• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.9-16
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• 2003

In this paper, we propose a method for supporting VCR operations in a patching based multicast VOD system. Random access, pause and resume operations are supported in our system, and the channel and session scheduling algorithms for the VCR operations are proposed. When it is necessary to join a sharable multicast channel in the admission control for the VCR operations, the patching technique, which shares an on-going regular channel and allocates a new patching channel for the missing data, is used. Therefore, unlike the previous approach that allocates an excessive number of I-channels, service latency is minimized and channel usage is optimized in our system. Moreover buffered data. which is saved in disk during patching, is reused to prevent unnecessary patching channel allocation. For this. the patching management information is extended and a buffed data management scheme is proposed. In our system, the First-Come-First-Served scheduling is used to inform clients the service latency for the VCR operations immediately.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.237-244
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• 2018

This paper deals with the viewer's recognition of diversity on digital media services. For this reason, the researcher focused on the IPTV user, how the perception of the diversity of the digital media service affected the user's satisfaction. The results are as follows. First, digital media service user recognized that supply side diversity of media channel and VOD affect recognition of accessibility (easy of use) and perceived playfulness. Second user recognized that variety of performers and actors affect recognition of accessibility and perceived playfulness. Moreover, it was found that recognition of accessibility, actor's diversity, perceived playfulness affect use's recognition for media player's contribution of diversity, and media satisfaction. As in this paper, the researcher expects that this kind of methodology for confirming of user's recognition of diversity will contribute to preparing a future media policy.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.5
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• pp.505-512
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• 2000

In this paper, an adaptive multimedia synchronization scheme for VOD (Video On Demand) services in internet environments is proposed. This scheme considers the characteristics of MPEG (Moving Picture Expert Group) system stream. Consequently, the intra-synchronization is handled at the pack layer, and the inter-synchronization is handled at the packet layer. The proposed scheme can cope adaptively with variation of packet loss, jitter and client's playback capacity. If there are variations of the packet loss or client's playback capacity, the server will change the transmission rate by selective picture skip. The client can then adjust and control the playback time according to the variation of the network jitter. Our experimental results show that the proposed scheme can quickly adapt to the network condition, and can guarantee a better quality of service than the other existing schemes.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.331-333
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• 2000

최근 VOD(Video On Demand)나 AOD(Audio On Demand) 서비스가 급증하면서 멀티미디어 스트리밍 기술에 대한 관심이 커지고 있다. 기존의 스트리밍 서비스는 정적으로 멀티미디어를 전송하므로 네트워크 환경의 대역폭(bandwidth) 변화에 대처하는데 한계가 있다. 이러한 문제점을 해결하기 위하여 본 논문에서는 적응형 스트리밍 서비스(ASS; Adaptive Streaming Service) 시스템을 제안한다. ASS 시스템은 가변 비트율을 통한 미디어 스케일링방식을 이용하여 멀티미디어 데이터를 동적으로 전송한다. 또한 프레임 조정방식과 화질 조정방식을 동시에 채택하여 적용함으로써 고화질이 보장되는 전송환경과 느린 회선에서도 끊김없이 안정적인 스트리밍 서비스를 제공받을 수 있도록 한다.

• Asian Journal of Innovation and Policy
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• v.5 no.2
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• pp.185-196
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• 2016

A digital cable broadcasting service is a multimedia broadcasting service that provides high definition and various supplementary services by using digital transmission. Korea implemented a complete digital broadcasting service by 2012. This study applied a choice experiment to investigate consumer preferences, and it calculated the marginal willingness to pay for this service. Moreover, we employed a multinomial probit model to relax the assumption that all respondents have the same preference for attributes being valued. The results suggest that respondents value channels, definition, video-on-demand (VOD) service, pay-per-view (PPV) service, and commerce based on TV (T-commerce). On the other hand, online gaming may be less important as an attribute for digital cable broadcasting service in Korea.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.11 s.353
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• pp.16-24
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• 2006

In this paper, we implement a U-healthcare system that can be applied to a service integration system. This system consists of a wireless network system a sensor module, and a integration server. The wireless network system collects data and the sensor module measures body fat, blood pressure, quantity of exercise, and SPO2. The server integrates user certification, security service and VOD service and collects user health information in real-time, and sends the data in case of emergency to a doctor or guardian.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.153-160
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• 2009

A hierarchical network between Mobile-WiMAX and WLAN systems is to make it possible to utilize wireless internet services including time sensitive applications such as VoIP, VOD, visual telephony etc. During the process of vertical handoff decision from Mobile-WiMAX to WLAN hotspot, vertical handoff delay causes user dissatisfaction because it doesn't provide the seamless wireless internet service. We make use of type of service (ToS) parameters in IEEE 802.16e specification as the criterion parameter of vertical handoff decision process in hierarchical Mobile-WiMAX/WLAN networks. In this paper, we propose the process of vertical handoff decision for seamless wireless internet service which is sensitive to time delay. If type of service is time sensitive application, the decision of vertical handoff is withdrawn until the service is terminated. In focus on user satisfaction, if the proposed traffic management strategy in hierarchical Mobile-WiMAX/WLAN networks is used, user will utilize seamless wireless internet services including time sensitive applications.

• Journal of the Korea Society of Computer and Information
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• v.7 no.1
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• pp.120-128
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• 2002

As mass data service like internet broadcasting and VOD is used widely, network traffic is increasing rapidly. In order to resolve this service delay caused by mass network traffic data, various techniques are tried. MPLS, as one of these techniques, supports network extensibility and high speed routing. But it generate delay while waiting to set the LSP from input node to output node. In order to resolve these delay Problems, this Paper Propose different label assign technic according to the hop count between input node and output node when data has to go through MPLS domain. The simulation results show that delay reduction was gained when the proposed technique is applied.

• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1209-1218
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• 2003

To guarantee client buffer stabilization and visual quality, the VOD service that provides real time video titles on requirements of numerous users, needs a mechanism which transfers frames with dropping or skipping algorithm by network condition. In this paper, we show an algorithm that transfers withdrawed skipped MPEG frames(I, P, B frame) from disk to client dependent on network load. Moreover, we verify through a simulation that adaptive dealing on network load can reduce the network load and stabilize client receiving buffer.

• Journal of the Korea Computer Industry Society
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• v.4 no.10
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• pp.741-750
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• 2003

$MTP^{TM}$ guarantees high bandwidth that is necessary to tansmit high qualify full motion video data effectively. In other hand TCP/IP which is used for information search does not guarentee high bandwidth as that in $MTP^{TM}$. Therefore VOD service system that searches information manged by DBMS and transmits required full motion video data should control different kinds of protocol simultaneously. This paper describes the configuration of VODB system that has solved these problems.