• Journal of the Korea Computer Industry Society
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• v.3 no.8
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• pp.1027-1038
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• 2002

Multimedia data services have been widely developed with the recent progression of the Internet technology. Multimedia services, especially, must guarantee Quality of Service with restricted environment resources. The abrupt increase of transmission quanta, so called burst, and the number of client that access multimedia server, with limited network bandwidth will demage the quality of service and the utilization of network resource. Smoothing techniques can reduce the burst of a variable bit rate stream by transmitting data at a series of fixed rates. In this paper, we present a new smoothing algorithm using MPEG's characteristics in transmitting stored video data with VBR. The smoothing algorithm we present will be verified with assorted existing techniques in diverse environments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.4068-4086
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• 2014

Due to the prevalence of powerful mobile terminals and the rapid advancements in wireless communication technologies, the wireless video streaming service has become increasingly more popular. Recent studies show that video streaming services via Transmission Control Protocol (TCP) are becoming more practical. TCP has more advantages than User Diagram Protocol (UDP), including firewall traversal, bandwidth fairness, and reliability. However, each video service shares an equal portion of the limited bandwidth because of the fair sharing characteristics inherent in TCP and this bandwidth fair sharing cannot always guarantee the video quality for each user. To solve this challenging problem, an Adaptive Multiple TCP (AM-TCP) scheme is proposed in this paper to guarantee the video quality for mobile devices in wireless networks. AM-TCP adaptively controls the number of TCP connections according to the video Rate Distortion (RD) characteristics of each stream and network status. The proposed scheme can minimize the total distortion of all participating video streams and maximize the service quality by guaranteeing the quality of each video streaming session. The simulation results show that the proposed scheme can significantly improve the quality of video streaming in wireless networks.

• Journal of Information Technology Services
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• v.8 no.3
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• pp.209-221
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• 2009

The successful mass media drama, 'The 1st Shop of Coffee Prince', has received lots of supports from the audience by showing them a vivid life and also enabling them to dream a real fantasy. One among the most powerful strategies that made this drama stay successful is the marketing value of the drama space fully maximized when doing the production. This study, introducing a unique representation of 2-D cell matrix with x-y plots of drama space set along the time stream following the scenario, first proposes a quantitative way of uncovering the hidden relation between drama space and scenario using nonlinear matrix filtering method and, secondly, suggests possible service designs mainly constrained by economical standpoints of the stakeholder in producing the drama. The methodology may invoke a plausible contradiction with art instincts that have hardly been supposed to be affected by financial debate, which, nevertheless, must sometimes be allowed under the circumstance of pursuing optimality in programming and producing the drama that must survive in the world of competitive market of service business.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.87-96
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• 2004

These days, it is essential that a business-class hotel provide customers with Internet service. So the most hotels have been installing facilities actively for Internet service. Businessmen also want to use Internet service level to their own office or home in hotel room. But now TV and VoD(partial) based-on CATV in hotel is supplied, and the additional network are installed for Internet service. The existing TV also must be replaced to HDTV within 2 or 3 years. The objective of this paper is to implement the next generation hotel multimedia service system using xDSL technology, VLAN mapping technology, and QoS technology. This system can provide each room in hotel with high-quality video service and Internet service simultaneously, and can also supply Internet access service using wireless LAN for the Places, such as lobby, conference room, and coffee shop in hotel. Therefore, this system can create the new market in hotel multimedia service field by connecting xDSL technology to VLAN mapping technology for charging and QoS technology for video stream transmission.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.488-493
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• 2002

