Browsing by Author "Chou, Kuan-Hung"

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Content-aware video adaptation under low-bitrate constraint
(2007)
Hsiao, Ming-Ho
;
Chen, Yi-Wen
;
Chen, Hua-Tsung
;
Chou, Kuan-Hung
;
Lee, Suh-Yin
With the development of wireless network and the improvement of mobile device capability, video streaming is more and more widespread in such an environment. Under the condition of limited resource and inherent constraints, appropriate video adaptations have become one of the most important and challenging issues in wireless multimedia applications. In this paper, we propose a novel content- aware video adaptation in order to e. effectively utilize resource and improve visual perceptual quality. First, the attention model is derived from analyzing the characteristics of brightness, location, motion vector, and energy features in compressed domain to reduce computation complexity. Then, through the integration of attention model, capability of client device and correlational statistic model, attractive regions of video scenes are derived. The information object- ( IOB-) weighted rate distortion model is used for adjusting the bit allocation. Finally, the video adaptation scheme dynamically adjusts video bitstream in frame level and object level. Experimental results validate that the proposed scheme achieves better visual quality effectively and effciently.
Intelligent Router-Assisted Power Saving Medium Access Control for Mobile Ad Hoc Networks
(2006)
Feng, Kai-Ten
;
Chou, Kuan-Hung
;
電信工程研究所
;
Institute of Communications Engineering
The limitation on the battery life has been a critical issue for the advancement of the mobile computers. Users encounter unsatisfactory battery power while using their mobile devices, especially on the occasions of transmitting data using the wireless networks. It has been studied that the amount of energy consumed within the mobile devices is significantly affected by the design of the Medium Access Control (MAC) protocol within the wireless interface. This paper presents a Intelligent Router-Assisted (IRouter) power-saving MAC algorithm that achieves energy conservation by predicting the next hopping node within the delivering route. With the assistance of the intelligent routers in the network, the packet delivery between several mobile nodes can be accomplished within the same beacon interval. The performance comparison between the proposed IRouter algorithm and the existing MAC protocols is conducted via simulations. It is observed that the IRouter scheme can achieve feasible performance in both energy conservation and routing efficiency.