中国科学院机构知识库网格系统: 检索

Optimal rotated block-diagonal preconditioning for discretized optimal control problems constrained with fractional time-dependent diffusive equations 期刊论文 OAI收割
APPLIED NUMERICAL MATHEMATICS, 2021, 卷号: 163, 页码: 126-146
作者: Bai, Zhong-Zhi; Lu, Kang-Ya

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收藏 | 浏览/下载：32/0 | 提交时间：2021/04/26

Fractional optimal control problem Numerical discretizations Block two-by-two linear system Preconditioning Spectral bounds Krylov subspace iteration methods Convergence property

On spectral clustering of HSS preconditioner for generalized saddle-point matrices 期刊论文 OAI收割
LINEAR ALGEBRA AND ITS APPLICATIONS, 2018, 卷号: 555, 页码: 285-300
作者: Bai, Zhong-Zhi

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收藏 | 浏览/下载：37/0 | 提交时间：2018/10/07

Generalized saddle-point problem Hermitian and skew-Hermitian splitting Preconditioning Spectral property

On the eigenvalues of the saddle point matrices discretized from Navier-Stokes equations 期刊论文 OAI收割
NUMERICAL ALGORITHMS, 2018, 卷号: 79, 期号: 1, 页码: 41-64
作者: Huang, Na; Ma, Chang-Feng

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收藏 | 浏览/下载：29/0 | 提交时间：2018/10/07

Navier-Stokes equations Saddle point problem Spectral estimates Preconditioner Nonsymmetric

Analysis on block diagonal and triangular preconditioners for a PML system of an electromagnetic scattering problem 期刊论文 OAI收割
COMPUTERS & MATHEMATICS WITH APPLICATIONS, 2017, 卷号: 74, 期号: 11, 页码: 2856-2873
作者: Huang, Na; Ma, Chang-Feng; Zou, Jun

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收藏 | 浏览/下载：33/0 | 提交时间：2018/07/30

Maxwell scattering problem PML equations Block triangular preconditioner Spectral distributions

A NODAL SPARSE GRID SPECTRAL ELEMENT METHOD FOR MULTI-DIMENSIONAL ELLIPTIC PARTIAL DIFFERENTIAL EQUATIONS 期刊论文 OAI收割
INTERNATIONAL JOURNAL OF NUMERICAL ANALYSIS AND MODELING, 2017, 卷号: 14, 期号: 4-5, 页码: 762-783
作者: Rong, Zhijian; Shen, Jie; Yu, Haijun

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收藏 | 浏览/下载：27/0 | 提交时间：2018/07/30

Sparse grid spectral element method high-dimensional problem adaptive method

Multipeakons of a two-component modified Camassa-Holm equation and the relation with the finite Kac-van Moerbeke lattice 期刊论文 OAI收割
ADVANCES IN MATHEMATICS, 2016, 卷号: 299, 页码: 1-35
作者: Chang, Xiang-Ke; Hu, Xing-Biao; Szmigielski, Jacek

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收藏 | 浏览/下载：23/0 | 提交时间：2018/07/30

Multipeakons Camassa-Holm Inverse spectral problem Kac-van Moerbeke lattice

Application of the restrained optimal perturbation method to study the backward heat conduction problem 期刊论文 OAI收割
APPLIED MATHEMATICS AND COMPUTATION, 2013, 卷号: 221, 页码: 703-709
作者: Wang, Bo; Zou, Guang-an; Wang, Qiang; Wang, B; Wang, B

收藏 | 浏览/下载：34/0 | 提交时间：2014/07/17

Backward heat conduction problem The restrained optimal perturbation method Spectral projected gradient algorithm Finite difference approximation Numerical experiments

Study on spectrograph for ionosphere: A broadband imaging instrument prototype for far-ultraviolet (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China
作者: Wang S.-R.; Lin G.-Y.; Yu L.

收藏 | 浏览/下载：39/0 | 提交时间：2013/03/25

Current research on space-based exploration for the ionosphere needs more advanced technologies. Because the spectral signals in the ionosphere distributing basically in the far-ultraviolet waveband are very weak. Usual spectrometer structures and detectors such as CCD can't receive enough information. Based on this principle of atmospheric sounding the imaging spectrometer prototype for ionosphere detection application was designed to solve the problem. This prototype consists of the telescope and the imaging spectrometer. The simple structure and small number of mirrors can help higher transmission efficiency be achieved and weak signals detection be implemented. The telescope is an off-axis parabolic mirror and the spectrometer is a modified Czerny-Turner spectral imaging system. Modified Czerny-Turner spectrometer contains a spherical mirror a fixed plane grating and a toroidal mirror. By adjusting the incident angle to the collimating mirror and using toroidal mirror coma and astigmatism were corrected well. We also optimize distances between the grating to the focusing mirror and the focusing mirror to the image plane to improve disadvantages of traditional Czerny-Turner structure. Designed results demonstrate that aberrations are substantially corrected and high image quality can be obtained in broad waveband. The photon counting Wedge-Strip-Anode detector with micro-channel planes as the receiving plane is accepted for the instrument prototype. The other photon counting 2-D detector responding well for weak light such as Cross-Delay line detector and MAMA detector can also be used for detection. The calibration and performances testing system is made of a vacuum system a deuterium lamp a monochrometer and the instrument prototype. Results obtained from the experiment show that the spectral resolution is 2.4 nm and the spatial resolution is 80 m. The other calibration experiments are running. The technology of the spectrometer prototype is important for the research and applications of ionosphere remote sensing. 2011 SPIE.

Modulation transfer function measurement of sampled imaging systems in field test (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
作者: Yang L.; Zhang J.; Zhang J.; Zhang J.; Wang J.

收藏 | 浏览/下载：36/0 | 提交时间：2013/03/25

A digital mirror device (DMD) based light projector was developed as the target generator in modulation transfer function (MTF) measurement. In order to overcome the sampling-scene phase effect in MTF measurement of sampled imaging systems a method using random targets is introduced to yield a phase-averaged MTF. The main potential problem of implementing this method is the fact that the stationary assumption of the random targets may be vitiated in practical measurement especially in field test due to the ill condition. We provide an efficient model-independent way of analyzing and isolating the spectral contents arising from these additional contributions to MTF measurement. Algorithms with adaptive parameter selection were also developed for spectral estimation of the test image in order to overcome the challenge brought by the size limit of the test matrices for one certain field of view derived from the isoplantic region. The MTF measurement of a CCD video imager is used to demonstrate the measurement technique and illustrate the benefits over other methods. In order to validate the results comparisons have been made between MTF measurements of imager implemented using this method and bar target direct measurements. 2010 Copyright SPIE - The International Society for Optical Engineering.

Quantative inversion based on hyperspectral data for soil salinization in the ecological corridor of tarim river, xinjiang,china 会议论文 OAI收割
2008 IEEE International Geoscience and Remote Sensing Symposium, Boston, MA, United states, 2008
Cun; Chang1; 2; Xi; Chen1; Anming; Bao1; Geping; Luo1

收藏 | 浏览/下载：21/0 | 提交时间：2011/08/23

Differential equations - Inverse problems - Problem solving - Regression analysis - Remote sensing - Rivers - Salinity measurement - Soils - Field sampling - Field test - Hyperion - HyperSpectral - Hyperspectral Data - Hyperspectral remote sensing - Key factors - Regression model - Sampling methods - Soil salinity - Soil salinization - Spectral estimation - Surface soil - Tarim river - Xinjiang