• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.107-108
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• 2006

In order to meet the customers'emerging demands for more bandwidth and diverse IP multimedia applications including high definition(HD) video streaming service, KT presents innovative FTTP solution using WDM-PON system. FTTP comprises an OLT inside the central office, a fiber optic distribution network including a passive remote node in the outside plant, and ONU installed on the pole or wall of customers premise. The passive remote node is located in a manhole near the subscribers and does not require any electrical power supply. And finally, UTP cable is connected from ONU to subscribers'IP appliances like PC or HGW or IP-STB. KT finished its FTTP trial service in 2004 and commercial deployment has begun since 2005. With this FTTP solution, each subscriber can enjoy high-speed internet service with speeds of up to symmetric 100 Mbit/s and various IP media applications including HD quality IP video streaming service and high quality video phone service.

• Journal of Digital Convergence
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• v.14 no.7
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• pp.411-418
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• 2016

Digital broadcast environment led to the emergence of UHDTV following HDTV. The demands for realistic images which are created with the use of UHDTV have been applied to various fields. Of various application methods, multiplanar imaging, which is used to display high definition image contents after multiple HD or UHD displays are connected with each other up and down, and left and right, is often applied to display images and the advertising market. Today, the firms that make high-definition multiplanar images mostly use their independently developed program. Therefore, it costs higher than other general works. For the reason, multiplanar image contents are mostly made in the way of enlarging HD images over 2 to 5 times. In this experiment, the software application widely known for UHDTV based multiplanar images is applied to test a method of implementing UHD panoramic realistic images without quality degradation.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.563-581
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• 2010

In this paper, we perform subjective visual quality assessments on UHD video for UHD TV services and analyze the assessment results. Demands for video services have been increased with availabilities of DTV, Internet and personal media equipments. With this trend, the demands for high definition video have also been increasing. Currently, 2K-HD ($1920{\times}1080$) video have been widely consumed over DTV, DVD, digital camcoders, security cameras and other multimedia terminals in various types, and recently digital cinema contents of 4K-UHD($3840{\times}2160$) have been popularly produced and the cameras, beam projects, display panels that support for 4K-UHD video start to come out into multimedia markets. Also it is expected that 4K-UHD service will appear soon in broadcasting and telecommunications environments. Therefore, in this paper, subjective assessments of visual quality on resolutions, color formats, frame rates and compression rates have been carried to provide basis information for standardization of signal specification of UHD video and viewing environments for future UHDTV. As the analysis on the assessments, UHD video exhibits better subjective visual quality than HD by the evaluators. Also, the 4K-UHD test sequences in YUV444 shows better subjective visual quality than the 4K-UHD test sequences in YUV422 and YUV420, but there is little perceptual difference on 4K-UHD test sequences between YUV422 and YUV420 formats. For the comparison between different frame rates, 4K-UHD test sequences of 60fps gives better subjective visual quality than those of 30fps. For bit-depth comparison, HD test sequences in 10-bit depth were little differentiated from those in 8-bit depth in subject visual quality assessment. Lastly, the larger the PSNR values of the reconstructed 4K-UHD test sequences are, the higher the subjective visual quality is. Against the viewing distances, the differences among encoded 4K-UHD test sequences were less distinguished in longer distances from the display.

• Journal of Satellite, Information and Communications
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• v.9 no.4
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• pp.38-41
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• 2014

Due to the diversity of device performances and the possibility of providing multimedia service through many networks, media consumption environment has been changed in various ways. In recent, mobile services and broadcasting services started to provided through IP network. According to this flow changes, there was great demand for various multimedia services through heterogenous networks. To solve this problem, MMT was suggested as a standard of multimedia transport which replaces MPEG-2 TS(Transport Stream) which is used for HD(High Definition) transport. MMT can be provided various broadcasting based on IP through terrestrial, satellite, cable broadcasting networks, and also deliver multimedia through many networks at the same time. MMT was risen as a method of servicing UHD broadcasting. In this paper, we present an implementation of service architecture for hierarchical UHD broadcasting over heterogenous networks using MMT.

• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1464-1474
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• 2012

In this paper, we propose a QoS (Quality of Service)-aware and cooperative resource reservation scheme using cross-layer link adaptation for wireless high definition video transmission through UWB (Ultra Wide Band) network with D-MAC (Distributed Medium Access Control). A wireless high definition video transmission system usually requires stable high throughput even without line-of-sight, e.g., a destination device in another room separated by a wall. Since the WiMedia D-MAC supporting DRP (Distributed Reservation Protocol) scheme causes lots of DRP resource reservation conflicts due to failure of beacon detection in wireless channel environment, overall performances of the WiMedia D-MAC can be deteriorated. And the current WiMedia MAC standard has not considered QoS provisioning even though QoS parameters such as a range of service rates are provided to each traffic stream. Therefore, we propose Relay DRP protocol with QoS-based relay node selection criterion, which makes a relay path to avoid DRP resource reservation conflicts and guarantee QoS more stably through cross-layer link adaptation of cooperative relay transmission scheme and is compliant with the current WiMedia D-MAC protocol. Simulation results demonstrate performance improvements of the proposed method for throughput and QoS provisioning.

• Journal of Korea Multimedia Society
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• v.18 no.7
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• pp.853-863
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• 2015

In this paper, we proposed cross-layered approach of video codec and communication system for the efficient video streaming service. Conventional video streaming is served by divided system which consist of video codec layer and communication layer. Its disintegration causes the limitation of the performance of video streaming service. With the cross-layered design, each layer could share the information and the service is able to enhance the performance. And we proposed the selective retransmission method in communication system based on the cross-layered system that reflect the information of encoded video data. Selective retransmission method which consider the characteristics of video data improves the performance of video streaming services. We verified the proposed method with raw format full HD test sequence with H.264/AVC codec and MATLAB simulation. The simulation results show that the proposed method improves about 10% PSNR performance.

• Journal of Korea Multimedia Society
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• v.21 no.3
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• pp.415-422
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• 2018

Advances of telecommunication technology bring various changes in journalism field. Reporters started to gather, edit, and transmit content to main server in media company using hand-held smart media and notebook computer. This paper tried to testify valid bit-rate of visual news content using LTE network and mobile phone. Field news like natural disasters need real-time transmission of video content. But broadcasting company normally use heavy ENG system and transmission satellite trucks. We prepared and experimented different types of visual content that has different bit-rates. Transmission tool was LU-60HD mobile system of LiveU Corporation. Transmission result shows that bit-rate of 2Mbps news content is not suitable for broadcasting and VBR (Variable Bit Rate) transmission has better definition quality than CBR (Constant Bit Rate) method. Three different bit-rate of VBR transmission result shows that 5Mbps clip has better quality than 1Mbps and 3Mbps. The higher bit-rate, the better video quality. But if the content has much movements, that cause delay and abnormal quality of video. So optimizing the balance between stability of signal and quality of bit-rate is crucial factor of real-time broadcasting news gathering business.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10B
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• pp.919-927
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• 2008

The growing availability of broadband multimedia applications are providing strict real-time services and enabling users to feel much interactivity as well as 'sense of presence'. In that sense, there would be increased demand for what network and system have to do to fulfill the user expectations. In this paper, we implement a real-time multimedia application which make use of real-time DXT CODEC and investigate what the challenges of networking and system are. We carry out various experiments over a research network test-bed to evaluate the performance of our proposals.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.285-285
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• 2009

Due to a development of a modem technology as Power Line Communication(PLC) over 200 Mbps, the high-speed multi-media data trasmission could be currently possible. In This paper we develop a high quality media transmitter-receiver based on merging the HomePlug AV, which is 200 Mbps class PLC technology and HDMI Interface technology. Smart Live 6 software were used for the assessment of audio property. As the result of measurement of the HD class images by capturing from the receiver of the PLC, the quality of images couldn't be confirm any deterioration, which has compared with original reflections. In case of audio part as the result of confirmation of the Phase, Magnitude, it has been confirmed that over 90% of nomal transmition and receiving of acoustic signal.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.304-306
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• 2004

With the developing of current multimedia broadcasting, user will be provided for lots of various content through the various channel and media. Content provider and consumer want the various service using content with the better quality which is fit to users' preference. For transmitting this content in the limited transmission channel capacity, it needs to transmit the highly compressed content. The content of 3D mesh model-based on MPEG-4 enables the various content service that provides the lower size and the resonable quality, and Personalize(Targeting) service just provide the contents that user more wants and likes. This paper presents the study on the targeting service using compression of 3D mesh model-based on MPEG-4 and the adaptation of Embedded Graphic application program using it.