• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.173-175
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• 2007

So far, almost all IP media services are targeted to the specific devices, for example, IPTV services are mainly for TV, and social community services are mainly for PC etc.. This paper describes newly developed media service platform in which the high quality video services can be provided not only to the TV or PC but also to the PMP(Portable Media Player) and even to the mobile phone. The major technical issues of the service platform are synchronization of contents among the different devices and high quality TV grade video display in PMP device. We confirmed successful operation of multi-device converged services in the developed media platform. We also have a trial service plan in Gwangju city at the end of this year.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1B
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• pp.9-18
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• 2006

Advances in wireless network are enabling the development of ubiquitous multimedia services. These multimedia services need efficient platforms to comply with the requirements of mobile computing. We introduce an adaptive service platform based on mobile agent and grid systems while specifying the challenges of ubiquitous multimedia services and focusing on frequent disconnections and scarce resources. We applied our platform to framework RtoA (Ready-to-Attend) which supports mobile users to access compute-intensive multimedia service, specifically, mobile education and video conferencing. RtoA includes hand-off, speaker and listener service which enable people to attend a conference or a class with satisfying quality of multimedia service. ns-2 based simulation verifies that our scheme is an efficient way to reduce energy consumption of mobile devices and to improve the response time of mobile applications.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.9
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• pp.381-392
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• 2013

During the last decade, the multitude of advances attained in terminal computers, along with the introduction of mobile hand-held devices, and the deployment of high speed networks have led to a recent surge of interest in Quality of Service (QoS) for video applications. The main difficulty is that mobile devices experience disparate channel conditions, which results in different rates and patterns of packet loss. One way of making more efficient use of network resources in video services over wireless channels with heterogeneous characteristics to heterogeneous types of mobile device is to use a scalable video coding (SVC). An SVC divides a video stream into a base layer and a single or multiple enhancement layers. We have to ensure that the base layer of the video stream is successfully received and decoded by the subscribers, because it provides the basis for the subsequent decoding of the enhancement layer(s). At the same time, a system should be designed so that the enhancement layer(s) can be successfully decoded by as many users as possible, so that the average QoS is as high as possible. To accommodate these characteristics, we propose an efficient transmission scheme which incorporates SVC-aware dual-channel repetition to improve the perceived quality of services. We repeat the base-layer data over two channels, with different characteristics, to exploit transmission diversity. On the other hand, those channels are utilized to increase the data rate of enhancement layer data. This arrangement reduces service disruption under poor channel conditions by protecting the data that is more important to video decoding. Simulations show that our scheme safeguards the important packets and improves perceived video quality at a mobile device.

• ETRI Journal
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• v.35 no.2
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• pp.234-244
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• 2013

Internet protocol television (IPTV) service depends on the network quality of service (QoS) and bandwidth of the broadband service provider. IEEE 802.16j mobile multihop relay Worldwide Interoperability for Microwave Access networks have the opportunity to offer high bandwidth capacity by introducing relay stations. However, to actually satisfy QoS requirements for offering IPTV services (HDTV, SDTV, Web TV, and mobile TV) for heterogeneous users' requests, providers must use a video server for each IPTV service type, which increases the network load, especially bandwidth consumption and forwarding time. In this paper, we present a solution for forwarding IPTV video streaming to diverse subscribers via an 802.16j broadband wireless access network. In particular, we propose a new multicast tree construction and aggregation mechanism based on the unique property of prime numbers. Performance evaluation results show that the proposed scheme reduces both bandwidth consumption and forwarding time.

• Journal of Korea Entertainment Industry Association
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• v.13 no.5
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• pp.119-126
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• 2019

Watching movies is common on a big screen like a theater or on a big-screen TV. nowadays, small platform such as mobile devices is increasing rapidly for watch a movie. These changes are deeply related to the advent of Internet-based video streaming services such as OTT. OTT's development has provided in free video viewing system without using the set-top box is free from the limitations of time and space. Leading the market is Netflix[1], which started its business with Internet-based DVD rental service. Netflix, which is growing in tandem with the mobile market, had 193.26[2] million members as of the end of 2018. Other OTT participating companies include content-based Pooq, TVing, platform-based Olleh TV Mobile, Oksusu and LTE video portal. The size of such new growth projects has grown gradually, with 25.4 percent of all smartphone users currently watching video content with small mobile devices. Therefore, de-largeization, it is thought that visual language is needed for viewing small mobile devices that are capable of OTT services. To this end, this paper will identify the problem in viewing popular video content with small mobile devices and Survey and study its impact on viewers using the questionnaire.

