• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.12
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• pp.2649-2656
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• 2012

Today, many enterprises have invested heavily for the part of information security in order to protect the internal critical information assets and the business agility. However, there is a big problem that big budget and too many manpower are needed to set the internal corporate network up to the same high level of defense for all of part. On the distributed enterprise networks in this paper, a defense model for effective and rapid response on the IP spoofing attack was designed to protect the enterprise network through the exchange of information between the trust hosts when an attacker attacked any target system using other trusted host.

• Journal of Communications and Networks
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• v.8 no.2
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• pp.169-174
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• 2006

In this paper, the algorithm of a methodology for the calculation of spectrum requirements was implemented. As well, the influence of traffic distribution ratio among radio access technology groups, spectral efficiency, and flexible spectrum usage (FSU) margin was analyzed in terms of the spectrum requirements, with a view toward for future development of international mobile telecommunication (IMT)-2000 and systems beyond IMT-2000. The calculated spectrum requirement in the maximum spectral efficiency case is reduced by approximately 40% compared to a minimum spectral efficiency case. The effect of the distribution ratio on the required spectrum is smaller than the effect of the spectral efficiency. As the flexible spectrum usage margin increases by 1.0 dB, the total spectrum requirement decreases by 0.9 dB. The required spectrum for the market input parameter, ${\rho}$ = 0.5 is 801.63 MHz, while the required spectrum for ${\rho}$ = 1.0 is 6295.4 MHz. This is equivalent to an increase of 785.32 %.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.4
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• pp.336-345
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• 1992

In this paper, the performance evaluation on the throughput and the delay between station under the interconnected LANs environments is studied. The connection is formed through bridges. Interconnected system is modelled as single-chain and multiple-chain closed queueing networks. For performance enaluation the iteration algorithm, which is based on the MVA(Mean Value Analysis)is proposed, Various system parameters, such as chain population interconnected communication link capacity, and service times of several queues, are used for the investigation of their influence of the station to station performance, Transport and MAC layers are mainly taken into consideration for the layer modeling. The analysis is shown as a graph by computer programming.

• Journal of Communications and Networks
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• v.12 no.4
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• pp.382-394
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• 2010

Cross-domain event information sharing is a topic of great interest in the area of event based network management. In this work we use data sets which represent actual attacks in the operational Internet. We analyze the data sets to understand the dynamics of the attacks and then go onto show the effectiveness of sharing incident related information to contain these attacks. We describe universal data acquisition system for event based management (UniDAS), a novel system for secure and automated cross-domain event information sharing. The system uses a generic, structured data format based on a standardized incident object description and exchange format (IODEF). IODEF is an XML-based extensible data format for security incident information exchange. We propose a simple and effective security model for IODEF and apply it to the secure and automated generic event information sharing system UniDAS. We present the system we have developed and evaluate its effectiveness.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.258-259
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• 2006

국내외적으로 전력산업분야의 가장 큰 화두중 하나는 변전소 단위의 디지털화이며 특히 국외에서는 국제표준 변전자동화 시스템 연구와 제품개발 등에 인력을 집중 투자하고 있다. 국제적으로 지금까지 축적된 변전소 관련 제반 기술력 및 경험 둥을 바탕으로 전 세계적으로 단일화시키고 표준화된 변전소 자동화 규격인 IEC 61850 (Communication networks and systems in substations) 규격이 제정되었으며 따라서 향후 전력 관련 기업은 시스템 엔지니어링 기술, 전력기기 공급능력, 유지/보수/운영기술 등을 종합적으로 보유하고 자산 및 위험관리를 종합적으로 제공할 수 있어야만 세계시장에서 생존할 수 있다. 또한 전력기기를 수출하는 국내업체는 향후 IEC(International Electrotechnical Commission) 등 국제표준에 따른 전력설비를 개발하지 않으면 수출경쟁력을 잃게 될 것이다. 이러한 세계화 추세에 발맞추어 한국전력공사와 관련 업체들은 공동으로 2005년 10월부터 6년의 기간으로 "디지털 기술기반의 변전소 자동화 시스템 개발" 사업을 진행 중에 있으며 특히 한국전력공사는 변전자동화 시스템의 성능검증 및 실증시험 절차를 구축하기 위한 과제를 수행 중이다.

