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Wyszukujesz frazę "Zhang, Dawei" wg kryterium: Autor


Wyświetlanie 1-4 z 4
Tytuł:
Design of aspheric spectacle lenses using non-dominated sorting genetic algorithm
Autorzy:
Xiang, Huazhong
Ding, Qihui
Li, Nianning
Zhang, Xin
Wang, Peng
Li, Hongtao
Zheng, Zexi
Zhang, Dawei
Tematy:
aspheric ophthalmic lens
genetic algorithm
multi-objective optimisation
aberration
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Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/58970191.pdf  Link otwiera się w nowym oknie
Opis:
Significance: An effective algorithm for optimization of lens parameter can greatly eliminate the aberration and reduce the thickness, making the wearer more comfortable. Aim: We proposed a non-dominated sorting genetic algorithm (NSGA-II) for generating sets of base curves and aspheric coefficients to minimize the residual astigmatism and aberration of the lenses, while satisfying the constraints on the lens thickness and power. Approach: By simulating natural selection using the NSGA-II algorithm, the design parameters considered the inventory of the semi-finished blank. A comparison of aspheric and spherical spectacle lenses with –8 diopters was designed, simulated, processed, and measured. Results: The measured spherical and cylindrical power distributions were consistent with the simulated results with corrected oblique astigmatism and distortion. Conclusions: The aspheric spectacle lenses had the required aesthetic shape and weight reduction compared to a spherical lenses of the same power. It is verified that this paper puts forward an effective NSGA-II algorithm for the optimization of lens parameters.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aspherical, sphero-cylindrical, toroidal, and ellipsoidal surfaces for designing astigmatic spectacle lenses with axis orientation
Autorzy:
Xiang, Huazhong
Wang, Peng
Zheng, Zexi
Zheng, Gang
Chen, Jiabi
Wang, Cheng
Zhang, Dawei
Zhuang, Songlin
Tematy:
toric
astigmatism
spherocylinder
aspheric
ellipsoidal surface
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Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/27310110.pdf  Link otwiera się w nowym oknie
Opis:
In this paper, formulas for aspherical, sphero-cylindrical, toroidal, and ellipsoidal surfaces with astigmatic axes are derived. Based on this, four types of curved surfaces were designed to correct astigmatism with axis, and, subsequently, the lenses were simulated, fabricated, and measured. A total of ten spectacle lenses in two groups were designed. Those in the first group used identical optical parameters. The spherical and cylindrical powers and maximum and minimum edge thicknesses of aspherical, sphero-cylindrical, and ellipsoidal surfaces were compared. The results indicated that the power of the lens constructed using the toroidal surface was more accurate than those of the other three lenses. Moreover, the minimum edge thickness of the toroidal surface was 1.2%, 4.98%, and 4.87% lower than those of the aspherical, sphero-cylindrical, and ellipsoidal surfaces, respectively. The powers and edge thicknesses of toroidal surfaces with different diopters were compared in the second group. The minimum and maximum edge thicknesses were observed to be reduced by 8.97% and 6.05%, respectively, corresponding to the conic constants obtained via ray tracing. The conclusion will be significant for clinical ophthalmology and optical design for the patients with astigmatism.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of stress intensity factor for surface cracks in the firtree groove structure of a turbine disk using pool-based active learning with Gaussian Process Regression
Autorzy:
Guo, Kaimin
Liu, Hongzhuo
Yan, Han
Song, Ziyuan
Zhang, Shengming
Huang, Dawei
Yan, Xiaojun
Tematy:
damage tolerance
stress intensity factor solutions
machine learning
active learning
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Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:
https://bibliotekanauki.pl/articles/63161973.pdf  Link otwiera się w nowym oknie
Opis:
Calculation of the stress intensity factor K is a crucial and difficult task in linear elastic fracture mechanics. With the capacity to solve complex input-output problems of an underlying system, machine learning is especially useful in the calculation of K. However, when faced with complex systems, such as the firtree groove structure of a turbine disk, the data-consuming issue has always been a thorny problem in K-solutions combined with machine learning studies for a long time. In this paper, a novel K-solution method called PA-GPR (Pool-based Active learning with Gaussian Process Regression) for the calculation of the stress intensity factor for surface cracks in the firtree groove structure of a turbine disk is proposed. Using the pool-based active learning strategy, the proposed K-solution method could make the GPR model have a great regression performance with a few samples required. In the pool-based active learning strategy analysis, the learning function based on greedy sampling is proposed to select samples with a high contribution to the training of the GPR model. The calculation of K for a semi-elliptical surface crack in the firtree groove structure is evaluated to verify the accuracy and effectiveness of the proposed method. The results show that this novel method is accurate, time-saving and effective.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular cloning and expression analysis of a new gene for short-chain dehydrogenase/reductase 9
Autorzy:
Liu, Shen
Huang, Chaoqun
Li, Dawei
Ren, Weihua
Zhang, Haoxing
Qi, Meiyan
Li, Xin
Yu, Long
Tematy:
liver
clone
short-chain dehydrogenase/reductase
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Wydawca:
Polskie Towarzystwo Biochemiczne
Powiązania:
https://bibliotekanauki.pl/articles/1041143.pdf  Link otwiera się w nowym oknie
Opis:
We report here the cloning and characterization of a novel human short-chain dehydrogenases/reductase gene SCDR9, isolated from a human liver cDNA library, and mapped to 4q22.1 by browsing the UCSC genomic database. SCDR9 containing an ORF with a length of 900 bp, encoding a protein with a signal peptide sequence and an adh_short domain. GFP localization shows SCDR9 protein concentrated in some site of the cytoplasm, but not in the ER. Expression pattern in eighteen tissues revealed that SCDR9 is expressed highly in liver. Soluble recombinant protein was successfully purified from Escherichia coli using pET28A(+) expression vector. Our data provides important information for further study of the function of the SCDR9 gene and its products.
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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