搜索结果: 1-10 共查到“frequency”相关记录10条 . 查询时间(0.203 秒)
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Numerical method for low-frequency electromagnetic fields and its applications
低频 电磁场数值 低频涡流场 有限元编程
2023/4/13
本报告首先回顾传统低频涡流场的两种计算格式，指出有限元编程实现过程中的基函数选择以及需要注意的难点问题。第二部分针对静磁场问题，通过引入规范条件提出了一种基于矢量磁位和磁场强度的新型的对偶格式，该方法通过巧妙构造基于矢量磁位和磁场强度的计算格式，整体矩阵完全一致并且可以给出系统电感参数的上下界，在实际参数提取中有很好的应用前景。在第三部分，由于传统低频涡流场近似不能有效考虑分布电容效应，而传统高频...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Estimation of Common Factors for Microstructure Noise and Effcient Price in a High-frequency Dual Factor Model
高频双因子模型 微结构 噪声公因数 效率价格 估计
2023/4/17
We develop the Double Principal Component Analysis (DPCA) based on a dual factor structure for high-frequency intraday returns contaminated by microstructure noise. The dual factor structure allows a ...
Academy of Mathematics and Systems Science, CAS Colloquia & Seminars：Estimating Factor-Based Spot Volatility Matrices with Noisy and Asynchronous High-Frequency Data
噪声 异步高频 数据估算 因子 现货波动率 矩阵
2023/5/4
With noisy and asynchronous high-frequency data collected for an ultra-large number of assets, we estimate high-dimensional spot volatility matrices satisfying a low-rank plus sparse structure. A loca...
Quantum sensors, which detect the most minute variations in magnetic or electrical fields, have enabled precision measurements in materials science and fundamental physics. But these sensors have only...
In the quest for fusion energy, understanding how radio-frequency (RF) waves travel (or “propagate”) in the turbulent interior of a fusion furnace is crucial to maintaining an efficient, continuously ...
May 10, 2007，A super stable fiber-optic network that can be tuned across a range of visible and near-infrared frequencies while synchronizing the oscillations of light waves from different sources has...
Hotter-than-expected neutron star surfaces help explain superburst frequency
neutron stars Astrophysical nuclear physics
2007/4/16
April 13, 2007，EAST LANSING, Mich. — A new theoretical thermometer built from heavy-duty mathematics and computer code suggests that the surfaces of certain neutron stars run significantly hotter than...
February 15, 2007，Physicists at the National Institute of Standards and Technology (NIST) have taken the first ever two-dimensional pictures of a “frequency comb,” providing extra information that enh...
High-Frequency Cryocooler Is Tiny, Cold and Efficient
cryogenic refrigerator microelectromechanical systems
2007/2/28
February 15, 2007，A new cryogenic refrigerator has been demonstrated at the National Institute of Standards and Technology (NIST) that operates at twice the usual frequency, achieving a long-sought co...
Feb. 7, 2007，BOULDER, Colo.—Physicists at the Commerce Department’s National Institute of Standards and Technology (NIST) have taken the first ever two-dimensional pictures of a “frequency comb,” prov...