Browsing by Author "Hung, Kuo-Chih"

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A 99.2% Tracking Accuracy Single-Inductor Quadruple-Input-Quadruple-Output Buck-Boost Converter Topology with Periodical Interval Perturbation and Observation MPPT
(2018-01-01)
Huang, Chao-Jen
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Ma, Yao-Sheng
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Yang, Wen-Hau
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Lin, Yen-Ting
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Kuo, Chun-Chieh
this paper provides a Single-Inductor Quadruple-Input--Quadruple-Output buck-boost converter to achieve maximum tracking efficiency of 99,2% due to continuous supply in one cycle. The Maximum Power Point (MPP) tracking mode and the Harvest Energy Delivering (RED) mode harvest each energy harvesting source, deliver energy to the battery and supply it to the loading system in one cycle. Each output voltage ranges from 600mV to 2.5V and the maximum output power is up to 60mW. The peak efficiency is 91.2%.
Global bifurcation and exact multiplicity of positive solutions for a positone problem with cubic nonlinearity
(2012-06-15)
Tzeng, Chih-Chun
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Hung, Kuo-Chih
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Wang, Shin-Hwa
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應用數學系
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Department of Applied Mathematics
We study the global bifurcation and exact multiplicity of positive solutions of {u'' (chi) + lambda f(epsilon)(u) = 0, -1 < chi < 1, u(-1) = u(1) = 0, f epsilon(u) = -epsilon u(3) + sigma u(2) - kappa u + rho, where lambda, epsilon > 0 are two bifurcation parameters, and sigma, rho > 0, 0 < kappa <= root sigma rho are constants. We prove the global bifurcation of bifurcation curves for varying epsilon > 0. More precisely, there exists (epsilon) over tilde > 0 such that, on the (lambda, parallel to u parallel to infinity)-plane, the bifurcation curve is S-shaped for 0 < epsilon < (epsilon) over tilde and is monotone increasing for epsilon >= (epsilon) over tilde. Thus we are able to determine the exact number of positive solutions by the values of epsilon and lambda. Our results extend those of Hung and Wang (K.-C. Hung, S.-H. Wang, Global bifurcation and exact multiplicity of positive solutions for a positone problem with cubic nonlinearity and their applications, Trans. Amer. Math. Soc., in press) from kappa <= 0 to kappa <= root sigma rho. (C) 2012 Elsevier Inc. All rights reserved.