• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.321-323
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• 1999

UNIX 시스템에서 로그 시스템은 공격시 쉽게 변경 및 삭제되는 위험성이 있고 제한된 시스템 및 네트워크 정보를 제공하므로, 보다 안전하고 풍부한 정보의 제공을 위해 패킷 필터링을 이용한 로그 시스템 등이 제안되어 왔다. 그러나 기존의 패킷 필터링을 이용한 로그 시스템에서는 모든 패킷을 기록하여 많은 양의 데이터가 발생하였으므로, 관리자가 그 정보를 분석하기란 어려웠다. 본 논문에서는 패킷을 처리하는 과정에서 각종 유형의 침입에 대한 사전 조사와 분석으로 얻은 명령어와 인자들의 결합에 의한 판정 규칙을 적용하여, 위험가능성이 내재된 패킷만을 수집, 기록함으로서 데이터의 양을 줄이고 보다 효율적인 로그 정보를 기록할 수 있었다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.302-304
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• 2003

최근 인터넷을 통하여 급속히 확산되고 있는 분산 서비스 거부 공격은 전 세계 웹 사이트들에 큰 피해를 입히면서 세계적인 문제로 부상되었다. 현재 이에 대한 대책으로 방화벽이나 침입 탐지 시스템을 이용하지만. 전 세계에서 동시 다발적으로 일어나는 이 공격을 근본적으로 방지하는 데는 적합지 않다. 이에 본 논문에서는 공격 트래픽의 송신자 주소를 임의의 IP 주소를 사용하여 공격의 발원지를 추적할 수 없는 기존 문제점을 해결할 수 있는 분산 서비스 거부 공격 발원지 자동 추적 모델을 제시하고자 한다.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.155-157
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• 2004

본 논문에서는 최근의 가장 대표적인 해킹 방법인 DDoS 공격도구들을 분석하고, DDoS 공격에 대한 기존에 제시된 대응방안들을 검토하여 보다 적절한 대응을 할 수 있는 DDoS 공격 탐지 및 대응 시스템을 설계한다. 제안된 시스템은 탐지 모듈에서 탐지된 공격에 대해 관리자에게 보고하여 적절한 대응을 하고 침입으로 판정되는 패킷들에 대해서는 필터링을 실시하여 네트워크 레벨에서 필터링하고 차단할 수 있는 장점을 살릴 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.923-926
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• 2002

인공면역시스템을 이용한 침입탐지시스템 개발을 위해 적용한 동적클론선택(Dynamic Clonal Selection) 알고리즘과 그의 문제점을 소개하고 개선된 동적클론선택 알고리즘을 제안한다. 개선된 동적클론선택 알고리즘은 정상행위를 비정상행위로 판단하는 기억 탐지 자들을 제거함으로써 기존에 동적클론선택 알고리즘이 안고 있던 오류를 감소시키는 방안을 제시한다.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.281-290
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• 2020

The purpose of this study was to examine how the consumer's entertainment, information, relevance, reliability, and perceived invasion affect the avoidance of advertising. Besides, the purpose of this study was to examine whether there is a difference according to the country and age in the effect of advertisement characteristics on the evasion. This study investigated the avoidance of mobile advertising among 254 Koreans and Chinese publics in their 20's and 40's, evaluated the results in terms of comparative analysis. Collected data were verified by multiple regression analysis and hierarchical regression analysis. The higher the advertising entertainment and relevance, the lower the avoidance of advertising. The higher the perceived penetration, the higher the avoidance of advertising. Besides, there were differences by country and age in the effects of advertising entertainment, information, relevance, and reliability on ad avoidance. The implications of this study are to find out how to reduce the mobile advertising avoidance of consumers by identifying the predictive factors that cause the avoidance of advertisements by country and age.

