| Project/Area Number |
09650063
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied physics, general
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| Research Institution | Nagoya University |
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Principal Investigator |
HANAI Takaaki Graduate School of Engineering, Nagoya University Assistant Professor, 工学研究科, 講師 (00156366)
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| Co-Investigator(Kenkyū-buntansha) |
MUROOKA Yoshie Graduate School of Engineering, Research Associate, 工学研究科, 助手 (40273263)
TANAKA Shigeyasu Graduate School of Engineering, Research Associate, 工学研究科, 助手 (70217032)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Maximum Entropy Method / Image Restoration / Electron Microscopy / Random Noise Constraint / Quantum Noise / Structure Analysis / Contrast Transfer Function / Complex Wave Function / ランダム空間分布制約条件 |
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| Research Abstract |
1.Implementation of Maximum Entropy (ME) Restoration Programs : Computer programs for the ME image restoration constrained by the spatially random distribution of quantum noise were developed and implemented on PCs. The programs allows visualization of changes in the image during the process of restorations and the difference between the modified ME restoration and conventional kai-squared constrained method. It also enables us to study the effect of the ME restoration in the Fourier space.
2.Restoration of TEM Images of Weak-phase Objects : The modified ME method was applied to deconvolution of largely defocused TEM images of ferritin particles. The cores of ferritin particles, which were blurred with reversed contrast due to the severely oscillating contrast transfer function (CTF) in the defocused image, are recovered to the original size with the correct contrast. The Fourier analysis showed that the frequency regions of reversed contrast in the defocused image is automatically reconstructed by the phase shift of pi as a result of the ME restoration even around zeros in the CTF.
3.Implementation of the Imaging of Crystals : For application of the ME restoration to crystal specimens, simulation of TEM imaging is required to calculate the image intensity from a simulated complex wave function just below the specimen and to compare the image intensity with the observed image. An image simulation program was, therefore, implemented with a C++ language and incorporated into ME restoration programs. The results of the simulation were in good agreement with those calculated with a standard program.
4.Development of ME Restoration of High-resolution Crystal Images : Existing ME methods cannot be applied to crystal images since they are designed. to treat only real number while the electron wave function is complex. To solve this problem, the algorism was extended to deal with complex function.
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