• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.8A
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• pp.859-867
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• 2004

To provide high-quality media streaming service over the best-effort Internet, a streaming methodology is required to response to the dynamic fluctuation of underlying networks. In this paper, we implement the MPEG-4 streaming system with adaptive transport based on priorities of media packets. The implemented system is composed of the common MPEG-4 streaming components such as elementary stream provider, sync and DMIF layer, and adaptive transport module including data prioritization and FEC control. More specifically, the prioritized sync layer packets (based on object level) are delivered to the transport module and then are encoded by an adaptive FEC encoder to help reliable transport. The FEC combination is dynamically adjusted by the feedback information from the receiver. In addition, low priority packets are selectively dropped to meet the limitation of available bandwidth. The experimental results over the emulation-based testbed show that the Proposed system can mitigate the impact of network fluctuation and thus improve the quality of streaming.

• Journal of the Korea Convergence Society
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• v.1 no.1
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• pp.69-75
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• 2010

The importance of a using the visual media in English education has been increased. By an importance of Characters in English language content, the more effort is needed for a learner to show the English pronunciation and a realistic implementation. In this paper, we tried to review the Syntax-based Educational Contents Authoring System. For the more realistic lip-sync character, 3D character to enhance the efficiency of the education was constructed. We used a chart of the association structure analysis of mouth's shape. we produced an optimized 3D character through a process of a concept, a modeling, a mapping and an animating design. For more effective educational content for 3D character creation, the next research will be continuously a 3d Character added to a hand motion and body motion in order to show an effective communication example.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.162-169
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• 2022

Arduino is used in various places such as education, experimentation, and industry. Due to the easy accessibility of Arduino, it is often used by non-majors, and it is also used in media art and toy programs. Although Arduino is relatively easy to use compared to other devices, it is not easy to control various IoT components at the same time. Some tasks run independently of other tasks, while others run dependently. In this paper, I proposed the Arduino Task Framework to efficiently execute many tasks in these various situations. The design framework of this paper is largely composed of two types: synchronous execution and asynchronous execution. These two execution methods can be combined to create several independent and dependent execution routines. Asynchronous tasks are independently executed tasks and are managed by AsyncTaskGroup, while synchronous tasks are dependently executed tasks and are managed by SyncTaskGroup. AsyncTaskGroup instance and SyncTaskGroup instance are instances of the same Task and can be used in combination with another task. The Arduino framework proposed in this paper simplifies the program structure and can easily compose various tasks.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.10
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• pp.373-380
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• 2022

This paper presents a deep learning based group synchronization that supports networked immersive interactions between remote users. The goal of group synchronization is to enable all participants to synchronously interact with others for increasing user presence Most previous methods focus on NTP-based clock synchronization to enhance time accuracy. Moving average filters are used to control media playout time on the synchronization server. As an example, the exponentially weighted moving average(EWMA) would be able to track and estimate accurate playout time if the changes in input data are not significant. However it needs more time to be stable for any given change over time due to codec and system loads or fluctuations in network status. To tackle this problem, this work proposes the Deep Group Synchronization(DeepGroupSync), a group synchronization based on deep learning that models important features from the data. This model consists of two Gated Recurrent Unit(GRU) layers and one fully-connected layer, which predicts an optimal playout time by utilizing the sequential playout delays. The experiments are conducted with an existing method that uses the EWMA and the proposed method that uses the DeepGroupSync. The results show that the proposed method are more robust against unpredictable or rapid network condition changes than the existing method.

• International journal of advanced smart convergence
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• v.5 no.3
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• pp.61-65
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• 2016

In the TV broadcasting, movie production and business the transportation of video between creators (programmers, studios) and distributors (broadcast and cable networks, cable and satellites companies) is still a mix of File Transfer Protocol (FTP), physical delivery, and expensive multicast satellite. Cloud-based file sync-and-share providers like Dropbox and box are playing an increasing role, but the industry's unique demands for speed and multicasting have fueled the growth of IP Video transport. This paper gives a solid grasp of the major elements of IP video technology, including content preparation, system architecture alternatives and network performance management.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.409-414
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• 2023

We described how to implement character expressions and animations that play an important role in expressing emotions and personalities in low-polygon character animation. With the development of the video industry, character expressions and mouth-shaped lip-syncing in animation can realize natural movements at a level close to real life. However, for non-experts, it is difficult to use expert-level advanced technology. Therefore, We aimed to present a guide for low-budget low-polygon character animators or non-experts to create mouth-shaped lip-syncing more naturally using accessible and highly usable features. A total of 8 mouth shapes were developed for mouth shape lip-sync animation: 'ㅏ', 'ㅔ', 'ㅣ', 'ㅗ', 'ㅜ', 'ㅡ', 'ㅓ' and a mouth shape that expresses a labial consonant. In the case of facial expression animation, a total of nine animations were produced by adding highly utilized interest, boredom, and pain to the six basic human emotions classified by Paul Ekman: surprise, fear, disgust, anger, happiness, and sadness. This study is meaningful in that it makes it easy to produce natural animation using the features built into the modeling program without using complex technologies or programs.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.11b
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• pp.239-242
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• 1999

