• Journal of Communications and Networks
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• v.1 no.2
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• pp.134-142
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• 1999

We have developed fully functional Video Server and Client applications which can transmit, receive, decompress and display compressed video over various networks. Our video trans-port allows dynamic rate control feedback, loss detection, and repair requests from Clients to the Server. Our experiments show how feedvack-before-degradation scheme for rate adaptation maintains good display frame-rate for video playback. We show how the playback degradation(reduction in display frame-rate) oc-curs and what happens if corrective measures are not taken to im-prove the situation. The degradation is attributed to the increased internal kernel buffering which consumes scarce CPU resources. We demontrate with our experimental results that ServerNet, with improved hardware delivery guarantees, can significantly reduce host CPU resource consumption while serving video streams. We present the maximum number of streams which can be served for each of ATM and ServerNet interconnects. The appropriate user-level packet size for the video server are also determined for each case.

• Journal of Information Processing Systems
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• v.11 no.1
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• pp.76-94
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• 2015

For different reasons, many viewers like to watch a summary of films without having to waste their time. Traditionally, video film was analyzed manually to provide a summary of it, but this costs an important amount of work time. Therefore, it has become urgent to propose a tool for the automatic video summarization job. The automatic video summarization aims at extracting all of the important moments in which viewers might be interested. All summarization criteria can differ from one video to another. This paper presents how the emotional dimensions issued from real viewers can be used as an important input for computing which part is the most interesting in the total time of a film. Our results, which are based on lab experiments that were carried out, are significant and promising.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.3200-3219
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• 2013

This paper proposes an adaptive combined scalable video coding (CSVC) system for video transmission over MIMO-OFDM (Multiple-Input Multiple-Output-Orthogonal Frequency Division Multiplexing) broadband wireless communication systems. The scalable combination method of CSVC adaptively combines the medium grain scalable (MGS), the coarse grain scalable (CGS) and the scalable spatial modes with the limited feedback partially from channel state information (CSI) of MIMO-OFDM systems. The objective is to improve the average of peak signal-to-noise ratio (PSNR) and bit error rate (BER) of the received video stream by exploiting partial CSI of video sources and channel condition. Experimental results show that the delivered quality using the proposed adaptive CSVC over MIMO-OFDM system performs better than those proposed previously in the literature.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.31-39
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• 2012

DVC(Distributed Video Coding) techniques have been attracting a lot of research works since these enable us to implement the light-weight video encoder and to provide good coding efficiency by introducing the feedback channel. However, the feedback channel causes the decoder to increase the decoding complexity and requires very high decoding latency because of numerous iterative decoding processes. So, in order to reduce the decoding delay and then to implement in a real-time environment, this paper proposes several parity bit estimation methods which are based on the temporal correlation, spatial correlation and spatio-temporal correlations between LDPCA frames on each bit plane in the consecutive video frames in pixel-domain Wyner-Ziv video coding scheme and then the performances of these methods are compared in fast DVC scheme. Through computer simulations, it is shown that the adaptive spatio-temporal correlation-based estimation method and the temporal correlation-based estimation method outperform others for the video frames with the highly active contents and the low active contents, respectively. By using these results, the proposed estimation schemes will be able to be effectively used in a variety of different applications.

• Science of Emotion and Sensibility
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• v.25 no.3
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• pp.3-14
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• 2022

With the increase of video conferencing users and the development of technology, the situations where video conferencing is used and the layout of video conferencing interfaces are diversifying. Social anxiety affects video conferencing communication and is closely related to the self-view function, which is characteristic of video conferencing. The self-view function is part of the video conferencing interface that provides a small preview of one's own camera feed. Self-view is known to degrade work performance and cause fatigue; however, it is set as the default function on video conferencing software in a way that users generally prefer. This study used an online survey to study the effect of task orientation, preferred self-view size, and social anxiety on video feedback preference. Participants responded to questions assessing work orientation, social anxiety level, preferred self-view size, and self-view preference. The results showed that preferred self-view size mediates task orientation and video feedback preference. There was no significant difference in the mediating effect of the preferred self-view size according to the degree of social anxiety. These results offer insights into the interactions between users and video conferencing software and provide information that can be useful for designing video conferencing interfaces.

