• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2493-2495
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• 2001

Burst Error Channel의 에러 정정 기술로써 Reed-Solomon Product Code(RSPC)가 광범위하게 사용되고 있다. 그러나 Random Error Channel과는 달리 Burst Error Channel 상에서 RSPC의 에러 정정 평가 방법에는 많은 어려움이 있다. 우리는 이번 논문에서 Burst Error Channel 상에서 RSPC의 Error Correction Capability의 확률적인 계산 방법을 기술하려 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.979-985
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• 2016

In this paper, a distributed instant message system with multiple servers architecture which can distribute system load effectively using an extended media control channel has been presented. A media control channel provides establishing a reliable control channel and also keeping a reliable control channel between SIP server and client in the field of real-time media transport area. In this study, a new instant message system architecture which can distribute massive instant message including multimedia data to multiple servers has been presented. The presented instant message system architecture can distribute system load by extending media control channel. For this purpose, media control channel messages, which distribute system load to multiple servers dynamically according to increasing number of users, have been designed in our presented system. And, in our research, an exchanging procedures of media control channel messages between servers have also been presented. The performance of the proposed system has been analysed by simulation.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2496-2498
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• 2001

광 디스크 channel상에서 RSPC의 error correction capability를 확률적인 계산 방법으로 계산하는 데는 많은 어려움이 있다. 그 이유는 바로 광 디스크 channel이 burst error channel이기 때문인데, 이 burst error를 어떻게 다루는 가에 따라 그 error correction capability는 사뭇 달라진다. 이 논문에서는 Sony의 dust error distribution[1] 아래에서 4-state Morkov Chain[2]로 modeling하고 그 결과를 가지고 burst error를 channel의 특성과 ECC format의 특성에 맞게 제어할 수 있는 확률적인 계산방법을 소개하고 그것을 simulation하고자 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.1
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• pp.27-32
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• 2016

In this paper, we proposed a soft decision-directed channel estimation based on MMSE estimation for MIMO-OFDM system. While the conventional method employs only pilot signals for channel estimation, the proposed algorithm performs channel estimation using pilot and reliable data signals. We also proposed selection criterion among reliable data signal for channel estimation. From numerical simulations, we show that the proposed channel estimator achieves 1 dB performance gain over conventional channel estimators.

• Analyses & Alternatives
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• v.1 no.2
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• pp.13-30
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• 2017

Referred to as a 'media war,' there is a fierce competition for media discourse between different countries. Twenty four hour global news channels like Al Jazeera, France 24, RT, NHK World, China's CCTV and teleSUR emerged to offer their own perspectives and stance in the global society, and to face the monopolization and distorted information created by the hegemony of English news channels which have swayed international public opinions for a long time. As a tool of public diplomacy, the media's role in determining the image of the nation and winning the 'Hearts and Minds' of the international community is decisive, but it cannot be said that they all have a similar influence or play a positive role in media diplomacy. A global news channel, which is both a media diplomatic subject and a journalism organization, can be in the position of acting as a public relations organization or a propaganda agency for the government depending on the regime's attitude because most of global news channels receive support from the government. Sometimes it is difficult for these media to implement quality journalism because of financial difficulties. Media discourse also has limitations in that it is dependent upon changes in foreign policy of its own government. This study examines the current status of global news channels, the dilemma these channels are facing, and suggests some potential directions that can be taken by global news channels in order to become more effective. It is becoming increasingly important for all nations to respond to distorted information about their own countries, to appropriately identify various issues and changes in the international community and to convey their views and positions to the international community. For now, there is a lack of awareness about the importance of media diplomacy in Korea: There are many English-language media, but as yet no global news channel which could have an influence on the international stage. However, there seems to be some understanding about the need for the media to present the Korean alternative discourse to the senseless dependency on Western media. We hope that this study will be an opportunity to think in depth about the attitude of the Korean global media, whether existing global media or new global news channels, in order to help them become more effective in media diplomacy.

• ETRI Journal
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• v.38 no.5
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• pp.952-961
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• 2016

In this paper, we study a spectrum sharing network (SSN) where a spectrum sharing device (SSD) coexists with multiple wireless communication systems (WCSs) in the same channel. The SSD can operate with either a duty cycle (DC) channel access mechanism or a listen-before-talk (LBT) channel access mechanism, whereas WCSs operate with an LBT mechanism. An opportunistic channel selection scheme for the SSD in the SSN is first proposed to minimize the outage probability. The optimal data transmission time for the DC-based SSD is derived to further improve the outage probability. We also derive the exact and closed-form outage probability of the proposed channel selection in the SSN by assuming that the number of WCSs operating in each channel is uniformly distributed. The simulation results show that the proposed channel selection scheme outperforms other channel selection schemes. It was also observed that a DC-based SSD with an optimal data transmission time provides a better outage performance than an LBT-based SSD. As the number of available channels increases, the channel selection scheme plays an important role in minimizing the outage probability of the SSNs.

