• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.609-614
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• 1999

Our present ability to work with video has not been confined to wired communication environment. This paper describes the new technological trend of wireless video communication. In wireless video communication, unlike wired network, several techniques are needed. At first, error robust video coding is essential. Due to characteristics of wireless channel, the system is exposed to more error prone environment. In addition, encoded video bit streams are vulnerable to the error because of the entropy coding. Recently many frameworks are developed to cope with this problem. We just explore the numerous robust video coding approaches with the viewing of error control. And more we discuss other on going research topics in this wireless video communication fields like low-power assumption design, trans-codec technique, and rate control schemes in brief.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.155-158
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• 2007

In this paper, we solved the underestimation problem of PSNR, which is caused by repeated frames, by easily synchronizing original and decoded frames using the proposed marks. Also we propose full-reference system which can be applied for measuring the quality of various kinds of video communication systems, e.g. wireless handsets, mobile phones and applications for PC. In addition, we propose a new video quality assessment metric using video communication parameters, i.e. frame rate and delay. According to the experiments, the proposed metric is not only appropriate for real-time video communication systems but also shows better correlation with the subjective video quality assessment than PSNR. The proposed measuring system and metric can be effectively used for measuring and standardizing the video quality of future communications.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.620-622
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• 2013

오늘날 웹 브라우저를 이용한 실시간 화상통신기술이 대두되고 있다. 기존의 화상통신 방식은 각각의 서비스 제공사의 특정 서버와 프로그램을 통해 화상통신을 제공하는 방식이었다. 화상통신 솔루션을 제공하는 회사의 서버를 이용하거나, 사용자 집단에서 별도의 화상통신을 이용하는 서버를 별도로 구축하여 이용하거나, 특정 소프트웨어를 사용한 자체네트워크를 사용하여 제한된 환경에서 화상통신을 이용하는 구조였다. 또한, 엑티브엑스(Active-X)나, 플러그인(Plug-in) 등을 별도로 설치해야 서비스의 이용이 가능하였다. 이에 본 논문에서는, HTTP를 활용한 웹상에서 HTML5와 스크립트를 사용하여 별도의 엑티브엑스나 플러그인을 설치하지 않고 웹 기반 실시간 화상통신 기술을 활용하여 웹 브라우저를 통해 실시간으로 인터넷이 가능한 환경에서 화상통신이 가능한 시스템을 구현하였다.

• 한국정보통신학회논문지
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• 제23권7호
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• pp.837-844
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• 2019

최근, 비디오 스트리밍에 대한 수요가 급증함에 따라서 무선 자원의 효율성을 높일 수 있는 스트리밍 기법에 대한 관심이 높아지고 있다. 본 논문에서는 무선 네트워크에서 수신단 캐싱 기능을 활용하여 비디오 스트리밍의 전송 효율을 획기적으로 개선할 수 있는 적응형 비디오 스트리밍 기법을 제안한다. 두 클라이언트가 동시에 동일한 비디오를 요청하는 경우에만 브로드캐스팅 기법으로 비디오 데이터를 전송할 수 있는 기존 방식과 달리, 제안 방식은 두 클라이언트들이 서로 다른 비디오를 요청하는 경우에도 각 클라이언트의 캐싱 정보가 특정 조건을 만족하면 브로드캐스트 기법으로 비디오를 전송할 수 있다. 본 논문에서는, 수학적 분석을 통하여 제안 방식의 평균 전송 시간을 분석하고 그 근사치를 제시한다. 또한, 다양한 시뮬레이션을 통하여 수학적 분석의 정확성을 검증한다. 수학적 분석과 시뮬레이션 결과에 따르면, 제안 방식은 기존 방식 대비 평균 전송 시간을 획기적으로 감소시킬 수 있다.

