• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.5
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• pp.985-990
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• 2007

The method of enhancing visibility in optical fiber sensor was investigated by improving coherence length of light source. The optical feedback technique is used to enhance coherence length in fiber laser which generates laser in near infrared wavelength region and utilizes low loss characteristics of optical communication grade fiber. In this paper, the effect to coherence length by short and long optical feedback paths are investigated by using Mach-Zehnder interferometer technique. The effect to coherence length by changing optical feedback power and optical modulation are investigated. The spectral drift was calculated by measuring the degree of phase perturbation in unbalanced Mach-Zehnder interferometer having loom path difference. The short optical feedback path was effective to reduce spectral drift to 450kHz/sec and the long optical feedback path in combination with short optical feedback path was found to further reduce spectral drift to 50kHz/sec.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.1
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• pp.1-6
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• 2021

Recently, unmanned facilities have been introduced and operated in a way that reduces the cost and development of IT technology. Although unmanned facilities have advantages in terms of efficiency and economy, they have disadvantages such as failure of unmanned facilities and malfunctions, causing damage to facilities caused by intruders, and information leakage. In addition, it is necessary to visit the person in charge at all times to inspect the unmanned facilities, resulting in management costs. In this paper, we designed a system that checks the status of unmanned surveillance facilities in real time to check and automatically recover problems such as malfunctions, and to notify managers of situations by text messages in real time. The system to be designed consists of an integrated network video server (NVR) that receives and determines information on the operation status of the main equipment such as video, sound, and lighting, and a real-time text message using an SMS server.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6845-6848
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• 2014

This paper proposes a system design of IDS for detecting and defending against DDoS attacks on a network. The proposed system has three parts; the Alert, Attack Analyzer and Defense agent. When the server resource was reduced too much by incoming traffic, the Alert Agent sends message and traffic information to the Attack Analyzer. The message and traffic to the Attack analyzer include only the sender & receiver address and packet numbers for minimizing the overload of Attack Analyzer. Message Received Attack Analyzer investigates the Message. If the pattern of traffic is the same as the DDoS Style, the Analyzer sends a message to the Defense Agent to block that traffic. In this system, at the serious state of the server-down, the Attack analyzer uncovers the DDoS Attacker and send a message to the Defense Agent to block that traffic. This works for server reactivation as soon as possible.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.3
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• pp.26-33
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• 2017

Recently container technologies have been receiving attention for efficient use of the cloud platform. Container virtualization technology has the advantage of a highly portable, high density when compared with the existing hypervisor. Container virtualization technology, however, uses a virtualization technology at the operating system level, which is shared by a single kernel to run multiple instances. For this reason, the feature of container is that the attacker can obtain the root privilege of the host operating system internal the container. Due to the characteristics of the container, the attacker can attack the root privilege of the host operating system in the container utilizing the vulnerability of the kernel. In this paper, we propose a framework for efficiently detecting and responding to root privilege attacks of a host operating system in a container. This framework uses a memory trap technique to detect changes in a specific memory area of a container and to suspend the operation of the container when it is detected.

• Journal of the Korea Society of Computer and Information
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• v.28 no.11
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• pp.89-101
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• 2023

In order to prevent damages caused by cyber-attacks on nations, businesses, and other entities, anomaly detection techniques for early detection of attackers have been consistently researched. Real-time reduction and false positive reduction are essential to promptly prevent external or internal intrusion attacks. In this study, we hypothesized that the type and frequency of attack events would influence the improvement of anomaly detection true positive rates and reduction of false positive rates. To validate this hypothesis, we utilized the 2015 login log dataset from the Los Alamos National Laboratory. Applying the preprocessed data to representative anomaly detection algorithms, we confirmed that using characteristics that simultaneously consider the type and frequency of attack events is highly effective in reducing false positives and execution time for anomaly detection.

• Korean Journal of Ichthyology
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• v.17 no.3
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• pp.187-194
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• 2005

Feeding of the maiden goby, Pterogobius virgo and multicolorfin rainbowfish, Halichoeres poecilopterus, was studied at Kurahashi Island in the Seto Inland Sea, Japan. P. virgo foraged on only benthic invertebrates in a pit on the bottom by spot-fixed fin digging. Territory size of P. virgo was very small, because they only defended the excavated pit. H. poecilopterus frequently intruded into the feeding territory of P. virgo and fed on benthic invertebrates flushed out by the fin digging of P. virgo. Feeding activity and vigilance time of P. virgo tended to decrease significantly more in such an association than when solitary. Frequency of aggression of P. virgo when H.poecilopterus intruded into the territory was higher the intruder came from the front of the territory than when the invasion was from the side and back, regardless of the size of the intruder. In small H.poecilopterus, feeding success rate was greater from the side and back of the territory than from the front. However, similar-sized H.poecilopterus were more successful in feeding from the front and side. Feeding association provides an antipredatory benefit to P. virgo because of less alert time against predators and earlier detection of predators, although their cost is great because of territory defense and decrease of feeding activity.

• Korean Security Journal
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• no.19
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• pp.225-244
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• 2009

Electronic security system is composed mainly of electronic-information-communication device, so system technology, configuration and management of the electronic security system could be affected by the change of information-communication environment. This study is to propose the future prospect on the development of technique for electronic security system through the analysis of the trend and the actual condition on the development of technique. This study is based on literature study and interview with user and provider of electronic security system, also survey was carried out by system provider and members of security integration company to come up with more practical result. Hybrid DVR technology that has multi-function such as motion detection, target tracking and image identification is expected to be developed. And 'Embedded IP camera' technology that internet server and image identification software are built in. Those technologies could change the configuration and management of CCTV system. Fingerprint identification technology and face identification technology are continually developed to get more reliability, but continual development of surveillance and three-dimension identification technology for more efficient face identification system is needed. As radio identification and tracking function of RFID is appreciated as very useful for access control system, hardware and software of RFID technology is expected to be developed, but government's support for market revitalization is necessary. Behavior pattern identification sensor technology is expected to be developed and could replace passive infrared sensor that cause system error, giving security guard firm confidence for response. The principle of behavior pattern identification is similar to image identification, so those two technology could be integrated with tracking technology and radio identification technology of RFID for total monitoring system. For more efficient electronic security system, middle-ware's role is very important to integrate the technology of electronic security system, this could make possible of installing the integrated security system.