collect the raw data. Early alarm system proposed realization of warning and response within 5 minute or less through development of sensor-based progress report and propagation automation system using the media such as MMS, VMS, EMS, FMS, SMS and web services of report and propagation. Based on this, the most effective u-Infrastructure Safety Management System is expected to be stably established at a less cost, thus making people's life more comfortable. Information obtained from such systems could be useful for maintenance or structural safety evaluation of existing structures, rapid evaluation of conditions of damaged structures after an earthquake, estimation of residual life of structures, repair and retrofitting of structures, maintenance, management or rehabilitation of historical structures.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.4
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• pp.469-479
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• 2015

This study have been conducted to analyze the feasibility of establishing Contamination Warning System(CWS) that is capable of monitoring early natural or intentional water quality accidents, and providing active and quick responses for domestic C_water supply system. In order to evaluate the water quality data set, pH, turbidity and free residual chlorine concentration data were collected and each statistical value(mean, variation, range) was calculated, then the seasonal variability of those were analyzed using the independent t-test. From the results of analyzing the distribution of outliers in the measurement data using a high-pass filter, it could be confirmed that a lot of lower outliers appeared due to data missing. In addition, linear filter model based on autoregressive model(AR(1) and AR(2)) was applied for the state estimation of each water quality data set. From the results of analyzing the variability of the autocorrelation coefficient structure according to the change of window size(6hours~48hours), at least the window size longer than 12hours should be necessary for estimating the state of water quality data satisfactorily.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.1
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• pp.35-43
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• 2020

Turbidity has various effects on the water quality and ecosystem of a river. High turbidity during floods increases the operation cost of a drinking water supply system. Thus, the management of turbidity is essential for providing safe water to the public. There have been various efforts to estimate turbidity in river systems for proper management and early warning of high turbidity in the water supply process. Advanced data analysis technology using machine learning has been increasingly used in water quality management processes. Artificial neural networks(ANNs) is one of the first algorithms applied, where the overfitting of a model to observed data and vanishing gradient in the backpropagation process limit the wide application of ANNs in practice. In recent years, deep learning, which overcomes the limitations of ANNs, has been applied in water quality management. LSTM(Long-Short Term Memory) is one of novel deep learning algorithms that is widely used in the analysis of time series data. In this study, LSTM is used for the prediction of high turbidity(>30 NTU) in a river from the relationship of turbidity to discharge, which enables early warning of high turbidity in a drinking water supply system. The model showed 0.98, 0.99, 0.98 and 0.99 for precision, recall, F1-score and accuracy respectively, for the prediction of high turbidity in a river with 2 hour frequency data. The sensitivity of the model to the observation intervals of data is also compared with time periods of 2 hour, 8 hour, 1 day and 2 days. The model shows higher precision with shorter observation intervals, which underscores the importance of collecting high frequency data for better management of water resources in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.5
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• pp.471-485
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• 2014

The monitoring method of geotechnical structures using acoustic emission(AE) and microseismicity(MS) is to detect the microscopic deformation and fracture behavior in the inner structures by measuring induced acoustics and vibrations. It can identify a pre-indication of failure by taking advantage of the characteristics that the amount and occurrence rates of AE and MS increase rapidly prior to large scale destruction of the target structures. The monitoring system consisting of high-quality sensors, high-speed data acquisition device and the operation program is required for the practical application of this method. Recently, the AE and MS monitoring systems have been localized. In particular, the developed operation software which can analyze and interpret the measured signals was demonstrated through a number of applications to domestic fields. This report introduces the configuration and features of developed monitoring system, then the challenges and future direction of AE monitoring in geotechnical structures are discussed.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10c
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• pp.19-27
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• 2001

Early detection of premonitory symptom of slope movement ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of both reinforced and un-reinforced cut slopes. We developed a novel monitoring system by using tension wire sensors. It's advantages are highly sensitivity, simple installation, large displacement measurement, durability of system, capability of remote sensing. Real-time measurement of slope surface movement is shown graphically and it gives a warning when the monitored value exceeds a given threshold level so that any sign of abnormal slope movement can be easily perceived.

• Journal of the Korean Geophysical Society
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• v.8 no.3
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• pp.137-143
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• 2005

Early detection of premonitory symptom of slope movement ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of both reinforced and un-reinforced cut slopes. We developed a novel monitoring system by using tension wire sensors. It's advantages are highly sensitivity, simple installation, large displacement measurement, durability of system, capability of remote sensing. Real-time measurement of slope surface movement is shown graphically and it gives a warning when the monitored value exceeds a given threshold level so that any sign of abnormal slope movement can be easily perceived.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.365-370
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• 2011

매년 반복되는 산간계곡에서의 인명피해를 저감하기 위하여 방재연구소에서는 "산지 돌발홍수 예측시스템"을 개발하였으며, '10년 우기철동안 시범지역의 모니터링을 통해 시스템의 문제점을 분석하고, 이를 개선하기 위한 방안을 검토하였다. 산지지역 강우에 대한 모니터링은 현재 지방자치단체에서 운영하고 있는 자동우량경보시설을 활용하였으며, 해당 시설중 특히 수위계가 설치된 지역에 대하여 검토하였다. 수위자료 모니터링 결과를 바탕으로 정확도를 검토한 결과, 5개 시범지역의 경우 약 56%의 정확도가 있는 것으로 나타났다. 산정되었다. 그러나 시스템을 수정 보완한 후에는 정확도가 66%로 증가하였다. 향후 지속적인 모니터링과 문제점 분석을 통해 정확도를 지속적으로 향상시킬 계획이다.