• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.9
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• pp.2154-2172
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• 2013

A centralized cognitive radio (CR) network is proposed and its system capacity is studied. The CR network is designed with power control and multi-user scheduling schemes to support best-effort traffics under peak interference power constraints. We provide an analytical framework to quantify its system capacity, taking into account various key factors such as interference constraints, density of primary users, cell radius, the number of CR users, and propagations effects. Furthermore, closed-form formulas are derived for its capacities when only path loss is considered in the channel model. Semi-analytical expressions for the capacities are also given when more realistic channel models that include path loss, shadowing, and small-scale fading are used. The accuracy of the proposed analytical framework is validated by Monte Carlo simulations. Illustrated with a practical example, the provided analytical framework is shown to be useful for the strategic planning of centralized CR networks.

• Journal of Information Processing Systems
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• v.17 no.2
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• pp.213-226
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• 2021

Given that most of the link prediction algorithms for signed social networks can only complete sign prediction, a novel algorithm is proposed aiming to achieve both link prediction and sign prediction in signed networks. Based on the structural balance theory, the local link tightness and global link tightness are defined respectively by using the structural information of paths with the step size of 2 and 3 between the two nodes. Then the total similarity of the node pair can be obtained by combining them. Its absolute value measures the possibility of the two nodes to establish a link, and its sign is the sign prediction result of the predicted link. The effectiveness and correctness of the proposed algorithm are verified on six typical datasets. Comparison and analysis are also carried out with the classical prediction algorithms in signed networks such as CN-Predict, ICN-Predict, and PSNBS (prediction in signed networks based on balance and similarity) using the evaluation indexes like area under the curve (AUC), Precision, improved AUC', improved Accuracy', and so on. Results show that the proposed algorithm achieves good performance in both link prediction and sign prediction, and its accuracy is higher than other algorithms. Moreover, it can achieve a good balance between prediction accuracy and computational complexity.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.500-507
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• 2008

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.231-237
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• 2007

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.289-296
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• 2007

• 한국ITS학회:학술대회논문집
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• v.2007 no.10
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• pp.283-288
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• 2007

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.4
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• pp.24-25
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• 1976

Complementary theorem and its corollaries are presented to describe properties of frequency spectrum of periodic gate function. The theorem shows that the frequency spectrum of a periodic gate function signal is the same as that of its complementary signal, and that a DC has no information.

• Korea Information Processing Society Review
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• v.5 no.3
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• pp.49-55
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• 1998

현재까지는 무선통신망을 통해 음성 전화 서비스가 주류를 이루고 있지만 향후에는 무선망과 컴퓨터를 결합한 신규 무선 멀티미디어 서비스의 수요가 폭발적으로 증가할 것이다 본 논문에서는 그 주요 서비스를 제공할 Mobile Computing System(MCS)를 개략적으로 설명하고 Mobile Computing의 선도적인 응용으로써 주목받고 있는 ITS서비스와 소요 기술에 대해서 기술한다.

• Bulletin of the Korean Chemical Society
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• v.17 no.7
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• pp.648-653
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• 1996

We have shown several examples of characterization of multicomponent polymer systems by size exclusion chromatography coupled with a light scattering detector. Although SEC cannot provide a complete information for such systems due to its intrinsic limitation, one can extend its capability by combining multiple detection in order to get relevant information to some extent.

• Information and Communications Magazine
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• v.19 no.9
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• pp.59-67
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• 2002