• Convergence Security Journal
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• v.23 no.3
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• pp.21-28
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• 2023

The development of information and communication technology in the 21st century has increased operational efficiency by providing hyper-connectivity and hyper-intelligence in the control systems of major infrastructure, but is also increasing security vulnerabilities, exposing it to hacking threats. Among them, the electric power system that supplies electric power essential for daily life has become a major target of cyber-attacks as a national critical infrastructure system. Recently, in order to protect these power systems, various security systems have been developed and the stability of the power systems has been maintained through practical cyber battle training. However, as cyber-attacks are combined with advanced ICT technologies such as artificial intelligence and big data, it is not easy to defend cyber-attacks that are becoming more intelligent with existing security systems. In order to defend against such intelligent cyber-attacks, it is necessary to know the types and aspects of intelligent cyber-attacks in advance. In this study, we analyzed the evolution of cyber attacks combined with advanced ICT technology.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.25-32
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• 2019

In this paper, we propose a method to apply the attack surface expansion through decoy traps to a protected server network. The network consists of a large number of decoys and protected servers. In the network, each protected server dynamically mutates its IP address and port numbers based on Hidden Tunnel Networking that is a network-based moving target defense scheme. The moving target defense is a new approach to cyber security and continuously changes system's attack surface to prevent attacks. And, the attack surface expansion is an approach that uses decoys and decoy groups to protect attacks. The proposed method modifies the NAT table of the protected server with a custom chain and a RETURN target in order to make attackers waste all their time and effort in the decoy traps. We theoretically analyze the attacker success rate for the protected server network before and after applying the proposed method. The proposed method is expected to significantly reduce the probability that a protected server will be identified and compromised by attackers.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.99-113
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• 2021

In these days, as cyberspace has been recognized as the fifth battlefield area following the land, sea, air, and space, attention has been focused on activities that view cyberspace as an operational and mission domain in earnest. Also, in the 21st century, cyber operations based on cyberspace are being developed as a 4th generation warfare method. In such an environment, the success of the operation is determined by the commander's decision. Therefore, in order to increase the rationality and objectivity of such decision-making, it is necessary to systematically establish and select a course of action (COA). In this study, COA is established by using the method of classifying operational elements necessary for cyber operation, and it is intended to suggest a direction for quantitative evaluation of COA. To this end, we propose a method of composing the COES (Cyber Operational Elements Set), which becomes the COA of operation, and classifying the cyber operational elements identified in the target development process based on the 5W1H Method. In addition, by applying the proposed classification method to the cyber operation elements used in the STUXNET attack case, the COES is formed to establish the attack COAs. Finally, after prioritizing the established COA, quantitative evaluation of the policy was performed to select the optimal COA.

• Journal of Internet Computing and Services
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• v.22 no.1
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• pp.41-50
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• 2021

Cyber Kill Chain is derived from Kill chain of traditional military terms. Kill chain means "a continuous and cyclical process from detection to destruction of military targets requiring destruction, or dividing it into several distinct actions." The kill chain has evolved the existing operational procedures to effectively deal with time-limited emergency targets that require immediate response due to changes in location and increased risk, such as nuclear weapons and missiles. It began with the military concept of incapacitating the attacker's intended purpose by preventing it from functioning at any one stage of the process of reaching it. Thus the basic concept of the cyber kill chain is that the attack performed by a cyber attacker consists of each stage, and the cyber attacker can achieve the attack goal only when each stage is successfully performed, and from a defense point of view, each stage is detailed. It is believed that if a response procedure is prepared and responded, the chain of attacks is broken, and the attack of the attacker can be neutralized or delayed. Also, from the point of view of an attack, if a specific response procedure is prepared at each stage, the chain of attacks can be successful and the target of the attack can be neutralized. The cyber command and control system is a system that is applied to both defense and attack, and should present defensive countermeasures and offensive countermeasures to neutralize the enemy's kill chain during defense, and each step-by-step procedure to neutralize the enemy when attacking. Therefore, thist paper proposed a cyber kill chain model from the perspective of defense and attack of the cyber command and control system, and also researched and presented the threat classification/analysis/prediction framework of the cyber command and control system from the defense aspect

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.629-636
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• 2022

We present a preprocessing method for an underwater target detection model based on a convolutional neural network. The acoustic characteristics of the ship show ambiguous expression due to the strong signal power of the low frequency. To solve this problem, we combine feature preprocessing methods with various feature scaling methods and spectrogram methods. Define a simple convolutional neural network model and train it to measure preprocessing performance. Through experiment, we found that the combination of log Mel-spectrogram and standardization and robust scaling methods gave the best classification performance.

• Annual Conference of KIPS
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• 2015.04a
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• pp.456-459
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• 2015

인터넷 활용이 다양해짐에 따라서, 사이버 상의 특정 조직에 대한 표적공격에서부터 불특정 다수에 대한 공격까지 불법적인 경로를 통해 목적을 달성하거나 금전적인 이득을 취하기 위한 사이버 공격기법은 갈수록 그 경로가 다양해지고 치밀해지고 있다. 스마트폰의 등장과 함께 휴대용 기기의 사용은 급증하였고, 휴대성과 편리성은 많은 사람들의 서비스 이용환경을 데스크톱환경에서 이동환경으로 변화되고 있다. 이러한 환경의 변화는 보안위협 경로를 확장시킨다. 지능적이고 다양해진 보안 위협으로부터 조직의 시스템에 대한 통합적 가시성을 확보하는 일은 위협에 대비할 수 있는 방법을 제공할 수 있게 된다. 본 연구에서는 보안위협이 될 수 있는 상황을 탐지하기 위해서 조직의 특성에 맞는 보안정책을 수립하는 방법에 대해 정리하고 이에 따른 보안 관제와 운영을 할 수 있는 시스템 설계 방법을 제안하고자 한다.

