Results 101 to 110 of about 296,140 (309)

Finite Sample Analysis of Weighted Realized Covariance with Noisy Asynchronous Observations [PDF]

In this paper, we provide a framework to evaluate finite sample MSE of several realized covariance estimators when using nonsynchronous observations contaminated with microstructure noise. This framework enables us to examine different estimators.
Taro Kanatani
core  

Consensus Formation and Change are Enhanced by Neutrality

Advanced Science, EarlyView.
Neutral agents are shown to enhance both the formation and overturning of consensus in collective decision‐making. A general mathematical model and experiments with locusts and humans reveal that neutrality enables robust consensus via simple interactions and accelerates consensus change by reducing effective population size.
Andrei Sontag, Janina A. Hoffmann, Tim Rogers, Christian A. Yates   +3 more
wiley   +1 more source

Minimax Powerful Functional Analysis of Covariance Tests: with Application to Longitudinal Genome-Wide Association Studies. [PDF]

Scand Stat Theory Appl, 2023
Zhu W, Xu S, Liu C, Li Y.
europepmc   +1 more source

In Situ X‐Ray Tomography and Acoustic Emission Monitoring of Damage Evolution in C/C‐SiC Composites Fabricated by Liquid Silicon Infiltration

Advanced Science, EarlyView.
This study investigates how the internal structure of fiber‐reinforced ceramic composites affects their resistance to damage. By combining 3D X‐ray imaging with acoustic emission monitoring during mechanical testing, it reveals how silicon distribution influences crack formation.
Yang Chen, Renato S. M. Almeida, Stefan Flauder, Guillaume Couégnat, Kamen Tushtev, Jürgen Horvath, Peter Wriggers, Kurosch Rezwan   +7 more
wiley   +1 more source

"Maximum Covariance Di erence Test for Equality of Two Covariance Matrices" [PDF]

We propose a test of equality of two covariance matrices based on the maximum standardized di erence of scalar covariances of two sample covariance matrices.We derive the tail probability of the asymptotic null distribution of the test statistic by the ...
Akimichi Takemura, Satoshi Kuriki
core  

Spectral analysis of the Moore-Penrose inverse of a large dimensional sample covariance matrix [PDF]

, 2016
For a sample of $n$ independent identically distributed $p$-dimensional centered random vectorswith covariance matrix $\bSigma_n$ let $\tilde{\bS}_n$ denote the usual sample covariance(centered by the mean) and $\bS_n$ the non-centered sample covariance ...
Parolya, Nestor, Bodnar, Taras,, Dette, Holger   +2 more
core   +1 more source

Canagliflozin Alleviates Diabetic Glomerular Endothelial Injury via Melibiose in a Microbiota‐Dependent Manner

Advanced Science, EarlyView.
Canagliflozin treatment reshapes the gut microbiota in DKD and elevates levels of melibiose, a metabolite derived from Roseburia intestinalis. Melibiose directly binds to and enhances the enzymatic activity of glyoxalase 1, leading to decreased methylglyoxal accumulation.
Wei Zhang, Yi Song, Changkun Li, Yuanyuan Luo, Mingwei Shao, Feng Guo, Fangyi Wei, Xunjie Fan, Wenwen Guo, Fengmei Xu, Yanhong Sang, Dongming Zhang, Yanhong Zhou, Lianwei Wang, Zhiqiang Kang, Yingjun Yang, Chunhua Song, Yanxia Liu, Xiaojun Ma, Jiao Wang, Chong Li, Shengnan Ma, Lin Zhao, Zhi Qin, Guolan Xing, Qiubo Zhao, Jun Li, Shumin Song, Dan Zhao, Ting Huang, Qingzhu Wang, Yanyan Zhao, Guijun Qin   +32 more
wiley   +1 more source

The Requirement of a Positive Definite Covariance Matrix of Security Returns for Mean-Variance Portfolio Analysis: A Pedagogic Illustration

Spreadsheets in Education, 2010
This study considers, from a pedagogic perspective, a crucial requirement for the covariance matrix of security returns in mean-variance portfolio analysis.
Clarence C. Y. Kwan
doaj  

Analysis of brain structural covariance network in Cushing disease

Heliyon
Background: Cushing disease (CD) is a rare clinical neuroendocrine disease. CD is characterized by abnormal hypercortisolism induced by a pituitary adenoma with the secretion of adrenocorticotropic hormone.
Can-Xin Xu, Linghan Kong, Hong Jiang, Yue Jiang, Yu-Hao Sun, Liu-Guan Bian, Yuan Feng, Qing-Fang Sun   +7 more
doaj   +1 more source

Sampled-data filtering with error covariance assignment [PDF]

, 2001
Copyright [2001] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services.
Huang, B, Wang, Z, Huo, P
core