• Proceedings of the KSR Conference
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• 2007.11a
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• pp.913-916
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• 2007

In this paper, the possibility of time reversal phenomenon was investigated in damage detection of structure. In conventional lamb wave techniques, damage is identified by comparing the measured data (baseline signals) and the current data. But this method can lead to high false signal in the intact condition of structures due to environmental conditions of the structures. So in this studying, we investigate the possibility of damage detection in the aluminum plate using the time reversal phenomenon of lamb waves.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.9 no.1
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• pp.45-48
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• 1984

A serious degradation of blocking of the detection performance in a cell aeraging-logarithmic detector/constant false alarm rate(CA-LOG/CFAR) is known to be caused by the presence of a large interfering noise in the set of sample mean. A technique consisting of the logarithmic circuit and inverter has been proposed to alleviate this problem, by modifying the conventional CA-LOG/CFAR receiver. The detection performance of the proposed technique is linearly improbed over the normal output level and the blocking characteristics of the CA-LOG/CFAR can be changed to finite output level.

• Convergence Security Journal
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• v.15 no.1
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• pp.27-36
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• 2015

A discussion on false alarm is a series of problems about a waste of police resources. The the false alarm primarily increase machine the cost of security firm but ultimately increase the costs of national and social management. Verified Report System has been in operation since July 1, 2013, We could analyze the actual operation of 112 report on false alarm rate was 82.4% before this system launched, but after implementation of the Verified Report System, this rate level downs below 69.7% records. So 12.7% is declined at the rate of false alarm. However, the actual alarm rate of Electronic Security itself is just only 0.3 % in the total number of cases responding in contrast to Police is considerable. It is more urgent to evolve the Verified Report System, so penalty system against the false alarm, Police registration system of sensors, and strengthening of the task of the company for installation and management of detection equipment are urgently needed.

• Convergence Security Journal
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• v.7 no.1
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• pp.63-75
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• 2007

Most of computer systems to be connected to network have been exposed to some network attacks and became to targets of system attack. System managers have established the IDS to prevent the system attacks over network. The previous IDS have decided intrusions detecting the requested connection packets more than critical values in order to detect attacks. This techniques have False Positive possibilities and have difficulties to detect the slow scan increasing the time between sending scan probes and the coordinated scan originating from multiple hosts. We propose the port scan detection rules detecting the RST/ACK flag packets to request some abnormal connections and design the data structures capturing some of packets. This proposed system is decreased a False Positive possibility and can detect the slow scan, because a few data can be maintained for long times. This system can also detect the coordinated scan effectively detecting the RST/ACK flag packets to be occurred the target system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.8C
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• pp.529-535
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• 2011

After permission for utilization of TV white space by FCC, a lot of attentions are focused on spectrum sensing, and various spectrum sensing methods have been proposed. However, they do not consider real environment, thus they are hard to achieve the required performance. In this paper, we propose resolutions for the problem which could be occurred in implementation of spectrum sensing module and verify performance of the proposed methods with computer simulation. The first proposed method utilizes channel status information to separate received signal and spurious for reducing false alarm probability caused by system internal spurious. The another proposed scheme is subband normalization method to prevent miss detection caused by multiple narrow band signals with different received signal strength. The simulation results verify that we can prevent false alarm cause by spurious components with the proposed system internal spurious cognition. Moreover, the proposed subband normalization method shows that it could overcome performance degradation caused by received signal strength difference.

• Convergence Security Journal
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• v.19 no.5
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• pp.47-53
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• 2019

Network-based sharing of information has evolved into a cloud service environment today, increasing its number of users rapidly, but has become a major target for network-based illegal attackers.. In addition, IP spoofing among attackers' various attack techniques generally involves resource exhaustion attacks. Therefore, fast detection and response techniques are required. The existing detection method for IP spoofing attack performs the final authentication process according to the analysis and matching of traceback information of the client who attempted the connection request. However, the simple comparison method of traceback information may require excessive OTP due to frequent false positives in an environment requiring service transparency. In this paper, symmetric key cryptography based on traceback information is used as mutual authentication information to improve this problem. That is, after generating a traceback-based encryption key, mutual authentication is possible by performing a normal decryption process. In addition, this process could improve the overhead caused by false positives.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.2
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• pp.457-469
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• 2018

This study aimed to investigate the fundamental reasons for the presence of multi-homed host and the risks associated with such risky system. Furthermore, multi-homed host detection methods that have been researched and developed so far were compared and analyzed to determine areas for improvement. Based on the results, we propose the model of an improved automatic detection system and we implemented it. The experimental environment was configured to simulate the actual network configuration and endpoints of an organization employing network segmentation. And the functionality and performance of the detection system were finally measured while generating multi-homed hosts by category, after the developed detection system had been installed in the experiment environment. We confirmed that the system work correctly without false-positive, false-negative in the scope of this study. To the best of our knowledge, the presented detection system is the first academic work targeting multi-homed host under agent-based.

• Journal of Korea Multimedia Society
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• v.17 no.3
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• pp.287-293
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• 2014

Early fire detection is very important to avoid loss of lives and material damage. The conventional smoke detector sensors have difficulties in detecting smoke in large outdoor areas. The video-based smoke detection can overcome these drawbacks. This paper proposes a new smoke detection method in video sequences. It uses the ratio of variation rate of subband energy in the wavelet transform domain. In order to reduce the false alarm, candidate smoke blocks are detected by using motion, decrease of chromaticity and the average intensity of block in the YUV color space. Finally, it decides whether the candidate smoke blocks are smokes or not by using their temporal changes of subband energies in the wavelet transform domain. Experimental results show that the proposed method noticeably increases the accuracy of smoke detection and reduces false alarm compared with the conventional smoke detection methods using wavelets.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.10
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• pp.1334-1339
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• 2018

Viola & Jones's face detection algorithm is a typical face detection algorithm and shows excellent face detection performance. However, the Viola & Jones's algorithm in images including many faces generates undetected faces and wrong detected faces, such as false faces and duplicate detected faces, due to face diversity. This paper proposes an improved face detection algorithm using a face verification algorithm that eliminates the false detected faces generated from the Viola & Jones's algorithm. The proposed face verification algorithm verifies whether the detected face is valid by evaluating its size, its skin color in the designated area, its edges generated from eyes and mouth, and its duplicate detection. In the face verification experiment of 658 face images detected by the Viola & Jones's algorithm, the proposed face verification algorithm shows that all the face images created in the real person are verified.

• Journal of the Society of Disaster Information
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• v.18 no.2
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• pp.364-373
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• 2022

Purpose: The purpose of this paper is to develope smoke detection using AI model for detecting the initial fire in underground utility tunnels using CCTV Method: To improve detection performance of smoke which is high irregular, a deep learning model for fire detection was trained to optimize smoke detection. Also, several approaches such as dataset cleansing and gradient exploding release were applied to enhance model, and compared with results of those. Result: Results show the proposed approaches can improve the model performance, and the final model has good prediction capability according to several indexes such as mAP. However, the final model has low false negative but high false positive capacities. Conclusion: The present model can apply to smoke detection in underground utility tunnel, fixing the defect by linking between the model and the utility tunnel control system.