• Journal of Korea Multimedia Society
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• v.21 no.10
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• pp.1182-1194
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• 2018

The Dynamic Adaptive Streaming over HTTP(DASH) is envisioned to evolve to meet an increasing demand on providing seamless video streaming services in the near future. The DASH performance heavily depends on the client's adaptive quality selection algorithm that is not included in the standard. The existing conventional algorithms are basically based on a procedural algorithm that is not easy to capture and reflect all variations of dynamic network and traffic conditions in a variety of network environments. To solve this problem, this paper proposes a novel quality selection mechanism based on the Deep Q-Network(DQN) model, the DQN-based DASH Adaptive Bitrate(ABR) mechanism. The proposed mechanism adopts a new reward calculation method based on five major performance metrics to reflect the current conditions of networks and devices in real time. In addition, the size of the consecutive video segment to be downloaded is also considered as a major learning metric to reflect a variety of video encodings. Experimental results show that the proposed mechanism quickly selects a suitable video quality even in high error rate environments, significantly reducing frequency of quality changes compared to the existing algorithm and simultaneously improving average video quality during video playback.

• ETRI Journal
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• v.31 no.3
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• pp.333-335
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• 2009

To match the requirements of heterogeneous mobile devices, video objects may be transcoded, which requires considerable CPU resources. Alternatively, multiple versions of the same video may be stored on servers, but this requires a lot of disk space. We formulate the trade-off between the versions that are stored on disk and the need for transcoding. We propose an optimal solution to this formulation based on dynamic programming. Experiments show that our scheme allows up to 68% more clients to be admitted than conventional schemes when a reasonable amount of storage is available.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2S
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• pp.621-628
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• 2000

A retrieval performance of VOD sever is estimated by how quickly it services popular videos to users and how many users it is able to service. Each video data is placed on heterogeneous disks and placement techniques are various, retrieval performance is under the control of these elements, so that a retrieval performance is affected by placement policy. In this paper, we place video data considering their characteristics, especially, we place videos distributively according to their popularity. To verify our policy, we make various environment of experiment, estimate a placement policy using popularity of videos and a contrary policy, and compare them.

• Journal of Information Processing Systems
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• v.14 no.5
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• pp.1272-1285
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• 2018

The paper presents a novel embedded multifunctional media sever (EMMS) for mobile devices to receive various media programs. Being different from other contemporary system research, the paper mainly studies how to design a reception solution for terrestrial digital television (DTV) on mobile devices and how to enable mobile devices can receive DTV program, enjoy video-on-demand (VOD), achieve video surveillance and relay Internet video program via local Wi-Fi simultaneously. In the system design, we integrate broadcasting-terrestrial DTV tuner, streaming media re-transmission system, VOD disk, video camera and access interface to the Internet into EMMS, which can either receive terrestrial DTV radio signals and demodulate out digital transport stream (TS), or can read streaming media bit-stream from VOD disk, surveillance camera or access interface to the Internet. The experimental results show the proposed system is stable and quality-efficient. Comparing with the other systems, the proposed system has the least packet loss rate and response time.

• The Transactions of the Korea Information Processing Society
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• v.6 no.5
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• pp.1410-1417
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• 1999

In this paper, we propose the method of extracting the caption regions from news video and the method of recognizing the captions that can be used mainly for content-based indexing and retrieving the MPEG-2 compressed news for NOD(News On Demand). The proposed method can reduce the searching time on detecting caption frames with minimum MPEG-2 decoding, and effectively eliminate the noise in caption regions by deliberately devised preprocessing. Because the kind of fonts that are used for captions is not various in the news video, an enhanced template matching method is used for recognizing characters. We could obtain good recognition result in the experiment of sports news video by the proposed methods.

