• Title/Summary/Keyword: Mechanics

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Parameterized Modeling of Spatially Varying PSF for Lens Aberration and Defocus

  • Wang, Chao;Chen, Juan;Jia, Hongguang;Shi, Baosong;Zhu, Ruifei;Wei, Qun;Yu, Linyao;Ge, Mingda
    • Journal of the Optical Society of Korea
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    • v.19 no.2
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    • pp.136-143
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    • 2015

  • Image deblurring by a deconvolution method requires accurate knowledge of the blur kernel. Existing point spread function (PSF) models in the literature corresponding to lens aberrations and defocus are either parameterized and spatially invariant or spatially varying but discretely defined. In this paper, a parameterized model is developed and presented for a PSF which is spatially varying due to lens aberrations and defocus in an imaging system. The model is established from the Seidel third-order aberration coefficient and the Hu moment. A skew normal Gauss model is selected for parameterized PSF geometry structure. The accuracy of the model is demonstrated with simulations and measurements for a defocused infrared camera and a single spherical lens digital camera. Compared with optical software Code V, the visual results of two optical systems validate our analysis and proposed method in size, shape and direction. Quantitative evaluation results reveal the excellent accuracy of the blur kernel model.

  • https://doi.org/10.3807/JOSK.2015.19.2.136 인용 PDF KSCI KPUBS HTML

New generation software of structural analysis and design optimization--JIFEX

  • Gu, Yuanxian;Zhang, Hongwu;Guan, Zhenqun;Kang, Zhan;Li, Yunpeng;Zhong, Wanxie
    • Structural Engineering and Mechanics
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    • v.7 no.6
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    • pp.589-599
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    • 1999

  • This paper presents the development and applications of the software package JIFEX, a new finite element system which can be used for structural analysis and optimum design by the modern computer hardware and software technologies such as MS Windows95/NT and Pentium PC platforms. The complete system of JIFEX is programmed with $C/C^{++}$ language to make full use of advanced facilities of MS Windows95/NT. In the system, the finite element data pre-processing, based on the most popular CAD package AutoCAD (R13, R14), has been implemented, so that the finite element modeling could be integrated with geometric modeling of CAD. The system not only has interactive graphics facility for data post-processing, but also realizes the real-time computing visualization by means of the Dynamic Data Exchange (DDE) technique. Running on the Pentium computers, JIFEX can solve large-scale finite element analysis problems such as the ones with more than 60000 nodes in the finite element model.

  • https://doi.org/10.12989/sem.1999.7.6.589 인용