• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.4
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• pp.175-181
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• 2008

This paper describes the SVC-based media adaptation system which can adapt video contents optimally to various consumption environments in an IP-based transmission scenario. As key technologies, we will present scalable video coding, SVC-based adaptive media transmission, and SVC-based adaptation signaling technology.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.6
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• pp.1324-1329
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• 2013

The WiMedia Alliance has specified a Distributed Medium Access Control (D-MAC) protocol based on UWB for high speed wireless home networks and WPANs. In this paper, firstly, the fair SoQ-based Distributed Reservation Protocol (DRP) for D-MAC is analyzed. And a novel SoQ-based relay transmission protocol is proposed to overcome DRP conflicts fast. In the proposed protocol, each device executes the Satisfaction of QoS (SoQ) time slot allocation algorithm independently. And, in order to give the loser device due to DRP conflicts another chance to maintain QoS resources, the proposed relay transmission protocol helps the device reserve another indirect link maintaining the required QoS resources via a relay node.

• 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 the Korea Contents Association
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• v.15 no.1
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• pp.324-330
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• 2015

When diagnostic ultrasounds are used, an ultrasonic transmission media is used to effectively transmit the ultrasonic energy. Types of ingredients of polymer hydro gel, emulsion, and oil gel were compared with commercialized products by measuring characteristics of ultrasonic transmission media such as skin lubricity, skin moisturizing, and dryness speed which were contained in each different media. The mean friction coefficient measured to investigate skin lubricity showed high in the agent containing a large amount of oil, whereas the mean friction coefficient of the low viscosity emulsion did not show a significant difference with that of the polymer hydro gel. The moisture evaporation measured to investigate the dryness speed of the agent showed highest in polymer hydro gel. This showed that the larger amount of oil it had, the less moisture evaporation occurred. For skin moisture measured to investigate moisturizing characteristics of skin, low viscosity emulsion showed high in moisture content, whereas it showed slowest reduction in moisture content. As a type of emulsion appropriately containing water and oil is superior in skin moisturizing and skin tenderness, it is expected to serve as a dosage form of new ultrasonic transmission media.

• ETRI Journal
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• v.39 no.6
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• pp.771-781
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• 2017

For efficient spectral utilization of satellite channels, a shared band transmission technique is introduced in this paper. A satellite transmits multiple received signals from a gateway and terminal in the common frequency band by superimposing the signals. To improve the power efficiency as well as the spectral efficiency, a travelling wave tube amplifier in the satellite should operate near the saturation level. This causes a nonlinear distortion of the superimposed transmit signal. Without mitigating this nonlinear effect, the self-interference cannot be properly cancelled and the desired signal cannot be demodulated. Therefore, an adaptive compensation scheme for nonlinearity is herein proposed with the proper operation scenario. It is shown through simulations that the proposed shared band transmission approach with nonlinear compensation and self-interference cancellation can achieve an acceptable system performance in nonlinear satellite channels.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.7
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• pp.3018-3038
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• 2020

In the stereoscopic or multiview display, the depth video illustrates visual distances between objects and camera. To promote the computational efficiency of depth video encoder, we exploit the intra prediction of depth videos under Versatile Video Coding (VVC) and observe a diverse distribution of intra prediction modes with different coding unit sizes. We propose a hybrid scheme to further boost fast depth video coding. In the first stage, we adaptively predict the HADamard (HAD) costs of intra prediction modes and initialize a candidate list according to the HAD costs. Then, the candidate list is further improved by considering the probability distribution of candidate modes with different CU sizes. Finally, early termination of CU splitting is performed at each CU depth level based on the Bayesian theorem. Our proposed method is incorporated into VVC intra prediction for fast coding of depth videos. Experiments with 7 standard sequences and 4 Quantization parameters (Qps) validate the efficiency of our method.

• The KIPS Transactions:PartA
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• v.9A no.2
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• pp.207-216
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• 2002

This paper present a design and implementation of a distributed audio, Video stream service framework based on CORBA for efficient processing and control of audio/video stream. We design software components which support processing, control and transmission of audio/video streams as distributed objects. For optimization of stream transmission performance, we separate the transmission path of control data and media data. Distributed objects are defined by IDL and implemented using JAVA. And device dependent facilities like media capturing, playing and communication channels are implemented using JMF (Java Media Framework) components. We show a connection establishment and control procedure of streams communication. And for evaluation, we implement a test system and experiment a system performance. Our experiments show that test system has somewhat longer connection latency time compared to TCP connection establishment, but has optimized media transmission time compared to CORBA IIOP. Also test system show acceptable service quality of media transmission.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2513-2530
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• 2021

With the fast development of information and communication technologies, video streaming services and applications are increasing rapidly. However, the network condition is volatile. In order to provide users with better quality of service, it is necessary to develop an accurate and low-complexity model for Quality of Experience (QoE) prediction of time-varying video. Memory effects refer to the psychological influence factor of historical experience, which can be taken into account to improve the accuracy of QoE evaluation. In this paper, we design subjective experiments to explore the impact of Short-Term Memory (STM) on QoE. The experimental results show that the user's real-time QoE is influenced by the duration of previous viewing experience and the expectations generated by STM. Furthermore, we propose analytical models to determine the relationship between intrinsic video quality, expectation and real-time QoE. The proposed models have better performance for real-time QoE prediction when the video is transmitted in a fluctuate network. The models are capable of providing more accurate guidance for improving the quality of video streaming services.

• Journal of Broadcast Engineering
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• v.24 no.4
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• pp.602-612
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• 2019

Various streaming technologies are being studied to guarantee the QoE of viewers due to the development of realistic media. HTTP adaptive streaming is a typical example, and it is based on HTTP / 1.1 and TCP. These protocols have become one of the causes of delaying the image delay and increasing the waiting time of web pages. Therefore, in this paper, we propose a QUIC-DASH system applying the UDP-based transmission protocols QUIC and HTTP / 2 to the MPEG-DASH system after analyzing various transmission protocols and development process of HTTP. Through experiments, the QUIC-DASH system confirmed the possibility of providing optimal performance in terms of transmission speed of LTE environment than existing system. We also suggest various future studies for better performance.

• International Journal of Advanced Culture Technology
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• v.4 no.4
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• pp.1-5
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• 2016

In this paper, we present the study on the proposed design of a real-time transmission of a video from the drone to broadcasting station (OBVan) by using F8L10D-N LoRa Module. Nowadays, LoRa technology is proved to be the mass of low cost, long range machine-to-machine connectivity. Particularly in the field of broadcasting and communication system, F8L10D-N LoRa RF Module spread spectrum technology with long transmission distance and strong penetrative ability that is double stronger than traditional FSK as well as PSK modulation scheme.