• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.203-210
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• 2003

격자망식 전선배치에 의한 전기비저항 측정기법을 이용한 침출수 누출감지시스템을 개발하여 그 적용성을 평가하기 위하여 현장모형시험을 수행하였다. 현장모형시험을 수행한 결과 침출수 누출지점에서 전기비저항이 크게 감소하여 누출지점을 정확하게 감지할 수 있었다. 격자망식 전선배치에 의한 전기회로적인 효과로 인하여 전기비저항이 감소된 지점과 동일 전선상에 연결된 다른 센서에서의 측정값도 다소 감소하는 경향을 나타내었다. 이를 보정하기 위하여 P-SPICE를 이용하여 전기회로 시뮬레이션을 수행하여 전기회로 효과를 정량적으로 평가하였다 P-SPICE 시뮬레이션의 결과를 토대로 보정계수를 도출하여 현장모형시험결과를 보정하였으며, 보정된 겉과에 의하면 전기회로적 특성에 의한 영향을 효과적으로 제거되어 누출지점에서의 전기비저항 감소가 명확하게 나타났다.

• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.225-233
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• 2001

Field model tests were performed to develop the grid-net landfill leachate leakage detection system using electrical resistance. Electric circuit tests were also carried out to investigate the expected electrical effects of grid-net electric circuit. The resistance of leaking point showed lower value than that of non leaking point. Grid-net leakage detection system was thought to be effective to locate the leachate leaking point. The measured electrical resistance along the wire including the leaking point was slightly reduced following the reduction of electrical resistance at the leaking point, which was explained by electric circuit test results.

• Composites Research
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• v.36 no.6
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• pp.429-434
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• 2023

In this study, aimed at improving the existing acoustic emission sensor for real time monitoring, a macro-fiber composite (MFC) transducer was employed as the acoustic emission sensor in the gas leak detection system. Prior to implementation, structural analysis was conducted to optimize the MFC's design. Consequently, the flexibility of the MFC facilitated excellent adherence to curved pipes, enabling the reception of acoustic emission (AE) signals without complications. Analysis of AE signals revealed substantial variations in parameter values for both high-pressure and low-pressure leaks. Notably, in the parameters of the Fast Fourier Transform (FFT) graph, the change amounted to 120% to 626% for high-pressure leaks compared to the case without leaks, and approximately 9% to 22% for low-pressure leaks. Furthermore, depending on the distance from the leak site, the magnitude of change in parameters tended to decrease as the distance increased. As the results, in the future, not only will it be possible to detect a leak by detecting the amount of parameter change in the future, but it will also be possible to identify the location of the leak from the amount of change.

• Journal of Energy Engineering
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• v.20 no.4
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• pp.292-297
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• 2011

Gas pipeline safety management and risk prediction are recognized as a very important issue. And the effort to prevent accidents is essential. So, in this study, it was studied through correlation of pressure changes for leak point detection in real-time. It experimented by installing the five leakage valves in the pipe of 378 m and compared the actual leak points with simulation results. The results showed that experimental leak points and the actual leak points have differences within the 6 m. And this technology has to be commercialized by the demonstration in dangerous zone.

• Journal of the Korean Institute of Gas
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• v.20 no.2
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• pp.66-71
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• 2016

Nowadays, a number of sensors which are placed in industrial complex are monitoring areas involving chemical leak and other faults. However, even in the presence of the sensors, chemical leaks, sometimes involving huge amount of chemicals, continuously led to big losses in the industrial complex. In most industries, sensor installation has been performed using past experience or using senor manufacturers' guideline; which leads to poor performance of the installed sensor grid. Therefore, we investigate an optimal placement methodology of point sensors for rapid detention and response when chemical leaks happen. This research suggests a generalized formulation suitable for the optimized decision making of minimizing number of sensors to be placed and increasing the fraction of covered scenarios under assumption of negligible effect of other structures. The proposed method has been verified for suitable performance for simple leak scenario simulations, by achieving the safety objectives and guaranteeing safe process operations.

• Journal of the Korean Institute of Gas
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• v.21 no.2
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• pp.41-49
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• 2017

Recently, as the number of facilities using chemicals is increasing, the amount of handling is rapidly increasing. However, chemical spills are occurring steadily, and if large quantities of chemicals are leaked in time, they are likely to cause major damage. These industrial complexes use information obtained from a number of sensors to detect and monitor leaking areas, and are used in industrial fields by applying existing fixed sensors to robots and drones. Therefore, it is necessary to propose a sensor placement method at the interface for rapid detection and response based on various leaking scenarios reflecting leaking conditions and environmental conditions of the chemical handling process. In this study, COMSOL was used to analyze the actual accident scenarios by applying the medium parameter to the case of chemical leaks. Based on the accident scenarios, the objective function is selected so that the velocity of each robot is calculated by attaching importance to each item of sensor detection probability, sensing time and sensing scenario number. We also confirmed the feasibility of this method of reliability analysis for unexpected leak accidents. Based on the above results, it is expected that it will be helpful to trace back the leakage source based on the concentration data of the portable sensor to be applied later.

• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.215-224
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• 2001

The concept that the electrical properties of subsurface material can be affected by the introduction of contaminants might be applicable fur developing the leakage detection system for petroleum hydrocarbons of underground storage tanks and leachate coming from landfill. Investigations were conducted with diesel, NaCl solution, and leachate by laboratory tests. Simulation test was performed leaking at a certain point in the field. The measured resistance was exponentially decreased as the water content of uncontaminated unsaturated sand was increased. The resistance of soil was increased by diesel but decreased by NaCl solution or leachate. The optimum electrode spacings were found for NaCl solution, leachate and diesel. Electrolytic solutions were better detected by wider spacing than non electrolytic solution.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.12
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• pp.525-534
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• 2023

Gas leak detection system is a key to minimize the loss of life due to the explosiveness and toxicity of gas. Most of the leak detection systems detect by gas sensors or thermal imaging cameras. To improve the performance of gas leak detection system using single-modal methods, the paper propose multimodal approach to gas sensor data and thermal camera data in developing a gas type identification model. MultimodalGasData, a multimodal open-dataset, is used to compare the performance of the four models developed through multimodal approach to gas sensors and thermal cameras with existing models. As a result, 1D CNN and GasNet models show the highest performance of 96.3% and 96.4%. The performance of the combined early fusion model of 1D CNN and GasNet reached 99.3%, 3.3% higher than the existing model. We hoped that further damage caused by gas leaks can be minimized through the gas leak detection system proposed in the study.

• Proceedings of the KSEEG Conference
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• 1999.04a
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• pp.260-264
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• 1999

• Bulletin of Korea Environmental Preservation Association
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• v.28 s.364
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• pp.42-44
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• 2006