• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.19-20
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• 2023

전이학습은 영상 분류를 진행한 모델을 사용하여 다른 종류의 영상 분류에 적용하여 문제를 푸는 것을 의미하며, 모델 설계부터 진행한 학습 모델보다 빠른 속도와 높은 정확도를 달성할 수 있다. 또한, 적은 데이터셋에 대하여 학습을 진행하여 좋은 결과를 도출할 수 있는 장점이 존재한다. 본 논문에서는 전이학습으로 사용되는 모델 중 Xception 모델을 사용하며, 욕창 이미지의 모델 입력 크기를 256, 512, 1024의 크기로 설정하여 학습을 진행 후 욕창 이미지 크기별 성능을 비교분석을 진행하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2024.05a
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• pp.262-264
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• 2024

본 연구에서는 안드로이드 부트로더의 취약점을 효과적으로 발견하기 위한 에뮬레이션 기반 퍼징 프레임워크를 제안한다. 부트로더는 높은 권한을 가지고 실행되기 때문에 취약점이 존재할 경우 심각한 보안 위협이 될 수 있다. 그러나 부트로더는 다양한 하드웨어와 상호작용하기 때문에 에뮬레이션 하기에 어려움이 많다. 이에 본 연구에서는 QEMU 에뮬레이터를 기반으로 부트로더의 주변 장치를 모델링하여 효율적인 퍼징을 수행하였다. 실험 결과, 에뮬레이션을 통해 실제 기기 대비 높은 퍼징 속도를 달성하였으며, 지속적으로 새로운 코드 영역을 발견할 수 있음을 확인하였다. 본 연구의 프레임워크는 향후 부트로더 취약점 분석 및 보안 검증에 활용될 수 있을 것으로 기대된다.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.12
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• pp.1264-1268
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• 2010

In this paper, we propose a behavior pattern analysis method for users tasking on hands-on security exercise missions. By analysing and evaluating the observed user behavior data, the proposed method discovers some significant patterns able to contribute mission successes or fails. A Markov chain modeling approach and algorithm is used to automate the whole analysis process. How to apply and understand our proposed method is briefly shown through a case study, "network service configurations for secure web service operation".

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.4
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• pp.639-653
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• 2013

Smart grid is a network of computers and power infrastructure that monitor and manage energy usage efficiently. Recently, the smart grid demonstration projects around the world, including the United States, Europe, Japan, and the technology being developed. The protection of the many components of the grid against cyber-threats has always been critical, but the recent Smart grid has been threatened by a variety of cyber and physical attacks. We model and analyze advanced metering infrastructure(AMI) in smart grid. Using attack countermeasure tree(ACT) we show qualitative and probabilistic security analysis of AMI. We implement using SHARPE(Symbolic Hierarchical Automated Reliability and Performance Evaluator) tool and calculate probability, ROA, ROI, Structure Importance, Birnbaum Importance.

• Journal of the Korea Society for Simulation
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• v.17 no.2
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• pp.83-90
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• 2008

We introduce the coordination among the intrusion detection agents by BBA(BlackBoard Architecture) that belongs to the field of distributed artificial intelligence. The system which uses BBA for the coordination can be easily expanded by adding new agents and increasing the number of BB(BlackBoard) levels. Several simulation tests performed on the targer network will illustrate our techniques. And this paper applies PBN(Policy-Based Network) to reduce the false positives that is one of the main problems of IDS. The performance obtained from the coordination of intrusion detection agent with PBN is compared against the corresponding non PBN type intrusion detection agent. The application of the research results lies in the experimentation of the various security policies according to the network types in selecting the best security policy that is most suitable for a given network.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.1
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• pp.135-143
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• 2018

Sony has recently launched a remote play service that connects PC and PlayStation4 using the Internet. This service enables the network connection between the external network and PS4 network. After the service released, additional security threats may arise in remote environments with new services. Therefore, those threats should have been analyzed. In this paper, as applying threat modeling to remote play system, threats have been analyzed and identified. After cost-effective and usability analysis, finally, reasonable security measure of each threat has been suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5238-5244
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• 2011

Recently, wireless sensor networks have become increasingly interesting areas over extensive application fields such as military, ecological, and health-related areas. Almost sensor networks have mission-critical tasks that requires very high security. Therefore, extensive work has been done for securing sensor networks from outside attackers, efficient cryptographic systems, secure key management and authorization, but little work has yet been done to protect these networks from inside threats. This paper proposed an method to select which nodes should activate their idle nodes as detectors to be able to watch all packets in the sensor network. Suggested method is modeled as optimization equation, and heuristic Greedy algorithm based simulation results are presented to verify my approach.

• Journal of Energy Engineering
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• v.24 no.1
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• pp.123-131
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• 2015

This paper aims to identify and clarify the cyber security risks and their interaction with the power system in Smart Grid. The EMS and other communication networks interact with the power system on a real time basis, so it is important to understand the interaction between two layers to protect the power system from potential cyber threats. In this study, the optimal power flow(OPF) and Power Flow Tracing are used to assess the interaction between the EMS and the power system. Through OPF and Power Flow Tracing based analysis, the physical and economic impacts from potential cyber threats are assessed, and thereby the quantitative risks are measured in a monetary unit.

• Journal of Internet Computing and Services
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• v.16 no.5
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• pp.1-9
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• 2015

As attacks in cyber space become advanced and complex, monotonous defense approach of one-one matching manner between attack and defense may be limited to defend them. More efficient defense method is required. This paper proposes multi layers security scheme that can support to defend assets against diverse cyber attacks in systematical and adaptive. We model multi layers security scheme based on Defense Zone including several defense layers and also discuss essential technical elements necessary to realize multi layers security scheme such as cyber threats analysis and automated assignment of defense techniques. Also effects of multi layers security scheme and its applicability are explained. In future, for embodiment of multi layers security scheme, researches about detailed architecture design for Defense Zone, automated method to select the best defense technique against attack and modeling normal state of asset for attack detection are needed.

• Convergence Security Journal
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• v.18 no.5_1
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• pp.45-51
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• 2018

As data utilization and importance becomes important, data-related accidents and damages are gradually increasing. Especially, insider threats are the most harmful threats. And these insider threats are difficult to detect by traditional security systems, so rule-based abnormal behavior detection method has been widely used. However, it has a lack of adapting flexibly to changes in new attacks and new environments. Therefore, in this paper, we propose an adaptive anomaly movement detection framework based on a statistical Markov model to detect insider threats in advance. This is designed to minimize false positive rate and false negative rate by adopting environment factors that directly influence the behavior, and learning data based on statistical Markov model. In the experimentation, the framework shows good performance with a high F2-score of 0.92 and suspicious behavior detection, which seen as a normal behavior usually. It is also extendable to detect various types of suspicious activities by applying multiple modeling algorithms based on statistical learning and environment factors.