Browsing by Author "Tsai, Cheng-Wei"

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Improving Adaptive Streaming Service across Wired/Wireless Networks
(2009)
Leu, Jenq-Shiou
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Tsai, Cheng-Wei
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Yi, Chih-Wei
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資訊工程學系
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Department of Computer Science
Thanks to the growing of the wireless networks, the video streaming application becomes a ubiquitous joyful service. In wireless communication networks, the service traffic spans across the wired and wireless domains. Hence, the service of quality (QoS) control becomes complicated. Generally, the QoS is manipulated by the receiving feedback from the mobile User Equipments (UEs) to the streaming server. If the feedback latency can be shortened, the streaming service can be adapted according to the individual network condition timely. Meanwhile, a public streaming service is normally realized by multiple uni-casting streams instead of the multicasting ones over IP. To make the service more efficient, an input video session can be encoded as multiple-quality streams so that some UEs with a similar receiving condition can share streams with the same service quality. In this article, SPONGE (Stream Pooler Over a Network Graded Environment) is proposed to improve the adaptive streaming service across wired/wireless networks. SPONGE can alleviate the direct load from the original streaming server to the end UEs and make each UE get an adaptive streaming service according to its network condition timely by the reduced feedback latency of network conditions. Our simulation results show that SPONGE can react to network condition accurately and quickly so as to have a smooth and better playback quality at the end user site across wired/wireless networks.
UV-treated graphene oxide as anode interfacial layers for P3HT: PCBM solar cells
(2015-07-01)
Cheng, Cheng-En
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Tsai, Cheng-Wei
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Pei, Zingway
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Lin, Tsung-Wu
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Chang, Chen-Shiung
Solution-processable graphene oxide (GO) ultrathin films were introduced as anode interfacial layers (AILs) for polymer solar cells (PSCs). The photovoltaic performance of PSCs containing thermal-and UV-treated GO was comparable to that of PSCs with conventional poly(3,4-ethyledioxythiphene): poly(styrenesulfonate) AILs. UV treatment induced the surface activation of GO; an increase in the work function of UV-treated GO improved the energy band alignment at the GO/poly(3-hexylthiophene) interface, which accounted for the efficient hole collection and photovoltaic performance of PSCs with treated GO.