Browsing by Author "Lin, Wen-Yi"

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A Highly Efficient Hybrid GaAs Solar Cell Based on Colloidal-Quantum-Dot-Sensitization
(2014-07-18)
Han, Hau-Vei
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Lin, Chien-Chung
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Tsai, Yu-Lin
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Chen, Hsin-Chu
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Chen, Kuo-Ju
This paper presents a hybrid design, featuring a traditional GaAs-based solar cell combined with various colloidal quantum dots. This hybrid design effectively boosts photon harvesting at long wavelengths while enhancing the collection of photogenerated carriers in the ultraviolet region. The merits of using highly efficient semiconductor solar cells and colloidal quantum dots were seamlessly combined to increase overall power conversion efficiency. Several photovoltaic parameters, including short-circuit current density, open circuit voltage, and external quantum efficiency, were measured and analyzed to investigate the performance of this hybrid device. Offering antireflective features at long wavelengths and luminescent downshifting for high-energy photons, the quantum dots effectively enhanced overall power conversion efficiency by as high as 24.65% compared with traditional GaAs-based devices. The evolution of weighted reflectance as a function of the dilution factor of QDs was investigated. Further analysis of the quantum efficiency response showed that the luminescent downshifting effect can be as much as 6.6% of the entire enhancement of photogenerated current.
Cuckoo search and teaching-learning-based optimization algorithms for optimum synthesis of path-generating four-bar mechanisms
(2017-01)
Lin, Wen-Yi
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Hsiao, Kuo-Mo
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機械工程學系
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Department of Mechanical Engineering
The optimization of one-phase dimensional synthesis problems for path-generating four-bar mechanisms is a difficult task. Such problems have mainly been solved in the literature using the differential evolution (DE) algorithm and its variants, such as a combined-mutation DE (CMDE). The shortcoming of using DE or its variants lies in the time-consuming parameter tuning that can take up to a dozen iterations. In this study, two well-known population-based metaheuristic optimization methods, i.e. the cuckoo search (CS) and teaching-learning-based optimization (TLBO) algorithms are employed to solve five representative problems. Only one user-supplied parameter is needed for CS and none for TLBO. Findings show that the solution accuracy of CS is superior to that of DE and TLBO. Moreover, CS, with its advantage of parameter tuning only four times, rivals CMDE in solution accuracy. The reason for the superior exploitation capability of CS lies in the special combination of two search modes, i.e. the Levy flight with respect to the best individual and the random walk. To bring the performance of TLBO into full play, the number of function evaluations is two times the original one. However, TLBO still fails to provide much more accurate solutions for the first two problems.
Higher NAFLD fibrosis score is associated with impaired eGFR
(2020-01-01)
Hsieh, Meng-Hsuan
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Wu, Kuan-Ta
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Chen, Yi-Yu
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Yang, Jeng-Fu
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Lin, Wen-Yi
Background/Purpose: Chronic kidney disease (CKD) has become a worldwide health problem, leading to high morbidity and mortality, and non-alcoholic fatty liver disease (NAFLD) is considered a risk factor for CKD. The aim of this study was to explore the relationship between NAFLD fibrosis score (NFS) and the estimated glomerular filtration rate (eGFR), and identify possible risk factors related to the NFS among Taiwanese subjects. Methods: Subjects were enrolled from the database of the Department of Preventive Medicine of Kaohsiung Municipal Hsiao-Kang Hospital. The eGFR was calculated according to the Taiwanese Modification of Diet in Renal Disease (TMDRD) equation, and the NFS was employed to evaluate the fibrotic level. Results: In total, 11,376 subjects were enrolled in this study, with a mean age of 52.0 +/- 6.81 years, including 4529 (39.8%) males. A fasting sugar level >= 100 mg/dL (OR = 1.70, 95% CI = 1.52-1.87) and an abnormal waist circumference (OR = 1.81, 95% CI = 1.65-1.99) were significant factors associated with NFS (p < 0.05). Trends of a decreasing TMDRD score and an increasing NFS with increasing age were noted (p < 0.05). The NFS was significantly negatively correlated with the TMDRD score (standard coefficients: -0.067, p < 0.001). Conclusion: A higher NFS is associated with an impaired eGFR in Taiwanese subjects. Controlling risk factors, especially fasting sugar level and waist circumference, may be useful in preventing NFS deterioration, which is negatively correlated with the eGFR. Copyright (C) 2019, Formosan Medical Association. Published by Elsevier Taiwan LLC.
Optimum design of involute tooth profiles for K-H-V planetary drives with small teeth number differences
(2019-01-01)
Lin, Wen-Yi
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Hsiao, Kuo-Mo
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Ke, Jun-Yu
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機械工程學系
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Department of Mechanical Engineering
The optimum design of an involute K-H-V PDSTND is restudied and remains a difficult task even using a profile shift for the design case discussed in the literature. In fact, the difficulty arises from the design with a very high efficiency and the peculiar tip interference. Because of the failure to obtain feasible designs using profile-shifted full-depth and stub teeth, another feasible design scheme is used by altering the addendums of involute profile-shifted full-depth teeth. In this study, the objective function of the optimum design is a weighted combination of two main performance factors, i.e., the reciprocal of the contact ratio and the working pressure angle. The optimization problem is solved using a combined-mutation differential evolution algorithm. The performance can be improved using the afore-mentioned design scheme; however, there is still room for improvements. Therefore, the use of different modules in mesh for involute profile-shifted full-depth teeth with variation in addendum is proposed and the corresponding meshing equation is derived. The findings show that further improvements on the performance can be achieved.
Optimum synthesis of a 10-link gripping mechanism using new grasping indices
(2016-10)
Lin, Wen-Yi
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Hsiao, Kuo-Mo
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機械工程學系
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Department of Mechanical Engineering
When the traditional grasping index is used as an objective function, the optimized mechanism obtained offers good force transmission performance but unsound motion transmission for a 10-link gripping mechanism. Therefore, we first propose a new grasping index that is the product of the traditional grasping index and the effective force ratio. The effective force ratio reflects the motion transmission for the output links. The proposed grasping index is similar to the force transmission index discussed in the literature; however, different views of the physical meaning of the two components of the index and the necessity of the effective force ratio for optimum synthesis of the mechanism are presented. The second new grasping index proposed is the product of the first grasping index and the cosine value of the angle between the contact force and the contact velocity, originally used as a constraint. Using these new grasping indices, one can obtain sound optimum mechanism designs with a very small input force and contact velocity and with the maximum opening dimension equal to the object size. Furthermore, optimum synthesis for the gripping mechanism with an opening dimension larger than the object size is also investigated.