• Journal of Digital Convergence
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• v.14 no.10
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• pp.261-269
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• 2016

This paper aims to propose a novel technology of network convergence to provide ultra high speed internet services over CATV networks, by which a CMC(cable modem concentrator) and CM(cable modem) of 1Gbps level are designed. This technology not only lowers the production cost in comparison to the existing bonding technology with DOCSIS specification but also enables the adjustment of data speed based on the channel bandwidth. According to the experiments, when convolutional code rate with 128QAM is changed to 1/2, 2/3, 3/4 and 7/8, the data recorded the maximum transmission speed of up to 299 Mbps at the zero error rate. As the convolutional code rates with 256QAM is increased, it showed 334Mbps at the error rate of $10^{-5}$. Based on the findings of this paper, if we secure the channel bandwidth of 200MHz and adjust the modulation order of QAM and the convolution code rate depending on the channel status, we can get the transmission speed of more than 1Gbps, which is much more competitive in its function and price than the existing technology based on DOCSIS.

• Fashion & Textile Research Journal
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• v.12 no.1
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• pp.38-45
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• 2010

Cosmetics retailers would benefit from studies that examine which shopping-mall attributes can be manipulated to favorably affect consumer satisfaction and revisit intention at Internet. The purposes of this study were (1) to examine the dimensionality of shopping-mall attribute for cosmetics retailers, (2) to determine which dimensions of shopping-mall attribute were significant predictors of consumer satisfaction and revisit intention and (3) to find out the moderating effect of consumer satisfaction through shopping-mall attributes on revisit intention to buy cosmetics across the types of shopping-mall at Internet (i.e., total mall and specialty mall). Data were collected from 209 online cosmetic shoppers among high school girls. Factor analysis identified five dimensions of shopping-mall attributes at Internet, such as Convenience, Price, Loading speed, Sales promotion, and Service. Only two dimensions(i.e., convenience and service) were significant predictors of online shopper satisfaction in both total mall and specialty mall. The moderating effect of consumer satisfaction on revisit intention was significant in both two mall types at Internet. For total mall, price was a significant predictor through consumer satisfaction on revisit intention, while loading speed was a significant predictor directly on revisit intention for specialty mall. In light of the major findings, this study sets forth strategic implications for consumer satisfaction and revisit intention to buy cosmetics in the setting of electronic commerce.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.4
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• pp.171-183
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• 2008

Nowadays, wireless packet data services are provided over Wireless MAN (WMAN) at a high data service rate, while 3G cellular networks provide wide-area coverage at a low data service rate. The integration of mobile WiMAX and 3G networks is essential, to serve users requiring both high-speed wireless access as well as wide-area connectivity. In this paper, we propose a cross-layer optimization scheme for a vertical handover between mobile WiMAX and 3G cellular networks. More specifically, L2 (layer 2) and L3 (layer 3) signaling messages for a vertical handover are analyzed and reordered/combined, to optimize the handover procedure. Extensive simulations using ns-2 demonstrate that the proposed scheme enhances the performance of a vertical handover between mobile WiMAX and 3G networks: low handover latency, high TCP throughput, and low UDP packet loss ratio.

• Korean Management Science Review
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• v.26 no.3
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• pp.67-78
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• 2009

In this paper, I analyze the mobile broadband services market characterized by vertical and horizontal differentiation. Vertical differentiation as service quality differentiation is based on the transmission speed of mobile internet service and horizontal differentiation as spatial differentiation is based on the service coverage. Theoretical explanations for the competitive price policy have been developed in the game context of WiBro which represent the high quality within the limited service coverage and HSDPA which represent relatively low quality with nation-wide service. When the WiBro has a mobile broadband service quality advantage and the difference in quality is sufficiently low, the price of WiBro with limited service coverage is relatively lower than that of HSDPA. This occurs because the advantage of WiBro's vertical service differentiation is offset by the disadvantage of horizontal differentiation. The difference in the quality of mobile internet service, however, is not too high, the price of WiBro is relatively higher than that of HSDPA. Moreover, when the service quality of WiBro is sufficiently high, the low quality HSDPA service faces no demand.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.231-236
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• 2003

Video conferencing system it is various at internet and uses the reading is become accomplished. Research of like this portion synchronization of audio, the video compression technique and multimedia data, supports the video conference the research of the Mbone of the If multicast for being active, being become accomplished the multimedia service which is various an video from internet, the line speed of communication becomes high-speed anger and to follow leads is become accomplished. The video conference from opening elder brother dispersion internet network environment the problem against the image which is an image conference data and a voice security is serious and it raises its head. To sleep it presents the security method which from the video conference it follows in quality of multimedia data from the dissertation which it sees and it does.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.143-148
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• 2005