• The KIPS Transactions:PartC
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• v.8C no.4
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• pp.459-468
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• 2001

실제적인 이동 Ad Hoc 망에서는 단말의 비대칭성이나 무선환경 특성으로 인해 단방향 링크가 존재할 수 있다. 그러나 현재 Zone 라우팅 프로토콜이외의 기존의 이동 Ad Hoc 라우팅 프로토콜은 양방향 링크들만을 지원하도록 구현되어 있다. 따라서 본 논문에서는 가장 대표적인 라우팅 프로토콜인 DSR(Dynamic Source Routing) 프로토콜이 단방향 링크를 포함하는 이동 Ad Hoc 망에서 구동될 수 있도록 동적 소스 라우팅을 이용한 새로운 단방향 라우팅 프로토콜을 제안한다. 단방향 링크 상에서 효율적으로 구동하기 위해서 제안한 단방향 라우팅 프로토콜은 새로운 경로발견 및 경로유지 방법을 사용하였다. 성능평가를 위해서 미국 버클리 대학의 NS-2 시뮬레이터 프로그램에 제안한 내용을 코드로 삽입시켰으며, 성능평가 파라미터를 얻기 위해 카네기멜론 대학에서 제공한 이동 패턴파일과 연결 패턴파일을 조합하여 사용하였다. 성능평가 항목으로 데이터수신율 및 평균경로 설정시간을 고려하였으며, 제안된 3가지 경로설정 방식들에 대해 비교·평가하였다.

• Journal of Information Processing Systems
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• v.7 no.3
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• pp.531-542
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• 2011

In this paper, we propose a new congestion control scheme for high-speed networks. The basic idea of our proposed scheme is to adopt a game theory called, "Minority Game" (MG), to realize a selective reduction of the transmission speed of senders. More concretely, upon detecting any congestion, the scheme starts a game among all senders who are participating in the communication. The losers of the game reduce the transmission speed by a multiplicative factor. MG is a game that has recently attracted considerable attention, and it is known to have a remarkable property so that the number of winners converges to a half the number of players in spite of the selfish behavior of the players to increase its own profit. By using this property of MG, we can realize a fair reduction of the transmission speed, which is more efficient than the previous schemes in which all senders uniformly reduce their transmission speed. The effect of the proposed scheme is evaluated by simulation. The result of simulations indicates that the proposed scheme certainly realizes a selective reduction of the transmission speed. It is sufficiently fair compared to other simple randomized schemes and is sufficiently efficient compared to other conventional schemes.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.1
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• pp.15-22
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• 2014

Delay-Tolerant Network employs message forwarding based on a Store, Carry and Forward method to conquer no guarantee of continue connectivity. For this reason, a lot of DTN routing scheme have been proposed recently. message forwarding is an important research issue in delay-tolerant network and In this paper, we propose a efficiency DTN routing scheme using node's social relation and expanded Ego-network betweenness centrality. Our simulation results show that it is more efficient to message delivery cost than Epidemic routing, Friendship routing while it has a little performance degradation of message delivery ratio.

• Journal of Korean Society of Archives and Records Management
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• v.12 no.1
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• pp.33-58
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• 2012

With technological and cultural changes around web and mobile networks, SNS would be considered as an important tool for information sharing. Especially, SNS represented Facebook and Twitter is being new paradigm for communication. This study seeks to methods to provide a service user participation and cooperation and expands use and access to archival information service through SNS. To achieve the goals, this study proposed a method to provide effective archival information service through literature research. Also, the proposed service was implemented with system design and components.

• Proceedings of the Technology Innovation Conference
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• 2006.02a
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• pp.78-102
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• 2006

Networks, services and industries have been converging with the advent of digital convergence by technology advancements of digitalization, broadband and interactivity in the areas of information-communication and broadcasting technologies. Especially, this convergence of technology and market has been blurring the boundary of telecommunication and broadcasting sectors, and the severe competition seems to be inevitable due to the lack of the differentiation in broadcasting media and contents. In this study, we regard the competition phenomenon in the digital convergence between telecommunication and broadcasting as the platform competition in two-sided markets which have been actively studied since 2000, and analyzed it using modified Hotelling's location model. According to the analysis of platform competition on the effects of the differentiation of platform (t) , killer component $(\mu)$ and component compatibility $(\theta)$ , it is shown that two differentiated platforms are simultaneously used in case of the decrease of substitution effects, and the profit of platform with killer contents is increased, but the profit of platforms with higher compatibility is decreased. The policy implication is that it is especially necessary to modify the policy and regulation on media contents considering the growing competition in media. On the other hand, differentiated and reasonable policy is required to make fair competition and active market environment.