Fast Fourier Transfer Image Processing was widely applied to the analysis of wood anatomy structure in re-cent years. The cells in the wood transverse section have obviously periodicity and regularity. FFT power spect...Fast Fourier Transfer Image Processing was widely applied to the analysis of wood anatomy structure in re-cent years. The cells in the wood transverse section have obviously periodicity and regularity. FFT power spectral patternscan extract the periodic characteristics so that they can be compared. identified and classified quaytitatively. This paperSummarizes the application of FFT image analysis in wood science and the general way to study wood anatomy by FFT.展开更多
An optical transfer function （OTF） reconstruction model is first embedded into incoherent Fourier ptychography （IFP）. The leading result is a proposed algorithm that can recover both the super-resolution image and...An optical transfer function （OTF） reconstruction model is first embedded into incoherent Fourier ptychography （IFP）. The leading result is a proposed algorithm that can recover both the super-resolution image and the OTF of an imaging system with unknown aberrations simultaneously. This model overcomes the difficult problem of OTF estimation that the previous IFP faces. The effectiveness of this algorithm is demonstrated by numerical simulations, and the superior reconstruction is presented. We believe that the reported algorithm can extend the original IFP for more complex conditions and may provide a solution by using structured light for characterization of optical systems＇ aberrations.展开更多
A new interpolation algorithm for Head-Related Transfer Function (HRTF) is proposed to realize 3D sound reproduction via headphones in arbitrary spatial direction. HRTFs are modeled as a weighted sum of spherical harm...A new interpolation algorithm for Head-Related Transfer Function (HRTF) is proposed to realize 3D sound reproduction via headphones in arbitrary spatial direction. HRTFs are modeled as a weighted sum of spherical harmonics on a spherical surface. Truncated Singular Value Decomposition (SVD) is adopted to calculate the weights of the model. The truncation number is chosen according to Frobenius norm ratio and the partial condition number. Compared with other interpolated methods, our proposed approach not only is continuous but exploits global information of available directions. The HRTF from any desired direction can be obtained more accurately and robustly. Reconstructed and interpolated results demonstrate that our proposed algorithm acquired better performance.展开更多
This paper describes the method of two important mathematical techniques used in chemical engineering applications. Solving a mass transfer problem, weather in finite or semi-infinite domain, may seem difficult withou...This paper describes the method of two important mathematical techniques used in chemical engineering applications. Solving a mass transfer problem, weather in finite or semi-infinite domain, may seem difficult without the practice of Finite Fourier Transform (FFT) and Similarity Transformation. Finite systems refer to any closed system that has a specific boundary that can be determined. For example, polymer sheets, membranes, storage tanks, oil reservoirs and a human stomach are determined to be finite systems where FFT is applicable to derive expressions for concentration profiles of the materials in the system. However, Similarity Transformation method is used to identify the concentration profile in semi-infinite systems that have no limits. It has been approved that we may also use the similarity procedure for finite systems since our results are almost the same. Methodologies of both techniques have been discussed thoroughly in order to apply them to a water-polymer diffusion system for the determination of the concentration of water in a polymer sheet of PET. Discussion and comparison between FFT and similarity is included to illustrate the power of each mathematical procedure in predicting and modeling mass concentrations.展开更多
研究了牛肉蛋白质二级结构稳定性在-18,-23及-38℃不同温度下的变化情况,明确了肉品工业中不同冷冻温度对肉品品质的作用机制。利用了傅里叶变换衰减全反射红外光谱（attenuated total reflectance Fourier transfer infrared spectrosc...研究了牛肉蛋白质二级结构稳定性在-18,-23及-38℃不同温度下的变化情况,明确了肉品工业中不同冷冻温度对肉品品质的作用机制。利用了傅里叶变换衰减全反射红外光谱（attenuated total reflectance Fourier transfer infrared spectroscopy,ATR-FTIR）技术、自动去卷积以及曲线拟合等计算方法,分析了-18,-23及-38℃三个温度下,牛肉肌原纤维蛋白（myofibrillar protein,MP）在冻结—解冻过程中的红外光谱图变化及蛋白质二级结构变性程度。ATR-FTIR结果显示,冻结—解冻过程中牛肉MP红外光谱图峰高、峰面积发生变化,且峰波数发生红移或者蓝移;冻结—解冻后牛肉MP红外光谱图中3 500~3 300cm-1波段的吸收峰强度减弱甚至消失,说明解冻后牛肉MP中的结合水中O—H基团与氨基酸CO基团形成的分子内和分子间氢键断裂;冻结会影响牛肉MP二级结构的稳定性,导致牛肉蛋白质二级结构发生变化,其中除了无规则卷曲比例上升以外,α-螺旋、β-折叠、β-转角含量均下降,造成有序结构向无序结构转变;解冻后,冻结温度为-38℃的处理组牛肉β-折叠增加量大于-23和-18℃处理组,-38℃冻结牛肉MP二级结构的稳定性最好,解冻后蛋白质复性也最好。即蛋白质冷冻变性程度随着冻结温度的降低而减轻,蛋白质二级结构特征保持也越好。该试验研究基于肉品工业生产实际,研究结果从微观层面揭示了冻结温度对牛肉蛋白质变性的影响规律及可能的机制,为冷冻肉冻藏保鲜工艺制定提供了参考。展开更多
文摘Fast Fourier Transfer Image Processing was widely applied to the analysis of wood anatomy structure in re-cent years. The cells in the wood transverse section have obviously periodicity and regularity. FFT power spectral patternscan extract the periodic characteristics so that they can be compared. identified and classified quaytitatively. This paperSummarizes the application of FFT image analysis in wood science and the general way to study wood anatomy by FFT.
