• Convergence Security Journal
• /
• v.19 no.4
• /
• pp.77-85
• /
• 2019

As the Internet continues to evolve, cyber attacks are becoming more precise and covert. Anonymous communication, which is used to protect personal privacy, is also being used for cyber attacks. Not only it hides the attacker's IP address but also encrypts traffic, which allows users to bypass the information protection system that most organizations and institutions are using to defend cyber attacks. For this reason, anonymous communication can be used as a means of attacking malicious code or for downloading additional malware. Therefore, this study aims to suggest a method to detect and block encrypted anonymous communication as quickly as possible through artificial intelligence. Furthermore, it will be applied to the defense to detect malicious communication and contribute to preventing the leakage of important data and cyber attacks.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.5
• /
• pp.145-154
• /
• 2007

Analyzed about a matter and requirements to intimidate security of ubiquitous and home network threatening various security for personal information protection in ubiquitous home networks at this paper, and studied. Got authentication procedures and verification procedures acid user approach to be reasonable through designs to the home security gateway which strengthened a security function in the outsides, and strengthened protection of a home network. Also, execute a DoS. DDoS, IP Spoofing attack protective at home network security gateways proved, and security regarding against the Hacker's attack was performed, and confirmed. Strengthen appliances and security regarding a user, and confirm a defense regarding an external attack and present a home network security model of this paper to the plans that can strengthen personal information protection in ubiquitous home networks in ubiquitous home networks through experiment.

• KSCI Review
• /
• v.15 no.1
• /
• pp.65-75
• /
• 2007

Analyzed about a matter and requirements to intimidate security of ubiquitous and home network threatening various security for personal information protection in ubiquitous home networks at these papers, and studied. Got authentication procedures and verification procedures acid user approach to be reasonable through designs to the home security gateway which strengthened a security function in the outsides, and strengthened protection of a home network. Also, execute a DoS, DDoS, IP Spoofing attack protective at home network security gateways proved, and security regarding an external denial of service attack was performed, and confirmed. Strengthen appliances and security regarding a user, and confirm a defense regarding an external attack like DoS, DDoS, IP Spoofing, and present a home network security model of this paper to the plans that can strengthen personal information protection in ubiquitous home networks in ubiquitous home networks through experiment.

• Journal of the Korean Society of Radiology
• /
• v.16 no.5
• /
• pp.527-536
• /
• 2022

The radiation shielding characteristic of neutron shielding material has been studied as the preliminary study in order to design cosmic-ray shielding material. Specially, Soft Magnetic Material, known to be effective in EMP and radiation shielding, has been investigated to check if the material would be applicable to cosmic-ray shielding. In this work, thermal neutron shielding experiment was conducted and the Monte Carlo N-Particle(MCNP) was applied to employ skymap.dat, which is cosmic-ray data embedded in MCNP. As a result, polyethylene, borated polyethylene, and carbon nano tube, containing carbon or hydrogen, have been found to be effective in reduction of neutron flux below 20 MeV (including thermal, epithermal, evaporation). In contrast, the materials composed of iron such as SS316 and Soft Magnetic Material show a good shielding performance in the cascade energy range (above 20 MeV). Since Soft Magnetic Material is consisting of 13% of boron, it can also decrease thermal neutron flux, so it is expected that it would show a significant reduction on the entire range of neutron energy if the Soft Magnetic Material is used with hydrogen and carbon, so called low Z material.

• Journal of Internet Computing and Services
• /
• v.23 no.6
• /
• pp.15-26
• /
• 2022

Various subjects are carrying out cyberattacks using a variety of tactics and techniques. Additionally, cyberattacks for political and economic purposes are also being carried out by groups which is sponsored by its nation. To deal with cyberattacks, researchers used to classify the malware family and the subjects of the attack based on malware signature. Unfortunately, attackers can easily masquerade as other group. Also, as the attack varies with subject, techniques, and purpose, it is more effective for defenders to identify the attacker's purpose and goal to respond appropriately. The essential goal of cyberattacks is to threaten the information security of the target assets. Information security is achieved by preserving the confidentiality, integrity, and availability of the assets. In this paper, we relabel the attacker's goal based on MITRE ATT&CK® in the point of CIA triad as well as classifying cyber security reports to verify the labeling method. Experimental results show that the model classified the proposed CIA label with at most 80% probability.

• Journal of Broadcast Engineering
• /
• v.27 no.6
• /
• pp.936-939
• /
• 2022

As air combat system technologies developed in recent years, the development of air defense systems is required. In the operating concept of the anti-aircraft defense system, selecting an appropriate armament for the target is one of the system's capabilities in efficiently responding to threats using limited anti-aircraft power. Much of the flying threat identification relies on the operator's visual identification. However, there are many limitations in visually discriminating a flying object maneuvering high speed from a distance. In addition, as the demand for unmanned and intelligent weapon systems on the modern battlefield increases, it is essential to develop a technology that automatically identifies and classifies the aircraft instead of the operator's visual identification. Although some examples of weapon system identification with deep learning-based models by collecting video data for tanks and warships have been presented, aerial vehicle identification is still lacking. Therefore, in this paper, we present a model for classifying fighters, helicopters, and drones using a convolutional neural network model and analyze the performance of the presented model.

