Results 41 to 50 of about 598 (181)

Block Toeplitz operators with frequency-modulated semi-almost periodic symbols

International Journal of Mathematics and Mathematical Sciences, 2003
This paper is concerned with the influence of frequency modulation on the semi-Fredholm properties of Toeplitz operators with oscillating matrix symbols.
A. Böttcher, S. Grudsky, I. Spitkovsky
doaj   +1 more source

Forecasting With Dynamic Factor Models Estimated by Partial Least Squares

Journal of Forecasting, EarlyView.
ABSTRACT Dynamic factor models (DFMs) have found great success in nowcasting and short‐term macroeconomic forecasting when incorporating large sets of predictive information. The factor loadings are typically estimated cross‐sectionally with principal component analysis (PCA) or maximum likelihood (ML), which ignore whether the factors have predictive ...
Samuel Rauhala
wiley   +1 more source

Toeplitz Operators on Harmonic Fock Spaces with Radial Symbols

Mathematics
The main aim of this paper is to study new features and specific properties of the Toeplitz operator with radial symbols in harmonic Fock spaces. A new spectral decomposition of a Toeplitz operator with Wick symbols is also established.
Zhi-Ling Sun, Wei-Shih Du, Feng Qi
doaj   +1 more source

Active Electromagnetic Interference Suppression for MRI and Proton Resonance Frequency Shift Thermometry During MRI‐Guided Microwave Ablation

Magnetic Resonance in Medicine, EarlyView.
ABSTRACT Purpose To develop a software‐based active electromagnetic interference (EMI) suppression (AES) framework on whole‐body multi‐channel MRI systems for reliable MRI and MR thermometry during MRI‐guided microwave ablation (MWA). Methods In addition to primary imaging coils, an unloaded standard body array coil was positioned outside the imaging ...
Qing Dai, Jason Chiang, Shu‐Fu Shih, Wenqi Zhou, David S. K. Lu, Holden H. Wu   +5 more
wiley   +1 more source

Commuting Toeplitz Operators With Mixed Quasihomogeneous and Analytic Symbols

Journal of Mathematics
A major open problem in the theory of Toeplitz operators on the analytic Bergman space over the unit disk is the characterization of the commutant of a given Toeplitz operator, that is, the set of all bounded Toeplitz operators that commute with it.
Aissa Bouhali, Issam Louhichi, Abdelrahman Yousef   +2 more
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Reducing Subspaces of the Dual Truncated Toeplitz Operator

Journal of Function Spaces, 2018
We define the dual truncated Toeplitz operators and give some basic properties of them. In particular, spectrum and reducing subspaces of some special dual truncated Toeplitz operator are characterized.
Yinyin Hu, Jia Deng, Tao Yu, Liu Liu, Yufeng Lu   +4 more
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A Quantised Push‐Sum Distributed Adaptive Momentum Algorithm for Optimisation Over Directed Networks

CAAI Transactions on Intelligence Technology, EarlyView.
ABSTRACT In this paper, we investigate a distributed constrained optimisation problem over directed networks. The agents in the networks conduct local computations and communications, endeavouring to collaboratively minimise the aggregation of all locally known convex cost functions subject to a global constraint set.
Qingguo Lü, Mingyu Guan, Chenglong He, Chen Chen, Xiangguang Dai, Man‐Fai Leung, Wei Zhang   +6 more
wiley   +1 more source

On Boundedness of Calderón–Toeplitz Operators [PDF]

Integral Equations and Operator Theory, 2011
We study the boundedness of Toeplitz-type operators defined in the context of the Calderón reproducing formula considering the specific wavelets whose Fourier transforms are related to Laguerre polynomials. Some sufficient conditions for simultaneous boundedness of these Calderón-Toeplitz operators on each wavelet subspace for unbounded symbols are ...
openaire   +2 more sources

DC Side Impedance Modelling of an Actual Line Commutated Converter High Voltage Direct Current System and DC Resonance Characteristics

High Voltage, EarlyView.
ABSTRACT The stability analysis of Line Commutated Converter High Voltage Direct Current (LCC‐HVDC) is of considerable engineering importance. Establishing its analytical mathematical model helps to analyse stability and the factors that affect stability of the system.
Juanjuan Wang, Juntao Liu, Qingming Xin, Ze Mo, Baixian Ye, Yuekun Liu, Chuang Fu   +6 more
wiley   +1 more source

On the product of Toeplitz and composition operators on Fock-Sobolev spaces

四川大学学报. 自然科学版, 2021
We characterize the boundedness of the product of Toeplitz and composition operators for two polynomials symbols on Fock-Sobolev spaces. We also consider the commutativity of Toeplitz and composition operator, and obtain several necessary and sufficient ...
QIN Jie, WANG Xiao-Feng
doaj