• Journal of Broadcast Engineering
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• v.24 no.7
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• pp.1209-1220
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• 2019

The demand for virtual reality (VR) is rapidly increasing. Providing the immersive experience requires much operation and many data to transmit. For example, a 360-degree video (360 video) with at least 4K resolution is needed to offer an immersive experience to users. Moreover, the MPEG-I group defined three degrees of freedom plus (3DoF+), and it requires the transmission of multiview 360 videos simultaneoulsy. This could be a burden for the VR streaming system. Accordingly, in this work, a bitrate-saving method using projection conversion is introduced, along with experimental results for streaming 3DoF+ 360 video. The results show that projection conversion of 360 video with 360lib shows a Bjontegaard delta bitrate gain of as much as 11.4%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3856-3872
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• 2018

HTTP-based adaptive streaming (HAS) has recently been widely deployed on the Internet. In the HAS system, a video content is encoded at multiple bitrates and the encoded video content is segmented into small parts of fixed durations. The HAS client requests a video segment and stores it in the playout buffer. The rate adaptation algorithm employed in HAS clients dynamically determines the video bitrate depending on the time-varying bandwidth. Many studies have shown that an efficient rate adaptation algorithm is critical to ensuring quality-of-experience in HAS systems. However, existing algorithms have problems estimating the network bandwidth because bandwidth estimation is performed on the client-side application stack. Without the help of transport layer protocols, it is difficult to achieve accurate bandwidth estimation due to the inherent segment-based transmission of the HAS. In this paper, we propose an alternative approach that utilizes the playout buffer occupancy rather than using bandwidth estimates obtained from the application layer. We start with a queueing analysis of the playout buffer. Then, we present a buffer-aware rate adaptation algorithm that is solely based on the mean buffer occupancy. Our simulation results show that compared to conventional algorithms, the proposed algorithm achieves very smooth video quality while delivering a similar average video bitrate.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.631-634
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• 2002

Video conference system has guided swiftness of information transmission and business processing taking away time and manufacturing drug of space that is happened that long-distance gather and talk. But, leakage of important meeting content, peculation etc., in that execute video-conferences can happen. Therefore, research about video conference system of safety is progressing under secure superhigh speed information communication fetters. This treatise studied about techniques to encipher videotex to prevent variation and outward flow of burn information, peculation etc., except general encryption notation such as user certification to have drawn problem about stability of general video conference system, and is used present as countermeasure about here. Used improved Vernam's encryption techniques to encrypt videotex.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.1063-1075
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• 2000

This paper proposes an adaptive error concealment technique for compressed video. Since redundancy is extracted out during compression process, compressed video is vulnerable to errors which occur during transmission of video over error prone networks such as wireless channels and Internet. Error concealment is a process of reconstructing video out of damaged video bit stream. We proved that scalable encoding is very useful for error concealment. Analysis of experiments shows that some part of image is better concealed by using base layer information and other part of image is better concealed by using previous frame information. We developed a technique which enables to decide which methodology is more effective, adaptively, based on motion vectors and regional spatial activity. We used H.263v2 for scalable encoding, but, our approach could be applied to all DCT based video codec.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8B
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• pp.707-715
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• 2006

One of the most promising services on the wireless network is multimedia data service. With recently emerged wireless communication technologies which conventionally were devoted to mobile phone services, pre-encoded contents as well as live video data can be transmitted via the same network. As there is enough room in the improvement of data transmission bandwidth in wireless network, video data service is likely to be more demanding. In this paper, real time MPEG-4 video encoder is described as apart of a whole system for live video services over wireless networks. As there are minimal assumptions on the underlying networks, presented system and service can be easily supported by different network system.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.329-332
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• 2005

