• Educational Technology International
• /
• v.18 no.2
• /
• pp.193-213
• /
• 2017

This study aimed to explore online learning profiles of in-service teachers in South Korea, focusing on video lecture and discussion activities. A total of 269 teachers took an online professional development course for 14 days, using an online learning platform from which web log data were collected. The data showed the frequency of participation and the initial participation time, which was closely related to procrastinating behaviors. A cluster analysis revealed three online learning profiles of in-service teachers: procrastinating (n=42), passive interaction (n=136), and active learning (n=91) clusters. The active learning cluster showed high-level participation in both video lecture and discussion activities from the beginning of the online course, whereas the procrastinating cluster was seldom engaged in learning activities for the first half of the learning period. The passive interaction cluster was actively engaged in watching video lectures from the beginning of the online course but passively participated in discussion activities. As a result, the active learning cluster outperformed the passive interaction cluster in learning achievements. The findings were discussed in regard to how to improve online learning environments through considering online learning profiles of in-service teachers.

• Journal of Broadcast Engineering
• /
• v.25 no.1
• /
• pp.113-116
• /
• 2020

This paper proposes a Quality of Experience (QoE) evaluation experiment to measure the effects of 360-degree video and sensory effects on the subject's degree of immersion, satisfaction, and sense of presence. The test subject responds to a questionnaire about the degree of immersion, satisfaction, and sense of presence after experiencing a 360-degree video accompanied by sensory effects while wearing a head-mounted display (HMD) with a scent diffusion device. As a result of the response analysis, it was confirmed that the proposed experimental method is suitable for measuring the subject's degree of immersion, satisfaction, and sense of presence about 360-degree video and sensory effects. On the other hand, inserting a gray screen for comparison experiments while watching a 360-degree video was found to cause a significant decrease in immersion and realism.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.4 no.4
• /
• pp.491-508
• /
• 2010

In peer-to-peer (P2P) on-demand streaming networks, the alleviation of server load depends on reciprocal stream sharing among peers. In general, on-demand video services enable clients to watch videos from beginning to end. As long as clients are able to buffer the initial part of the video they are watching, on-demand service can provide access to the video to the next clients who request to watch it. Therefore, the key challenge is how to keep the initial part of a video in a peer's buffer for as long as possible, and thus maximize the availability of a video for stream relay. In addition, to address the issues of delivering data on lossy network and providing scalable quality of services for clients, the adoption of multiple description coding (MDC) has been proven as a feasible resolution by much research work. In this paper, we propose a novel caching scheme for P2P on-demand streaming, called Dynamic Buffering. The proposed Dynamic Buffering relies on the feature of MDC to gradually reduce the number of cached descriptions held in a client's buffers, once the buffer is full. Preserving as many initial parts of descriptions in the buffer as possible, instead of losing them all at one time, effectively extends peers’ service time. In addition, this study proposes a description distribution balancing scheme to further improve the use of resources. Simulation experiments show that Dynamic Buffering can make efficient use of cache space, reduce server bandwidth consumption, and increase the number of peers being served.

• Journal of Broadcast Engineering
• /
• v.26 no.5
• /
• pp.621-642
• /
• 2021

In this paper, the subjective video quality assessment of the content quality was to examine by the assessors about the three content quality of HD, Up-scaling UHD, 4K UHD Native that is currently broadcasted. The comparative assessment was conducted using three types of TV sets, 55, 65, 75 inches, at a distance of 2.5 meters which is the distance of watching TV in general households. Among the participants who took part in the video quality evaluating experiment and the questionnaire survey, the answering data of the final 169 persons were adopted after removing the data of 4 persons who answered inadequately in the evaluation of the video quality. The effects of gender, preference of program genre, size of TV sets were analyzed statistically using SPSS 25.0 analysis package. In addition to these, the objective video quality assessment through the measuring instrument was performed, and compared with the results of subjective video quality assessment.

• Physical Therapy Korea
• /
• v.28 no.2
• /
• pp.101-107
• /
• 2021

Background: Studies suggest that induced emotional changes can affect the sensory-motor system involved in the practice of muscle activity and movement in physical aspects. Previous studies have shown focused on effects just feedback on muscle activity associated with emotions but rarely have focused induced emotional change on gross motor function such as muscle activity. Objects: The purpose of this study was to compare biceps activity and emotion that before and after viewing a video was induced positive or negative emotion. Methods: The study enrolled 34 healthy male and female who scored at normal points on the Center for Epidermiological Studies-Depression Scale. The study measured over two weeks, showing subjects pleasant and sad videos one by one in a week. We performed to measure the biceps brachii activity which is maximal voluntary isometric contraction (MVIC) and the visual analog mood scale (VAMS) scores before and after one week. The significance level was set to α = 0.05. Results: There was no significant difference in muscle activity of the biceps brachii before and after each video was viewed (p > 0.05). However, the visual analogue mood scale showed an increase in VAMS after viewing each video (p < 0.05). Conclusion: We figured out induced emotional changes are cause actual emotional changes but there are no differences in muscle activity. In this research, watching the video with a short time looks like insufficient to change muscle activity. Nevertheless, there might be different when we check various muscles with sufficient time for viewing the video. Further study is needed to measure a variety of muscles with more time for viewing the video.

