• Journal of the Korea Computer Graphics Society
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• v.13 no.4
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• pp.7-12
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• 2007

With the advent of digital cinema, more and more movies are digitally produced, distributed via digital medium such as hard drives and network, and finally projected using a digital projector. However, digital cameras capable of shotting at 2K or higher resolution for digital cinema are still very expensive and bulky, which impedes rapid transition to digital production. As a low-cost solution for acquiring high resolution digital videos, we propose a hybrid camera consisting of a low-resolution CCD for capturing videos and a high-resolution CCD for capturing still images at regular intervals. From the output of the hybrid camera, we can synthesize high-resolution videos by software as follows: for each frame, 1. find pixel correspondences from the current frame to the previous and subsequent keyframes associated with high resolution still images, 2. synthesize a high-resolution image for the current frame by copying the image blocks associated with the corresponding pixels from the high-resolution keyframe images, and 3. complete the synthesis by filling holes in the synthesized image. This framework can be extended to making NPR video effects and capturing HDR videos.

• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.750-761
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• 2011

Currently, 3DTV technologies are being developed as the future services of the HD digital broadcast environment. As one of the various research topics to apply 3DTV technologies to the conventional broadcasting network, methods to configure stereoscopic videos are being studied. In this paper, we proposed a method to broadcast high quality stereoscopic videos based on analysis of a method to add a stereoscopic descriptor to the PMT of MPEG-2 transport streams and a method to transmit stereoscopic videos by the expansion of MPEG-C part 3 which are from precedent studies. The proposed technique maintains compatibility with conventional MPEG-2 transport streams by showing only reference video for models that do not support 3D broadcasting. Therefore, the compatibility between conventional broadcasting and stereoscopic videos should make this method useful when activating 3D services in the communications and broadcasting area

• Journal of Broadcast Engineering
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• v.24 no.6
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• pp.1085-1095
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• 2019

In this paper, we perform a subjective quality assessment on low-resolution surveillance videos, which are encoded with a very low target bit-rate to use in an ultra-low band transmission system and investigate the encoding effects on the perceived video quality. The test videos are collected based on their spatial and temporal characteristics which affect the perceived quality. H.265/HEVC encoder is used to prepare the impaired sequences for three target bit-rates 20, 45, and 65 kbps and subjective quality assessment is conducted to evaluate the quality from a viewing distance of 3H. The experimental results show that the quality of encoded videos, even at target bit-rate of 45 kbps can satisfy the users. Also we compare objective image/video quality assessment methods on the proposed dataset to measure their correlation with subjective scores. The experimental results show that the existing methods poorly performed, that indicates the need for a better quality assessment method.

• Journal of KIISE:Databases
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• v.37 no.3
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• pp.127-136
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• 2010

With rapid growth of information and computer communication technologies, the numbers of digital documents including multimedia data have been recently exploded. In particular, news video database and news video mining have became the subject of extensive research, to develop effective and efficient tools for manipulation and analysis of news videos, because of their information richness. However, many research focus on browsing, retrieval and summarization of news videos. Up to date, it is a relatively early state to discover and to analyse the plentiful latent semantic knowledge from news videos. In this paper, we propose the news video mining system based on multi-modal approach and text mining, which uses the visual-textual information of news video clips and their scripts. The proposed system systematically constructs a taxonomy of news video stories in automatic manner with hierarchical clustering algorithm which is one of text mining methods. Then, it multilaterally analyzes the topics of news video stories by means of time-cluster trend graph, weighted cluster growth index, and network analysis. To clarify the validity of our approach, we analyzed the news videos on "The Second Summit of South and North Korea in 2007".

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.7-13
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• 2019

Unlike a typical video wall system, video wall systems used for integrated monitoring in smart city environments should be able to display various videos, images, and texts simultaneously. In this paper, we propose an Internet Protocol (IP)-based video wall system that has no limit on the number of videos that can be monitored simultaneously, and that can arrange the monitor screen layout without restrictions. The proposed system is composed of multiple display servers, a wall controller, and video source providers, and they communicate with each other through an IP network. Since the display server receives and decodes the video stream directly from the video source devices, and displays it on the attached monitor screens, more videos can be simultaneously displayed on the entire video wall. When one video is displayed over several screens attached to multiple display servers, only one display server receives the video stream and transmits it to the other display servers by using IP multicast communications, thereby reducing the network load and synchronizing the video frames. Experiments show that as the number of videos increases, a system consisting of more display servers shows better decoding and rendering performance, and there is no performance degradation, even if the display server continues to be expanded.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.107-114
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• 2021

