• Nuclear Engineering and Technology
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• v.39 no.3
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• pp.221-230
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• 2007

Wavelet theory was applied to detect a singularity in a reactor power signal. Compared to Fourier transform, wavelet transform has localization properties in space and frequency. Therefore, using wavelet transform after de-noising, singular points can easily be found. To test this theory, reactor power signals were generated using the HANARO(a Korean multi-purpose research reactor) dynamics model consisting of 39 nonlinear differential equations contaminated with Gaussian noise. Wavelet transform decomposition and de-noising procedures were applied to these signals. It was possible to detect singular events such as a sudden reactivity change and abrupt intrinsic property changes. Thus, this method could be profitably utilized in a real-time system for automatic event recognition(e.g., reactor condition monitoring).

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.335-338
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• 2011

최근 정보화가 고도화됨에 따라 해킹, 웜 바이러스 등 사이버 침해사고 또한 증가하고 있다. 이에 따라 사이버 침해사고를 예방하고 대응하기 위하여 보안관제의 필요성이 대두되고 있으며 이를 지원하기 위한 시스템이 등장하고 있다. 단순한 사이버 공격을 탐지하는 수준에서 벗어나 분석 및 대응 등 넓은 의미의 보안관제 활동을 수행하기 위한 시스템은 이기종 환경에서 대용량의 데이터를 처리하여 신속하고 정확한 탐지 결과를 보여줄 수 있어야 한다. 또한 다양한 보안관제 활동을 원활히 수행할 수 있는 기능을 제공하여야 한다. 본 논문에서는 이러한 요구사항을 반영하여 대용량 보안이벤트 데이터를 동적으로 상관 분석하여 탐지 효율성과 신속성을 향상시킬 수 있는 보안관제시스템을 설계 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.493-495
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• 2016

The framework and application model for risk mitigation service based on network provides monitoring function of the risk event data to be inputted and analyses it for mitigation process. Furthermore, it performs the analysis of the manmade calamities such as accident, building destruction, natural calamities caused by climate change, and animal harms caused by bird flu and foot-and-mouth disease occurring in livestock and wild animals, and provides the mitigation service of it. The application model for risk mitigation is combined with network and carries out the real time acquisition and monitoring of risk events, and provides mitigation service for the risks caused by calamities and reduces economic losses.

• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1423-1430
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• 2003

In this paper, we develop a real time monitoring system to detect third-party damage on natural gas pipeline. When the damage due to third-party incidents causes an immediate rupture, the developed on-line monitoring system can help reducing the sequences of event at once. Moreover, since many third-party incidents cause damage that does not lead to immediate rupture but can grow with time, the developed on-line monitoring system can execute a significant role in reducing many third-party damage incidents. Also, when the damage is given at a point on natural gas pipeline, the acoustic wave is propagated very fast about 421.3 m/s. Therefore, the data processing time should be very short in order to detect precisely the impact position. Generally, the pipeline is laid under ground or sea and the length is very long. So a wireless data communication method is recommendable and the sensing positions are limited by laid circumstance and setting cost of sensors. The calculation and monitoring software is developed by an algorithm using the propagation speed of acoustic wave and data base system based on wireless communication and DSP systems. The developed monitoring system is examined by field testing at Balan pilot plant, KOGAS being done in order to demonstrate its validity through reactive detection of third-party contact with pipelines. Furthermore, the development system was set at the practical pipelines such as an offshore pipeline between two islands Yul-Do and Youngjong-Do, and a land branch of Pyoungtaek, Korea and it has been operating in real time.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.4
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• pp.65-72
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• 2014

To improve the productivity of manufacturing company, the analysis of loss in shop floor has to be conducted and validated. This paper introduces the downtime tracking module using the pre-developed shop floor information acquisition system. To collect the downtime, it utilized shop floor monitoring information, user-registered downtime event, equipment diagnosis algorithm and operator's input. Also, it provided the user interface for the analysis of downtime. From the results of a pilot study, the usability of developed system was validated.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.2
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• pp.31-39
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• 2016