• Journal of Agricultural Extension & Community Development
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• v.10 no.2
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• pp.229-237
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• 2003

Since the 1960s in Korea, major broadcasting channels broadcasted farm television programs, however, airing of these programs were reduced in the 1990s. This was due to the declining number of farmers, and the low popularity rating of farm television programs. To cope with the situation, agriculture businessmen, farmers, and the officials concerned tried to acquire the independent farming television channel in cable television and satellite television, In 1998, one cable television channel started broadcasting, while another channel in satellite television began its broadcasting in 2001. One of the major concerns of the people in the broadcasting was actualization of the public interests in the new media multi-channel age. Recognizing this point, the study explored a few areas of concern such as conceptualizations of the public interest of the people in the digital age, examination of the surroundings of program production and marketing, and survey the media use behavior of target audience - rural residents; In the concept of the public interest, there are two points of view; market focused and democratic principle oriented. As the digitalization of broadcast advances and the logic of economics prevails, it is difficult to offer the public broadcasting service to farmers, however, democratic principles should be more emphasized. The rural resident prefer major terrestrial television channel to cable television and satellite television channel, and in media use behavior, the medium of major terrestrial television would be more useful for farm broadcasting.

• Journal of Broadcast Engineering
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• v.12 no.3
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• pp.222-229
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• 2007

According to the advancement of multimedia compression technologies, high quality multi-media services are easily found in common life. Along with this situation, 5.1-channel audio service also has expanded the application area to home theater system and car theater system and consumer can easily take a chance to experience the feeling of 5.1-channel audio. On the other hand, terrestrial DMB service has been launched in Korea from Dec. 2005 as a handhold multi-media broadcasting service. However, multi-channel audio was not considered due to the insufficiency of bandwidth and the handhold usage. Lately, MPEG is standardizing high efficiency multi-channel audio compression technology for handheld broadcasting service, and several trial for application is introduced in Europe. In this paper, we would like to explain multi-channel audio compression technology, describe the implementation of the verification system for the multi-channel audio service over T-DMB and investigate the possibility of further realization of the service.

• ETRI Journal
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• v.44 no.6
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• pp.915-924
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• 2022

In this paper, we present a two-stage scalable channel estimator (TSCE), a deep learning (DL)-based scalable, and robust channel estimator for wireless cellular networks, which is made up of two DL networks to efficiently support different resource allocation sizes and reference signal configurations. Both networks use the transformer, one of cutting-edge neural network architecture, as a backbone for accurate estimation. For computation-efficient global feature extractions, we propose using window and window averaging-based self-attentions. Our results show that TSCE learns wireless propagation channels correctly and outperforms both traditional estimators and baseline DL-based estimators. Additionally, scalability and robustness evaluations are performed, revealing that TSCE is more robust in various environments than the baseline DL-based estimators.

• Cartoon and Animation Studies
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• s.49
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• pp.425-464
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• 2017

The Knowledge of the Channel (e) is often used as educational materials; it delivers very short but compelling message of strong or interesting timeliness. However, as the media environment changes, expectations and demands for The Knowledge The Knowledge of the Channel (e) is used in school education and what should be improved upon to increase utilization of educational resources. We surveyed 361 elementary, middle and high school teachers and analyzed the frequency of using, approach and learning activities of The Knowledge of the Channel (e) in school education. We also analyzed difficulties in using it in the school and what improvements should be made. Result show that the frequency of using The Knowledge of the Channel (e) in school is highest in elementary schools, followed by middle school, and then high school. Teachers strongly consider curricular relevance when selecting broadcasting contents for education, and among programs of EBS(Educational Broadcasting System), most frequently use The Knowledge of the Channel (e). The The Knowledge of the Channel (e) is mainly used as an incentive for increasing motivation. When examined by elementary school curriculum, this material is highly utilized in subjects with content such as society, morality, and science, or with approaches that require various perspectives. However, it is difficult for teachers to find materials directly related to their classes, and since other media content similar to The Knowledge of the Channel (e) is abundant, the utilization of The Knowledge of the Channel (e) is decreasing. To improve this, The Knowledge of the Channel (e) needs to improve its platform and transformed the type of The Knowledge of the Channel (e) content being provided on social media.