• The KIPS Transactions:PartB
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• v.10B no.7
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• pp.847-852
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• 2003

This paper implements MOD system using multicast delivery. Conventional system provide server-based system in multicast delivery but implemented system provides on-demand client-based multicast system. The scheduler aggregates clients' request and it generate multcast group addresses and port numbers according to requested video items and service request time. Then it transmits immediately multicast address to MOD server and client who request service. And then MOD server transmits requested streams with a multicast group address and the client joins the group automatically. The scheduler assigns the same multicast group address when other clients request an identical video within the same scheduling duration. The system can reduce load of server and support many clients at the same time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.3121-3135
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• 2015

Owing to the increase in consumption of multimedia content and the improvement of device capacity, user demand for high-quality content has increased. However, it is difficult to transport such large amounts of content over the existing broadcasting network with limited bandwidth. To provide high-definition broadcasting, some studies suggest methods of transporting multimedia over heterogeneous networks after encoding content hierarchically. MPEG Media Transport (MMT), standardized by Moving Picture Experts Group (MPEG), is a solution that enables large-volume media transport over heterogeneous networks such as digital broadcasting networks and packet-switched networks. In the case of delivering a scalable encoded video over different networks, synchronization of each stream is an important issue. MMT defines a synchronization scheme, but does not contain sufficient functions to implement it. In this paper, we propose a synchronization scheme for media streams that are encoded hierarchically, divided into layers, and transported over heterogeneous networks. We implement our scheme using MMT and HTTP, and experimented using three encapsulated video streams with different durations. As a result, we show that the proposed scheme can reduce the waiting time to display high-quality video, relative to Dynamic Adaptive Streaming over HTTP-Scalable Video Coding (DASH-SVC) by requesting segments of enhanced layers after calculating the transmission time. Additionally, we find out that the selection of durations have a relation to the characteristics of the video.

• Korean Journal of Health Education and Promotion
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• v.17 no.2
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• pp.75-85
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• 2000

The National Health Promotion Law passed in 1995 was a milestone for initiating a national health promotion program in Korea, and local governments and health related organizations are developing and providing health promotion programs for the public. The purpose of this study was to explore the effectiveness of a smoking prevention video for adolescents. There was no educational video on smoking prevention for school students in Korea. Based on funding from the National Health Promotion Fund, an educational video on smoking prevention has been developed and tested for the effectiveness. The primary subject of the video was middle school students. The result of the study has shown that there was a statistically significant difference between pre-and post test among middle school students and elementary school students. Students' knowledge on the harm of smoking has been increased after the video education. In addition, more than half of the students responded that the educational video was interesting and helpful. To reduce initiation of smoking among adolescents, both policies and school health education programs should be reinforced. Policies on tobacco should focus on demand of smokers and potential smokers. So government officials should keep monitor obedience of the law on prohibition of smoking for those under age 19. School teachers should focus on social influence of smoking for adolescents.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.235-237
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• 2022

Video content is divided into long-form video content and short-form video content according to the length. Long form video content is created with a length of 15 minutes or longer, and all frames of the captured video are included without editing. Short-form video content can be edited to a shorter length from 1 minute to 15 minutes, and only some frames from the frames of the captured video. Due to the recent growth of the single-person broadcasting market, the demand for short-form video content to increase viewers is increasing. Therefore, there is a need for research on content editing technology for editing and generating short-form video content. This study studies the technology to create short-form videos of main scenes by capturing images, voices, and motions. Short-form videos of key scenes use a pre-trained highlight extraction model through machine learning. An automatic video editing system and method for automatically generating a highlight video is a core technology of short-form video content. Machine learning-based automatic video editing method and system research will contribute to competitive content activities by reducing the effort and cost and time invested by single creators for video editing

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.10
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• pp.2479-2496
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• 2013

Increasing demand for Full High-Definition (FHD) video and Ultra High-Definition (UHD) video services has led to active research on high speed video processing. Widespread deployment of multi-core systems has accelerated studies on high resolution video processing based on parallelization of multimedia software. Even if parallelization of a specific decoding step may improve decoding performance partially, such partial parallelization may not result in sufficient performance improvement. Particularly, entropy decoding has often been considered separately from other decoding steps since the entropy decoding step could not be parallelized easily. In this paper, we propose a parallelization technique called Integrated Multi-Threaded Parallelization (IMTP) which takes parallelization of the entropy decoding step, with other decoding steps, into consideration in an integrated fashion. We used the Simultaneous Multi-Threading (SMT) technique with appropriate thread scheduling techniques to achieve the best performance for the entire decoding step. The speedup of the proposed IMTP method is up to 3.35 times faster with respect to the entire decoding time over a conventional decoding technique for H.264/AVC videos.