• Cartoon and Animation Studies
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• s.18
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• pp.73-88
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• 2010

With the recent trend of Web 2.0, experts argue that the UCC age has blossomed where people themselves produce their own content and share it on the Internet. However, more academic studies on video UCC production are needed to understand fully the video UCC phenomenon in Korea. This study was done as an exploratory study to investigate the motivations for video UCC production and its effects. Results reveal that the important motivations for participating in video UCC creation are fun, sharing, and self-expression. For the rewards for video UCC creation participation, feedback, sharing and self-satisfaction are considered valuable psychological rewards by the video UCC creators. Furthermore, the total amount of video UCC production is positively correlated with self-evaluation of fun, importance, and practicality of the video UCC content.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.107-108
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• 2012

For low complexity encoder, the parity bit transmission through a feedback channel is an essential part of DVC. But feedback channel-based parity bit control is a major cause for the high decoding time latency. In this paper, we propose a fast distributed video decoding by parity bit request estimation using rate-distortion model. Through computer simulations, it is shown that the proposed method can achieve complexity reduction compared to other methods.

• Korean Journal of Child Studies
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• v.25 no.5
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• pp.73-94
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• 2004

The study examined the effects of an intervention program for improving mother-child interaction behaviors of mothers with developmentally delayed young children. The program consisted of three main activities, lectures for good parenting, video-feedback of mother-child interactions, and consultation for problem behaviors of children. The subjects were 4 mothers of 5-6 years old children with developmental delays who were referred to a social competence program of a child counseling center. The mothers were identified to have problematic mother-child interaction behaviors through clinical interviews. The program ran for 16 sessions, one parent group leader implemented each session for 90-120 minutes once a week. The videotaped data of mother-child interactions for 10 minutes every 4 sessions were estimated by Maternal Behavior Rating Scale(MBRS) and qualitatively analyzed by transcription of communications between mothers and their children. It concluded that the intervention program enhanced mother-child interaction behaviors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.11
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• pp.952-960
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• 2012

In the distributed video coding (DVC) system, the difference between the side information and the original Wyner-Ziv frame is corrected using channel codes and the additional parity bits are requested through feedback channel if the error is not corrected. The efficient bit rate control is important to use the DVC system in the band-limited channel, such as mobile communication environments. In this paper, the constant bit rate control method in the encoder of the DVC system is proposed. The coding performance as well as the bit rate is efficiently controlled by the proposed method.

• School Mathematics
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• v.19 no.1
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• pp.19-41
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• 2017

The purpose of this article was to a) identify how preservice teachers conceive feedbacks and subsequent classroom discourses, and b) compare them with those in reform-oriented mathematics classroom video for mathematics teachers' professional development about classroom discourse. This article analyzes feedback patterns and subsequent classroom discourses in preservice teachers' imaginary classroom scripts (lesson plays) and compares them with those in the reform-oriented classroom video dealing with the same teaching situation. Most of the preservice teachers' feedbacks focused the evaluation of students' responses and transmission of meaning (univocal function), whereas the teacher's feedback in the reform-oriented classroom allowed the whole class to validate or challenge the answers, thereby facilitating students' generation of meaning (dialogic function). The comparison analysis between the univocal discourse in a preservice teacher's lesson play and the dialogical discourse in the reform-oriented classroom video shows that teacher feedback serves as an important indicator for the main function of classroom discourse and the levels of students' cognitive participation, and also as a variable that determines and changes them. This case study suggests that to improve the quality of classroom discourse, preservice and in-service teachers need experience of perceiving the variety of feedback patterns available in specific teaching contexts and exploring ways to balance the univocal and dialogical functioning in their feedback move during the teacher training courses.