• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.975-978
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• 2002

본 연구는 네트워크 기반 침입탐지 시스템(NIDS)의 우회공격 방지를 위한 적응적 규칙 추정 알고리즘(ARE; Adaptive Rule Estimation)을 제안한다. 네트워크 기반 침입탐지 시스템에서 가장 많이 사용하는 침입탐지 방법은 규칙 기반의 패턴 매칭 기법이며, 이 방법은 삽입과 삭제에 의한 우회 공격에 많은 취약성을 가지고 있다. 본 연구에서는 이러한 삽입과 삭제에 의한 우회 공격을 방지 하고자 하는 취지에서 제안된 알고리즘이다. 적응적 규칙 추정에 의한 침입 탐지 알고리즘은 두 개의 과정으로 구성되며, 전처리 부분에서는 최적의 규칙을 선택하고, 주처리 부분에서 적응적으로 규칙 패턴의 변형된 위치를 찾아서 비교 판단하는 과정으로 이루어져 있다. 제안된 적응적 규칙 추정 알고리즘은 기존의 규칙 기반 패턴 매칭에서 우회공격이 가능한 것들이 탐지되며, 미탐지 확률을 줄일 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.468-470
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• 2015

ActiveX가 법규제로 인해 없어지고 새로운 간편 절제 시스템이 출시되고 있다. 새롭게 도입되는 간편 결제 시스템의 경우 사용자가 한 번 내려 받으면 인터넷 익스플로러뿐만 아니라 사파리나 크롬 등 다른 브라우저를 사용 시 따로 보안프로그램을 내려 받지 않아도 된다고 한다. ActiveX대신 새로운 결제 시스템의 'exe'방식의 프로그램은 한 번 내려 받아 영구 사용할 수 있으며, 이러한 'exe' 프로그램은 인증우회가 가능하여 해커가 제3자의 금융정보를 가지게 된다면 간단한 우회를 통한 공격이 가능할 것으로 예측된다. 본 논문에서는 이러한 인증우회 공격에 관한 시나리오 및 'exe'프로그램 내부의 보안프로그램에서의 이상 징후 조기 탐지를 이용한 사전 예방기법을 제안한다.

• KIISE Transactions on Computing Practices
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• v.20 no.12
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• pp.694-699
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• 2014

In mobile ad-hoc networks (MANET), the network topology and neighboring nodes change frequently, since MANET is composed of nodes that have mobility without a fixed network infrastructure. The AODV routing protocol is advantageous for MANET, but AODV has a delay in the transmission of data packets because AODV can not transmit data during route recovery. This paper proposes solving the above problem of AODV by using a bypass generation mechanism for data transmission during route recovery. For further improvement, additional mechanisms that coordinate the reception threshold of a hello packet are proposed in order to improve the accuracy of the information obtained from the neighboring nodes when the bypass is generated due to a link failure and the immediacy of the route recovery. Simulation results show that the proposed technique improves the performance in terms of the delay in transmission compared to traditional AODV.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.54-67
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• 2013

The main purpose of this study is to analyze the diversion rate by the levels of delay and the types of display. For this study, we developed the logit model by analyzing the result of SP survey of drivers who have driver's licence after manipulating a virtual driving simulator. The result of analysis was that the types of display was not statistically significant to the diversion rate. On the other hand, the levels of delay was very meaningful factor with the diversion rate. When the main road was flowing smoothly, drivers started to detour at the levels of delay 125% under the traffic free flow state. Similarly, when the levels of delay got worse, the diversion rate kept the same percentage as it was at the levels of delay 125% state which represented a smooth road condition. Likewise, when the main road's traffic flow was slow, drivers appeared to make detours at the same state of the levels of delay 125%. It was found that as the levels of delay got worse, the diversion rose higher than the diversion rate at the condition of slow traffic flow situation with the levels of delay 125%. The result of this study suggests the criterion of drivers detour point. For the conclusion, the result of study would be a reasonable reference for establishing transportation strategies by reflecting drivers' detouring property and would improve the efficiency of traffic flow.

• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.91-102
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• 1999

The objective of this study is to evaluate traffic management strategies using Variable Message Signs(MCS) on urban freeways. It is well known that real-time information on traffic conditions increases driver's comfort, and reduces the risks of accidents if drivers are aware of the traffic situation in advance, they decide whether to divert from the freeway or continue on the planned route. The experimental data collected on the Olympic highway we have shown the following results : 1. when the information on both the congested freeway and uncontested diversion route is displayed on the variable message sign. an additional 1.7 percent of traffic diverted, which results in a 3.7 percent reduction in total travel time. 2 Compared with one Proposed VMS message of 'reduce the speed', the other Proposed VMS message of 'keep speed 70km/h' is found to be much more effective in reducing mean speed.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.651-653
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• 2011

본 논문에서는 모바일 노드들의 움직임이 심한 MANET 환경에서의 데이터의 전송을 안정적이고 신뢰성있게 하기 위한 방법을 제시하고자 한다. 우회경로가 적은 경우보다 우회경로가 많이 확보되었을 때 상호간의 통신이 더욱 안정적이나, 기존 연구에서는 이러한 고려가 충분히 되어있지 않고, 경로 설정 당시 알고리즘에 의해 최적화된 경로라고 판단된 경로만 기억해 놓기때문에 경로 손실이 되었을 때에 우회경로가 존재 함에도 불구하고 패킷 전송을 실패하게 된다. 본 논문에서는 확률에 기반한 안정도를 측정하고 MANET 환경에서 패킷전달 가능성이 높은 다중경로 라우팅 프로토콜 아이디어를 제시한다.

• 한국ITS학회:학술대회논문집
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• 2003.11a
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• pp.241-246
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• 2003

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.156-161
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• 2007

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.39-49
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• 2010

Although many studies have been carried out on the pattern of behavior of drivers which result from the provision of traffic information, there have been few detailed studies on the composition of message, method for message expression, timing of provision, point of provision, media for provision, changes by traffic condition, etc. This study was intended to provide an insight into the changes in the characteristics related to the provision of information by analyzing how the patterns of information utilization change depending on the traffic condition and reclassifying such patterns according to the characteristics of media. Unlike the existing studies, this study adopted the traffic condition, using rate of information media, and the correlation coefficient label as the basis for information media classification, and categorized them into passive utilization media, active utilization media, and past experience in order to ensure the statistical reasonability. The categorized using rate of information media and traffic condition was found to have a positive(+) correlation with the travel speed in the case of passive utilization media during both consecutive holidays(Korea's traditional Thanksgiving day) and weekends, but had a negative(-) correlation with the positive utilization media and past experience. The rate of decision to take a detour based on the past experience was high at the condition of congestion or slow during both consecutive holidays and weekends, but the rate of decision to take a detour through passive utilization media was high in a smooth traffic. In other words, if the traffic condition worsens, using rate of passive utilization media would be low while the diversion rate would be high which uses the active utilization media and past experience. Therefore, it should be established to suit the traffic condition and media characteristics for strategies of traffic distribution through drivers' diversion behavior on weekends and consecutive holidays.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1442-1448
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• 2003

Network Management become more and more important issue in the network environment in which many applications such as Mail, teleconferencing, WWW and database software are operated. It can be possible for The Bridge and Router forwarding data to select next hop device which results in routing incorrect path from the viewpoint of network design. In this paper we address the problem of finding the detour routing path due to incorrect setting on routing devices. We propose the new algorithm for finding detour muting path based on hierarchical network structure analysis using information from SNMP MIB. To prove the correctness of the unposed algorithm we have done simulation with predefined data. Simulation results show that the algorithm finds detour path correctly.