• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1583-1586
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• 2002

Mobile IP Scheme의 이동 에이전트들은 이동 노드가 무선환경에서 망의 경계를 지나 다른 망으로 소속이 변경되었는지, 어떤 망으로 변경되었는지를 알려주기 위해 주기적으로 방송을 한다. 홈 네트웍에서 외부 망으로 이동하는 경우에 외부 망에서 CoA 할당 및 바인딩 업 데이트를 통하여 이동성을 지원할 수 있지만 무선 인터넷과 같은 이동성이 빈번한 경우에는 이동에 따른 데이터의 손실과 전송지연에 따른 QoS를 보장할 수 없게 되는 주요한 문제가 발생하게 된다. 또한 MN 가 되돌아 오는 경우 모바일 단말이 현재의 셀에서 멀어지고 있거나, 이동했을 경우 이동감지 단계와 CoA 를 재 설정하고 등록에 따른 메시지 전달이 증가하기 때문에 오버헤드가 상당히 증가하게 되는 문제점을 가지고 있다. 본 논문에서는 모바일 단말이 이동이 빈번하거나 기존의 셀로 되돌아오는 경우에 모바일 단말에 프리픽스를 비교하여 재 등록에 따른 메시지 교환을 생략할 수 있게 함으로써 빠른 핸드오프를 가능하게 했다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.580-582
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• 2004

방대한 양의 웹 정보를 적절히 가공하여 사용자가 원하는 서비스를 생성하기란 쉽지 않다. 웹서비스는 사용자가 원하는 적절한 정보를 표준화된 인터페이스를 통해 처리할 수 있는 기능을 제공하고 결합을 통해 보다 복잡한 서비스를 생성할 수 있도록 해준다. 오프라인에서 물품을 사기 위해 상점에 들어갈 때 점원의 도움을 받는 것처럼 웹서비스도 상황에 맞춰 유연하게 제공되어야 한다 그러나 일반 웹서비스 생성은 사용자의 정보를 능동적으로 판단하지 않고 정적인 규칙에 의존한 결합이 주를 이루고 있다 본 논문의 서비스 에이전트는 행동 네트워크를 사용하여 사용자에게 적절한 서비스를 제공한다. 행동 네트워크는 외부환경과 내부목표를 바탕으로 각각의 행동들이 서로 연결 관계를 가지고 있다. 각각의 행동의 선택은 다른 행동과 외부환경에 영향을 주기 때문에 동적으로 사용자의 환경과 입력이 변하여도 적절히 대처하며 서비스 선택을 할 수 있다. 행동 네트워크를 바탕으로 동적 서비스 생성 시스템을 만들었고, 이를 이용하여 Amazon 도메인에서 능동적인 서비스 제공이 가능함을 보였다.

• The KIPS Transactions:PartC
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• v.13C no.3 s.106
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• pp.359-368
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• 2006

AAA(Authentication, Authorization, Accounting) is the service that offers authentication, authorization, and accounting method, and every terminal that accesses the network requires this AAA service. The authentication process of a mobile terminal is as follows: a mobile phone accesses an authentication server in a home network via the authentication service in an external network, which receives the authentication result. And, for the home authentication server to offer secure service, a unique key is distributed for the secure communication between the external agent and the user, the external agent and the home authentication server, and the user and the home authentication server. This paper discusses and proposes the key distribution for secure communication among external authentication servers when a mobile terminal travels to an external network. As the proposed method does not require the home authentication server to reissue another authentication when a user travels to other external networks, it reduces the overload in the home authentication server. It can also distribute a PIN-driven key.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1169-1177
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• 2018

Modern society is a period of rapid digital transformation. This digital-centric business proliferation offers convenience and efficiency to businesses and individuals, but cyber threats are increasing. In particular, cyber attacks are becoming more and more intelligent and precise, and various attempts have been made to prevent these attacks from being discovered. Therefore, it is increasingly difficult to respond to such attacks. According to the cyber kill chain concept, the attacker penetrates to achieve the goal in several stages. We aim to detect one of these stages and neutralize the attack. In this paper, we propose a method to detect anomalous traffic caused by an agent attacking an external attacker, assuming that an agent executing a malicious action has been introduced in advance due to various reasons such as a system error or a user's mistake.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1363-1372
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• 2011

