Browsing by Author "Chiu, Chun-Chieh"

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CUDT: A CUDA Based Decision Tree Algorithm
(2014-01-01)
Lo, Win-Tsung
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Chang, Yue-Shan
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Sheu, Ruey-Kai
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Chiu, Chun-Chieh
;
Yuan, Shyan-Ming
Decision tree is one of the famous classification methods in data mining. Many researches have been proposed, which were focusing on improving the performance of decision tree. However, those algorithms are developed and run on traditional distributed systems. Obviously the latency could not be improved while processing huge data generated by ubiquitous sensing node in the era without new technology help. In order to improve data processing latency in huge data mining, in this paper, we design and implement a new parallelized decision tree algorithm on a CUDA (compute unified device architecture), which is a GPGPU solution provided by NVIDIA. In the proposed system, CPU is responsible for flow control while the GPU is responsible for computation. We have conducted many experiments to evaluate system performance of CUDT and made a comparison with traditional CPU version. The results show that CUDT is 5 similar to 55 times faster than Weka-j48 and is 18 times speedup than SPRINT for large data set.
The backbone rigidity and its influence on the morphology and charge mobility of FBT based conjugated polymers
(2015-01-01)
Wu, Kuan-Yi
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Chiu, Chun-Chieh
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Chuang, Wei-Tsung
;
Wang, Chien-Lung
;
Hsu, Chain-Shu
A series of three PVTh4FBT polymers containing different alkyl side chain placement was synthesized. The thermochromic behaviors and DFT calculations indicated that the backbone coplanarity and rigidity of the PVTh4FBT polymers can be effectively modulated by adjusting the side chain position and density. Higher ordered and better oriented edge-on lamellar packing was formed by P1, which possesses the most rigid backbone among the three polymers and pre-aggregates in the solution. P1 also delivered the highest hole mobility (0.26 cm(2) V-1 s(-1)) among the three analogues because its thin-film morphology is in favor of charge transport.