• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.223-228
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• 2015

Korean climate becoming increasingly subtropical by climate warming makes local heavy rainfall frequently. To avoid damages from the local heavy rainfall, we need a forecasting service for a great number of clients. However, there is not the framework for the service based on wireless data broadcasting yet. In this paper, we design and implement a service framework for local heavy rainfall forecasting using wireless data broadcast. The developed service framework has scalability that can adopt various data scheduling and indexing schemes. We show the efficiency of the proposed framework to forecast local heavy rainfall through a simulation study.

• Journal of Broadcast Engineering
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• v.6 no.1
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• pp.3-12
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• 2001

Over the last few years, digital audio watermarking has become an interesting issue In many application areas, including digital broadcasting. This is primarily motivated by a need to provide copyright protection of digital audio content. Digital watermarking is a technique to embed copyright or other information int? the underlying data. Several possible audio watermarking techniques have been developed including spread spectrum watermarking, echo watermarking, phase coding, and patchwork. In this paper, we describe some requirements of digital audio watermarking as a tool for copyright protection of broadcasting content, and compare popular audio watermarking algorithms in some significant aspects.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.1-7
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• 2001

WRC-2000 adopted the Regions 1 and 3 BSS and associated feeder-link Plans as well as the Regions 1 and 3 BSS and associated feeder-link Lists. These Regions 1 and 3 BSS and associated feeder-link Plans provide, in general, each country of Region 1 with 10 digital channels of 27MHZ bandwidth and each country of Region 3 with 12 digital channels of 27MHZ bandwidth. In this study, we summarize the results of associated meetings and analyze the effects of BSS replanning in Korea. We study the effective interference analysis through the review of Radio Regulations and associate Resolution. Furthermore, interference analysis of inter-broadcasting satellite systems will be done with MSPACEG S/W.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.175-185
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• 2009

In this paper, performance of OFDM systems with turbo code is analyzed and simulated in a satellite broadcasting channel. The performance is evaluated in terms of bit error probability. The satellite channel is modeled as a combination of Rayleigh fading with shadowing and Rician fading channels. As turbo decoding algorithms, MAP (maximum a posteriori), Max-Log-MAP, and SOVA (soft decision Viterbi output) algorithms are chosen and their performances are compared. From simulation results, it is demonstrated that Max-Log-MAP algorithm is promising in terms of performance and complexity. It is shown that performance is substantially improved by increasing the number of iterations and interleaver length of a turbo encoder. The results in this paper can be applied to OFDM-based satellite broadcasting systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.75-84
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• 2015

A data allocation technique is essential to improve the performance of data broadcast systems. This paper explores the issues for allocating data items on broadcast channels to process multiple-data queries in the environment where query profiles and query request rates are given, and proposes a new data allocation scheme named IDAS. The proposed scheme employs the strategy that the broadcast frequency of each data is determined by the square root value of its relative access probability. IDAS could enhance the performance of query response time since it can process queries of high request rate fast and show a resonable degree of query data adjacency. Simulation is performed to evaluate the performance of the proposed scheme. The simulation results show that IDAS outperforms other schemes in terms of the average response time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.217-223
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• 2012

Time synchronization problems is very important in everyday life and a variety of industries, In this paper, we developed PLB(Power Line Broadcasting) system which broadcast time information to each device through power line modems. In our system, the smartphone synchronized to GPS time is used as a time source and we propose, develop and evaluate a relay system to solve the difficulties of long-distance transmission of power line modem technology.

• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.55-64
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• 2009

In this paper, we design and implement verification and interface application for interactive data broadcasting middleware. This application implements ACAP and OCAP verification item according to their types (format, protocol. resource, presentation). Therefore, using this application, we can verify whether digital settop-boxes used in digital terrestrial television and digital cable television conforms to the ACAP and OCAP standards. In this paper, we evaluate our proposed application using TVPLUSiTM verifier which can verify interactive TV application in real broadcasting environment. Through performance evaluation, we show that the DTB-H650F set-top-box supports OCAP and ACAP standard 80% and 95%, respectively.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.191-195
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• 2006

국내와 북미 지역에서 ATSC DTV 방송 서비스가 시작된 이래 수신 성능을 개선하기 위한 계속적인 노력이 경주되어 왔다 [1]-[6]. 본 논문에서는 2005 년 8 월 캐나다 CRC (Communications Research Center) 센터의 테스트 결과를 토대로 최신 ATSC 수신기의 성능을 고찰해 보고자 한다 [4]. CRC 테스트는 수신 감도, 다중 경로 환경에서의 수신 성능, 간섭 신호에 대한 강건성 등 다양한 항목에 걸려 실시되었으며, A/74 권고안에 기술된 난시청 지역의 50 개 신호 샘플에 대한 성능 평가를 포함하고 있다. 테스트에 사용된 ATSC 수신기는 당사에서 개발한 최신 칩 (GEMINI)을 탑재한 것으로 파일럿 (pilot) 신호가 손상된 경우에도 안정적인 동기 획득이 가능하며 현존 수신기 중 가장 넓고 강력한 반사파 (ghost) 제거 성능을 보유하고 있다. CRC 테스트 결과와 국내외 필드테스트 결과는 최신 ATSC 수신기가 A/74 권고안뿐만 아니라 각종 성능 지표에서 이전 수신기에 비해 대폭 개선되었음을 확인시켜 준다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.131-136
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• 2016

An appropriate evaluation on learner's pronunciation has been an important part of foreign language education. The learners should be evaluated and receive proper feedback for pronunciation improvement. Due to the cost and consistency problem of human evaluation, automatic pronunciation evaluation system has been studied. The most of the current automatic evaluation systems utilizes underlying Automatic Speech Recognition (ASR) technology. We suggest in this work to evaluate learner's pronunciation accuracy and fluency in word-level using the ASR and non-native teacher's speech model. Through the performance evaluation on our system, we confirm the overall evaluation result of pronunciation accuracy and fluency actually represents the learner's English skill level quite accurately.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.11b
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• pp.123-128
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• 1999

본 논문에서는 기존에는 샷 경계 검출에 초점을 맞춘 것과는 달리 본 논문에서는 샷 보다 상위레벨인 비디오 씬 추출에 초점을 맞추어 디지털 비디오를 구조화하는 시스템을 제안한다. 샷간의 유사도를 측정하기 위해서 칼라와 모션 특징을 이용하였으며, 비디오 내의 동적 또는 정적 특성을 반영하기 위해서 적응적 가중치를 적용하였다. 칼라 특징을 추출하기 위해서 각 샷의 내부에서 대표 프레임을 추출하였고, 각 샷 내부의 모션 정보는 MPEG 비디오 모션 벡터를 이응해서 추출하였다. 또한, 비디오 씬 분할 시 연산 시간을 줄이기 위한 기법을 제시하였다. 마지막으로 추출된 비디오 씬에 대해서 성능평가를 하였다.