• ETRI Journal
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• 제35권1호
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• pp.27-34
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• 2013

This paper proposes a network-adaptive mechanism for HTTP-based video streaming over wireless/mobile networks. To provide adaptive video streaming over wireless/mobile networks, the proposed mechanism consists of a throughput estimation scheme in the time-variant wireless network environment and a video rate selection algorithm used to increase the streaming quality. The adaptive video streaming system with proposed modules is implemented using an open source multimedia framework and is validated over emulated wireless/mobile networks. The emulator helps to model and emulate network conditions based on data collected from actual experiments. The experiment results show that the proposed mechanism provides higher video quality than the existing system provides and a rate of video streaming almost void of freezing.

• International journal of advanced smart convergence
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• 제11권4호
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• pp.1-9
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• 2022

The recent development of information and communication technology is also affecting audio/video systems used in industry. The audio/video device configuration system changes from analog to digital, and the network-based audio/video system control has the advantage of reducing costs in accordance with system operation. However, audio/video systems released on the market have limitations in that they can only control their own products or can only be performed on specific platforms (Windows, Mac, Linux). This paper is a study on a device (Network Audio Video Integrated Control: NAVICS) that can integrate and control multiple audio / video devices with different functions, and can control digitalized audio / video devices through network and serial communication. As a result of the study, it was confirmed that individual control and integrated control were possible through the protocol provided by each audio/video device by NAVICS, and that even non-experts could easily control the audio/video system. In the future, it is expected that network-based audio/video integrated control technology will become the technical standard for complex audio/video system control.

• 제어로봇시스템학회논문지
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• 제20권5호
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• pp.513-519
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• 2014

Videoconferencing technology is increasingly used in classrooms to introduce children to people from other countries and cultures in order to provide a wider learning experience. However, with traditional screen-based video conferencing technology, research has shown that it is easy for students to miss non-verbal cues that play a key role in developing human relationships. To investigate how children interact differently when their interactions are mediated through screen-based video communication versus robot-mediated communication, we conducted a study with elementary students in Korea, comparing the use of both technologies to introduce classroom students with peer-aged individuals in America. Our findings show that the children displayed more positive emotions during certain tasks and exhibited more interest and intimacy to remote participants in the context of robot-mediated communication than with video-mediated communication.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.37-42
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• 2022

Communication as a process of interpreting signs has always existed in people's life. In post-information society, the communication between a person and a technological system through the specific sign-attaching process becomes widespread. Moreover, it somehow replaces usual communication between people. One of the means of communication in the digital space are video games. They not only play an important role in communication processes, but also are a special case of sign-creating and interpreting. The purpose of the article is to examine video games as a space of sign-based communication between a person and a game as a specific digital system. With the help of general scientific and hermeneutic methodology, the analysis of video games as a post-information society phenomenon which people communicate to has been conducted. The process of semiosis as attaching special meanings to signs has been traced in both manipulating in-game objects and characters and understanding rules of an in-game world.

• 한국멀티미디어학회논문지
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• 제17권9호
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• pp.1084-1091
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• 2014

When demand for transmitting multimedia data increases, network congestion is more likely to occur and users will suffer high loss rate as well as high delay. In order to enhance quality-of-service (QoS) of video multicasting, we need to raise transmission reliability and reduce end-to-end delay. This paper proposes a routing mechanism for a OpenFlow-based small-scale network in order to multicast video reliably with low delay. In our method, multipath routing will be applied to Multiple Description (MD) Coded video to exploit its multi-description property. Through performance evaluation, our method shows improvement on loss rate, delay and video distortion.

• International Journal of Contents
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• 제4권2호
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• pp.24-28
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• 2008

In this paper, we propose a new approach for content-based video retrieval using non-parametric based motion classification in the shot-based video indexing structure. Our system proposed in this paper has supported the real-time video retrieval using spatio-temporal feature comparison by measuring the similarity between visual features and between motion features, respectively, after extracting representative frame and non-parametric motion information from shot-based video clips segmented by scene change detection method. The extraction of non-parametric based motion features, after the normalized motion vectors are created from an MPEG-compressed stream, is effectively fulfilled by discretizing each normalized motion vector into various angle bins, and by considering the mean, variance, and direction of motion vectors in these bins. To obtain visual feature in representative frame, we use the edge-based spatial descriptor. Experimental results show that our approach is superior to conventional methods with regard to the performance for video indexing and retrieval.