應(yīng)yl7703永利官網(wǎng)黃玉梅教授的邀請，湖南師范大學(xué)文有為教授將于近期訪問蘭州大學(xué)并作學(xué)術(shù)報告。

報告題目：Orientation estimation of cryo-EM images using projected gradient descent method

時 間：2023年11月4日 下午16:00-18：00

地 點(diǎn)：城關(guān)校區(qū)理工樓631

報告摘要：

Orientation estimation is an important task in three-dimensional cryo-EM image reconstruction. By applying the common line method, the orientation estimation task can be formulated as a least squares (LS) problem or a least unsquared deviation (LUD) problem with orthogonality constraint. However, the non-convexity of the orthogonality constraint introduces numerical difficulties to the orientation estimation. The conventional approach is to reformulate the orthogonality constrained minimization problem into a semi-definite program- ming problem using convex relaxation strategies. In this paper, we consider a direct way to solve the constrained minimization problem without relaxation. Experimental results show that the proposed method significantly outperforms the semi-definite relaxation methods from a computation standpoint, and the mean square error is almost the same or smaller.

報告人簡介

文有為，湖南師范大學(xué)yl7703永利官網(wǎng)教授，博導(dǎo)，湖南省計算數(shù)學(xué)與應(yīng)用軟件學(xué)會副理事長、湖南省運(yùn)籌學(xué)會副理事長。獲香港大學(xué)博士學(xué)位，曾在新加坡國立大學(xué)、香港中文大學(xué)從事訪問研究員、博士后等工作。主要研究方向?yàn)榭茖W(xué)計算、數(shù)字圖像處理與計算機(jī)視覺，在SIAM J. Sci. Comput., SIAM J. Imaging Sciences, Multiscale Model. Simul.，SIAM J. Matrix Anal., IEEE Trans. Image Process.等期刊發(fā)表論文30余篇，主持國家自然科學(xué)基金4項。獲2019年度湖南省自然科學(xué)獎二等獎(第一完成人)。

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2023年11月3日