Results 91 to 100 of about 402,138 (284)

Robust Covariance Adaptation in Adaptive Importance Sampling

, 2018
Importance sampling (IS) is a Monte Carlo methodology that allows for approximation of a target distribution using weighted samples generated from another proposal distribution.
Bugallo, Monica F., El-Laham, Yousef, Elvira, Victor   +2 more
core   +1 more source

Cognitive Trajectories from Preclinical Alzheimer's Disease to Dementia

Advanced Science, EarlyView.
A continuous, multi‐domain characterization of cognitive decline across the Alzheimer's disease spectrum identifies when individual cognitive measures become abnormal. Episodic memory declines first, followed by executive function, language, processing speed, and visuospatial abilities, supporting improved clinical interpretation and optimized endpoint
Fredrik Öhman, Lars Lau Raket, Michael Schöll, for the Alzheimer's Disease Neuroimaging Initiative†   +3 more
wiley   +1 more source

Optimal algorithm for distributed scatterer InSAR phase estimation based on cross-correlation complex coherence matrix

International Journal of Applied Earth Observations and Geoinformation
Low scattering terrain areas introduce complex phase interference, which reduces the accuracy of deformation signal estimation in InSAR(Interferometric Synthetic Aperture Radar) techniques. Existing covariance matrix-based InSAR phase calculation methods
Dingyi Zhou, Zhifang Zhao
doaj   +1 more source

Covariance Matrix Reconstruction via Residual Noise Elimination and Interference Powers Estimation for Robust Adaptive Beamforming

IEEE Access, 2019
Recently, a number of robust adaptive beamforming (RAB) methods based on Capon power spectrum estimator integrated over a specific region for covariance matrix reconstruction have been proposed.
Xingyu Zhu, Zhongfu Ye, Xu Xu, Rui Zheng
doaj   +1 more source

Microscale Mapping of Fiber Strain and Damage in Composite Wrinkled Laminates Using Computed Tomography Assisted Wide‐Angle X‐Ray Scattering

Advanced Science, EarlyView.
This study combines full‐field tomography with diffraction mapping to quantify radial (ε002$\varepsilon _{002}$) and axial (ε100$\varepsilon _{100}$) lattice strain in wrinkled carbon‐fiber specimens for the first time. Radial microstrain gradients (−14.5 µεMPa$\varepsilon \mathrm{MPa}$−1) are found to signal damage‐prone zones ahead of failure, which ...
Hoang Minh Luong, James Trevarthen, Igor Dolbnya, Wadwan Singhapong, Nicholas Pilato, Richard Butler, Jiraphant Srisuriyachot, Alexander J. G. Lunt   +7 more
wiley   +1 more source

Information Geometry for Covariance Estimation in Heterogeneous Clutter with Total Bregman Divergence

Entropy, 2018
This paper presents a covariance matrix estimation method based on information geometry in a heterogeneous clutter. In particular, the problem of covariance estimation is reformulated as the computation of geometric median for covariance matrices ...
Xiaoqiang Hua, Yongqiang Cheng, Hongqiang Wang, Yuliang Qin   +3 more
doaj   +1 more source

Learnable Diffusion Framework for Mouse V1 Neural Decoding

Advanced Science, EarlyView.
We introduce Sensorium‐Viz, a diffusion‐based framework for reconstructing high‐fidelity visual stimuli from mouse primary visual cortex activity. By integrating a novel spatial embedding module with a Diffusion Transformer (DiT) and a synthetic‐response augmentation strategy, our model outperforms state‐of‐the‐art fMRI‐based baselines, enabling robust
Kaiwen Deng, Peter S. Schwendeman, Yuanfang Guan   +2 more
wiley   +1 more source

Direction of Arrival Estimation for the Coexistence of Uncorrelated and Coherent Signals via Rotation Spatial Differencing Method

IEEE Open Journal of Signal Processing
This paper presents a novel direction of arrival (DOA) estimation method via rotation spatial differencing technique that offers high resolution, robustness, and stable performance. To suppress external environmental noise and improve estimation accuracy,
Peng Luo, Boyu Pang, Defeng Wu, W. Zeng
doaj   +1 more source

Direction of Arrival Estimation in Low-Grazing Angle: A Partial Spatial-Differencing Approach

IEEE Access, 2017
This paper addresses a partial spatial-differencing (PSD) approach for the direction of arrival estimation in a low-grazing angle (LGA) condition. By dividing the sample covariance matrix into several column subvectors, we first form the corresponding ...
Junpeng Shi, Guoping Hu, Xiaofei Zhang
doaj   +1 more source

Robust Covariance Matrix Estimation for High-Dimensional Compositional Data with Application to Sales Data Analysis. [PDF]

J Bus Econ Stat, 2023
Li D, Srinivasan A, Chen Q, Xue L.
europepmc   +1 more source