• Journal of Radiation Protection and Research
• /
• v.20 no.4
• /
• pp.227-236
• /
• 1995

Using beam data and accurate 3D dose model, a study of the spatial dose distribution for various arcs was carried out. The dose dirstibution generated by the accurate dose model could be represented by a simple approximate analytic form which is convenient and very efficient for calculating dose distribution iteratively in the optimization procedure. We developed an empirical cylindrical dose model to compute dose for one full rotational arc or partial rotational arc. After a tedious search for fits to a collection of 200 points of accurate dose data, we found simple formular with 7 parameters search. As a consequence, the programs required approximately less than 1 second to compute dose for one single arc on a 20 by 20 matrix (400 points) using fast approximate dose model. In conclusion the fast approximate dose model give dose distributions similar to the accurate dose model, which makes this fast dose model an attractive alternative to the accurate 3D dose model.

• Annual Conference of KIPS
• /
• 2024.05a
• /
• pp.666-669
• /
• 2024

연합학습은 원본 데이터를 공유하지 않고 모델을 학습할 수 있는 각광받는 프라이버시를 위한 학습방법론이다. 이를 위해 참여자의 데이터를 수집하는 대신, 데이터를 인공지능 모델 학습의 요소들(가중치, 기울기 등)로 변환한 뒤, 이를 공유한다. 이러한 강점에 더해 기존 연합학습을 개선하는 방법론들이 추가적으로 연구되고 있다. 기존 연합학습은 모델 가중치를 평균내는 것으로 참여자 간에 동일한 모델 구조를 강요하기 때문에, 참여자 별로 자신의 환경에 알맞은 모델 구조를 사용하기 어렵다. 이를 해결하기 위해 지식 증류 기반의 연합학습 방법(Knowledge Distillation-based Federated Learning)으로 서로 다른 모델 구조를 가질 수 있도록(Model Heterogenousity) 하는 방법이 제시되고 있다. 연합학습은 여러 참여자가 연합하기 때문에 일부 악의적인 참여자로 인한 모델 포이즈닝 공격에 취약하다. 수많은 연구들이 기존 가중치를 기반으로한 연합학습에서의 위협을 연구하였지만, 지식 증류 기반의 연합학습에서는 이러한 위협에 대한 조사가 부족하다. 본 연구에서는 최초로 지식 증류 기반의 연합학습에서의 모델 성능 하락 공격에 대한 위협을 실체화하고자 한다. 이를 위해 우리는 GMA(Gaussian-based Model Poisoning Attack)과 SMA(Sign-Flip based Model Poisoning Attack)을 제안한다. 결과적으로 우리가 제안한 공격 방법은 실험에서 최신 학습 기법에 대해 평균적으로 모델 정확도를 83.43%에서 무작위 추론에 가깝게 떨어뜨리는 것으로 공격 성능을 입증하였다. 우리는 지식 증류 기반의 연합학습의 강건성을 평가하기 위해, 새로운 공격 방법을 제안하였고, 이를통해 현재 지식 증류 기반의 연합학습이 악의적인 공격자에 의한 모델 성능 하락 공격에 취약한 것을 보였다. 우리는 방대한 실험을 통해 제안하는 방법의 성능을 입증하고, 결과적으로 강건성을 높이기 위한 많은 방어 연구가 필요함을 시사한다.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.34 no.5
• /
• pp.875-884
• /
• 2024

The proliferation of IoT networks has led to an increase in cyber attacks, highlighting the importance of Network Intrusion Detection Systems (NIDS). To overcome the limitations of traditional NIDS and cope with more sophisticated cyber attacks, there is a trend towards integrating artificial intelligence models into NIDS. However, AI-based NIDS are vulnerable to adversarial attacks, which exploit the weaknesses of algorithm. Model Type Inference Attack is one of the types of attacks that infer information inside the model. This paper proposes an optimized framework for Model Type Inference attacks against NIDS models, applying more realistic assumptions. The proposed method successfully trained an attack model to infer the type of NIDS models with an accuracy of approximately 0.92, presenting a new security threat to AI-based NIDS and emphasizing the importance of developing defence method against such attacks.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05b
• /
• pp.730-734
• /
• 1998

난포성숙호르몬(FSH)은 난소내 난포의 성장인자로 작용한다. 본 실험은 방사선 조사된 미성숙 생쥐의 난포 폐쇄가 ESH에 의해 억제되는지를 확인하는 한편 방사선어제 개발을 위한 실험모델로서의 가능성을 평가하기 위해 수행되었다. PCNA 에 의한 염색의 정도는 FSH군의 경우, 1이에 최저, 12시간과 8일에 가장 많이 염색되었으며, 방사선을 조사한 후 ESH를 주사한 경우, PCNA에 의한 염색용은 6시간 경과시어 제일 낮게 나타나고 이후 증가하는 경향성을 보였다. 즉, FSH는 방사선에 피폭된 난소내 난포외 apoptosis를 지연시키는 효과를 갖고 있음을 알 수 있었다. 본 연구의 결과, 특정물질의 방사선방어효능 평가를 위한 실험모델로서 난소내 난포를 활용할 수 있으며 특히 FSH가 나타내는 난포폐쇄 억제효과도 방사선방어제 개발을 위한 실험연구에 중요한 역할을 할 것으로 기대된다.