In this paper, we describe implementation of personal media gateway (PMG) for applications over BcN networks. PMG is a TV based set-top terminal, which enables transmission of Full D1 high quality video and audio at the speed of maximum 2Mbps. It supports SIP protocol and QoS for the BcN networks. The hardware of the PMG consists of host module, audio/video codec processing module, DTMF module, and remote control I/O module. H.263 and MPEG4 software are implemented in DSP as codec for hi-directional communication and streaming, respectively. G.711 and Ogg-Vorbis are implemented as audio codec. We examined the quality of video using the Video Quality Test Equpment, which was developed by KT Convergence Lab. The experimental results show the video quality of MOS 4.1 and audio quality of MOS 4.3. We expect that PMG will be prospective business models, and create new customer value.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.1
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• pp.70-75
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• 2002

Video conference system has guided swiftness of information transmission and business processing taking away time and manufacturing drug of space that is happened that long-distance people gather and talk. But, leakage of important meeting contents, peculation etc.. in that execute video -conferences can happen. Therefore, research about video conference system of safety is progressing under secure superhigh speed information communication fetters. This treatise studied about techniques to encipher videotex to prevent variation and outward flow of burn information, peculation etc.. except general encryption notation such as user certification to have drawn problem about stability of general video conference system, and is used present as countermeasure about here. Used improved Vernam's encryption techniques to encrypt videotex.

• The Journal of Korean Institute of Information Technology
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• v.17 no.10
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• pp.101-113
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• 2019

Recently, the intelligent video surveillance technology has become able to provide various services such as predictive surveillance that have not been provided previously. Securing the security of the intelligent video surveillance is essential, and malicious manipulation of the original CCTV video data can lead to serious social problems. Therefore, in this paper, we proposed an intelligent video surveillance environment based on blockchain. The proposed scheme guarantees the integrity of the CCTV image data and protects the ROI privacy through the edge blockchain, so there is no privacy exposure of the object. In addition, it is effective because it is possible to increase the transmission efficiency and reduce storage by enabling video deduplication.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.860-872
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• 2018

In this Paper, we propose 8K UHD (Ultra High Definition) encapsulation method for efficient transmission and reception based on MMT (MPEG Media Transport). Broadcasting services for 8K UHD allow users to feel the maximized reality. However, present technology is difficult to provide 8K UHD in broadcasting networks, because the 8K UHD bitrate is too high to be transmitted in the current broadcasting networks. Research for transmitting 8K UHD is underway. In some researches, a receiver is implemented with four 4K UHD display instead of a 8K UHD display. In order to transmit 8K UHD within the limited transmission bitrate of broadcasting network, 8K UHD contents encoded by SHVC (Scalable High Efficiency Video Coding) and then transmitted over heterogeneous network. For using the broadcasting and communication networks, MMT standard is used. MMT is IP based transmission protocol as the next generation transmission protocol. According to the MMT standard, video stream encapsulated and transmitted in MMTP (MMT Protocol) packet. IP-based broadcasting and communication networks can be used to transmit simultaneously, and the receiver can synchronize and play it. We propose an encapsulation method that can efficiently transmit and receive 8K UHD. The proposed method increases a payload rate and decreases an initial delay at the receiver. We show that the efficiency of the proposed method is verified by experimental tests.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1618-1626
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• 2013

Virtualization service processes all operation including the data creation, storing, and disposal in a server and transmits processed data as the streaming media form. Therefore, client can use the same environment as the traditional desktop environment without considering the type of device. Virtualization service should consider not only the video quality but also the delay bounds and continuity of video playback for improving the user perceived Quality of Service(QoS) of streaming service. In this paper, we propose a network-adaptive transmission architecture that focuses on guaranteeing QoS requirements for virtualization service. In order to provide those, the proposed architecture have the transmission rate adaptation function based on available bandwidth and the content bit-rate control function based on sender buffer state. Through each function, proposed architecture guarantee the delay bounds and continuity of virtualization contents playback. The simulation results show that proposed network-adaptive transmission architecture provides a improve performance of throughput and transmission delay.