• Journal of Internet Computing and Services
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• v.4 no.5
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• pp.43-49
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• 2003

Analytical performance evaluation is crucial for justifying the merit of the design in different operational conditions. While several analytical models have been proposed for the performance evaluation of Multistage Interconnection Networks(MINs), they are mainly for uniform traffics. Even models for nonuniform traffics have several shortcomings such as they only consider output buffered structure or do not consider blocking conditions. In this paper the mere accurate models than any other ones so far have been proposed for the performance evaluation of banyan-type MIN's under nonuniform traffic condition is obtained. The accuracy of proposed model is conformed by comparing with the results from simulation.

• BMB Reports
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• v.43 no.10
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• pp.677-682
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• 2010

Kv4.2, a pore-forming $\alpha$-subunit of voltage-gated A-type potassium channels, is expressed abundantly in the soma and dendrites of hippocampal neurons, and is responsible for somatodendritic $I_A$ current. Recent studies have suggested that changes in the surface levels of Kv4.2 potassium channels might be relevant to synaptic plasticity. Although the function and expression of Kv4.2 protein have been extensively studied, the dendritic localization of Kv4.2 mRNA is not well described. In this study, Kv4.2 mRNAs were shown to be localized in the dendrites near postsynaptic regions. The dendritic transport of Kv4.2 mRNAs were mediated by microtubule-based movement. The 500 nucleotides of specific regions within the 3'-untranslated region of Kv4.2 mRNA were found to be necessary and sufficient for its dendritic localization. Collectively, these results suggest that the dendritic localization of Kv4.2 mRNAs might regulate the dendritic surface level of Kv4.2 channels and synaptic plasticity.

• The Transactions of the Korea Information Processing Society
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• v.6 no.1
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• pp.167-174
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• 1999

In this paper, we propose the adaptive separated-queueing ATM switching model for the effective processing of the various types of multimedia traffic by virtue of ATM switching network with multiple outlets which is the essential part of B-ISDN. This proposed model employs the dynamically separated buffering mechanism in the processing of two classes of cell, realtime service traffic and non-realtime service traffic, at the output buffer to enhance the overall QoS(Quality of Service). The adopted ATM switch architecture has Batcher-banyan based network, but it uses different topologies and control techniques 6to resolve the cell contention. For the performance evaluation of our proposed method, we have done both analytical modeling and simulation. The both results show that our proposed queueing strategy is quite appropriate to the ATM switch with multiple outlets and can quarantee the QoS requirements of the incoming multimedia traffic.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1276-1284
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• 1999

We have evaluated the BER's and CLP's of Wireless ATM (WATM) cells employing the concatenated FEC code with pilot symbols for fading compensation through the simulation in indoor wireless channel modeled as a Rayleigh and a Rician fading channel, respectively. The results of the performance evaluation are compared with those obtained by employing the convolutional code in the same condition. In Rayleigh fading channel, considering the maximum tolerance BER ( $10^-3$) as a criterion of the voice service, it is blown that the performance improvement of about 4 dB is obtained in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols rather than the convolutional code with pilot symbols.When the values of K parameter which means the ratio of the direct signal to scattered signal power in Rician fading channel are 6 and 10, it is shown that the performance improvement of about 4 dB and 2 dB is obtained, respectively, in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols considering the maximum tolerance BER of the voice service. Also in Rician fading channel of K=6 and K= 10, considering CLP = $10^-3$ as a criterion, it is observed that the performance improvement of about 3.5 dB and1.5 dB is obtained, respectively, in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.134-142
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• 2003

We present an ATM switch architectures based on the multistage interconnection network(MIN) for the efficient multicast traffic control. Many of these applications require multicast connections as well as point-to-point connections. Muiticast connection in which the same message is delivered from a source to arbitrary number of destinations is fundamental in the areas such as teleconferencing, VOD(video on demand), distributed data processing, etc. In designing the multicast ATM switches to support those services, we should consider the fairness(impartiality) and priority control, in addition to the overflow problem, cell processing with large number of copies, and the blocking problem. In particular, the fairness problem which is to distribute the incoming cells to input ports smoothly is occurred when a cell with the large copy number enters upper input port. In this case, the upper input port sends before the lower input port because of the calculating method of running sum, and therefore cell arrived into lower input port Is delayed to next cycle to be sent and transmission delay time becomes longer. In this paper, we propose the cell splitting and group splitting algorithm, and also the fairness scheme on the basis of the nonblocking characteristics for issuing appropriate copy number depending on the number of Input cell in demand. We evaluate the performance of the proposed schemes in terms of the throughput, cell loss rate and cell delay.