• Annual Conference of KIPS
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• 2015.10a
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• pp.872-874
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• 2015

최근 침해사고는 특정 목적을 지닌 공격자들은 자신의 목적을 달성하기 위해 공격을 지속적으로 감행하는 특징을 보인다. 하지만, 기존에 진행된 악성코드 감염 호스트 분석, 네트워크 행위기반 분석 등의 단일 침해사고에 대한 분석은 다른 침해사고와의 관계를 유기적으로 연결하지 못하기 때문에, 타 침해사고와의 연관성 분석, 동일 공격자의 특성 파악을 통한 표적형 공격 및 향후 공격예측을 지원하지 못한다는 단점이 있다. 본 논문에서는 이러한 문제점을 해결하기 위해서, 상용에서 서비스되고 있는 사이버 위협정보 공유 시스템의 정보를 기반으로 이와 연관된 정보의 이력 및 유사관계를 관리하여 침해사고간의 연관성을 파악하는 방법을 제시한다.

• Convergence Security Journal
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• v.11 no.6
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• pp.53-58
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• 2011

There is increasing use of common commercial operation system and standard PCs to control industrial production systems, and cyber security threat for industrial facilities have emerged as a serious problem. Now these network connected ICS(Industrial Control Systems) stand vulnerable to the same threats that the enterprise information systems have faced and they are exposed to malicious attacks. In particular Stuxnet is a computer worm targeting a specific industrial control system, such as a gas pipeline or power plant and in theory, being able to cause physical damage. In this paper we present an overview of the general configuration and cyber security threats of a SCADA and investigate the attack tree analysis to identify and assess security vulnerabilities in SCADA for the purpose of response to cyber attacks in advance.

• Electronics and Telecommunications Trends
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• v.30 no.4
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• pp.92-101
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• 2015

미래 전장은 정보 지식 기반의 첨단 전력체계를 확충하기 위해 향후 전력구조를 통합, 지휘통제통신(C4I) 체계와 생존성과 통합성이 향상된 전장의 네트워크중심전(NCW) 수행능력을 향상시킬 것이다. 사이버물리시스템(Cyber-Physical Systems: CPS)은 함정전투체계에 적용되고 있는 DDS를 포함하여 국방 M&S의 근간인 Live, Virture, Constructive(L-V-C) 체계의 큰 축을 형성하고 있다. 사물인터넷(Internet of Things: IoT) 기술은 센서네트워크, 통신, Radio Frequency Identification(RFID), Ubiquitous Sensor Network(USN), Machine to Machine(M2M), D2D 기술 및 상황인지, 지능서비스를 위한 정보수집/가공/융합/분석/예측기술을 포괄적으로 포함한 기술로서 미래산업을 이끌어 갈 차세대 선도 기술이며, 특히 군사적으로도 감시정찰 센서네트워크(USN), 견마형로봇, 경전투로봇과 무인기 기술 및 전술정보통신망체계(TICN) 등 첨단 통신네트워크 기술의 전력화 추세는 IoT 기술의 적용영역을 넓혀주고 있다. 감시정찰체계(Sensor)에서는 감시정찰 분야 영상정보 처리, 표적탐지 등과 관련된 IoT 기술 소요와 지휘통제통신(C4I) 체계의 상호운용성, 데이터링크, 지능형 통신체계 등 C4I 관련 IoT 기술 소요 및 타격체계(Shooter)의 내장형 SW 등 유 무인 무기체계 관련 IoT 기술의 소요가 증대될 것으로 예상된다. 본고는 CPS 및 IoT 기술의 군사적 활용방안 및 획득전략에 대한 적용기술 및 발전방향을 살펴본다.

• Radiation Oncology Journal
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• v.24 no.2
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• pp.88-95
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• 2006

Purpose: We evaluated whether Cyberknife radiosurgery is an effective and safe method of therapy for medically intractable trigeminal neuralgia (TN). Materials and Methods: We retrospectively analyzed the outcome of 26 patients, who failed to surgery or were not suitable candidates for invasive intervention and were treated by Cyberknife radiosurgery between March 2004 and May 2005. Radiosurgery doses of $60{\sim}64 Gy$ were delivered to the 80% isodose line prescribed to an 6 mm length of the nerve, sparing the most proximal 3 mm away from the trigeminal nerve root entry zone (median dose: 64 Gy). Results: Follow-up period was $3{\sim}15$ months (median follow-up period: 9 months) Preliminary results from a cohort of 26 patients undergoing Cyberknife radiosurgery for TN showed that pain relief was achieved in 50% (13/26) of patients within the first 24 hrs after treatment. At last follow-up, 96.2% (25/26) of patients reported early pain relief within 7 days. Treatment failure developed in 2 of 26. Poor response occurred in one patient and relapse was observed in the other patient. 3 patients had hypoesthesia (11.5%), which was the only complication observed with any of our patients. Conclusion: With these results, authors assumed that Cyberknife radiosurgery for TN could be one of safe and effective therapeutic methods.