• Annual Conference of KIPS
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• 2004.05a
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• pp.707-710
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• 2004

In the case of terrestrial DMB(Digital Multimedia Broadcasting) system that offers mobile multimedia broadcasting services, transmission error must be considered. Although DMB transmission system provides the error protection functions of convolution coding and Reed-Solomon (204,188,t=8) coding, additional error resilience video coding methods are needed to satisfy the requirement of BER lower than $10^{-8}$. In this thesis, we propose and evaluate effective error resilience coding schemes using the MPEG-4 redundant slice for MPEG-4 video services in the DMB environment. In this scheme, we analyze the drift error caused by transmission error based on the random noise concept and the redundant slice selection algorithm that selects the most influential slice in the view of the drift error increment.

• ETRI Journal
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• v.27 no.1
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• pp.13-21
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• 2005

Many multicast applications, such as video-on-demand and video conferencing, desire quality of service (QoS) support from an underlying network. The differentiated services (DiffServ) approach will bring benefits for theses applications. However, difficulties arise while integrating native IP multicasting with DiffServ, such as multicast group states in the core routers and a heterogeneous QoS requirement within the same multicast group. In addition, a missing per-flow reservation in DiffServ and a dynamic join/leave in the group introduce heavier and uncontrollable traffic in a network. In this paper, we propose a distributed and stateless admission control in the edge routers. We also use a mobile agents-based approach for dynamic resource availability checking. In this approach, mobile agents act in a parallel and distributed fashion and cooperate with each other in order to construct the multicast tree satisfying the QoS requirements.

• International Journal of Advanced Culture Technology
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• v.12 no.2
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• pp.30-35
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• 2024

With the recent commercialization of the 5th generation mobile communication technology (5G), interest is focused on full-fledged wireless communication service products in related industries that apply the technology. In this paper, "the problems of the cloud-based video game streaming service market, which has been stagnant for a long time due to the existing 4G-based transmission delay, processing delay, and price issues, and the problems of 5G mobile communication, which began commercialization in 2019." We contains information about what type of positive changes a cloud-based video game streaming service incorporating technology will bring.

• Journal of Internet Computing and Services
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• v.8 no.6
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• pp.21-28
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• 2007

Hierarchical Mobile IPv6 improves performance of Mobile IPv6 by managing Binding Update in terms of location, With improved handover delay, realization of delay-sensitive services (e,g, VoIP or video streaming) has become more persuadable, Comparing with Mobile IPv6, however, Hierarchical Mobile IPv6 brings security threats related to Local Binding Update to mobile network, In the RFC 4140, specific methods to authenticate Local Binding Update message are not explicitly presented. It is essential that design secure architecture to address problems related to authenticating Local Binding Update, Many secure suggestions for Local Binding Update, however, concentrate on infrastructure-based solutions such as AAA PKI. These approaches may cause scalability problem when the suggested solutions are applied to real network. Therefore we suggest authentication method that doesn't require infrastructure, In addition to authentication of Local Binding Update, our method also provides mobile node with power saving ability.

• Journal of Information Technology Services
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• v.13 no.4
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• pp.289-308
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• 2014

Mobile instant messaging (MIM) has been widely used in modern society due to its portability, speed and ease of use. In addition to simple text-based messaging, mobile instant message has now expanded to include graphics, images, and video. Many instant message service providers attempt to differentiate their service by providing an unique emoticon. Therefore, understanding the factors that affecting the continuous usage of emoticon is essential to capture users' interest. There is relatively little study on emoticon in information systems field. Hence, this study attempts to explore the continuous usage of emoticon through exploring the property of emoticon and usage motivation of emoticon. Based on the results, this study attempts to demonstrate practical implication of marketing on understanding user interest to mobile instant messenger service provider.