• ETRI Journal
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• v.34 no.5
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• pp.753-758
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• 2012

As the next-generation video coding standard, High Efficiency Video Coding (HEVC) has adopted advanced coding tools despite the increase in computational complexity. In this paper, we propose a selective bi-prediction method to reduce the encoding complexity of HEVC. The proposed method evaluates the statistical property of the sum of absolute differences in the motion estimation process and determines whether bi-prediction is performed. A performance comparison of the complexity reduction is provided to show the effectiveness of the proposed method compared to the HEVC test model version 4.0. On average, 50% of the bi-prediction time can be reduced by the proposed method, while maintaining a negligible bit increment and a minimal loss of image quality.

• ETRI Journal
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• v.31 no.5
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• pp.631-633
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• 2009

We introduce an improved Ethernet ring protection method, selective filtering database (FDB) advertisement, to minimize traffic overshoot in the event of a failure or recovery. On the protection switching event, the proposed method makes all ring nodes perform an FDB flush except the FDB entries associated with their client subnets. Then, ring nodes rapidly exchange their client MAC address lists so that their FDBs are immediately updated by indirect MAC address learning. The proposed scheme guarantees fast and reliable protection switching over the standard scheme.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.6
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• pp.552-557
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• 2017

Wire, wireless digital broadcasting has sharply expanded with the birth of high definition TV since 2010, the use of duplex contents as well as simplex contents has rapidly increased. Currently, our satellite communications system adopted DVB by European digital broadcasting standardization organization as a standard of domestic data broadcasting, the method how to use selective contents has been studied variously according to the development of IPTV. Digital broadcasting utilizes the method using Transport Stream Packet(TSP) by the way of multiplexing of information in order to send multimedia information such as video, audio and data of MPEG-2, this streams include detail information on TV guide and program as well as video and audio information. In order to understand these data broadcasting system, this study realized TS analyzer that divides transport stream (TS) by packet in Linux environment, analyzes and prints by function, it can help the understanding of TS, the enhancement of stream parsing ability.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.451-453
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• 2011

VANET 환경에서 차량의 안전을 위한 긴급 메시지 전달 기법의 연구가 활발히 이뤄지고 있다. 차량이 긴급 상황에 대처하기 위해서는 긴급메시지가 신속하게 주변 전파되어야 한다. 많은 노드들에게 빠른 시간에 전파하기 위해 이용되는 Flooding 방식은 빈번한 브로드캐스트로 인하여 네트워크 전체의 트래픽이 증가하게 된다. 이로 인하여 데이터의 전송 지연상황이 발생한다. 이러한 문제점을 막기 위해 Selective Flooding 방식이 도입되었으나 메시지의 중복으로 인한 Flooding은 고려되지 않았다. 따라서 본 논문에서는 클러스터링을 활용하여 기존의 Selective Flooding 방식에서의 overhead를 줄여 빠른 메시지 전달을 할 수 있는 방법을 제안한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.19-25
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• 2011

With the issue of a Green IT Technology, studies on a environment-friendly luminous source that can reduce Carbon discharge and increase energy efficiency are actively progressed all over the world. Especially, with the problems of high oil price and environmental pollution, LED has made a great attention as a new luminous source that can replace the existing incandescent bulbs and fluorescent lights. In this paper, the proposed streetlight system becomes more intellectual by combining the low power consuming, high efficient, and high luminous LED module with a complex sensor module with temperature, humidity, illumination and motion sensors. Then, we design and implement the Ad-Hoc based LED-IT-Sensor integrated streetlight system that can maximize the energy savings efficiently with central monitoring system and selective remote dimming control by connecting them to the wireless ubiquitous sensor network(USN) using a Zigbee module.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.141-144
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• 2020

Iterative decision feedback equalizer (IDFE) is a recursive equalization technique that can help to achieve an additional performance gain for the system by combining iterative channel decoding and interference cancellation. In a single carrier-based system, the intersymbol interference (ISI) is a critical problem that must be resolved since it causes frequency selective fading. Based on the idea of sharing the estimated information in the process of iteration, IDFE is considered as an efficient solution to improve the robustness of the system performance on the ISI channel. In this paper, the IDFE is applied on single carrier FDMA (SC-FDMA) system to evaluate the performance under ISI channel. The simulation results illustrate that IDFE helps to improve the performance of the SC-FDMA system, especially with long delay spread channels.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3449-3467
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• 2015

