• Journal of KIISE:Software and Applications
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• v.32 no.11
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• pp.1029-1035
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• 2005

Web streaming environment need a suitable video playback service technique, a streaming technique for real-time delivery and an efficient control technique due to its limited environment. In this paper, we propose an effective control technique for real-time media stream playback as a connection technique between the high-quality media player and web browser based on Linux environment. The proposed stream control technique presents control data through 050 on media playback screen of web browser, and process the user's input data. It acts GUI-independently, and is designed considering addition and extension for control data.

• The KIPS Transactions:PartB
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• v.12B no.6 s.102
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• pp.661-670
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• 2005

According as services that offer multimedia streams are activated on the Internet, users who use these services we increased extremely. As a result of this, the increase of network traffic was occurred. Also it caused the problems such as the discontinuous playback in case of the s#ream playback and the asynchronization between a video and an audio. To solve these problems, it needs a method that guarantee the stable playback of media streams and a method of media transfer that can interact between a service user and media. Existing related researches has achieved the synchronization through various methods, but did not shown the results of satisfaction in the aspect of interaction. In this paper, we inserted the interactive objects in each media file, designed functions that these objects can use each other's information, and solved the interaction and the synchronization between a video and an audio. Also, we solved the discontinuous playback of a stream by the insufficiency of network bandwidth through using variable buffers.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.471-482
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• 2011

This paper introduces an development of high-definition(HD) 3DTV experimental broadcasting system and its experimental service that has been launched via three broadcasting network including terrestrial, cable and satellite in the late of 2010. This 3DTV experimental broadcasting service employs an innovative 3DTV broadcasting mechanism, called as dual stream method in which left and right images are encoded by using each video encoder and multiplexed using MPEG-2 system technology for guaranteeing backward-compatibility with legacy DTV. This paper specifically describes the developed experimental broadcasting system, concentrating on 3DTV re-multiplexer and 3DTV receiver. Finally, implementation and terrestrial 3DTV experimental broadcasting service results will be introduced from the point of objective and subjective evaluation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.10
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• pp.1190-1196
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• 2016

In this paper, a cross-layer interworking scheme for different protocols is proposed to provide an efficient internet services in very small aperture terminal (VSAT) based satellite communication systems. In addition, we implement the proposed interworking model and prove the feasibility of the proposed system. VSAT based satellite communication systems commonly use digital video broadcasting (DVB)-S2 standard. Unfortunately, DVB-S2 has inefficient parts to support IP based internet services because it has originally been designed to support broadcasting services. Generic stream encapsulation (GSE) protocol, which is a layer 2 protocol, has been proposed to mitigate this inefficiency. We propose a cross-layer interworking scheme to cooperate efficiently between IP and GSE protocols and between GSE protocol and DVB-S2, respectively. In addtion, we implement the proposed interworking schemes via computer softwares and prove the feasibility using NI-USRP and commercial DVB receiver.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.337-346
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• 2000

In a Vod(video0on-demand) system, a scheduling strategy is designed to increase the system efficiency and to eatisfy the isochronous requirements of showing a video to multiple viewers with one disk access. In this paper, we have proposed the Stream Relay Scheme (SRS) which utilizes the client's buffer space to reduce the server's disk I/O, buffer consumption, and stream capacity. Under the SRS which we have proposed in this paper, the server does not service all the requests directly but forwards the new request selectively to the client who is being served currently in order to reduce the initial latency and increase the system throughput. The SRS-BAT which integrated the SRS with the Batching technique is introduced. The results of the simulated experiments which compared the SRS with the conventional technique have shown the noticeable performance improvements in terms of initial latency and the server throughput.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.219-232
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• 2005

With the rapid progress of computer technology in recent years, a digital video data has been used in many applications. As a result, various technologies have been introduced to discover knowledge embedded in a video database. However, few researches on data mining for a video database have been performed due to the unclear boundary of the information in a large amount of a video stream. This paper proposes an efficient generation method of a feature profile in a set of similar video data. To extract the information embedded in original video data efficiently, several refinement techniques are also presented. These methods include merging pixels, restricting preferred areas, removing noises under a minimum repeat factor, extracting important key frames, generating derived blocks and applying weights to dynamic and static areas differently. Finally, the performance of these methods is evaluated by comparing a result profile obtained by a data mining process with original video streams.

