• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.3
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• pp.125-131
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• 2011

Water leak detection system is a system based on wireless sensor networks(WSNs) which detect a leak on water supply, localize the leak position and finally inform a water management center. A traditional leak detection method is to use experienced personnel who walk along a pipeline listening to the sound that is generated by the leaks and their effectiveness depend on the experience of the user. Also making more successful detection, it should be processed at middle of the night when people do not use water, as the result users have to operate the leak detection system at midnight. In this paper, we propose a new method for the water leak detection system based on the WSNs and describe it in detail. Leak detection devices which detect a leakage of water transmit and receive the result of water leak detection with each other by configuring WSNs to improve reliability of the detection result. Also, we analyzed the sound from water flowed in pipeline, proposed the pre-signal processing to separate a leakage sound from noisy sound. And lastly, It is especially important to make a time synchronization with water leak detection devices that are installed on the pipeline, we used 1PPS(1 Pulse Per Second) signal generated by GPS, therefore we could get a precise time synchronization. The proposed system set up in Namyangju and performances were evaluated.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.229-232
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• 2003

나날이 발전하는 인터넷 기반의 네트워크 환경에서 보안의 중요성은 아무리 강조해도 지나치지 않다. 바이러스와 해킹 기술의 발전 속도는 항상 방어자의 능력을 앞지르고 있으며, 공격자들의 능력과 무관한 해킹 툴의 보급은 누구나가 해커가 될 수 있도록 하는데 일조하고 있다. 이제 더 이상 해킹과 바이러스로부터 안전지대는 없다고 해도 과언이 아니다. 이에 본 논문에서는 일정한 환경에서의 침입에 대해 학습을 하여 그 침입을 탐지할 수 있는 디텍터를 생성할 수 있는 알고리즘을 제안한다. 공격 유형의 수에 비해 적은, 그러나 인공 면역계의 T 세포 형성과정인 부정선택을 이용한 학습알고리즘을 기반으로 생성된 디텍터들은 상대적으로 다양한 공격의 침입을 탐지한다. 이의 유효성을 시뮬레이션을 이용하여 확인한다.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.607-614
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• 2019

It has been an issue among researchers that the tsunamis that occurred on the west coast of Japan in 1983 and 1993 damaged the coastal cities on the east coast of Korea. In order to predict and reduce the damage to the Korean Peninsula effectively, it is necessary to install offshore tsunami observation instruments as part of the system for the early detection of tsunamis. The purpose of this study is to recommend the optimal deployment of tsunami observation instruments in terms of the higher probability of tsunami detection with the minimum equipment and the maximum evacuation and warning time according to the current situation in Korea. In order to propose the optimal location of the tsunami observation equipment, this study will analyze the tsunami propagation phenomena on the east sea by considering the potential tsunami scenario on the west coast of Japan through numerical modeling using the COrnell Multi-grid COupled Tsunami (COMCOT) model. Based on the results of the numerical model, this study suggested the optimal deployment of Korea's offshore tsunami observation instruments on the northeast side of Ulleung Island.

• Korean Journal of Remote Sensing
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• v.24 no.6
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• pp.571-581
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• 2008

The sea fog occurs frequently in the west coast of Korea in spring and summer. This study focused on the detection of sea fog using MODIS satellite images. We presented a method for sea fog detection based on the homogeneity level between low stratus and sea fog, which was that the top surface of sea fog had a homogeneous aspect while that of low stratus had a heterogenous aspect. The results showed that the both homogeneity of $11{\mu}m$ brightness temperature (BT) and brightness temperature difference (BTD, $BT_{3.7{\mu}m}-BT_{11{\mu}m}$) were available to discriminate sea fog from low stratus. The frequency of difference between BT in fog/stratus area and BT in clear area provided reasonable result. In addition, the threshold values of standard deviations of BT and BTD in the fog/stratus area were applicable to differentiate fog from low stratus.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.202-207
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• 2016

Checkpoint placement is an effective fault tolerance technique against transient faults in which the task is re-executed from the latest checkpoint when a fault is detected. In this paper, we propose a new checkpoint placement strategy separating data saving and fault detection processes that are performed together in conventional checkpoints. Several fault detection processes are performed in one checkpoint interval in order to decrease the latency between the occurrence and detection of faults. We address the placement method of fault detection processes to maximize the probability of successful execution of a task within the given deadline. We develop the Markov chain model for a real-time task having the proposed checkpoints, and derive the optimal fault detection and checkpoint interval.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.579-581
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• 2023

