Results 81 to 90 of about 3,211,049 (333)

A Synovium‐on‐Chip Platform to Study Multicellular Interactions in Arthritis

Advanced Healthcare Materials, EarlyView.
The Synovium‐on‐Chip comprises a thin microporous PDMS membrane to support co‐culture of fibroblast‐like synoviocytes (FLS), THP‐1‐derived macrophages, and endothelial cells, enabling real‐time analysis of synovial‐vascular interactions. FLS migration through the pores drives endothelial remodeling, while TNF‐α stimulation induces robust inflammatory ...
Laurens R. Spoelstra, Fleur R. Semmekrot, Nuno Araújo‐Gomes, Daniël Wijnperle, Monique M. A. Helsen, Martijn H.J. Van Den Bosch, Loes. I. Segerink, Séverine Le Gac, Marcel Karperien   +8 more
wiley   +1 more source

Improved Large Dynamic Covariance Matrix Estimation With Graphical Lasso and Its Application in Portfolio Selection

IEEE Access, 2020
The estimation of the large and high-dimensional covariance matrix and precision matrix is a fundamental problem in modern multivariate analysis. It has been widely applied in economics, finance, biology, social networks and health sciences. However, the
Xin Yuan, Weiqin Yu, Zhixiang Yin, Guoqiang Wang   +3 more
doaj   +1 more source

Sample Space-time Covariance Matrix Estimation [PDF]

ICASSP 2019 - 2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 2019
Estimation errors are incurred when calculating the sample space-time covariance matrix. We formulate the variance of this estimator when operating on a finite sample set, compare it to known results, and demonstrate its precision in simulations.
Delaosa, Connor, Pestana, Jennifer, Goddard, Nicholas J., Somasundaram, Samuel, Weiss, Stephan   +4 more
openaire   +1 more source

Mixed‐Metal Promotion in a Manganese‐Molybdenum Oxynitride as Catalyst to Integrate C─C and C─N Coupling Reactions for the Direct Synthesis of Acetonitrile from Syngas and Ammonia

Advanced Materials, EarlyView.
Transition metal oxy/carbo‐nitrides show great promise as catalysts for sustainable processes. A Mn‐Mo mixed‐metal oxynitride attains remarkable performance for the direct synthesis of acetonitrile, an important commodity chemical, via sequential C─N and C─C coupling from syngas (C1) and ammonia (N1) feedstocks.
M. Elena Martínez‐Monje, Wilson Henao, Tania Rodenas, Patricia Concepción, Virginia Pérez Dieste, Alexander Missyul, Giovanni Agostini, Gonzalo Prieto   +7 more
wiley   +1 more source

Portfolio Optimization Using a Consistent Vector-Based MSE Estimation Approach

IEEE Access, 2022
This paper is concerned with optimizing the weights of the global minimum-variance portfolio (GMVP) in high-dimensional settings where both observation and population dimensions grow at a bounded ratio. Optimizing the GMVP weights is highly influenced by
Maaz Mahadi, Tarig Ballal, Muhammad Moinuddin, Ubaid M. Al-Saggaf   +3 more
doaj   +1 more source

Convex Banding of the Covariance Matrix [PDF]

, 2014
We introduce a new sparse estimator of the covariance matrix for high-dimensional models in which the variables have a known ordering. Our estimator, which is the solution to a convex optimization problem, is equivalently expressed as an estimator which ...
Bien, Jacob, Bunea, Florentina, Xiao, Luo   +2 more
core   +2 more sources

Risk evaluation with enhanced covariance matrix [PDF]

Physica A: Statistical Mechanics and its Applications, 2007
We propose a route for the evaluation of risk based on a transformation of the covariance matrix. The approach uses a `potential' or `objective' function. This allows us to rescale data from different assets (or sources) such that each data set then has similar statistical properties in terms of their probability distributions.
Krzysztof Urbanowicz, Peter Richmond, Janusz A. Holyst   +2 more
openaire   +2 more sources

Beyond Presumptions: Toward Mechanistic Clarity in Metal‐Free Carbon Catalysts for Electrochemical H2O2 Production via Data Science

Advanced Materials, EarlyView.
Metal‐free carbon catalysts enable the sustainable synthesis of hydrogen peroxide via two‐electron oxygen reduction; however, active site complexity continues to hinder reliable interpretation. This review critiques correlation‐based approaches and highlights the importance of orthogonal experimental designs, standardized catalyst passports ...
Dayu Zhu, Hsi‐wen Wu, Xiao Wang, Jie Zhang   +3 more
wiley   +1 more source

Multivariate time series classification using kernel matrix

Electronics Letters, 2022
Multivariate time series (MTS) classification is a fundamental problem in time series mining, and the approach based on covariance matrix is an attractive way to solve the classification. In this study, it is noted that a traditional covariance matrix is
Jiancheng Sun, Huimin Niu, Zongqing Tu, Zhinan Wu, Si Chen   +4 more
doaj   +1 more source

On the regularity of the covariance matrix of a discretized scalar field on the sphere

, 2017
We present a comprehensive study of the regularity of the covariance matrix of a discretized field on the sphere. In a particular situation, the rank of the matrix depends on the number of pixels, the number of spherical harmonics, the symmetries of the ...
Barreiro, R. B., Bilbao-Ahedo, J. D., Herranz, D., Martínez-González, E., Vielva, P.   +4 more
core   +1 more source