• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.7-12
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• 2009

In JPEG2000, the Cohen-Daubechies-Feauveau (CDF) 9/7-tap wavelet filter adopted in lossy compression is implemented by the lifting scheme or by the convolution scheme while the LeGall 5/3-tap wavelet filter adopted in lossless compression is implemented just by the lifting scheme. However, these filters are not optimal in terms of Peak Signal-to-Noise Ratio (PSNR) values, and irrational coefficients of wavelet filters are complicated. In this paper, we proposed a method to optimize image quality based on wavelet filter design and on wavelet decomposition. First, we propose a design of wavelet filters by selecting the most appropriate rational coefficients of wavelet filters. These filters are shown to have better performance than previous wavelet ones. Then, we choose the most appropriate wavelet decomposition to get the optimal PSNR values of images.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.184-186
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• 2016

기술의 발전으로 방송환경이 다양화되면서 전문가가 아니어도 단순한 제작 환경에서 직접 콘텐츠를 제공할 수 있는 개인 방송 산업 규모가 점차 증가하고 있다. 그로 인해 개인 방송 제작자들은 필요에 의해 선택적으로 최적의 시스템을 구성하기 위한 기술들을 요구하고, 개인 방송 시청자들은 PC뿐만 아니라 모바일 등의 선호하는 디스플레이 장치를 선택하여 언제 어디서나 시청하는 것을 원한다. 이를 위해서는 제작자와 시청자를 고려한 개인방송 서비스 모델 및 기술을 제공하는 것이 필요하다. 이에 본 논문에서는 IP 네트워크 및 클라우드 컴퓨팅 환경을 활용하여 제작에서부터 전송 및 표출에 대한 전체적인 시스템 기술과 서비스 모델에 대해 논한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.173-178
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• 2014

Smart devices linked to high speed networks enable us to obtain location dependent data at anywhere and anytime. In this environment, a wireless data broadcast system can deal with enormous data request from a great number of clients effectively. In order to set up an efficient wireless data broadcast system, various data scheduling and indexing schemes have been proposed. However, a simulation framework to evaluate the schemes is not reported yet. In this paper, we design and develop a simulation framework for a wireless data broadcast system. The developed simulation framework can evaluate quickly a wireless data broadcast system and has scalability to adopt various data scheduling and indexing schemes for wireless data broadcasting.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.4
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• pp.193-202
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• 2016

The Korea Augmentation Satellite System (KASS), which is under development in Korea as a Satellite Based Augmentation System (SBAS) is expected to broadcast SBAS messages to air space in Korea according to the international standards defined by the International Civil Aviation Organization (ICAO) and the Radio Technical Commission for Aeronautics (RTCA). Around 13 SBAS messages are broadcast in every second to transmit augmentation information which can be applicable to a wide area in common. Each of the messages requires a different update interval and time-out according to the characteristics, purpose, and importance of transmitted information, and users should receive and combine multiple SBAS messages to calculate SBAS augmented information. Thus, a time to take acquiring first SBAS position by users differs depending on broadcasting various SBAS messages with which order and intervals. The present paper analyzes the considerations on message scheduling for broadcasting of KASS augmentation information and proposes a design of KASS message scheduler using the considerations. Compared to existing SBAS systems, which have a wide range of service area, a service area of the KASS is limited to Korea only. Thus, the numbers of ionosphere grid points and satellites to be augmented are expected to be smaller than those of existing SBAS. By reflecting this characteristic to the proposed design, shortening of broadcast interval of KASS message is verified compared to existing SBAS and a measure to increase a speed of acquisition of user navigation solution is proposed utilizing remaining message slots. The simulation result according to the proposed measure showed that the maximum broadcast interval can be reduced by up to 20% compared to that of existing SBAS, and users can acquire KASS position solution faster than existing SBAS.