본 논문에서는 8VSB수신기가 다중경로신호에 따른 성능이 나쁜 것에 대한 원인 분석과 나아가 개선책을 제시하기 위해 다중경로 신호가 디지털 지상파 TV의 수신성능에 미치는 영향에 대해 수신단의 STR(Symbol Timing Recovery)과 등화기를 중심으로 분석한다. 첫째 등화기의 성능 분석을 위해 에코의지연시간이 7.5 $\mu$sec일 때 시불변 환경에서 전산 모의 실험을 하였다. 등화기 수렴후의 에로 레벨에 따른 TOV(Threshold of Visibility) S/N(Signal to Noise)를 구해보면 호주의 실험실 측정과는 달리 0dB에서도 S/N이 26dB 정도이면 등화기는 안정적으로 수렴한다. 둘째 세그먼트 동기 복원을 세그먼트 싱크 필터(Segment Sync:+1, +1. -1, -1)를 사용했을 때 짧은 시간 지연 에코와 긴 시간 지연 에코에 대해 S 커브를 보면 짧은 시간 지연에코에서는 심볼 타이밍이 어긋났으며 긴 시간 지연 에로에서는 문제가 없이 타이밍 동기가 된다. 셋째 짧은 시간 지연 에코신호가 있을 때 세그먼트 동기 복원과 등화기를 연동한 전산 모의 실험을 하여 에코의 영향을 분석하고 FSE(Fractionally Spaced Equalizer) 등화기 사용에 따른 장점을 분석한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.384-387
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• 2016

본 논문에서는 4K UHD 방송장비 중 디스플레이기기와 인코더의 성능 시험을 위해 개발된 패턴 발생장비를 소개하고 있다. 패턴의 제작 및 재생 방법에 따라 표출되는 패턴의 종류를 그래픽/실사, 정지/동영상으로 구분할 수 있는데 본 논문에서는 모션블러, 모션져더, AV lip sync, 텍스트 주변 인코딩 화질 열화 확인, 화이트 노이즈, 프레임 누락, HDR 확인, 지연시간 측정, 계단현상 확인, 이미지 스티킹 등 그래픽 동영상 패턴에 대해 각각의 제작 의도를 설명하고 이를 통해 디스플레이기기와 인코더의 성능을 평가하는 방법에 대한 간략한 소개와 개발된 패턴발생장비의 입출력 사양을 제시하고 있다.

• Journal of Sensor Science and Technology
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• v.29 no.3
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• pp.149-155
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• 2020

In this study, we employed Manchester code for illumination control and flicker prevention of the light-emitting diode (LED) used in a visible light communication (VLC) system. In the VLC transmitter, the duty factor of the Manchester code was utilized for illumination control; in the VLC receiver, the spike signal from an RC-high pass filter was utilized to recover the transmitted signal whilst suppressing the 120-Hz noise arising from adjacent lighting lamps. Instead of the clock being transmitted in a separate channel, a syncmark signal was transmitted in front of each data byte and used as the reference time for transforming the Manchester code to non-return-to-zero (NRZ) data in the receiver. In experiments, the LED illumination was controlled in the range of approximately 12-84% of the constant wave (CW) light via changing of the duty factor from 10% to 90%. This scheme is useful for constructing indoor wireless sensor networks using LED light that is flicker-free and presents capability for illumination control.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1329-1332
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• 2002

최근 고속 통신망과 멀티미디어 기술의 급속한 발전으로 다양한 멀티미디어 서비스에 대한 연구와 그에 대한 응용 개발이 활발하게 이루어지고 있다. 그러나, 멀티미디어 응용 서비스는 기존의 단일미디어 서비스와는 달리 다양한 미디어의 통합된 전송을 필요로 하며, 개별 미디어의 정확한 연속성 및 관련된 미디어들 간의 적절한 시간적 동기화가 확보된 실시간 재생이 요구되는 고도화된 처리 기술을 필요로 하기 때문에 멀티미디어 동기화 알고리즘에 대한 연구는 필수적이고 매우 중요하다고 볼 수 있다. 본 논문은 Multimedia Data Streaming 을 위한 미디어 동기 방식 제어 알고리즘 고안 및 Lip Sync 방식 설계에 그 연구 목적이 있다.