Due to the temporal variation of inflow/outflow, the water tank is needed. For the calculation of water tank capacity, the absolute difference between cumulative amounts of supply(e.g., rainfall) and demand(e.g.,watering) is used. No matter the (-) and (+) the absolute maximum capacity of the subtraction is calculated as the capacity. In this paper, using rainfall and watering of greenhouse facilities, it is proved that the non-linear supply or demand can be applied, and it is proved also that the greater non-linear variation case. And as the time interval for monitoring is decreased, the basin or tank volume are increased, with approximately 10 days as the critical monitoring interval for the annual natural rainfall event.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.4
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• pp.107-113
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• 2007

The Kuem-River, one of the largest rivers in Korea, is the primary water source for more than 4 million people in Kongju city and surrounding area. To study the effect of stormwater runoff to CSOs, twelve monitoring sites were selected in two large cities (City of Kongju and City of Buyeo) near the Kuem-River. Monitoring was reformed by collecting grab samples, measuring flow rates during dry and wet seasons during over two rainy seasons. Generally the flow rate of wastewater in combined sewers was rapidly decreased after 23:00 P.M. and gradually increased from 06:30 A.M. in all sites during the dry season. The concentrations of pollutant increase approximately 5 to 7 fold for TSS and 1.5 to 2.5 fold for BOD during the rainy season. Monitoring and statistical analysis show that the groundwater contributes on sewage volume increase (average 25-45% more) during dry periods and the stormwater runoff contributes approximately 51-72% increase during rainy periods. Generally the concentrations of combined sewage were more polluted during the first flush period than after the first flush during a storm event.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.95-100
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• 2009

Nowadays there are many studies and there's huge development about USN/RFID which have great developmental potential to many kinds of applications. More and more real time application apply USN/RFID technology to identify data collect and locate objects. Wide deployment of USN/RFID will generate an unprecedented volume of primitive data in a short time. Duplication and redundancy of primitive data will affect real time performance of application. Thus, security applications must filter primitive data and correlate them for complex pattern detection and transform them to events that provide meaningful, actionable information to end application. In this paper, we design a ECA Rule system for security monitoring of exhibition. This system will process USN/RFID primitive data and event and perform data transformation. It's had applied each now in exhibition hall through this study and efficient data transmission and management forecast that is possible.

• Structural Monitoring and Maintenance
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• v.3 no.3
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• pp.195-214
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• 2016

Monitoring of impact loads is a very important technique in the field of structural health monitoring (SHM). However, in most cases it is not possible to measure impact events directly, so they need to be reconstructed. Impact load reconstruction refers to the problem of estimating an input to a dynamic system when the system output and the impulse response function are usually known. Generally this leads to a so called ill-posed inverse problem. It is reasonable to use prior knowledge of the force in order to develop more suitable reconstruction strategies and to increase accuracy. An impact event is characterized by a short time duration and a spatial concentration. Moreover the force time history of an impact has a specific shape, which also can be taken into account. In this contribution these properties of the external force are employed to create a sample-force-dictionary and thus to transform the ill-posed problem into a sparse recovery task. The sparse solution is acquired by solving a minimization problem known as basis pursuit denoising (BPDN). The reconstruction approach shown here is capable to estimate simultaneously the magnitude of the impact and the impact location, with a minimum number of accelerometers. The possibility of reconstructing the impact based on a noisy output signal is first demonstrated with simulated measurements of a simple beam structure. Then an experimental investigation of a real beam is performed.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1027-1028
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• 2008

Most of the urban transit operation company in Korea have a passive surveillance system to monitor the status of the passengers and facilities in the urban transit service area. The surveillance system is based on CCTV, closed circuit television, and several sensors, such as a fire sensor. However, this system has some limitations to prevent and cope with the emergency quickly. So the urban transit operation companies have plans to be change their surveillance system to be active. The active surveillance system has an intelligent function to detect the event predefined by managers automatically. To construct the active surveillance system, there are a standard concept design and a function analysis. In this paper, we propose the classification of the functions of the active surveillance system for urban transit. We divide the functions into five parts, ordinary monitoring, safety monitoring, environment monitoring, administration support, and record management. And we describe the systems related to the every functions to clarify the classified functions.