• Journal of Information Processing Systems
• /
• v.18 no.6
• /
• pp.729-740
• /
• 2022

Netflix, Amazon Prime, and YouTube are the most popular and fastest-growing streaming services globally. It is a matter of great interest for the streaming service providers to preview their service infrastructure and streaming strategy in order to provide new streaming services. Hence, the first part of the paper presents a detailed survey of the Content Distribution Network (CDN) and cloud infrastructure of these service providers. To understand the streaming strategy of these service providers, the second part of the paper deduces a common quality-of-service (QoS) model based on rebuffering time, bitrate, progressive download ratio, and standard deviation of the On-Off cycle. This model is then used to analyze and compare the streaming behaviors of these services. This study concluded that the streaming behaviors of all these services are similar as they all use Dynamic Adaptive Streaming over HTTP (DASH) on top of TCP. However, the amount of data that they download in the buffering state and steady-state vary, resulting in different progressive download ratios, rebuffering levels, and bitrates. The characteristics of their On-Off cycle are also different resulting in different QoS. Hence a thorough adaptive bit rate (ABR) analysis is presented in this paper. The streaming behaviors of these services are tested on different access network bandwidths, ranging from 75 kbps to 30 Mbps. The survey results indicate that Netflix QoS and streaming behavior are significantly consistent followed by Amazon Prime and YouTube. Our approach can be used to compare and contrast the streaming services' strategies and finetune their ABR and flow control mechanisms.

• Asia pacific journal of information systems
• /
• v.29 no.4
• /
• pp.856-874
• /
• 2019

The performance of recommender systems (RS) has been measured mainly in terms of accuracy. However, there are other aspects of performance that are difficult to understand in terms of accuracy, such as coverage, serendipity, and satisfaction with recommended results. Moreover, particularly with RSs that suggest multiple items at a time, such as YouTube, user satisfaction with recommended results may vary not only depending on their accuracy, but also on their configuration, content, and design displayed to the user. This is true when classifying an RS as a single RS with one recommended result and as a multiple RS with diverse results. No empirical analysis has been conducted on the influence of the content and distribution of recommendation items on user satisfaction. In this study, we propose a research model representing the content and distribution of recommended items and how they affect user satisfaction with the RS. We focus on RSs that recommend multiple items. We performed an empirical analysis involving 149 YouTube users. The results suggest that user satisfaction with recommended results is significantly affected according to the HHI (Herfindahl-Hirschman Index). In addition, satisfaction significantly increased when the recommended item on the top of the list was the same category in terms of content that users were currently watching. Particularly when the purpose of using RS is hedonic, not utilitarian, the results showed greater satisfaction when the number of views of the recommended items was evenly distributed. However, other characteristics of selected content, such as view count and playback time, had relatively less impact on satisfaction with recommended items. To the best of our knowledge, this study is the first to show that the category concentration of items impacts user satisfaction on websites recommending diverse items in different categories using a content-based filtering system, such as YouTube. In addition, our use of the HHI index, which has been extensively used in economics research, to show the distributional characteristics of recommended items, is also unique. The HHI for categories of recommended items was useful in explaining user satisfaction.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.9
• /
• pp.27-34
• /
• 2018

Personal media centered on blogs, Twitter, and Facebook has opened up a personal broadcasting area while meeting platforms such as YouTube and Africa TV. Due to the many advantages and disadvantages of personal broadcasting, a study on it was necessary and statistical survey was conducted. The study conducted opinion survey of 118 university students on personal broadcasting. As a result, we are getting news using smartphones and mainly watching videos through YouTube, and watching videos type in the order of games, music videos and sports. Satisfaction rate of video was 72.4%, 80.2% of survey did not use paid services, experiences about personal broadcasting was 96.6% and 90.5% of survey the prospect of person broadcasting of the opinion that "it will be expanded". The first thing we want to be improved in personal broadcasting is the prevention of abusive language and hate speech. Second, we were reluctant to sensational content. Third, the survey results are the improvement of excessive advertising.

• 한국체육학회지인문사회과학편
• /
• v.55 no.3
• /
• pp.349-363
• /
• 2016

The purpose of this study was to perceived interactivity about experience of using dance video contents and intention to use. This study was examine an adaptive model of Technology Acceptance Model and focused on YouTube. In order to achieve the purpose of this study, total 350 questionnaires were surveyed and 311 data were finally analyzed. All data were processed through SPSS for Windows 20.0 version and AMOS 18.0. For the analysis of data, frequency analysis, reliability analysis, confirmatory factor analysis, correlation analysis, model evaluation, and structural equation modeling techniques. The results were as follows. first. Perceived Interactivity had not affect on perceived usefulness but two-way communication, user control among the sub-factor in perceived Interactivity had a positive effect on perceived ease of use. second, perceived ease of use had a positive effect on perceived usefulness. Lastly, Perceived usefulness had not affect intention to use, but perceived ease of use had a positive effect on intention use.

• The Journal of the Korea Contents Association
• /
• v.20 no.4
• /
• pp.189-201
• /
• 2020

As communicating with friends by recording their daily lives in video clips has become a trend for the Z-generation or the Millennial generation, interest in the vlog is increasing. This study analyzed the effects of motivation and user characteristics on use satisfaction and intention to use vlog in 168 participants in their 20s and 30s who have experience using YouTube vlog. The results of the study showed all hypotheses established in this study were adopted. Specifically, habits and killing time, information-seeking, entertainment and relaxation, voyeurism, openness and emotional identification were found to have a positive effect on the use satisfaction. Also, satisfaction with the use of vlog has a significant impact on continuous use intention. Therefore, it can be seen that exploring the vlog will provide theoretical and practical implications.

• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.2
• /
• pp.63-69
• /
• 2022

We develop a smart tourism information system that provides smart tourism services to free independent tourists (FITs) through various content distribution channels such as mobile apps, Instagram, YouTube, and chatbots. The smart tourism information system provides location and storytelling-based tourism information, accommodation, restaurant information, and recommended travel products so that tourists can create a travel itinerary based on personalized situation awareness. The smart tourism information system also provides smart tourism services using commercial maps, navigation, and weather forecast APIs from the Korea Meteorological Administration to provide smart tour guide services to tourists who travel according to the travel itinerary. In this paper, we develop the React Native app that provides smart tourism services provided by the smart tourism information system. The smart tourism React Native app has implemented two methods: a method that directly connects to the smart tourism information system, and a method that provides services by interworking through the GraphQL Query Language developed by META (Facebook). The smart tourism React Native app implements OSMU (One Source Multi-use) by providing tourism information from mobile apps, photos from Instagram, and drone videos from YouTube as an integrated UI.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.4
• /
• pp.435-444
• /
• 2022

There are three focuses in the paper. Firstly, the study identified what channels were most viewed by YouTube users to watch the 'Daejang-dong scandal,' which was the most powerful agenda to influence the candidate preference among voters during the 20th presidential election. Secondly, the study analyzed whether the political tone of the first videos was in line with that of the subsequent videos. Finally, we compared the sentiment of comments on the first and subsequent videos. The results showed that TBS 'News Factory' and 'TV Chosun News' represented liberal and conservative factions, respectively. Secondly, the political tone of channels that were viewed subsequently was neutral, but the conservative channel users left more negative comments and that was significant statistically. In addition, about 80% of the conservative and liberal channel users shared the same political tendency with the channel they watched first, and more than 90% of the comments left at the subsequent videos in line with that of at the first news. Based on these results, the study concluded that the voters tended to seek political news that was similar with their political ideology, and it was considered a sort of echo chamber phenomenon on the YouTube. The study suggests that the performance of high-quality journalism by traditional news outlet might contribute to decrease the negative influence of political contents on YouTube users.

• The Journal of the Korea Contents Association
• /
• v.20 no.2
• /
• pp.150-161
• /
• 2020

Generation Z(Gen Z), which is referred to people in their late teens to early 20s, becomes one of new major consumer groups in the society. More than 80 percent Gen Z use YouTube content as a main information channel. In this study, we investigate what kind of factors make Gen Z immersed when watching YouTube content. In the background study, we examined immersion and set the cognitive conditions of immersion as reality, fascination, control, and driving as a framework for analysis of case study. In the case study, we analyzed the most popular YouTube channels of each category among the Gen Z with the established framework and then identified 3 main factors: reality, 5 senses, and unpretentiousness and 8 characteristics of them. By conducting survey with Gen Z, we wanted to verify the validity of the characteristics and find out the difference among categories. Subjects answered on a five-point scale how the characteristics of each immersion factor corresponded to their favorite channels. As a result, seven characteristics: 1) familiarity of background, 2) reality of acting, 3)familiarity of material, 4)YouTubers' appearance and 5) voice, 6)multi-sensory, and 7)YouTuber's ability to resemble viewers influenced more than 50% of users' immersion. Although there was no significant difference among categories, the familiarity of the material and the five senses stimulus (YouTube's appearance, voice, audiovisual and surrogate taste) were the most important factors in the entertainment category.

• Journal of radiological science and technology
• /
• v.19 no.2
• /
• pp.71-77
• /
• 1996

Studies were conducted to determine the clinical application of photodiode. We compared photodiode with ion-chamber as to change of tube potential, tube current, mAs and measured decreasing rate of penetration dose. When tube potential was changed from 60 kVp to 120 kVp, output of photodiode and ion-chamber were changed from 0.4 to 1.625, and 1.018 to 4.268, respectively. This was a good agreement to theory that $I=Kv^2it$(I is intensity, K is constant, v is tube potential, i is tube current, t is time). Characteristics for change of tube current and mAs were also a good agreement to theory. And comparison in decreasing rate of penetration dose was similar except above 6 cm in depth. Our results indicated that photodiode was a good instrument for relative measurement of radiation exposure, but we can not use the photodiode for absolute radiation dose.

• Journal of the Korea Convergence Society
• /
• v.11 no.10
• /
• pp.197-205
• /
• 2020

The present study analyzed the effector that has an influence on continuance intention to use YouTube that is a prime platform to distribute visual contents. Whether the dispersion of information communication technology succeeds or not is determined by a more extent which user uses active and continued than adopts fast. From this point of view, we employed partial least square(PLS) path modeling to analyze structural causality among constructs in the post-adoption model(PAM). As a result, all paths given in PAM except for the path 'confirmation-satisfaction' were validated. Especially, confirmation mediated with satisfaction than perceived usefulness has a more effect on continuance intention. Finally, we described the limitation of the present study and the suggestion for future research.