MPEG-4 movies are composed of several media objects, organized in a hierarchical fashion. Those media objects are served to the clients as elementary streams. To play the movie, client players compose the elementary streams according to the meta- information called the scene graph. The meta-information streams are delivered as BIFS and OD elementary stream. Using dynamically generated BIFS and OD streams, we can provide a service something differs from traditional file services. For example, we can insert weather or stock information into the bottom of the screen while an existing movie was played in the screen. In this paper, we propose a dynamic service framework and dynamic server. Dynamic service framework is an object-oriented framework dynamically generating BIFS and OD streams based on the external DB information. Dynamic server provides a GUI for the server management and interface for registering dynamic services. In this framework, the dynamic service has the same interface as a file service. So, a dynamic service is considered as a file service by clients and other services.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1661-1664
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• 2003

The transcoding is a method which converts a multimedia stream to an adaptive format, such as frame rate and resolution, that can be played in the mobile devices. Due to the heavy consumption of CPU power for transcoding, the server in charge cannot supply all streams requested from clients if it is already occupied by several streams. The load balancing among proxies is a common approach for solving such problem. In addition to collaborative works for load balancing, the mobility must be taken into account in the mobile environments. Thus, the wired-network based algorithm is not suitable for the streams service in the mobile environments. In this paper, we propose an alternative scheme for cooperative proxy architecture that considers the case in which mobile devices are moving over other zones.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.123-126
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• 1998

Generally, in a VOD(video on Demand) system, batching technique is oten used to improve throughput. Since subscribers to VOD servives tend to withdraw their requests as the latency becomes large, an optimal scheduling scheme should consider not only batching size but also withdrawal rae, service latency and fairness between different programs. In this paper, we propose a new scheduling scheme, which shows improvement in fairness and reduction in withdrawal rate and service latency compared with other well known schemes. When there are 2 or more streams are available in the VOD server, proposed scheme apply different program selection policies to each streams. Using this approach effectiveness of stream usage can be improved.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.213-219
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• 2017

Streaming server is that an image produced in real time or a file form of image produced ahead consists of SNS service, and the relay module of streaming server includes output management module that set an output channel more than 2 and control transmission of video content. This thesis intends to suggest how to stream through plural output channel that contains output channel of external streaming server using relay module and do streaming provided to terminal receiving image, and streaming server, streaming system for this. Thus, by extending output channel sending out image to output channel of external streaming server, the scale of streaming server is not limited and the process allotting external streaming server into output channel sending the image becomes simple, so management of output channel becomes efficient even when sending several images.

• ETRI Journal
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• v.18 no.4
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• pp.229-244
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• 1997

Realization of the economical, reliable, and efficient ATM interface block becomes an important key to development of the ATM switching system when we consider new issues raised recently. In this paper, we summarize requirements for the ATM interface block and present the UNI (User Network Interface)/NNI (Network Node Interface) architecture to meet these requirements. We also evaluate the performance of the multiplexer adopting the various multiplexing schemes and service disciplines. For ATM UNI/NNI interface technologies, we have developed a new policing device using the priority encoding scheme. It can reduce the decision time for policing significantly. We have also designed a new spacer that can space out the clumped cell stream almost perfectly. This algorithm guarantees more than 99 % conformance to the negotiated peak cell rate. Finally, we propose the interface architecture for accommodation of the ABR (Available Bit Rate) transfer capability. The proposed structure that performs virtual source and virtual destination functions as well as a switch algorithm can efficiently accommodate the ABR service.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.83-86
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• 2002

In this paper while a router is routing all packet to the next hop, it inspects whether there is congestion on this current hop router or not and if the router discovers that it has some congestion, it informs that the packet is experienced to congestion. The packet arrived to next hop including some information about the congestion is processed first and it has wider bandwidth than another packet The amount of congestion is recorded to the DS field of IP header by congestion experience level. In the next hop when the packet including the congestion information is routed, the standard packet dropping ratio of the current router is changed in proportion to congestion experience that is recorded in IP header on of that. When the packet that has experienced congestion before is arrived, the router extends the drop threshold value not to drop the packet. It mean that transferring the audio or video stream, if the packet is already experienced the congestion in another hop, the router can provide the better service quality about 15∼25% than another.