基金Supported by the National Natural Science Foundation of China under Grant No 61205144the Research Project of National University of Defense Technology under Grant No JC13-07-01the Key Laboratory of High Power Laser and Physics of Chinese Academy of Sciences
文摘An optical transfer function （OTF） reconstruction model is first embedded into incoherent Fourier ptychography （IFP）. The leading result is a proposed algorithm that can recover both the super-resolution image and the OTF of an imaging system with unknown aberrations simultaneously. This model overcomes the difficult problem of OTF estimation that the previous IFP faces. The effectiveness of this algorithm is demonstrated by numerical simulations, and the superior reconstruction is presented. We believe that the reported algorithm can extend the original IFP for more complex conditions and may provide a solution by using structured light for characterization of optical systems＇ aberrations.
基金Supported by Shanghai Natural Science Foundation, Shanghai Leading Academic Discipline Project, and STCSM of China (No. 08ZR1408300, S30108, and 08DZ2231100)
文摘A new interpolation algorithm for Head-Related Transfer Function (HRTF) is proposed to realize 3D sound reproduction via headphones in arbitrary spatial direction. HRTFs are modeled as a weighted sum of spherical harmonics on a spherical surface. Truncated Singular Value Decomposition (SVD) is adopted to calculate the weights of the model. The truncation number is chosen according to Frobenius norm ratio and the partial condition number. Compared with other interpolated methods, our proposed approach not only is continuous but exploits global information of available directions. The HRTF from any desired direction can be obtained more accurately and robustly. Reconstructed and interpolated results demonstrate that our proposed algorithm acquired better performance.
文摘This paper describes the method of two important mathematical techniques used in chemical engineering applications. Solving a mass transfer problem, weather in finite or semi-infinite domain, may seem difficult without the practice of Finite Fourier Transform (FFT) and Similarity Transformation. Finite systems refer to any closed system that has a specific boundary that can be determined. For example, polymer sheets, membranes, storage tanks, oil reservoirs and a human stomach are determined to be finite systems where FFT is applicable to derive expressions for concentration profiles of the materials in the system. However, Similarity Transformation method is used to identify the concentration profile in semi-infinite systems that have no limits. It has been approved that we may also use the similarity procedure for finite systems since our results are almost the same. Methodologies of both techniques have been discussed thoroughly in order to apply them to a water-polymer diffusion system for the determination of the concentration of water in a polymer sheet of PET. Discussion and comparison between FFT and similarity is included to illustrate the power of each mathematical procedure in predicting and modeling mass concentrations.
文摘研究了牛肉蛋白质二级结构稳定性在-18,-23及-38℃不同温度下的变化情况,明确了肉品工业中不同冷冻温度对肉品品质的作用机制。利用了傅里叶变换衰减全反射红外光谱（attenuated total reflectance Fourier transfer infrared spectroscopy,ATR-FTIR）技术、自动去卷积以及曲线拟合等计算方法,分析了-18,-23及-38℃三个温度下,牛肉肌原纤维蛋白（myofibrillar protein,MP）在冻结—解冻过程中的红外光谱图变化及蛋白质二级结构变性程度。ATR-FTIR结果显示,冻结—解冻过程中牛肉MP红外光谱图峰高、峰面积发生变化,且峰波数发生红移或者蓝移;冻结—解冻后牛肉MP红外光谱图中3 500~3 300cm-1波段的吸收峰强度减弱甚至消失,说明解冻后牛肉MP中的结合水中O—H基团与氨基酸CO基团形成的分子内和分子间氢键断裂;冻结会影响牛肉MP二级结构的稳定性,导致牛肉蛋白质二级结构发生变化,其中除了无规则卷曲比例上升以外,α-螺旋、β-折叠、β-转角含量均下降,造成有序结构向无序结构转变;解冻后,冻结温度为-38℃的处理组牛肉β-折叠增加量大于-23和-18℃处理组,-38℃冻结牛肉MP二级结构的稳定性最好,解冻后蛋白质复性也最好。即蛋白质冷冻变性程度随着冻结温度的降低而减轻,蛋白质二级结构特征保持也越好。该试验研究基于肉品工业生产实际,研究结果从微观层面揭示了冻结温度对牛肉蛋白质变性的影响规律及可能的机制,为冷冻肉冻藏保鲜工艺制定提供了参考。
