搜索结果: 1-15 共查到“数学 Gradient”相关记录73条 . 查询时间(0.026 秒)
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Liouville Properties on gradient shrinking Ricci solitons with constant scalar curvature
常标量 曲率梯度收缩 Ricci孤子 Liouville性质
2023/11/13
In this talk we show that bounded harmonic functions are constant on gradient shrinking Ricci solitons with CSC by frequency function method. As an application, we show that the space of harmonic func...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Some recent progress on the gradient estimates for the insulated conductivity problem
绝缘 电导率 梯度估计 椭圆偏微分方程
2023/4/17
In this talk, I will describe an elliptic PDE that models electric conduction, and the electric field concentration phenomenon between closely spaced inclusions of high contrast. In the first part, I ...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：O(2)-symmetry of 3D steady gradient solitons
O(2) 三维稳态 梯度孤子 对称性
2023/4/13
In this talk, we talk about the proof of the O(2)-symmetry of 3D steady gradient solitons. The proof consists of four parts: the asymptotic analysis at infinity, the symmetry improvement theorem, the ...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Construction of steady gradient solitons by interpolation
插值 稳态梯度孤子 坍塌式
2023/4/13
In this talk, we give an overall description of the construction of the collapsed flying-wing-like steady gradient solitons, as well as the high dimension non-collapsed steady gradient solitons. In pa...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Primal Dual Alternating Proximal Gradient Algorithms for Nonsmooth Nonconvex Minimax Problems with Coupled Linear Constraints
耦合 线性约束 非光滑 非凸极小问题 基本对偶交替 近端梯度算法
2023/4/14
Nonconvex minimax problems have attracted wide attention in machine learning, signal processing and many other fields in recent years. In this paper, we propose a primal dual alternating proximal grad...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Steady gradient Ricci solitons with positive curvature
正曲率 稳态梯度 利玛窦孤子
2023/4/17
We will construct some new examples of steady gradient Ricci solitons with positive curvature operator. Moreover, for any 3D steady gradient Ricci soliton with positive curvature, if it is asymptotic ...
中国地质大学科学技术发展院左博新，胡祥云*等，计算机学院，Geophysical Research Letters （2020），Downward Continuation and Transformation of Total‐Field Magnetic Anomalies Into Magnetic Gradient Tensors Between Arbitrary Surfaces Using Multilayer Equivalent Sources
资源勘探；等效源方法；磁测；数据；下延拓；磁梯度；张量；转换计算
2021/10/15
近日，地球物理著名期刊《Geophysical Research Letters》正式刊发了中国地质大学胡祥云教授团队研究成果 -“Downward continuation and transformation of total-field magnetic anomalies into magnetic gradient tensors between arbitrary surfaces u...
Boundary Harnack principle and gradient estimates for fractional Laplacian perturbed by non-local operators
Harmonic function boundary Harnack principle gradient estimate
2016/1/20
Boundary Harnack principle and gradient estimates for fractional Laplacian perturbed by non-local operators.
Discrete Gradient Flows for Shape Optimization and Applications
Shape optimization scalar product gradient flow
2015/12/11
We present a variational framework for shape optimization problems
that establishes clear and explicit connections among the continuous formulation, its full discretization and the resulting linear a...
ON LOCALLY CONFORMALLY FLAT GRADIENT SHRINKING RICCI SOLITONS
SHRINKING RICCI SOLITONS CONFORMALLY FLAT
2015/8/17
In this paper, we first apply an integral identity on Ricci solitons to prove that
closed locally conformally flat gradient Ricci solitons are of constant sectional curvature.
We then ge...
The paper considers a manifold M evolving under the Ricci
ow and establishes a series of gradient
estimates for positive solutions of the heat equation on M. Among other results, we prove Li-Yau-ty...
Compact Gradient Shrinking Ricci Solitons with Positive Curvature Operator
Positive Curvature Operator Shrinking Ricci Solitons
2015/8/17
In this paper, we first derive several identities on a compact shrinking Ricci
soliton. We then show that a compact gradient shrinking soliton must be
Einstein, if it admits a Riemannian metri...
Monotonicity and restart in fast gradient methods
flat gradient algorithm oscillation values
2015/8/7
Fast gradient methods are known to be non-monotone algorithms, and oscillations typically occur around the solution. To avoid this behavior, we propose in this paper a fast gradient method with restar...
First order optimization methods often perform poorly on ill-conditioned optimization problems. However, by preconditioning the problem data and solving the preconditioned problem, the performance of ...
A Differential Equation for Modeling Nesterov’s Accelerated Gradient Method:Theory and Insights
Differential Equation Modeling Nesterov’s Accelerated Gradient Method
2015/7/8
We derive a second-order ordinary differential equation (ODE), which is the limit of Nesterov’s accelerated gradient method. This ODE exhibits approximate equivalence to Nesterov’s scheme and thus can...