The purpose of this study is to investigate whether there is a difference in the effect of learning flow and teaching presence according to the lecturer's appearance and students' behavioral patterns in video learning. For this experiment, 183 freshmen from Xingtai University in China were selected as subjects. After being classified according to DISC, students were assigned to study the lecture videos with the appearance of the lecturer and the video without the appearance of the lecturer. After testing the level of their learning flow and teaching presence, the differences between groups were analyzed. According to the results of the analysis, the learning flow and teaching presence of groups who learned the videos in which the lecturer appeared were significantly higher than the groups who learned the videos without the appearance of the lecturer. Second, the effects of whether the lecturer appears or not according to DISC on learning flow were significant. However, the effects of DISC, and the interactive effect of DISC and the lecturer appearance were found to have no significant interactive effect on learning flow. Third, the effects of whether the lecturer appears or not according to DISC on teaching presence were significant, and the effects of DISC on teaching presence were not significant, but the interactive effect of lecturer appearance and DISC was significant. These findings suggest that lecture videos with the appearance of the lecturer generally have better effect. In particular, in order to enhance teaching presence, it is effective to decide whether the lecturer appears or not by considering its interactive effects with learners' DISC.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.435-444
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• 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 Convergence on Culture Technology
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• v.8 no.5
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• pp.459-468
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• 2022

This study searched and analyzed news and information on the Korea-U.S. Summit to explore which political agenda is spreading among Korean newspapers and social media. The result of the analysis revealed that, on the one hand, the conservative-leaning newspaper, Chosunilbo, covered the unresolved issue between two countries. The principal source of news was the opposition party. On the other hand, the progressive-leaning newspaper, Kyunghany Sinmun, highlighted President Moon's visit to the United States and described the visit to the United States as an achievement. In this paper, the principal source of news is the ruling party. Both conservative and the progressive newspapers did not present a negative view of the United States. In the case of Chosunilbo, it mentioned that foreign policy priority of President Biden is human rights in North Korea. If the two countries do not solve this issue, the relationship between Korea and the United States will not develop further. Second, I searched YouTube videos about the Korea-U.S. summit and conducted a network analysis to understand the influence of YouTube videos and explore their relationship the each other. The results of the analysis revealed that the 10 most influential videos portrayed the Moon government positively. These videos held the achievement of the visit to the United States in highly esteem and framed it positively, similarly to the progressive newspaper.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.4
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• pp.59-76
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• 2023

This study examines critical issues and topics related to services using YouTube videos and research publications. We analyzed 2,853 YouTube videos and 19,973 research papers related to services, released during the 2013-June, 2023 period, using text mining and network analysis. In addition, the collected data was divided into pre- and post-COVID-19 pandemic periods to explore how key issues and topics regarding services have changed. These papers were sequentially analyzed through text mining and network construction and procedures. The results indicate that the central themes of YouTube videos were IT, data, and solution, while academic research focused on service quality, quality, and customer satisfaction. Regarding ego network analysis, the key issues in YouTube video contents revolved primarily around words related to the service industry. Although it was found that they generally lacked specific industry fields, academic papers explored diverse issues in various service fields. The results of this study can be utilized to understand changes in customer concerns in the service industry from practical and academic perspectives.

• Journal of Advanced Navigation Technology
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• v.27 no.3
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• pp.306-313
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• 2023

Realistic and graphics-based virtual reality content is based on 360-degree videos, and viewport extraction through the viewer's intention or automatic recommendation function is essential. This paper designs a viewport extraction system based on multiple object tracking in 360-degree videos and proposes a parallel computing structure necessary for multiple viewport extraction. The viewport extraction process in 360-degree videos is parallelized by composing pixel-wise threads, through 3D spherical surface coordinate transformation from ERP coordinates and 2D coordinate transformation of 3D spherical surface coordinates within the viewport. The proposed structure evaluated the computation time for up to 30 viewport extraction processes in aerial 360-degree video sequences and confirmed up to 5240 times acceleration compared to the CPU-based computation time proportional to the number of viewports. When using high-speed I/O or memory buffers that can reduce ERP frame I/O time, viewport extraction time can be further accelerated by 7.82 times. The proposed parallelized viewport extraction structure can be applied to simultaneous multi-access services for 360-degree videos or virtual reality contents and video summarization services for individual users.