搜索结果: 1-15 共查到“approximation”相关记录448条 . 查询时间(0.093 秒)
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Random phase approximation for the mean-field electron gas （3）
平均场 电子气 随机相位近似
2023/11/29
Random phase approximation (RPA) was proposed by Bohm and Pines in four seminal papers during 1951-1953 to describe the correlation of fermions, namely the correction to the Hartree-Fock theory. While...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：A 1.344-approximation algorithm for the vertex cover problem
顶点覆盖问题 1.344 近似算法
2023/12/11
We present an algorithm for the vertex cover problem by combining the LP relaxation and the random edge-reductions. The algorithm has the expected approximation ratio of 1.344.
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Approximation and computation for the linear and nonlinear eigenvalue problems in photonic crystals
光子晶体 线性非线性特征值问题 近似 计算
2023/5/15
In this talk, we discuss the approximation and computation for the linear and nonlinear eigenvalue problems in photonic crystals. We discretize the shifted Maxwell operator with edge finite elements a...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：On forward/inverse spectral problems, approximation problems and multiple integral formulae for non-smooth solitons
非光滑孤子 正/逆谱问题 近似问题 多重积分公式
2023/4/28
A class of nonlinear integrable PDEs admit non-smooth solitary wave solutions as certain special weak solutions. These solutions can be used to capture main attributes of solutions of these PDEs, e.g....
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Barron Type Spaces in Neural Network Approximation
神经网络 巴伦类型空间 经典函数空间
2023/4/13
We shall discuss various Barron type spaces arising from neural networks. The relations among these spaces will be clarified, and we shall also establish the relationship between Barron type spaces an...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Pandora Box Problem with Nonobligatory Inspection: Hardness and Approximation Scheme
潘多拉盒问题 非强制性检查 硬度 近似方案
2023/4/14
Weitzman (1979) introduced the Pandora Box problem as a model for sequential search with inspection costs, and gave an elegant index-based policy that attains provably optimal expected payoff. In vari...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Stochastic approximation methods for nonconvex constrained optimization
非凸 约束优化 随机逼近方法
2023/4/14
Nonconvex constrained optimization (NCO) has been one of the important research fields in optimization community. It has widely appeared in many application fields. However, challenges for solving NCO...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Deep neural network approximation to inverse conductivity problems for elliptic equations
椭圆方程 反电导率 深度神经网络
2023/4/14
The focus of this talk is on the numerical methods used to identify parameters in partial differential equations. Typically, an optimization approach is used to solve this class of inverse problems, w...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Arithmetic purity of strong approximation for complete toric varieties
完整 复曲面品种 强近似 算术纯度
2023/4/18
In this talk, I will discuss arithmetic purity of strong approximation : motivations and related results. Finally, for complete toric varieties, I will briefly explain my work on this topic.
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Graph Refinement via Simultaneously Low-rank and Sparse Approximation
低秩 稀疏近似 图细化
2023/4/18
Graphs play an important role in many fields of machine learning such as clustering. Many graph-based machine learning approaches assume that the graphs have hidden group structures. However, the grou...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Approximation Distillation of Quantum Coherence
量子相干性 近似蒸馏 相干资源理论
2023/4/18
Coherence distillation is a basic information-theoretic task in the resource theory of coherence. In this talk, I will report the framework of the approximate coherence distillation under strictly inc...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Improved Approximation Ratios of Fixed-Price Mechanisms in Bilateral Trades
双边贸易 固定价格机制 近似比率
2023/4/18
We study the performance of fixed-price mechanisms in the bilateral trade problem. We improve the approximation ratios of welfare-optimal mechanisms in several settings. In particular, when we have on...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：A Landscape View of Eigenvalues Approximation
特征值近似 景观视图 无序系统
2023/4/24
Waves of all sorts, including electromagnetic waves, acoustic waves, and mechanical vibrations, play a role in shaping our world. In disordered systems, the transport of waves is hindered, resulting i...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：ENERGY, POINTWISE, AND FREE BOUNDARY APPROXIMATION OF THE OBSTACLE PROBLEM FOR NONLOCAL OPERATORS
非局部 算子障碍物 自由边界 近似
2023/4/28
We consider the obstacle problem for a nonlocal elliptic operator, like the integral fractional Laplacian of order $s \in (0,1)$. We derive regularity results in weighted Sobolev spaces, where the wei...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：ANALYSIS AND APPROXIMATION OF FLUIDS UNDER SINGULAR FORCING
奇异强迫体 分析 近似 牛顿流体
2023/5/5
Motivated by applications, like modeling of thin structures immersed in a fluid, we develop a well posedness theory for Newtonian and some non-Newtonian fluids under singular forcing in Lipschitz doma...