Results 121 to 130 of about 341,424 (240)
A Global Krylov Subspace Method for the Sylvester Quaternion Matrix Equation
Journal of New TheoryThis study concerns the Sylvester matrix equation in the quaternion setting when the coefficient matrices as well as the unknown matrix have quaternion entries.
Sinem Şimşek
doaj +1 more source
Inequalities for the Frobenius norm [PDF]
Journal of Mathematical Inequalities, 2015 openaire +1 more source
A spectral analysis extension to DEMATEL for strategic leverage points identification
International Transactions in Operational Research, EarlyView.Abstract Efforts to intervene in complex systems often emphasize influential factors, yet system behavior is equally shaped by the relationships among them. Methods such as Decision‐Making Trial and Evaluation Laboratory (DEMATEL) map causal structures but remain descriptive and do not identify which relationships provide the greatest leverage for ...
Pavlos Delias, Kerasia Kalkitsa
wiley +1 more source
On the Existence of One‐Sided Representations for the Generalised Dynamic Factor Model
Journal of Time Series Analysis, EarlyView.ABSTRACT We study the Generalised Dynamic Factor Model (GDFM) and show that the dynamic common component, that is, the common component of the GDFM, can be expressed using only current and past observations under mild assumptions. Specifically, we require (i) the dynamic common component to be purely non‐deterministic and (ii) the exclusion of ...
Philipp Gersing
wiley +1 more source
Remote SensingTraditional antenna arrays for direction-of-arrival (DOA) estimation typically require numerous elements to achieve target performance, increasing system complexity and cost.
Changcheng Hu +6 more
doaj +1 more source
On The Frobenius Norm of Commutators Involving Exponential Matrices
Gazi University Journal of ScienceIn this paper, we first establish a different generalization of the equality proposed by Farhadian for iterated exponentials with the matrix J_n, where J_n is an n×n matrix with all entries equal to 1. Then, using this new generalization, we derive commutator identities involving iterated exponential matrices.
Ahmet Öksüz, Süleyman Solak
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Journal of Time Series Analysis, EarlyView.ABSTRACT Traditional graph representations are insufficient for modelling real‐world phenomena involving multi‐entity interactions, such as collaborative projects or protein complexes, necessitating the use of hypergraphs. While hypergraphs preserve the intrinsic nature of such complex relationships, existing models often overlook temporal evolution in
Xianghe Zhu, Qiwei Yao
wiley +1 more source
Sparse Causal Dynamic Linear Regression
Journal of Time Series Analysis, EarlyView.ABSTRACT We develop a sparse causal dynamic regression framework for long multivariate time series. With very long time series, the potentially large number of lags and leads in a dynamic regression model often makes time‐domain estimation numerically unstable or intractable.
Rui Huang, Kung‐Sik Chan
wiley +1 more source
Journal of Time Series Analysis, EarlyView.ABSTRACT We consider estimation of large approximate factor models in high‐dimensional panels of stationary time series using Principal Component Analysis (PCA). We review the key results establishing the necessary and sufficient conditions for consistency and asymptotic normality of the estimators, which hold when both the cross‐sectional dimension n$$
Matteo Barigozzi
wiley +1 more source
Partial Time‐Varying Regression Modelling Under General Heterogeneity
Journal of Time Series Analysis, EarlyView.ABSTRACT This paper studies a semiparametric time‐varying regression model in which a subset of regressors is associated with fixed parameters, while the remaining regressors have parameters that evolve smoothly over time. We propose a closed‐form semiparametric Frisch‐Waugh‐Lovell estimator for the fixed parameters, and a non‐parametric kernel type ...
Liudas Giraitis +3 more
wiley +1 more source