• 한국컴퓨터정보학회논문지
• /
• 제23권9호
• /
• pp.35-42
• /
• 2018

In this paper, we propose an optimal streaming service method based on Hybrid CDN/P2P architecture. Recently, video streaming utilizes a CDN (Content Delivery Network) operation technique based on a Proxy Server, which is an end node located close to a user. However, since CDN has a fixed network traffic bandwidth and data information exchange among CDNs in the network is not smooth, it is difficult to guarantee traffic congestion and quality of image service. In the hybrid CDN/P2P network, a data selection technique is used to select only the data that is expected to be continuously requested among all the data in order to guarantee the QoS of the user who utilizes the limited bandwidth efficiently. In order to search user requested data, this technique effectively retrieves the storage information of the constituent nodes of CDN and P2P, and stores the new image information and calculates the deletion priority based on the request possibility as needed. Therefore, the streaming service scheme proposed in this paper can effectively improve the quality of the video streaming service on the network.

• 한국IT서비스학회지
• /
• 제14권1호
• /
• pp.99-113
• /
• 2015

Adaptive bitrate (ABR) streaming technology has become an important and prevalent feature in many multimedia delivery systems, with content providers such as Netflix and Amazon using ABR streaming to increase bandwidth efficiency and provide the maximum user experience when channel conditions are not ideal. Where such systems could see improvement is in the delivery of live video with a closed loop cognitive control of video encoding. In this paper, we present streaming camera system which provides spatially and temporally adaptive video streams, learning the user's preferences in order to make intelligent scaling decisions. The system employs a hardware based H.264/AVC encoder for video compression. The encoding parameters can be configured by the user or by the cognitive system on behalf of the user when the bandwidth changes. A cognitive video client developed in this study learns the user's preferences (i.e. video size over frame rate) over time and intelligently adapts encoding parameters when the channel conditions change. It has been demonstrated that the cognitive decision system developed has the ability to control video bandwidth by altering the spatial and temporal resolution, as well as the ability to make scaling decisions

• 디지털콘텐츠학회 논문지
• /
• 제12권4호
• /
• pp.449-456
• /
• 2011

UCC(User Created Contents) 동영상은 온라인상에서 사용자가 상업적인 의도없이 제작한 '감성 전달' 매체로서 최근 인터넷 대중문화의 핵심 콘텐츠로 급부상하였다. '감성 전달'은 UCC 동영상의 궁극적인 목적으로 '기 승 전 결'의 스토리텔링(Storytelling)이 뒷받침되어야 가능하다. 그러나 비상업적인 UCC 동영상은 불안정한 제작 환경, 다양한 변수들로 인하여 완성도 높은 작품을 기대하기 어렵다. 따라서 본 논문에서는 불안정한 UCC 동영상의 문제점을 최소화하기 위해 편집 단계에서 '세부적인 스토리텔링 편집' 과정을 제안하였다. 연구자의 실무 결과물과 UCC 동영상 공모전 수상작품을 토대로 연구한 이 제안은 공감대를 키우고, 창의적인 변화를 유도하며, 통일성있는 마무리 편집으로 작품의 완성도를 높임으로서 '감성 전달'의 기능을 확대할 수 있다.

• 임상간호연구
• /
• 제15권3호
• /
• pp.117-128
• /
• 2009

Purpose: This study was conducted to evaluate the effects of different methods of information delivery(information provided by nurses vs. information provided by video) on environmental stress and the satisfaction of nursing needs in families of intensive care unit patients. Methods: A nonequivalent pretest-posttest control group design was used in this study. The data were collected from March 24 to May 7, 2009. The subjects, 52 family members of ICU patients (26 for the control group, 26 for the experimental group), were selected from a hospital located in Gyeonggido. Information was given by video to the experimental group whereas the information was directly given by nurses to the control group. Results: Environmental stress and satisfaction of nursing needs were not statistically different between the two groups. Conclusion: The findings of the study suggest that the information given by video may be compatible with that given by nurses. Therefore, nurses need to be flexible in using these different methods to maximize the benefits of direct and indirect information delivery method for families in ICU setting.

• 한국정보통신학회논문지
• /
• 제25권4호
• /
• pp.581-587
• /
• 2021

실시간 비디오 스트리밍은 컨텐츠 전달 및 원격회의 등에 사용되는 기술로, 전송지연에 민감한 기술 중 하나이다. 최근 코로나바이러스 감염증(COVID-19)으로 인해 개인방송/원격회의와 같은 개인이 제작 및 이용하는 컨텐츠들이 증가하면서, 실시간 비디오 스트리밍 시 전송지연 저감과 더불어 스트리밍 되는 컨텐츠에 대한 보호의 필요성이 강조되고 있다. 따라서, 본 연구에서는 실시간 비디오 스트리밍에 선별적 비디오 암호화 방법을 적용할 경우 발생하는 전송지연을 저감하기 위한 패킷 응집 관련 알고리즘을 제안하였다. 제안 방법은 선별적 비디오 암호화 프레임워크에서 패킷 단위로 재배치된 비디오 데이터 전송 시 한 번에 전송되는 크기의 조절이 가능하도록 개선하였으며, 실제 테스트베드를 통한 실험결과는 제안 방법 적용 시 기존대비 전송지연을 약 11% 저감할 수 있음을 보여주었다.

