Browsing by Author "Chen, Hung-Lin"

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Analysis of Relative Intensity Noise Spectra for Uniformly and Chirpily Stacked InAs-InGaAs-GaAs Quantum Dot Lasers
(2012-02-01)
Lin, Gray
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Tang, Hao-Ling
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Cheng, Hsu-Chieh
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Chen, Hung-Lin
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電子工程學系及電子研究所
The dynamic properties of uniformly and chirpily stacked InAs-InGaAs-GaAs quantum dot lasers are analyzed in terms of relative intensity noise spectra. For uniformly stacked quantum dot laser with ground-state lasing emissions of 1.3 mu m, the K-factor limited bandwidth is 13 GHz. The extracted differential gain and gain compression factor are 1.7 x 10(-15) cm(2) and 2 x 10(-16) cm(3), respectively. For chirpily stacked quantum dot laser with excited-state lasing emissions of 1.2 mu m, the K-factor limited bandwidth is 14 GHz. Yet the nonproportional dependence between resonance frequency and square root of incremental current yields differential gain of 4.3 x 10(-15) cm(2) and huge gain compression factor of 1.4 x 10(-14) cm(3).
Monitoring displays coupled with speed cameras - Effectiveness on speed reduction
(2007)
Woo, T. Hugh
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Ho, Shih-Ming
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Chen, Hung-Lin
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
Speeding is a common behavior of drivers all over the world. Traditional speed-controlling measures fail to reduce speeding effectively. With advances in technology, new devices have been developed for such a purpose, including a speed-monitoring display (SMD) that detects the speed of vehicles and displays it on an electronic board, informing drivers of their current speed, It has been hypothesized that SMDs coupled with speed cameras to catch violators may deter drivers from speeding. This study examined the effectiveness of SMDs with enforcement cameras on speed reduction. Speed data of free-flowing vehicles were collected before and after the SMD and enforcement cameras were installed. Speed data were also collected with the SMD turned off and then on again. The results showed that mean speeds of vehicles were significantly reduced after SMD and camera installation. Even with the SMD turned off, the speed reduction was not significantly affected, but the proportion of speeding vehicles became higher. It was found that the presence of SMDs could alert drivers of enforcement cameras downstream, making speeders adjust their speed to comply with the limit.