• Journal of the Korea Computer Industry Society
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• v.4 no.12
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• pp.965-974
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• 2003

Today's network consists of a large number of routers and servers running a variety of applications. In this paper, we have designed and constructed the general simulation environment of network security model composed of multiple IDSs agent and a firewall agent which coordinate by CNP (Contract Net Protocol). The CNP, the methodology for efficient integration of computer systems on heterogeneous environment such as distributed systems, is essentially a collection of agents, which cooperate to resolve a problem. Command console in the CNP is a manager who controls the execution of agents or a contractee, who performs intrusion detection. In the knowledge-based network security model, each model of simulation environment is hierarchically designed by DEVS (Discrete Event system Specification) formalism. The purpose of this simulation is the application of rete pattern-matching algorithm speeding up the inference cycle phases of the intrusion detection expert system. we evaluate the characteristics and performance of CNP architecture with rete pattern-matching algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.1B
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• pp.11-16
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• 2007

This paper describes the design and performance of a secure routing protocol with time-space cryptography for mobile ad-hoc networks. The proposed time-space scheme works in the time domain for key distribution between source and destination as well as in the space domain for intrusion detection along the route between them. For data authentication, it relies on the symmetric key cryptography due to high efficiency and a secret key is distributed using a time difference from the source to the destination. Also, a one-way hash chain is formed on a hop-by-hop basis to prevent a compromised node or an intruder from manipulating the routing information. In order to evaluate the performance of our routing protocol, we compare it with the existing AODV protocol by simulation under the same conditions. The proposed protocol has been validated using the ns-2 network simulator with wireless and mobility extensions.

• Korean Journal Plant Pathology
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• v.3 no.2
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• pp.100-107
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• 1987

Pre-pentration activity of Pyricularia oryzae Cav. from the stage of conidia germination to appressorium formation was examined on rice leaf epidermis under light and scanning electron microscopes to determine the causes· for differences in blast susceptibility between plants grown under three different soil moisture conditions in the greenhouse. No significant differences were found in the external shape of leaf epidermal cells including bulliform cells between plants grown under different soil moisture conditions. Growth and orientation of germ tube and morphology and size of appressorium of P. oryzae did not vary with soil moisture treatment. Site of appressorium formation was consistent over soil moisture treatment with the highest frequency of bulliform cell $(35\~48\%)$, followed by short cell $(19\~27\%)$, and long and guard cells $(13\~20\%)$. No appressorium was formed on trichome. This result suggests that the observed differences in blast susceptibility between plants grown under different soil moisture conditions were not due to the differences in the pre-pentration activity of P. oryzae on those plants.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.4
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• pp.267-272
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• 2016

Wireless sensor networks (WSNs) are vulnerable to external intrusions due to the wireless communication characteristics and limited hardware resources. Thus, the attacker can cause sinkhole attack while intruding the network. INSENS is proposed for preventing the sinkhole attack. INSENS uses the three symmetric keys in order to prevent such sinkhole attacks. However, the sinkhole attack occurs again, even in the presence of INSENS, through the compromised node because INSENS does not consider the node being compromised. In this paper, we propose a method to counter the sinkhole attack by considering the compromised node, based on the neighboring nodes' information. The goals of the proposed method are i) network reliability improvement and ii) energy conservation through effective prevention of the sinkhole attack by detecting compromised nodes. The experimental results demonstrate that the proposed method can save up to, on average, 19.90% of energy while increasing up to, on average, 71.50%, the report reliability against internal sinkhole attacks in comparison to INSENS.

• Korean Journal of Environment and Ecology
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• v.31 no.1
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• pp.54-61
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• 2017

We investigate predation rates of larvae and juveniles of Rana catesbeiana by using six native predatory fishes and six birds to select effective species to ecological control and management of R. catesbeiana that is invasive alien species and affects seriously wetland in Korea. Among freshwater fishes, Pseudobagrus fulvidraco, Silurus asotus and Channa argus ate larvae and juveniles of R. catesbeiana, and prefer the former, however Opsariichthys uncirostris, Monopterus albus and Anguilla japonica didn't eat at all. Six experimental water birds, Cygnus columbianus, Cygnus cygnus, Anas crecca, Aix galericulata, Anas penelope and Anas formosa nerver ate them. We were able to confirm control of R. catesbeiana probability using the native predatory fishes in Korea wetland.