Browsing by Author "Chen, Ming-Dao"

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A Complete System for Analysis of Video Lecture Based on Eye Tracking
(2018-01-01)
Zhang, Xuebai
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Yuan, Shyan-Ming
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Chen, Ming-Dao
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Liu, Xiaolong
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資訊工程學系
An eye tracking technology provides a faster and more intuitive interface to explore the learner psychology. In this paper, with the aim of assisting researcher to expand the knowledge of video lectures, we present an efficient system named VLEYE based on eye tracking. The system allows gathering the dynamic areas of interest (AOIs) and combining them with eye movement data. There are mainly three modules in the proposed system, including "eye movement recorder," "dynamic AOI module," and "video analyzer." The "eye movement recorder" records the eye movement data by eye tracking device, where mouse cursor control function is applied to support the use of low-cost devices. The AOIs could be drawn manually or detected and tracked by the provided algorithm automatically in the "dynamic AOI module." The "video analyzer" provides various visualization modes to view and compare the eye movement information for single or multiple subject, as well as statistical charts and detail fixation information. In addition to performance testing, a case study was conducted to verify the applicability of the proposed system. We demonstrate that this system works well and is an essential step forward in efficiently helping studies to better understand learner cognitive processes for dynamic stimuli within video.
Cross-Layer Error Recovery Scheme for Data Transmission over 4G Wireless Networks
(2015)
Yang, Wen-Chih
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Chen, Ming-Dao
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Hsiao, Hsu-Feng
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資訊工程學系
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Department of Computer Science
In a video streaming application, quality of experience for a user can be affected by various factors. The video quality can be improved if the effective throughput can be increased at an acceptable packet loss rate and low latency. To reduce the packet loss rate over error-prone channels, a cross-layer error control scheme is developed for heterogeneous data transmission over wireless channels in this paper. The error control scheme utilizes both link-layer automatic repeat request and application-layer channel coding. The automatic repeat request is served as providing a basic level of loss recovery without introducing intolerable delay, while the application-layer channel coding is based on the previously developed layer-aligned multipriority rateless codes to satisfy a desired packet loss rate at a minimal bandwidth overhead. The cross-layer architecture of the error control scheme will control the retransmission timers based on the channel conditions while the control parameters of the layer-aligned multipriority rateless codes will be determined to fulfill the heterogeneous requirement of overall packet loss rate required by an application at a minimal cost. The improved performance of the developed cross-layer scheme is confirmed with the experiments using a real-world 4G system.