网络空间安全学院学术讲座(四、五、六、七)

发布单位:成果专利综合科 [2021-03-19 11:02:54] 打印此信息

题目一:A novel L1 scheme for reaction-subdiffusion equations

内容简介:This talk is concerned with numerical solutions of reaction-subdiffusion equations. Due to the Caputo time derivative being involved, the solutions of equations are usually singular near the initial time $t=0$ even for a smooth setting. Based on a simple change of variable $s=t^\beta$, an equivalent $s$-fractional differential equation is derived and analyzed. Two type finite difference methods based on linear and quadratic approximations in the $s$-direction are presented, respectively. Our numerical results show clearly the accuracy and efficiency of the proposed methods.

报告人:华中科技大学李东方教授

报告人简介:华中科技大学数学与统计学院教授,博导,中国系统仿真学会仿真算法专业委员会委员。曾先后赴加拿大McGill大学,香港城市大学从事博士后研究。主要研究微分方程数值解、系统仿真和信号处理等领域,在微分方程保结构算法和分数阶微分方程的高效数值算法和理论上取得一些有意义的进展。主要工作发表在《SIAM. J. Numer. Anal.》,《SIAM. J. Sci. Comput.》、《J. Comp. Phys.》、《Appl. Comp. Harm. Appl.》、《J. Sci. Comput》等多个国际著名计算学科SCI期刊上,多篇为高被引论文。

 

题目二:后摩尔时代高性能并行应用挑战

内容简介:信息科技发展依赖于芯片制程的发展,随着摩尔定律的终结,整个信息产业及人类科技都将面临巨大挑战。介绍了美国NSCI计划、常用的核心算法和高性能并行应用处理挑战的方向。

报告人:国防科技大学龚春叶副研究员

报告人简介:国防科大计算机学院副研究员,计算机所应用室主任,主任设计师,天河团队高性能并行应用方向带头人。应用数学学士、计算机科学与技术博士、航空宇航科学与技术博士后。带领团队完成天河二号、天河三号原型机等重大工程项目并行应用研发工作,在面向核数值模拟、航空航天CFD计算、密码破解待国家重大领域的并行算法、国产网格生成软件等领域有深入研究。负责科技部重点研发计划、国家数值风洞、自然科学基金等项目多项,团队经费超4000万。发表论文20余篇,专利10余项。

 

题目三:Some techniques for accelerating parallel direct method for symmetric eigenvalue problems

内容简介:In this talk, we will introduce some techniques for accelerating parallel direct methods for symmetric eigenvalue problems, which can be divided into two different approaches. One is based on the techniques of rank-structure matrices, and it can make the tridiagonal DC algorithm in Scalapack 40-60% times faster. Another is a hybrid algorithm and combines the techniques of direct methods with iterative methods, and finally can be used to compute partial or full eigendecomposition of symmetric dense matrices. This hybrid algorithm is named PDESHEP, and the iterative method in PDESHEP is based on the contour integral method implemented in FEAST.  Numerical results show that PDESHEP can be 25% times faster than the state-of-the-art direct solver in ELPA when using 4096 processes on Tianhe-2 supercomputer.

报告人:国防科技大学李胜国助理研究员

报告人简介:计算数学博士,国防科技大学计算机学院助理研究员,2006-2013年获得国防科技大学的应用数学学士、计算数学硕士和博士学位,2010年在美国加州大学伯克利分校联合培养两年,2020年访问西班牙UPV大学10个月。2013年参加工作以来,主要从事并行算法设计、特征值计算、共性算法库研制、Benchmark程序测试与优化工作,参与天河2A、银河-X研制与系统调试工作,曾主持国家青年和湖南省面上自然科学基金1项,发表SCI论文20多篇,两篇进入ESI检索前10%,部分论文发表在SIAM J. Sci. Comput., SIAM J. Matrix Anal. Appl., Numer. Math., Numer. Linear Algebra Appl. Parallel Computing, IEEE TPDS等国际期刊。

 

题目四:Dynamics of the generalized Kuramoto model with nonlinear coupling: Bifurcation and stability

内容简介:We systematically study dynamics of a generalized Kuramoto model of globally coupled phase oscillators. The coupling of modified model depends on the fraction of phase-locked oscillators via a power-law function of the Kuramoto order parameter r through an exponent α, such that α = 1 corresponds to the standard Kuramoto model, α < 1 strengthens the global coupling, and the global coupling is weakened if α > 1. With a self-consistency approach, we demonstrate that bifurcation diagrams of synchronization for different values of α are thoroughly constructed from two parametric equations. In contrast to the case of α = 1 with a typical second-order phase transition to synchronization, no phase transition to synchronization is predicted for α < 1, as the onset of partial locking takes place once the coupling strength K > 0. For α > 1, we establish an abrupt desynchronization transition from the partially (fully) locked state to the incoherent state, whereas there is no counterpart of abrupt synchronization transition from incoherence to coherence due to that the incoherent state remains linearly neutrally stable for all K > 0. For each case of α, by performing a standard linear stability analysis for the reduced system with Ott-Antonsen ansatz, we analytically derive the continuous and discrete spectra of both the incoherent state and the partially (fully) locked states. All our theoretical results are obtained in the thermodynamic limit, which have been well validated by extensive numerical simulations of the phase-model with a sufficiently large number of oscillators.

报告人:华南师范大学邹为副教授

报告人简介:华南师范大学数学科学学院副教授,广东省青年珠江学者,2010年获得中科院武汉物理与数学研究所应用数学博士学位,博士论文获2011年度中国科学院百篇优秀博士论文奖,2011年至2013年获得德国洪堡奖学金资助在德国柏林洪堡大学从事博士后研究工作,2016年至2018年在香港浸会大学从事香江学者博士后研究工作,长期从事复杂系统、非线性科学理论研究,在耦合非线性系统的群体动力学行为研究问题上取得系统成果。目前已在非线性动力学主流期刊发表SCI论文40余篇, H指数16SCI总引用1000余次。 以第一作者发表了20多篇SCI学术论文,包括1Nature Communications1Physical Review Letters等。目前主持1项国家自然科学基金面上项目,主持并完成国家自然科学基金2项。

 

时间:2021320日(周六)下午1430?1800

地点:腾讯会议 ID509 142 563会议密码:200320

 

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网络空间安全学院

2021319