에너지바우처 사업은 해마다 지원 예산의 규모를 증액하고 대상 가구원 특성 기준을 추가하는 등 지속적인 노력에도 불구하고 현재 에너지바우처 사용률은 전국 평균 약 81.8%로 여전히 목표치에는 못 미치는 상황이다. 본 논문에서는 2015년 최초 시행 이후부터 누적된 에너지바우처의 데이터와 에너지연료비(유가 정보, 지역 난방비 등), 기상청의 개방된 기상자료(기상특보, 예보), 한전의 실시간 전력 소비데이터 등 타 정보를 결합하여 인공지능 기반 데이터 분석으로 에너지바우처 사용률을 높여 사용률 저조 원인을 분석하고 이를 기반으로 위험 가구에 대한 사전 탐지와 관리를 위한 시스템을 제안한다. 향후, 제안 시스템의 현실적인 운영을 위해서는 사용률과 연관된 다양한 변수에 대한 분석과 시스템 성능평가가 필요하다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.43-54
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• 2016

The occurrence of cyber crime is on the rise every year, and the security control center, which should play a crucial role in monitoring and early response against the cyber attacks targeting various information systems, its importance has increased accordingly. Every endeavors to prevent cyber attacks is being attempted by information security personnel of government and financial sector's security control center, threat response Center, cyber terror response center, Cert Team, SOC(Security Operator Center) and else. The ordinary method to monitor cyber attacks consists of utilizing the security system or the network security device. It is anticipated, however, to be insufficient since this is simply one dimensional way of monitoring them based on signatures. There has been considerable improvement of the security control system and researchers also have conducted a number of studies on monitoring methods to prevent threats to security. In accordance with the environment changes from ESM to SIEM, the security control system is able to be provided with more input data as well as generate the correlation analysis which integrates the processed data, by extraction and parsing, into the potential scenarios of attack or threat. This article shows case studies how to detect the threat to security in effective ways, from the initial phase of the security control system to current SIEM circumstances. Furthermore, scenarios based security control systems rather than simple monitoring is introduced, and finally methods of producing the correlation analysis and its verification methods are presented. It is expected that this result contributes to the development of cyber attack monitoring system in other security centers.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.527-534
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• 2023

Triple modular redundancy (TMR) systems can continue their mission by virtue of their structural redundancy even if one processor is attacked by faults. In this paper, we propose a new fault tolerance strategy by introducing checkpoints into the TMR system in which data saving and fault detection processes are separated while they corporate together in the conventional checkpoints. Faults in one processor are tolerated by synchronizing the state of three processors upon detecting faults. Simultaneous faults occurring to more than one processor are tolerated by re-executing the task from the latest checkpoint. We propose the checkpoint placement and fault detection strategy to maximize the probability of successful execution of a task within the given deadline. We develop the Markov chain model for the TMR system having the proposed checkpoint strategy, and derive the optimal fault detection and checkpoint interval.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.55-57
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• 2006

본 논문에서는 컬러코드를 이용하여 증강현실 시스템에 사용 가능한 태그를 탐지하는 알고리즘을 설계하고 차단 현상에 강인한 알고리즘을 제안하였다. 기존의 ARToolkit에서 태그의 일부분이 사용자 또는 다른 물체에 의해 가려지게 될 경우 증강되었던 객체가 순간 사라져 버리는 불안정성 (Instability) 문제를 해결하기 위한 방법에 초점을 맞춘다. 불안정성의 문제는 이미지 안에 태그가 존재하지만 해당하는 객체를 증강시키지 못하는 False Negative 에러와 태그가 존재하지 않는 곳에 잘못된 객체를 증강시키는 False Positive 에러로 분류 될 수 있다. 제안된 탐지 알고리즘으로 특정 컬러 영역을 분리하여 모서리 여부를 판별하고 모서리인 경우 가려진 꼭지점의 위치를 추출하여 태그가 차단에 의하여 가려졌을 때에도 객체를 안정적으로 증강시킬 수 있다. 기존 AR 시스템들의 태그를 가지고 Daylight 65, Illuminant A. CWF, TL84의 4가지의 표준 조명하에 컬러코드 4종류, ARToolkit 태그 4개, ARTag 4개를 이용하여 실험을 진행하여 차단 현상이 발생하면 전혀 객체를 증강시킬 수 없었던 ARToolkit에서도 DayLight65의 경우 50%의 False Negative. False Positive rate을 보여 기존 증강현실 시스템에서 보였던 불안정성 문제를 개선하였다.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.486-489
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• 2012

본 논문에서는 인간의 주의시각(Human Visual Attention)에 기반하여 영상에서 가장 유용하다고 생각되는 관심 영역(Salient Region)을 새로운 방식으로 탐지해내고 관심-객체를 검출하는 방법을 제안한다. 제안하는 시스템은 인간의 주의시각 특성인 주파수와 명도, 색상 특징을 이용하는데, 먼저 주파수-명도 정보를 이용한 특징 지도(Feature map)와 색상 정보를 이용한 특징 지도를 각각 생성 한 후 영상의 특징 점(Saliency Point)을 추출한다. 이렇게 생성된 특징 지도와 특징 점을 이용하여 집중 윈도우의 위치와 크기를 결정하고 집중 윈도우 내에 특징 지도를 결합하여 관심 영역을 탐지하고 해당하는 영역에 대해 관심-객체를 추출한다.