• Journal of Korean Society for Geospatial Information Science
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• v.10 no.4 s.22
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• pp.31-39
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• 2002

In this paper, we propose Media CIS system architecture which provides geographical information of geo-features in video sequences by using 3D geographical database and GPS-related data resulted from 4S-Van. We introduce a novel interoperable geographical data service concept, so-called, Virtual World Mapping (VWA) that can map 3D graphic world with real-world video to provide geographical information. Our proposed method can easily retrieve geographical information and attributes to reconstruct 3D virtual space according to certain frame in video sequences. Our proposed system architecture also has an advantage that can provide geographical information service with video stream without any image processing procedures. In addition to, describing the details of our components, we present a Media GIS web service system by using GeoVideo Server, which performs VWM technique.

• Journal of Communications and Networks
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• v.7 no.2
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• pp.144-156
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• 2005

Video streaming over wireless networks is challenging due to node mobility and high channel error rate. In this paper, we propose a multi-source video streaming (MUVIS) system to support high quality video streaming service over IEEE 802.1l-based wireless networks. We begin by collocating a streaming proxy with the wireless access point to help leverage both the media server and peers in the WLAN. By tracking the peer mobility patterns and performing content discovery among peers, we construct a multi-source sender group and stream video using a rate-distortion optimized scheme. We formulate such a multi-source streaming scenario as a combinatorial packet scheduling problem and introduce the concept of asynchronous clocks to decouple the problem into three steps. First, we decide the membership of the multisource sender group based on the mobility pattern tracking, available video content in each peer and the bandwidth each peer allocates to the multi-source streaming service. Then, we select one sender from the sender group in each optimization instance using asynchronous clocks. Finally, we apply the point-to-point rate-distortion optimization framework between the selected sender-receiver pair. In addition, we implement two different caching strategies, simple caching simple fetching (SCSF) and distortion minimized smart caching (DMSC), in the proxy to investigate the effect of caching on the streaming performance. To design more realistic simulation models, we use the empirical results from corporate wireless networks to generate node mobility. Simulation results show that our proposed multi-source streaming scheme has better performance than the traditional server-only streaming scheme and that proxy-based caching can potentially improve video streaming performance.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1033-1043
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• 2000

Recently as the user request on NoD (News-on-Demand) is largely increasing, there are a lot of researches to fulfill it. However, because of short life-cycle of new video data and periodical change of video data depending on anchor, it is difficult to apply the conventional video storage techniques to NOD applications directly. For this, we design and implement low-level storage manager for efficient storage and retrieval of multimedia data in NOD Services. Our low-level storage manager not only efficiently sotres video stream dat of new video itself, but also handles its index information. It provides an inverted file method for efficient text-based retrieval and an X-tree index structure for high-dimensional feature vectors. In addition, our low-level storage manager provides some application program interfaces (APIs) for storing video objects itself and index information extracted from hierarchial new video and some APIs for retrieving video objects easily by using cursors. Finally, we implement our low-level storage manager based on SHORE (Scalable Heterogeneous Object REpository) storage system by sunig a standard C++ language under UNIX operating system.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.367-376
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• 1999

A variable bit-rate based video services have much limitation for bandwidth management, since its trarfic has a some variances in frame level. In particular, the bandwidth management for video which has characteristics of VBR traffic such a MPEG video could be more complicated. Also, it is difficult to manage the bandwidth effectively for proving a VCR function from VOD service, since we don't know the traffic variance exactly at that time. In this paper, we proposed the dynamic bandwidth allocation a scheme based on VBR traffic based stored video such as MPEG for interactive video service. This scheme can maximize the given total bandwidth through the prefetch based variable length bandwidth allocation scheme and dynamic bandwidth management scheme for multiple streams. Also, our scheme can be used for a MPEG-based bandwidth allocation scheme, and provides the method that can maximize the utilization of network resource for multiple stream by using a dynamic bandwidth management.