• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.9
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• pp.3196-3210
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• 2014

This paper presents a novel video metrology approach based on robust tracking. From videos acquired by an uncalibrated stationary camera, the foreground likelihood map is obtained by using the Codebook background modeling algorithm, and the multiple moving objects are tracked by a combined tracking algorithm. Then, we compute vanishing line of the ground plane and the vertical vanishing point of the scene, and extract the head feature points and the feet feature points in each frame of video sequences. Finally, we apply a single view mensuration algorithm to each of the frames to obtain height measurements and fuse the multi-frame measurements using RANSAC algorithm. Compared with other popular methods, our proposed algorithm does not require calibrating the camera, and can track the multiple moving objects when occlusion occurs. Therefore, it reduces the complexity of calculation and improves the accuracy of measurement simultaneously. The experimental results demonstrate that our method is effective and robust to occlusion.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.139-142
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• 2004

본 논문에서는 MPEG-21 Digital Item Adaptation(DIA)에 의한 워터마크 신호의 영향을 실험하고 분석한다. MPEG-21 DIA에서는 다양한 소비환경에 맞게 멀티미디어 컨텐츠를 변할 수 있는 기능들을 제공하고 있다. 그러나 컨텐츠 변환기능들은 저작권 보호를 위해 컨텐츠에 삽입된 워터마크신호를 홰손시킬 수 있으므로, DIA 환경에서 워터마킹기술을 사용하기 위해서는 워터마킹기술에 대한 DIA의 영향을 분석할 필요가 있다. 본 논문에서는 일반적으로 널리 알려진 대표적인 워터마킹기술을 이용하여 MPEG-21 DIA에서 정의하고 있는 각각의 적응변환기능에 대한 워터마크의 강인성을 실험하여, 그 결과를 바탕으로 DIA 환경에서 워터마킹기술을 적용할 때 필요한 요구사항을 분석하였다.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.84-92
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• 2019

While the Internet continues to integrate with modern lives, the risks of negative outcomes resulting from problematic use (PU) are also increasing. Although psychological well-being and use motivations have been shown to play major roles in Internet PU, understanding the moderating mechanism is critical for advanced knowledge. The present study employed survey data from users of a live video-game streaming service (LVGS) that is an area rarely been studied. Result concluded a positive moderating effect of escapism motive (EM) on the association between loneliness and the PU of LVGS, while the moderating mechanism between EM and stress was not indicated. A moderating effect of information seeking (IS) on the relationship between stress and the PU of LVGS was found negative, but no mechanism between IS and loneliness was indicated. This study highlights how the interplay of different motivation and pathologies may induce or prevent video-game-related addiction.

• Journal of Korea Multimedia Society
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• v.24 no.3
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• pp.423-430
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• 2021

Aiming Graph convolutional networks (GCNs) have achieved outstanding performances on skeleton-based action recognition. However, several problems remain in existing GCN-based methods, and the problem of low recognition rate caused by single input data information has not been effectively solved. In this article, we propose a Dual-stream fusion method that combines video data and skeleton data. The two networks respectively identify skeleton data and video data and fuse the probabilities of the two outputs to achieve the effect of information fusion. Experiments on two large dataset, Kinetics and NTU-RGBC+D Human Action Dataset, illustrate that our proposed method achieves state-of-the-art. Compared with the traditional method, the recognition accuracy is improved better.

• Educational Technology International
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• v.10 no.2
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• pp.107-125
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• 2009

This study seeks to prove three points through the research. The first point is to examine the changes of international attitudes with actual experiences using synchronous international distance learning. The second point is to examine the effectiveness of a synchronous international distance system. And the final point is to compare international attitudes among middle school and undergraduate school students in Korea and Japan. The study used the DVTS for audio and video communication tools and automatic translating chat as a text communication tool. This combination of communication tools was very effective for students from both countries to communicate for international collaborative learning activities. The study found several interesting patterns of attitude change from the results of the study. For whole category analysis, there are positive changes in four categories of international attitudes: consciousness to foreign countries, consideration for other's viewpoints, motivation for international education, and recognition for the counterpart country. However, there was no change in the nationality category.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.5149-5167
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• 2017

