• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.2B
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• pp.111-119
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• 2011

As Green-IT has attracted a lot of attention in recent years, many researches have been interested in reducing the energy consumption of network equipments. In this paper, we analyze the energy saving ratio and delay performance according to various traffic patterns and burst assemble algorithms in OBS network with sleeping mode. To do this, we design the traffic generators, which are based on exponential distribution and Pareto distribution, and the router model, which has the time based and length based burst assemble algorithms by using OPNET modeler. Through OPNET simulator, we evaluate the energy saving performance in terms of the sleeping time, the number of transitions and packet delay.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.3
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• pp.416-420
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• 2002

Traditional queueing analyses are very useful for designing a network's capacity and predicting there performances, however most of the predicted results from the queueing analyses are quite different from the realistic measured performance. And recent empirical studies on LAN, WAN and VBR traffic characteristics have indicated that the models used in the traditional Poisson assumption can't properly predict the real traffic properties due to under estimation of the long range dependence of network traffic and self-similarity In this parer self-similar characteristics over statistical approaches and real time network traffic measurements are estimated It is also shown that the self- similar traffic reflects network traffic characteristics by comparing source model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.4
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• pp.633-638
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• 1994

Asynchronous Transfer Model(ATM) has a fixed-length packet transport scheme. It is one of promising proposals in Broadband ISDN(B-ISDN). Since the packet length is fixed, it can be potentially to perform the various service to user. In this paper, a queueing model for an ATM Multiplexer loaded by the Continuous Bit Rate(CBR) traffic and the bursty traffic sources is analyzed. The queueing system has a finite buffer size. The cell loss probabilities with the simple and recurcive form for a performance measures of ATM multiplexer are derived, and are also evaluated through numerical examples. The results of this study may be used as guidelines in buffer design problems and performance analysis of ATM multiplexing system.

• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.89-96
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• 2000

ABR service is defined by ATM Forum and ITU for the efficient use of link bandwidth, and 2-pass service policing is proposed for this service. 2-pass service policing is effective by the real-time measurement of the used bandwidth, and this scheme obtains multiplexing gam and control efficiently ABR traffic as dynamically allocating rate by residual bandwidth information. In this study, we propose the real-time bandwidth prediction scheme for ABR traffic control, as using dynamic rate allocation by available bandwidth information. This study can obtain the simple hardware structure by means of as predicting available bandwidth by the total link bandwidth and the sum of transmission rate on the backlogged state connections.

• The Journal of the Korea Contents Association
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• v.5 no.2
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• pp.79-85
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• 2005

In order to handle client's requests while multiple servers seamlessly work in the web server cluster environment, it is vital to implement a router that execute a routing using TCP information and requested target content. The implemented package software measured packet volume that was generated from data generator, virtual server, and server 1, 2, 3, and could find out traffic distribution toward Server 1, 2, 3. As the result of the study shows, Round Robin Algorithm ensured definite traffic distribution, unless incoming data loads differ much. Although error levels were high in some partial cases, they were eventually alleviated by repeated tests for a longer time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.5
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• pp.368-376
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• 2013

The importance of application traffic identification is emphasized for the efficient network management with recent rapid development of internet. In this paper, we present the application traffic identification method using the behavior based signature to improve the previous limitations. The behavior based signature is made by combining the existing various traffic features, and uses the Inter-Flow unit that is combination of the first request packet of each flow. All signatures have 100% precision when measured the accuracy of 5 applications using at home and abroad to prove the feasibility of the proposed signature.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.104-107
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• 2002

Traditional queueing analyses are very useful for designing a network's capacity and predicting there performances, however most of the predicted results from the queueing analyses are quite different from the realistic measured performance. And recent empirical studies on LAN, WAN and VBR traffic characteristics have indicated that the models used in the traditional Poisson assumption can't properly predict the real traffic properties due to under estimation of the long range dependence of network traffic and self-similarity. In this paper self-similar characteristics over statistical approaches and real time network traffic measurements are estimated. It is also shown that the self-similar traffic reflects network traffic characteristics by comparing source model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7B
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• pp.789-794
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• 2011

We analyze the capacity of CDMA base stations in the subway environment. We investigate the characteristics of multipath fading, cell structures, and propagation environment in the subway, analyze signal to noise ratio, sectorization gain, path-loss exponent, frequency reuse factor, and obtain the link capacity of a base station in the subway. We measure the peakedness factor and reveal that base stations in the subway have peaked traffic. We use Neal-Wilkinson model to obtain the Erlang capacity instead of Erlang-B model based on Poisson traffic.

• 전자공학회논문지 IE
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• v.45 no.1
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• pp.15-23
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• 2008

In this paper, an algorithm, that provisions absolute differentiation of packet delays is proposed, simulated, and implemented with VHDL on XPC 860 CPU based test board with an objective for enhancing quality of service (QoS) in future packet networks. It features a scheme that compensates the deviation for prediction on the traffic to be arrived continuously. It predicts the traffic to be arrived at the beginning of a time slot and measures the actual arrived traffic at the end of the time slot and derives the difference between them. The deviation is utilized to the delay control operation for the next time slot to offset it. As it compensates the prediction error continuously, it shows superior adaptability to the bursty traffic as well as the exponential traffic. It is demonstrated through both simulation and the real traffic test on the board that the algorithm meets the quantitative delay bounds and shows superiority to the traffic fluctuation in comparison with the conventional non-adaptive mechanism.

• Journal of KIISE:Information Networking
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• v.34 no.4
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• pp.246-255
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• 2007

Due to the bandwidth-consuming characteristics of the heavy-hitter P2P applications, it has become critical to have the capability of pinpointing and mitigating P2P traffic. Traditional port-based classification scheme is no more adequate for this purpose because of newer P2P applications, which incorporating port-hopping techniques or disguising themselves as HTTP-based Internet disk services. Alternatively, packet filtering scheme based on payload signatures suggests more practical and accurate solution for this problem. Moreover, it can be easily deployed on existing IDSes. However, it is significantly difficult to maintain up-to-date signatures of P2P applications. Hence, the automatic signature generation method is essential and will be useful for successful signature-based traffic identification. In this paper, we suggest an automatic signature generation method for Internet disk P2P applications and provide an experimental results on CNU campus network.