• Journal of the Korean Data and Information Science Society
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• v.21 no.4
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• pp.783-793
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• 2010

Several multi-hop applications developed for vehicular ad hoc networks use broadcast as a means to either discover nearby neighbors or propagate useful traffic information to other vehicles located within a certain geographical area. However, the conventional broadcast mechanism may lead to the so-called broadcast storm problem, a scenario in which there is a high level of contention and collisions at the link layer due to an excessive number of broadcast packets. We present a fuzzy alert message dissemination algorithm to improve performance for road safety alert application in Vehicular Ad-hoc Network (VANET). In the proposed algorithm, when a vehicle receives an alert message for the first time, the vehicle rebroadcasts the alert message according to the fuzzy control rules for rebroadcast degree, where the rebroadcast degree depends on the current traffic density of the road and the distance between source vehicle and destination vehicle. Also, the proposed algorithm is the hybrid algorithm that uses broadcast protocol together with token protocol according to traffic density. The performance of the proposed algorithm is evaluated through simulation and compared with that of other alert message dissemination algorithms.

• The Journal of Information Systems
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• v.29 no.1
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• pp.113-136
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• 2020

Purpose In recent years, "Internet + " is a new social form. Has already brought the vitality of social and economic entities. The rapid development of Internet globalization, promote the development of an emerging network interaction, "Live broadcast". Viewers from all over the world can watch various types of live programs by connecting to the Internet. Viewers and live broadcasters can generate instant and efficient interactions. Design Many companies have taken advantage of the advantages of the live broadcast platform. Use live broadcasts for brand marketing activities. Branding compared to offline, online advertising is cheaper, Spread more quickly, get feedback from consumers more realistic. Merchants are also aware that this type of interaction creates a closer connection between consumers and businesses. This article will deduce a unique research model through lots of prior studies. Establish independent variables from two aspects of live software features and consumer features, and from the seven hypotheses derived, summarize how to make consumers more loyal to the same brand. The audience of Korean and Chinese live broadcast software is also growing. In order compare the differences between the consumer groups in Korea and China, this article uses the same research model, analysis of consumers in Korea and China. Findings Finally based on the results of the study. Proposal for rationalization of companies that use Korean-Chinese live broadcast platforms for brand marketing.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.46-47
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• 2013

In the satellite system design, the processes from the initial design to launch take about 5 years and the broadcasting satellite lifetime goes over 15 years. Furthermore, global warming phenomenon causes rainfall rate increasing more and more in some regions on the earth. Consequently, at the stage of the satellite link design, we need to consider the future rain attenuation over 20 years. In this paper, we investigated two time-series system models for forecasting to consider the future rainfall rate for the satellite broadcasting service. We found that rainfall rate of the future 30 years is increasing continuously.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1995.06a
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• pp.155-157
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• 1995

New formulas for McClellan transform parameters for the design of 2-D Zero-phase FIR fan filters are optimally derived under the integral squared error(ISE) criterion. By imposing the constraint that F(0,0)=coswc, where F($.$) is the McClellan transform and w is the cutoff frequency of the 1-D prototype filter, the ISE is directly minimized without modifying it and, as a consequence, closed-form formulas for the McClellan transform parameters are obtained. It is shows that these formulas lead to a very efficient design for 2-D zero-phase FIR fan filters.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.199-200
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• 2016

전 세계적으로 효율이 높은 LED 조명이 각광 받기 시작하면서 기존의 조명보다 에너지 효율이 높은 LED 조명을 보다 효율적으로 사용하기 위한 다양한 방법들에 대한 관심이 높아지고 있다. 이에 본 논문에서는 기존의 스위치 구조의 제품을 분석하여 한계점을 파악하고, 사용자가 스위치를 교체하는 단순한 방식으로도 스마트 조명을 경험 할 수 있도록 LED조명을 효율적으로 사용하기 위한 벽면형 스위치 구조를 디자인 하고자한다.

• Broadcasting and Media Magazine
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• v.16 no.3
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• pp.36-43
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• 2011