• 한국산업정보학회논문지
• /
• 제16권2호
• /
• pp.39-47
• /
• 2011

Adapting content services to the needs of the users requires content adaptation for context and sensibility. Adapting to context may necessitate distinguishing between video delivery to a PC versus a smart phone, while adapting to sensibility may necessitate between video delivery outside, in a quiet environment, or at home, or offering different movie choices on a sunny summer day, a cold winter day or a holiday season. One key area to address in providing adaptive content services is the design of the delivery system architecture of the adaptive content server. This paper describes several alternatives for this architecture, and outlines some additional concerns that must be considered when the chosen architecture is implemented.

• Journal of Computing Science and Engineering
• /
• 제7권3호
• /
• pp.168-176
• /
• 2013

Long-term evolution (LTE) is emerging as a major candidate for 4G cellular networks to satisfy the increasing demands for mobile broadband services, particularly multimedia delivery. Multiple-input multiple-output (MIMO) technology combined with orthogonal frequency division multiple access and more efficient modulation/coding schemes (MCS) are key physical layer technologies in LTE networks. However, in order to fully utilize the benefits of the advances in physical layer technologies, the MIMO configuration and MCS need to be dynamically adjusted to derive the promised gains of 4G at the application level. This paper provides a performance evaluation of video traffic with variations in the physical layer transmission parameters to suit the varying channel conditions. A quantitative analysis is provided using the perceived video quality as a video quality measure (evaluated using no-reference blocking and blurring metrics), as well as transmission delay. Experiments are performed to measure the performance with changes in modulation and code rates in poor and good channel conditions. We discuss how an adaptive scheme can optimize the performance over a varying channel.

• Journal of information and communication convergence engineering
• /
• 제11권4호
• /
• pp.293-297
• /
• 2013

Delivery of high quality video over a wide area network with large number of users poses great challenges for the video communication system. To ensure video quality, multiple descriptions have recently attracted various attention as a way of encoding and visual information delivery over wireless network. We propose a new efficient multiple description coding (MDC) technique. Quincunx lattice sub-sampling is used for generating multiple descriptions of an image. In this paper, we propose the application of a directional discrete cosine transform (DCT) to a sub-sampled quincunx lattice to create an MDC representation. On the decoder side, the image is decoded from the received side information. If all the descriptions arrive successfully, the image is reconstructed by combining the descriptions. However, if only one side description is received, decoding is executed using an interpolation process. The experimental results show that such the directional DCT can achieve a better coding gain as well as energy packing efficiency than the conventional DCT with re-alignment.

• Journal of information and communication convergence engineering
• /
• 제3권1호
• /
• pp.56-61
• /
• 2005

In this paper, we present a video rate control scheme for storage and delivery in which the time-varying viewing interests are controlled by human gaze. To track the gaze, the pupil's movement is detected using the three-step process : detecting face region, eye region, and pupil point. To control bit rates, the quantization parameter (QP) is changed by considering the static parameters, the video object priority derived from the pupil tracking, the target PSNR, and the weighted distortion value of the coder. As results, we achieved human interfaced visual model and corresponding region-of-interest rate control system.

• 한국항행학회논문지
• /
• 제18권1호
• /
• pp.67-73
• /
• 2014

통신 기술의 발달과 고성능 무선 단말기들의 출시로 무선 환경에서 비디오 스트리밍 서비스 사용자 수는 빠른 속도로 증가하고 있다. 제한된 네트워크 환경에서 많은 사용자에게 UHD급 화질의 비디오 스트리밍 서비스를 제공하기 위해서는 오류 제어 기술은 필수적이다. 이전에 지연에 민감한 비디오 서비스의 오류 제어를 위해서 packet-level FEC(Forward Error Control)기법이 사용되었지만, 이 기술은 중복 데이터에 의한 네트워크 자원 점유가 크다는 단점이 존재한다. 따라서 본 논문에서는 제한된 대역폭을 가진 네트워크 환경에서 기존 FEC 기법들이 제공하는 비디오 서비스 품질은 유지하면서 FEC 데이터에 의한 네트워크 점유를 줄이는 packet-level FEC 알고리즘을 제안한다. 제안 알고리즘은 비디오 압축 기술의 전송 특성을 이용하여 FEC 중복비율을 조정하며, 실험 결과 이전 기법과 비교하여 약 33% 정도의 전송량을 줄임으로써 네트워크 자원 효율을 향상시킬 수 있다.