A broadcast operation is the fundamental transmission technique in mobile ad-hoc networks (MANETs). Because a broadcast operation can cause a broadcast storm, only selected forwarding nodes have the right to rebroadcast a broadcast message among the one-hop and two-hop neighboring nodes of a sender. This paper proposes the maximum intersection self-pruning (MISP) algorithm to minimize broadcasting redundancy. Herein, an example is given to help describe the main concept of MISP and upper bounds of forward node have been derived based on induction. A simulation conducted demonstrated that when conventional blind flooding (BF), self-pruning (SP), an optimized link state routing (OLSR) multipoint relay (MPR) set, and dominant pruning (DP), are replaced with the MISP in executing Strong duplicate address detection (DAD), the performances in terms of the energy consumption, upper bounds of the number of forward nodes, and message complexity have been improved. In addition, to evaluate the performance in reference to the link error probability, P_e, an enhancement was achieved by computing a proposed retransmission limit, S, for error recovery based on this probability. Retransmission limit control is critical for efficient energy consumption of MANET nodes operating with limited portable energy where Strong DAD reacts differently to link errors based on the operational procedures.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.195-201
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• 2011

Cognitive radio (CR), which is proposed as a technology that utilizes the frequency resources effectively, has studied to relive scarcity of the frequency resources. CR provides opportunistically under-utilize licensed frequency to the secondary user. However, in the wireless channels, due to the effect of fading and shadowing environments, spectrum sensing performance is compromised. Besides, to detect and classify various CR systems, a novel spectrum sensing algorithm is needed. Therefore, in this paper, we proposed the spectrum sensing algorithm with water marking scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.2
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• pp.695-712
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• 2021

As the use of smart devices is being increased rapidly by the development of internet and IT technology, the contents production and utilization rate are showing higher increase, too. In addition, the type of contents also shows very diverse forms such as education, game, video, UCC, etc. In the meantime, the contents are reproduced in diverse forms by reprocessing the original contents, and they are being serviced through the contents service platform. Therefore, the platform to make the contents reprocessing easy and fast is needed. As the diverse contents distribution channels such as YouTube, SNS, App Service, etc, easier contents distribution platform is needed, and the development of the relevant area is expected. In addition, as the selective consumption of the contents having easy accessibility through diverse smart devices is distinguished, the demand for the platform and service that can identify the contents consumption propensity by individual is being increased. Therefore, in this study, to vitalize the online contents distribution, the contents reproduction and publishing platform, was designed and materialized, which can reproduce and distribute the contents based on the real-time contents editing technology in URL unit and the consumer propensity analysis technology using the data management-based broadcasting contents distribution metadata technology and the edited image contents streaming technology. In addition, in the results of comparing with other platforms through the experiment, the performance superiority of the suggested platform was verified. If the suggested platform is applied to the areas of education, broadcasting, press, etc, the multi-media contents can be reproduced and distributed easily, through which the vitalization of contents-related industry is expected.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.8
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• pp.15-27
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• 2008

In this paper, an EBG(Electromagnetic BandGap) resonator antenna with a stripline type FSS(Frequency Selective Surface) superstrate for PCS-band base station antennas is proposed. The characteristics of resonant frequency and -3dB bandwidth of a unit cell of a superstrate are first analyzed by varing several design parameters such as a strip width and a unit cell width in order to design an EBG resonator antenna satisfying the required antenna gain and bandwidth for PCS-band base station antennas. Among various unit cell shapes, strip dipole and stripline are considered and their characteristics are compared. It was found that a resonant length of the EBG resonator antenna becomes smaller when the stripline shape is used and the control of the bandwidth is also much easier. By using the unit cell simulation results, planar and cylindrical EBG resonator antennas at PCS-band are designed.