Reducing energy consumption in a wireless video sensor network (WVSN) is a crucial problem because of the high video data volume and severe energy constraints of battery-powered WVSN nodes. In this paper, we present an adaptive dynamic resizing approach for a SRAM communication buffer in a WVSN node in order to reduce the energy consumption and thereby, to maximize the lifetime of the WVSN nodes. To reduce the power consumption of the communication part, which is typically the most energy-consuming component in the WVSN nodes, the radio needs to remain turned off during the data buffer-filling period as well as idle period. As the radio ON/OFF transition incurs extra energy consumption, we need to reduce the ON/OFF transition frequency, which requires a large-sized buffer. However, a large-sized SRAM buffer results in more energy consumption because SRAM power consumption is proportional to the memory size. We can dynamically adjust any active buffer memory size by utilizing a power-gating technique to reflect the optimal control on the buffer size. This paper aims at finding the optimal buffer size, based on the trade-off between the respective energy consumption ratios of the communication buffer and the radio part, respectively. We derive a formula showing the relationship between control variables, including active buffer size and total energy consumption, to mathematically determine the optimal buffer size for any given conditions to minimize total energy consumption. Simulation results show that the overall energy reduction, using our approach, is up to 40.48% (26.96% on average) compared to the conventional wireless communication scheme. In addition, the lifetime of the WVSN node has been extended by 22.17% on average, compared to the existing approaches.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.4026-4040
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• 2019

In this paper, we present an approach for detecting slide transitions in lecture videos by introducing the spatio-temporal residual networks. Given a lecture video which records the digital slides, the speaker, and the audience by multiple cameras, our goal is to find keyframes where slide content changes. Since temporal dependency among video frames is important for detecting slide changes, 3D Convolutional Networks has been regarded as an efficient approach to learn the spatio-temporal features in videos. However, 3D ConvNet will cost much training time and need lots of memory. Hence, we utilize ResNet to ease the training of network, which is easy to optimize. Consequently, we present a novel ConvNet architecture based on 3D ConvNet and ResNet for slide transition detection in lecture videos. Experimental results show that the proposed novel ConvNet architecture achieves the better accuracy than other slide progression detection approaches.

• Journal of Satellite, Information and Communications
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• v.10 no.2
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• pp.70-74
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• 2015

In this paper, satellite communication based video surveillance system that consisted of ultra-small aperture terminals with small-size smart vision sensor is proposed. The events such as forest fire, smoke, intruder movement are detected automatically in field and false alarms are minimized by using intelligent and high-reliable video analysis algorithms. The smart vision sensor is necessary to achieve high-confidence, high hardware endurance, seamless communication and easy maintenance requirements. To satisfy these requirements, real-time digital signal processor, camera module and satellite transceiver are integrated as a smart vision sensor-based ultra-small aperture terminal. Also, high-performance video analysis and image coding algorithms are embedded. The video analysis functions and performances were verified and confirmed practicality through computer simulation and vision sensor prototype test.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.90-97
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• 2020

Recently, with the growth of mixed reality industrial infrastructure, relevant convergence research has been proposed. For real-time mixed reality services such as remote video conferencing, the research on real-time acquisition-process-transfer methods is required. This paper aims to implement an AR remote rendering method of volumetric 3D video data. We have proposed and implemented two modules; one, the parsing module of the volumetric 3D video to a game engine, and two, the server rendering module. The result of the experiment showed that the volumetric 3D video sequence data of about 15 MB was compressed by 6-7%. The remote module was streamed at 27 fps at a 1200 by 1200 resolution. The results of this paper are expected to be applied to an AR cloud service.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.1-10
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• 2018

In cognitive radio (CR), secondary users (SUs) are able to sense the absence of primary users (PUs) in the spectrum. Then, SUs use this information to opportunistically access the licensed spectrum in the PUs' absence. In this paper, we present an implementation of real-time video transmission with spectrum-sensing between two points using GNU Radio and a National Instruments 2900 Universal Software Radio Peripheral (USRP). In our project, spectrum-sensing is implemented at both transmitter and receiver. The transmitter senses the channel, and if the channel is free, a video signal (which could be a real-time signal from a video file) will be modulated and processed by GNU Radio and transmitted using a USRP. A USRP receiver also senses the channel, but in contrast, if the channel is busy, the signal is demodulated to reproduce the transmitted video signal. This project brings in several challenges, like spectrum-sensing in the devices' environment, and packets getting lost or corrupted over the air.