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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 한국광학회 2015 Current Optics and Photonics Vol.19 No.2
Image deblurring by a deconvolution method requires accurate knowledge of the blur kernel. Existingpoint spread function (PSF) models in the literature corresponding to lens aberrations and defocus are eitherparameterized and spatially invariant or spatially varying but discretely defined. In this paper, aparameterized model is developed and presented for a PSF which is spatially varying due to lens aberrationsand defocus in an imaging system. The model is established from the Seidel third-order aberrationcoefficient and the Hu moment. A skew normal Gauss model is selected for parameterized PSF geometrystructure. The accuracy of the model is demonstrated with simulations and measurements for a defocusedinfrared camera and a single spherical lens digital camera. Compared with optical software Code V, thevisual 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
Liao Yi,Cai Qi,He Shaopeng,Wang Mingjun,Xiao Hongguang,Gong Zili,Wang Cong,Jia Zhen,Feng Tangtao,Qiu Suizheng 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4
Shell-and-tube heat exchanger (STHX) is widely used by virtue of its simple structure and high reliability, especially in a space-constrained surface ship. For the STHX of the surface ship, roll, pitch and other motion of the ship will affect the heat transfer performance, resistance characteristics and structural strength of the heat exchanger. Therefore, it is urgent to carry out numerical simulation research on three-dimensional thermal hydraulic characteristics of surface ship STHX under the marine conditions. In this paper, the numerical simulation of marine shell and tube heat exchanger of surface ship was carried out using the porous media model. Firstly, the mathematical physical model and numerical method are validated based on the experimental data of a marine engine cooling water shell and tube heat exchanger. The simulation results are in good agreement with the experimental results. The prediction errors of pressure drop and heat transfer are less than 10% and 1% respectively. The effect of marine conditions on the heat transfer characteristics of the heat exchanger is investigated by introducing the additional force model of marine condition to evaluate the effect of different motion parameters on the heat transfer performance of the heat exchanger. This study could provide a reference for the optimization of marine heat exchanger design.
Magnetic-field-tuned Insulator to Conductor Transition in Magnetorheological Suspension
Xiongbo Yang,Yuhuan Jiang,Yuehua Huang,Ruizhen Xu,Hongguang Piao,Gaomeng Jia,Xinyu Tan 한국자기학회 2014 Journal of Magnetics Vol.19 No.4
Magnetorheological suspensions (MRSs) are smart materials that have the potential to revolutionize several industrial sectors because of their special rheological behaviors. In this paper, MRS, based on carbonyl iron (CI) microparticles that were dispersed in silicone oil with oleic acid, were prepared. We showed that the electroconductibility of MRS was significantly influenced by the intensity of the external magnetic field that was applied. The resistance value can vary from infinite to below 300 Ω after applying an external magnetic field. The results indicated that this MRS had the property of magnetic-field-tuned insulator to conductor transition. This system has potential applications in controllable MRS electrical devices.