• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.125-130
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• 2004

The Internet is aggregate of trustless networks essentially. Because the Internet is very difficult to control flowing of information, taking advantage of enough sporadic resource, security problem that can protect internal important stock from the Internet is risen seriously. Recently, virus accident and generation rate about system intrusion that happen become much higher and various than past. On these time, is progressing researcher for invasion cutout to keep away illegal act vigorouslyand do continuous development. In this paper, reporting administrator log information about invader's illegal act depending on XML format form, and I wished to solve problem that happen in administration side developing invasion interception system that can control to remote.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.6
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• pp.852-857
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• 2010

In this paper, we proposed and demonstrated an indoor visible-light communication system using an array of light-emitting diodes (LEDs). The main idea is based on that the LEDs can be used not only for lighting but also for free-space optical communications. Because LEDs offer advantageous properties such as high brightness, reliability, lower power consumption and long lifetime, the indoor visible-light communication systems are going to provide high quality of service by the high radiation power of the LED lighting. Prototype of simplex channel for audio and the full-duplex channel for text message were developed. Results indicates the viability of creating inexpensive free-space optical communication transceivers that might be embedded in commercial light products to supports indoor wireless networking.

• Journal of Korea Multimedia Society
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• v.1 no.1
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• pp.120-129
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• 1998

The mobile computing is a new network environment that support s wireless network connection seamless while the portable computer is moving. This environment involves the problem of re-establishing of new network connection. The mobile computing should provide multicasting service, because multicasting is widely-used application service which delivers messages to the members of the groups. In this paper, we proposed 3-tiered mobile multicasting protocol that transfers multicast packets efficiently and reliablely. Also, we analyzed the performance of 3-tiered mobile multicasting protocol comparing with other mechanism. Our protocol is superior to other mechanism in the aspects of the handoff costs and packet delivery costs.

• Journal of Korea Multimedia Society
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• v.16 no.4
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• pp.464-471
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• 2013

With the advance of wireless sensor networks, WMSN(Wireless Multimedia Sensor Networks) researches to transfers multimedia data have been studied actively. First of all, three basic protocols, End-to-end, Hop-by-hop, and Unreliable transmission method, are compared to transfer multimedia data using simulations. This paper presents an efficient protocol to transfer multimedia data by overhearing messages of nodes and by transmitting next packets during the unused time interval. The proposed method is verified its performance by simulations and experiments. The results shows that the transmission rate of the proposed method 22% higher than that of End-to-end protocol with half of transmission time. Also the performance of the proposed method is compared with that of PIGAB(Packet Interval Gap based on Adaptive Backoff).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.2
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• pp.123-132
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• 2014

In this paper, an IEEE1588 based clock synchronization technique for CAN (Controller Area Network) is presented. Clock synchronization plays a key role to the success of a networked embedded system. Recently, the IEEE1588 algorithm making use of dedicated chipsets has been widely adopted for the synchronization of various industrial applications using Ethernet. However, there is no chipset available for CAN. This paper presents the implementation of IEEE1588 for CAN, which is implemented using only software and CAN packets without any dedicated chipset. The proposed approach is verified by the comparison between the estimated synchronization precision with a simple model and the measured precision with experimental setup.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.786-790
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• 2006

현재 많은 사람들의 관심을 받고 있는 유비쿼터스 시스템(Ubiquitous System)이 주는 가장 큰 이점은 언제 어디서나 원하는 서비스를 사용할 수 있는 것이다. 따라서 이를 사용가능하게 하기 위해서는 유비쿼터스 시스템이 무선네트워크를 지원하여야 하며 또한 소형의 장치로 사용자가 간편하게 사용할 수 있어야 한다. 그러나 이러한 특성들로 인하여 유비쿼터스 시스템은 네트워크 불량, 자원 부족 등과 같은 문제점을 가지고 있으며 이것은 사용자 서비스의 질과 직접적으로 연결된다. 더욱이 이것으로 인하여 사용자가 서비스 사용에 불편을 겪는다면 유비쿼터스 시스템 사용에 대한 신뢰도는 떨어질 것이다. 이런 문제를 해결하기 위해서는 유비쿼터스 시스템에서 일어날 수 있는 결함을 분석하고 이에 대한 적절한 조치를 취하여 사용자가 서비스를 사용하는데 있어서 불편을 초래하지 않아야 한다. 따라서 본 논문에서는 유비쿼터스 시스템에서 사용될 수 있는 결함 분석기를 개발하였으며 또한 실제로 유비쿼터스 시스템 관리 유틸리티에 적용하였다. 본 결함 분석기에서는 메모리 결함, 배터리 결함, 네트워크 결함, 및 heartbit 결함에 대하여 정의하고 결함을 감지할 수 있도록 하였으며 또한 Java Exception 메시지를 이용하여 조기에 결함을 분석할 수 있도록 개발하였다.

• The KIPS Transactions:PartA
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• v.10A no.1
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• pp.35-42
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• 2003

In this paper, we analyzed the known agent tracking models and proposed a new agent tracking model based on the distributed event service that always assures reliable tracking. Also we experimented the Performance of the event servers on the agent monitoring system that implements the distributed event service and showed their performance to decrement gracefully. The proposed tracking model doesn't make only several clients trace a mobile agent which moves among agent servers autonomously, but also supports two types of agent tracking agent location tracking that notifies agent location to the clients and path establishment that maintains reliable connection between agent servers for message delivery.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.425-426
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• 2016

In this paper, we proposed an algorithm based on movement prediction using Markov chain in delay tolerant networks(DTNs). The existing prediction algorithms require additional information such as a node's schedule and connectivity between nodes. However, network reliability is lowered when additional information is unknown. To solve this problem, we proposed an algorithm for predicting a movement path of the node by using Markov chain. The proposed algorithm maps speed and direction for a node into state, and predict movement path of the node using transition probability matrix generated by Markov chain. As the result, proposed algorithm show that the proposed algorithms has competitive delivery ratio but with less average latency.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.6
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• pp.1037-1044
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• 2014

A (t,n) threshold secret sharing scheme is the scheme which allows a trusted party to distribute the shares among n participants in such a way that any t of them can recover the original secret, but any group knowing only t-1 or fewer shares can not. Recently, Eslami et al. and Tadayon et al. proposed threshold multi-secret sharing schemes, respectively. They proposed that their schemes don't require secure channels. But, without secure channels in their schemes, everyone can get the shares and find the secrets. The proposed scheme does not use secure channels and only t participants can solve the equations of the system from the delivered share shadows and find the secrets.

• The KIPS Transactions:PartD
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• v.15D no.5
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• pp.699-704
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• 2008

By the dependence on Web from popularization of internet and increasing number of users, web services capability and security problem of communication is becoming a great issue. Existing web services technology decrease the capability of web application server by limiting the number of synchronous client, decreasing the processing load and increasing average response time. The encryption process to secure communication and the early expense of handshake decrease transmission speed and server capability by increasing the calculation time for connecting. Accordingly, this paper executes an encryption procedure by elliptical encryption algorithm to satisfy secure demands, improve the overload of server for web services and get reliability and security of web server architecture and proposes an improved mobile web sever which provides better ability and the techniques for deferred processing.