Video conference system it is various at internet and uses the reading is become accomplished. Research of like this portion synchronization of audio, the compression technique and multimedia data, supports the video conference the research of the Mbone of the IP multicast for being active. being become accomplished the multimedia service which is various an video from internet, the line speed of communication becomes high-speed anger and to follow leads is become accomplished. The video conference from opening elder brother dispersion internet network environment the problem against the image which is an image conference data and a voice security is serious and it raises its head. To sleep it presents the security method which from the video conference it follows in quality of multimedia data from the dissertation which it sees and it does.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.2
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• pp.637-658
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• 2015

The development of multimedia applications has followed the development of high-speed networks. By improving the performance of mobile devices, it is possible to provide high-transfer-speed broadband and seamless mobile multicasting services between indoor and outdoor environments. Multicasting services support efficient group communications. However, mobile multicasting services have two constraints: tunnel convergence and handoff latency. In order to solve these problems, many protocols and handoff methods have been studied. In this paper, we propose inter local mobility anchor (inter-LMA) optimized handoff model for mobile multicasting services in proxy mobility IPv6 based (PMIPv6-based) networks. The proposed model removes the tunnel convergence issue and reduces the router processing costs. Further, it the proposed model allows for the execution of fast handoff operations with adaptive transmission mechanisms. In addition, the proposed scheme exhibits low packet delivery costs and handoff latency in comparison with existing schemes and ensures fast handoff when moving the inter-LMA domain.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.7
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• pp.1705-1720
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• 2013

Human face gender recognition requires fast image processing with high accuracy. Existing face gender recognition methods used traditional local features and machine learning methods have shortcomings of low accuracy or slow speed. In this paper, a new framework for face gender recognition to reach fast face gender recognition is proposed, which is based on Local Ternary Pattern (LTP) and Extreme Learning Machine (ELM). LTP is a generalization of Local Binary Pattern (LBP) that is in the presence of monotonic illumination variations on a face image, and has high discriminative power for texture classification. It is also more discriminate and less sensitive to noise in uniform regions. On the other hand, ELM is a new learning algorithm for generalizing single hidden layer feed forward networks without tuning parameters. The main advantages of ELM are the less stringent optimization constraints, faster operations, easy implementation, and usually improved generalization performance. The experimental results on public databases show that, in comparisons with existing algorithms, the proposed method has higher precision and better generalization performance at extremely fast learning speed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.9
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• pp.2388-2404
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• 2012

Cryptographic hash functions are widely used in many information security applications like digital signatures, message authentication codes (MACs), and other forms of authentication. In response to recent advances in cryptanalysis of commonly used hash algorithms, National Institute of Standards and Technology (NIST) announced a publicly open competition for selection of new standard Secure Hash Algorithm called SHA-3. One important aspect of this competition is evaluation of hardware performances of the candidates. In this work we present efficient hardware implementations of SHA-3 finalists: JH, Keccak and Skein. We propose high speed architectures using Look-Up Table (LUT) resources on FPGAs, to minimize chip area and to reduce critical path lengths. This approach allows us to design data paths of SHA-3 finalists with minimum resources and higher clock frequencies. We implemented and investigated the performance of these candidates on modern and latest FPGA devices from Xilinx. This work serves as performance investigation of leading SHA-3 finalists on most up-to-date FPGAs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.10
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• pp.4015-4033
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• 2015

The future mobile networks consist of hyper-dense heterogeneous and small cell networks of same or different radio access technologies (RAT). Integrating mobile networks of different RATs to provide seamless and smooth mobility service will be the target of future mobile converged network. Generally, handover from high-speed networks to low-speed networks faces many challenges from application perspective, such as abrupt bandwidth variation, packet loss, round trip time variation, connection disruption, and transmission blackout. Existing inter-RAT handover solutions cannot solve all the problems at the same time. Based on the high-layer convergence sublayer design, a new receiver-aided soft inter-RAT handover is proposed. This soft handover scheme takes advantage of multihoming ability of multi-mode mobile station (MS) to smooth handover procedure. In addition, handover procedure is seamless and applicable to frequent handover scenarios. The simulation results conducted in UMTS-WiMAX converged network scenario show that: in case of TCP traffics for handover from WiMAX to UMTS, not only handover latency and packet loss are eliminated completely, but also abrupt bandwidth/wireless RTT variation is smoothed. These delightful features make this soft handover scheme be a reasonable candidate of mobility management for future mobile converged networks.