Flooding based routing protocols are usually used to disseminate information in wireless sensor networks. Those approaches, however, require message retransmissions to all nodes and induce huge collision rate and high energy consumption. In this paper, HoGoP (Hop based Gossiping Protocol) in which all nodes consider the number of hops from sink node to them, and decide own gossiping probabilities, is introduced. A node can decide its gossiping probability according to the required average reception percentage and the number of parent nodes which is counted with the difference between its hop and neighbors' ones. Therefore the decision of gossiping probability for network topology is adaptive and this approach achieves higher message reception percentage with low message retransmission than the flooding scheme. Through simulation, we compare the proposed protocol with some previous ones and evaluate its performance in terms of average reception percentage, average forwarding percentage, and forwarding efficiency. In addition, average reception percentage is analyzed according to the application requirement.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.858-861
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• 2002

As mobile devices have become widely popular, users want to use devices not only wireless but also mobile. Mobile IP is used to support mobility on TCP/IP network. In mobile IP, when a terminal changes location, the terminal requests a registration to Home Agent through Foreign Agent in new location. After the request is accepted by Home Agent, the terminal can use network again. We call this process as handoff. In mobile n, handoff provokes loss of data packets and network delay. In this paper, we describe the implementation of pre-registration which is a solution of the handoff problems. Pre-registration improves the traditional handoff mechanism by requesting registration through current FA before location change. This muchanism can decrease packet loss and network delay.

• The Journal of the Korea Contents Association
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• v.6 no.11
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• pp.285-294
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• 2006

In this paper, we propose a new remote control and monitoring technique using web-service technology for URC robot. URC robot needs the architecture which can be applied all over the variety hardware and software platform for supporting the several interface with external world in the ubiquitous environment. In this paper, web-service technology is preferentially deliberated how to adopt into the embedded environment and the remote control and monitoring technology based on web-service technology for URC robot is designed and implemented as to support the interaction with agent programs. It has been carried out through simulating and implementing this technology into the target robot called NETTORO and proved its practical worth.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.3
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• pp.99-106
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• 2018

In the process of acquiring information through the cyber ISR (Intelligence Surveillance Reconnaissance) and research into the agent to help decision-making, periodic communication between the C&C (Command and Control) server and the agent may not be possible. In this case, we have studied how to effectively surveillance and reconnaissance. Due to the network configuration, agents planted on infiltrated computers can not communicate seamlessly with C&C servers. In this case, the agent continues to collect data continuously, and in order to analyze the collected data within a short time in When communication is possible with the C&C server, it can utilize limited resources and time to continue its mission without being discovered. This research shows the superiority of incremental learning method over batch method through experiments. At an experiment with the restricted memory of 500 mega bytes, incremental learning method shows 10 times decrease in learning time. But at an experiment with the reuse of incorrectly classified data, the required time for relearn takes twice more.

• Journal of the Korea Society for Simulation
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• v.27 no.4
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• pp.1-8
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• 2018

The most common way to control a target point using artificial intelligence is through reinforcement learning. However, it had to process complicated calculations that were difficult to implement in order to process reinforcement learning. In this paper, the enhanced Proximal Policy Optimization (PPO) algorithm was used to simulate finding the planned flight trajectory to reach the target point in the virtual environment. In this paper, we simulated how this problem was used to find the planned flight trajectory to reach the target point in the virtual environment using the enhanced Proximal Policy Optimization(PPO) algorithm. In addition, variables such as changes in trajectory, effects of rewards, and external winds are added to determine the zero conditions of external environmental factors on flight trajectory learning, and the effects on trajectory learning performance and learning speed are compared. From this result, the simulation results have shown that the agent can find the optimal trajectory in spite of changes in the various external environments, which will be applicable to the actual vehicle.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.491-494
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• 2002

기존의 네트워크 보안은 침입 징후를 탐지하여 외부 공격자로부터 오는 트래픽을 차단함으로써 자신의 도매인만을 보호하였다. 이는 공격자로 하여금 제 2, 제 3의 공격을 가능하게 하고 공격자에 대한 대응에 있어서도 각 도매인간의 협력이 없는 상태를 야기하였다. 따라서 각 도메인 간의 데이터의 상호 결합과 협력을 통해 공격자의 실제 위치를 추적하여 침입 근원지로부터의 트래픽을 차단함으로써 공격자를 네트워크로부터 고립시키고자 하는 연구가 진행되고 있지만, 이는 분산서비스거부 공격의 경우 제한적이다. 그러므로 본 논문은 분산서비스거부 공격에 있어 에이전트와 마스터의 위치를 추적하여 제거하고 실제 공격자를 고립시킬 수 대응 메커니즘에 대해 논의한다.