• Journal of the Korean Society of Physical Medicine
• /
• v.8 no.3
• /
• pp.351-360
• /
• 2013

PURPOSE: The purpose of this study was to investigate the effects of observed action gait training on stroke patients. METHODS: 22 subjects were randomized into two groups. The observed action gait training performed that watched a video of normal gait before gait training and the general gait training without watching it. The experimental group(n=11) performed observed action gait training and the control group(n=11) performed general gait training. Both group received gait training for 3 times per week during 8 weeks. RESULTS: The experimental group showed significant differences in the cadence, gait velocity, stride, step, single limb support, double limb support, stride length and step length(p<.05). The control group showed significant differences only in the stride(p<.05). CONCLUSION: The observed action gait training affected coordination and weight shift, as well as symmetry of the body. Plasticity of the brain was facilitated by repetitive visual and sensory stimulation. The observed action gait training promoted the normal gait by watching the normal gait pattern. In conclusion, motor learning through the sensory stimulation promotes brain plasticity that could improve motor function, and observed action gait training indirectly identified stimulated brain activities.

• Proceedings of the Korea Contents Association Conference
• /
• 2009.05a
• /
• pp.268-272
• /
• 2009

Reportedly it says that 45% teenagers in the United State exchange the SMS with their friends during television watching. In other word TV viewing moulds the social community between audiences. In terms of social television it is all about interaction or communication technology relevant to TV watching as well as social behaviour. Besides it integrates voice communication, text chat, context awareness, TV recommendations, ratings, video conference and so forth. So far it approaches the conceptual stage or pilot production and remains more research and development. This study is to scrutinise whether the functionality of social TV enables to substitute for social activities of TV viewers or not.

• Journal of Digital Contents Society
• /
• v.16 no.2
• /
• pp.291-298
• /
• 2015

In a fast-paced information technology environment, consumption of video content is changing from one-way television viewing to VOD (Video on Demand) playing anywhere, anytime, on any device. This video-watching trend gives additional importance to videos with fine-speed-control, in addition to the strength of the digital video signal. Currently, many video players provide a fine-speed-control function which can speed up the video to skip a boring part, or slow it down to focus on an exciting scene. The audio information is just as important as the visual information for understanding the content of the speed-controlled video. Thus, a number of algorithms for fine-speed-control video-playing technologies have been proposed to solve the pitch distortion in the audio-processing area. In this study, well-known techniques for prosodic modification of speech signals, WSOLA (Waveform-Similarity-Based Overlap-Add), have been applied to analyze users' needs for fine-speed-control video playing. By surveying the users' preferred speeds on categorized video content and analyzing the results, this paper proposes that various fine-speed adjustments are needed to accommodate users' preferred video consumption.

• The Journal of the Korea Contents Association
• /
• v.22 no.4
• /
• pp.273-283
• /
• 2022

This study focused on the psychological characteristics of viewers watching the video, the effect of the variables of the viewer's self-control and impulsiveness level on the purchase intention was examined. In addition, the relationship between viewers' psychological characteristics and product types was also examined, reflecting that the factors that viewers consider in the purchase decision-making process may vary depending on the product type. As a result of conducting a survey of a total of 214 people, it was confirmed that the group with a low level of self-control or high impulsiveness had a higher purchase intention after watching YouTube videos on specific products than the group without. In addition, it was confirmed that the effect was same when utilitarian product purchase situation is given.

• Journal of The Korean Ophthalmological Society
• /
• v.58 no.6
• /
• pp.706-711
• /
• 2017

Purpose: To analyze blinking patterns when watching an ultra-high definition (UHD) television and to compare the results between normal eyes and dry eyes. Methods: A total of 59 participants aged from 13 to 69 years were instructed to watch a colorful and dynamic video on a UHD television for 10 minutes. Before and after watching the UHD television, we measured the best corrected visual acuities, autorefraction, tear-break-up-time, degree of corneal erosion and conjunctival hyperemia via slit lamp biomicroscopy. In addition, questionnaires for the evaluation of eye fatigue and symptoms of a dry eye were completed. The definition of dry eye syndrome was that the tear-break-up-time of one of the eyes was less than 5 seconds, conjunctival injection, or marked corneal erosion. The number of blinks and the duration of blinking were both measured and analyzed at the early and late phases of video-watching. Results: After watching the UHD television in the normal eye group, the tear-break-up-time was significantly decreased (p < 0.001) and the degree of corneal erosion was significantly increased (p = 0.023). However, the subjective symptoms of participants were not aggravated (p = 0.080). There were no significant differences in blinking patterns in the dry eye group. On the other hand, in the normal eye group, the mean blinking time was significantly increased (p = 0.030). Conclusions: Watching an UHD television changes the tear-break-up-time, degree of corneal erosion, and blinking pattern in normal eyes, which may increase the risk of dry eye syndrome.