• Journal of Korea Society of Industrial Information Systems
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• v.12 no.3
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• pp.95-103
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• 2007

Portable multimedia Player (PMP) devices have been gaining in its popularity with the emerging digital convergence of data, video, audio, etc. Since the PMP devices are typically equipped with DSP, a bigger LCD screen, and a hard disk, efficient power management has become more crucial than the other portable devices. This paper builds up a hardware/software-based power measurement system based on data acquisition devices. Subsequently, it measures and analyzes the power consumed in commercial PMP devices under different types of events: the system boot & shutdown, video playback, and the use of different video-coding types. Finally, our analysis of the measured power consumption patterns reveals useful information for the design of low-power PMP devices.

• International Journal of Computer Science & Network Security
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• v.22 no.12
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• pp.13-18
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• 2022

In the post-information era, most of technologies have a visual part, or at least some functions related to visualization. It is also one of the popular means of presenting materials in education area. However, despite its popularity, the impact of visualization on the effectiveness of learning still remains controversial. Even more controversial is its usefulness in developing creativity, which is one of the most important skills for today's employee. The authors considered the use of visualization as a tool for the development of children's creativity on the example of learning video games, in particular, ClassCraft to distinguish features that, from the point of view of psychology, may lead to developing creativity even being not useful for educational purposes. It is concluded that video games useful for learning may have features, that are inappropriate in formal educational context, but important to develop creative thinking.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.989-993
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• 2009

Wireless LAN(WLAN) is a rather mature communication technology connecting mobile terminals. IEEE 802.11 is a representative protocol among WLAN technologies. With the rising popularity of delay-sensitive real-time multimedia applications(video, voice and data) in IEEE 802.11 wireless LAN, it is important to study the MAC layer delay performance of WLANs. In this paper, performance for packet delay that recently have been proposed schemes is analysed in wireless LAN and proved performance results via simulation.

• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.864-871
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• 2006

With the advancement of the digital broadcasting and popularity of Internet, there is an increasing demand for digital data. Recently, several studies have been made on the digital watermarking for copyright protection of digital data. We propose a blind video watermarking using minimum modification of motion vectors. Conventional methods based on motion vectors do watermarking using modification of motion vectors. However, change of motion vectors results in the degradation of video quality. Thus, our proposed algorithm minimizes modification of the original motion vectors to avoid degradation of video quality using simple embedded conditions. Besides, our scheme guarantees the amount of embedded watermark data using the adaptive threshold considering the human visual characteristic. In addition, this is compatible with current video compression standards without changing the bitstream. Experimental result shows that the proposed scheme obtains better video quality than other previous algorithms by about $0.5{\sim}1.0\;dB$.

• Journal of Chest Surgery
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• v.47 no.4
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• pp.327-332
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• 2014

Single-port video-assisted thoracic surgery (VATS) has slowly established itself as an alternate surgical approach for the treatment of an increasingly wide range of thoracic conditions. The potential benefits of fewer surgical incisions, better cosmesis, and less postoperative pain and paraesthesia have led to the technique's popularity worldwide. The limited single small incision through which the surgeon has to operate poses challenges that are slowly being addressed by improvements in instrument design. Of note, instruments and video-camera systems that are narrower and angulated have made single-port VATS major lung resection easier to perform and learn. In the future, we may see the development of subcostal or embryonic natural orifice translumenal endoscopic surgery access, evolution in anaesthesia strategies, and cross-discipline imaging-assisted lesion localization for single-port VATS procedures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.8
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• pp.607-614
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• 2013

In this work we investigate the power of power law in the VoD service over IP network. Especially, we show that the power of power law is strong in the location of the contents storage for the VoD service and its impact on the link dimensioning. This work first shows the instance of the power law in the popularity of the video contents from the real data for the IPTV service. After that we propose an analytic model that characterizes the behavior of customers in accessing the video servers as well as the power law in the viewing pattern. Finally, we show the impact of the power law by proposing a model for the cost as well as link dimensioning. Via numerical experiment we show the implication of the proposition.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.425-428
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• 2003

Recently, the IDS(Intrusion Detection System) using a video camera is an important part of the home security systems which start gaining popularity. However, the video intruder detection has not been widely used in the home surveillance systems due to its unreliable performance in the environment with abrupt illumination change. In this paper, we propose an effective moving edge extraction algorithm from a sequence image. The proposed algorithm extracts edge segments from current image and eliminates the background edge segments by matching them with reference edge list, which is updated at every frame, to find the moving edge segments. The test results show that it can detect the contour of moving object in the noisy environment with abrupt illumination change.

• Journal of Korea Multimedia Society
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• v.17 no.4
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• pp.405-412
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• 2014

Due to the popularity of mobile phones, Peer-to-Peer (P2P) content sharing in mobile phones is highly desirable, especially in a mobile data connection. In addition, there has been an increasing demand for content sharing applications for P2P communication in Android-based smartphones as ubiquitous mobile devices. However, due to wireless network limits, unstable characteristic and restricted storage space, mobile users confront challenges in establishing connections and sharing video frames with other users. To solve this issue, we propose an architectural design and implementation of key frame sharing application that uses Chord, a distributed lookup protocol to establish a content sharing platform for mobile devices, combined with the Chord SDK based on Android. Our proposed system enables users easily to share key information on video data in real-time over a wireless network without manual processing of devices which join or leave the group and cost associated with the 3G/4G network.

• International journal of advanced smart convergence
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• v.10 no.4
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• pp.273-277
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• 2021

As society gradually enters a virtual, non-face-to-face society, the use of online content is increasing as well. In particular, as smartphones are thoroughly established in our daily life, the platforms of webtoons, mobile broadcasting, and education are shifting from personal computers to smartphones. Recently, the development of the Over-The-Top media service (OTT service) enabled streaming services of various media contents through the internet and activation of IPTV. Therefore, the rapid increase of popularity of short-form content is a natural phenomenon with smartphone platforms with fast, improvised, and endless communication. Lately, TikTok became the favored platform with prosumers, defined as people who are both producers and consumers. In this study, I studied the experiential response of YouTube and TikTok users as representative examples of a short-form content platform developed after the 2000s, the flourishing years of digital content with a length of 30 seconds.

• Journal of Communications and Networks
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• v.14 no.3
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• pp.286-295
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• 2012

To meet the increased demand of video-on-demand (VoD) services, peer-to-peer (P2P) mesh-based multiple video approaches have been recently proposed, where each peer is able to find a video segment interested without resort to the video server. However, they have not considered the constraint of the server's upload bandwidth and the fairness between upload and download amounts at each peer. In this paper, we propose a novel P2P VoD streaming system, named peer cache adaptation (PECAN) where each peer adjusts its cache capacity adaptively to meet the server's upload bandwidth constraint and achieve the fairness. For doing so, we first propose a new cache replacement algorithm that designs the number of caches for a segment to be proportional to its popularity. Second, we mathematically prove that if the cache capacity of a peer is proportional to its segment request rate, the fairness between upload and download amounts at each peer can be achieved. Third, we propose a method that determines each peer's cache capacity adaptively according to the constraint of the server's upload bandwidth. Against the proposed design objective, some selfish peers may not follow our protocol to increase their payoff. To detect such peers, we design a simple distributed reputation and monitoring system. Through simulations, we show that PECAN meets the server upload bandwidth constraint, and achieves the fairness well at each peer. We finally verify that the control overhead in PECAN caused by the search, reputation, and monitoring systems is very small, which is an important factor for real deployment.