• The Journal of Information Systems
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• v.16 no.2
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• pp.35-49
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• 2007

The web monitoring is a procedure to detect and monitor the change of a particular information from the web site. In this paper, we propose a monitoring system to survey the response time for the customers chi an internet shopping mall. This system we designed, decreases the network overload and guarantees the accuracy as well as the reliability of the information by using an interactive agent. This interactive agent we constructed, is written in Java and controlled by the high-level information such as the index or the robot. from the N web site, we extracted the web monitoring results of keyword "LCD Monitor" and verified our system's efficiency. The performance of the system is tested and the result is illustrated.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.5
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• pp.522-527
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• 2010

In the connected environment by network, clients shared resources as that requested the file that a server had, but P2P system is alternative because of the overload of servers. To improve the performance of this P2P system, we are studying about that. In this study, we can improve a usability for users using P2P search system, and suggest a group search algorithm based on a preprocessing search.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1475-1478
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• 2002

멀티캐스트는 현재 일-대-일 통신서비스로 부터 일-대-다 또는 다-대-다 통신서비스에서 신뢰성을 요구하는 새로운 요구가 많아지고 있다. 그리고 최근 대두되고 있는 멀티미디어 응용을 지원하기 위해서는 광대역 네트워크의 링크, 실시간 전송, 보나 효과적인 멀티캐스트 프로토콜이 요구된다. 그러나 DVMRP, MOSPF, CBT, PIM 구조의 멀티캐스팅 프로토콜은 단지 송수신의 패킷의 경로비용으로 라우터 자체의 근거리 알고리즘이 적용되기 때문에 멀티캐스트가 수행될 때 통신의 전반적 사항인 통신처리능력, 대역폭, QoS(quality of service)대한 능력이 부족하다. 그러므로 멀티미디어에서 사용되는 패킷의 계층적 특성이 제외된 상태로 데이터가 전송되는 단점이 있다. 본 연구에서는 액티브 네트워크를 이용해서 카 데이터 패킷 전송을 위한 공정하고 실용적인 대역폭 사용하고 대역폭과 데이터처리능력을 액티브 전송 패킷을 통해서 액티브 라우터로 전송된 데이터를 필터링 해서 보나 효과적인 멀티미디어 데이터 패킷을 카 계층에 따라 다양한 수신자가 데이터 패킷을 전송 받고 액티브 라우터로부터 공정한 대역폭 전송할 수 있는 라우터를 시뮬레이션 상에서 구현하고 성능을 평가한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.5 no.1
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• pp.54-59
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• 1980

Adaptive version of the delta modulator that is akin to wyllabic companding for telephony is described. A digital technique is used to sense the slope of the input signal and to control the amplitude of the pulses supplied to the RC network in the feed back loop. Thus the development was stimulated by the suitability of delta modulator for low-cost integrated circuits. Analysis are made of the optimum overload characteristics, stability, SNR for improving the frequency range and these results have been esperimentally verfied.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.315-325
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• 1999

Indexing techniques for distributed resources have much effect on an information service system based on distributed environment like digital library. There is a centralized indexing technique, a distributed technique, and a mixed technique for distributed indexing techniques. In this paper, we propose new distributed indexing technique using EIF(extended Inverted File) structure that mix the centralized technique and t도 distributed technique. And we propose management techniques using EIF structure and retrieval technique using EIF structure. This distributed indexing technique proposed is able to fast process retrieval request and reduce network overload and select servers relevant to query terms. This paper investigated performance of a proposed distributed indexing technique.

• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.291-298
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• 2010

In wireless sensor networks, energy is the most important consideration because the lifetime of the sensor node is limited by battery. The clustering is the one of methods used to manage network energy consumption efficiently and LEACH(Low-Energy Adaptive Clustering Hierarchy) is one of the most famous clustering algorithms. LEACH utilizes randomized rotation of cluster-head to evenly distribute the energy load among the sensor nodes in the network. The random selection method of cluster-head does not guarantee the number of cluster-heads produced in each round to be equal to expected optimal value. And, the cluster head in a high-density cluster has an overload condition. In this paper, we proposed both a token based cluster-head selection algorithm for guarantee the number of cluster-heads and a cluster selection algorithm for uniform-density cluster. Through simulation, it is shown that the proposed algorithm improve the network lifetime about 9.3% better than LEACH.

• Convergence Security Journal
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• v.8 no.1
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• pp.1-7
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• 2008

The hacking method came to be more complicated, became program ant it was automated. That is hacking trend of recent times. Before, The password crack, catch root authority is trend of hacking which uses the vulnerability of server. Hacker attack network or all of domain not some host. Web application system at hacking technique develops and improve transmitted data through the network shows many vulnerability. The massive data are transmitted through the network without encipherment filtering. It will be able to bring about the neck of a bottle actual condition which is serious in security system because of the network where the user comes to be many it leads and the data which is delivered comes to be many. In this paper, we propose web application system to prevent overload from bottleneck in encipherment system. It can solve security key trust problem in encoding and decoding with public key infrastructure.

• Journal of the Korea Society of Computer and Information
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• v.17 no.5
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• pp.49-57
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• 2012

In P2P streaming management, peer's churning and finding efficient topology architecture optimization algorithm that reduces streaming delay is important. This paper studies a topology optimization algorithm based on the P2P streaming using peer's link information. The proposed algorithm is based on the estimation of peer's upload bandwidth using peer's link information on mesh-network. The existing algorithm that uses the information of connected links is efficient to reduce message overload in the point of resource management. But it has a risk of making unreliable topology not considering upload bandwidth. And when some network error occurs in a server-closer-peer, it may make the topology worse. In this paper we propose an algorithm that makes up for the weak point of the existing algorithm. We compare the existing algorithm with the proposed algorithm using test data and analyze each simulation result.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.1
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• pp.77-85
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• 2003

The conversion into a new Local Area Network (LAN) environment without clear analysis of the problems with the conventional LAN environment nay bring about some improvement of performance, but in general, the result would not be as good as expected. Besides, in case new traffic or application programs are added In the near future, traffic overload similar to the past may incur. Therefore, the conversion into a new LAN environment should not only relieve the problems with the conventional environment but also be able to cope with future expansion of the network flexibly. In the present paper, in view of the above, the problems with protocols and traffic that may occur in the Bus-structured 10/100 Mbps shared Ethernet that has been widely used by many institutions are reviewed, and as a case study whether such conversion into a new LAN environment in order to increase the efficiency in the operation, management, and utilization of the network would be proper for the actual operational environment is implemented, and the results are analyzed.

• 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.