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Application of regularized covariance matrices in logistic regression and portfolio optimization [PDF]
Scientific ReportsCovariance estimation has widespread applications in various fields such as logistic regression and portfolio optimization. However, in high-dimensional or small-sample scenarios, traditional covariance matrix estimation often encounters the problem of ...
Fang Sun, Xiaoqing Huang
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Invertibility of Multipliers for Continuous G-frames [PDF]
Sahand Communications in Mathematical Analysis, 2022 In this paper, we study the concept of multipliers for the continuous $g$-Bessel families in Hilbert spaces. We present necessary conditions for invertibility of multipliers for the continuous $g$-Bessel families and sufficient conditions for ...
Mohammad Reza Abdollahpour +1 more
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Invertibility of Generalized Space-Time Autoregressive Model with Random Weight
Cauchy: Jurnal Matematika Murni dan Aplikasi, 2021 The generalized linear process accomplishes stationarity and invertibility properties. The invertibility property must be having a series of convergence conditions of the process parameter.
Yundari Yundari, Setyo Wira Rizki
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On Invertibility of an Interconnected System Composed of Two Dynamic Subsystems
Applied Sciences, 2021 In this paper, the invertibility of an interconnected system that consists of two dynamic subsystems was studied. It can be viewed as the distinguishability of the impacts of local input on the final global output, that is to say, whether the input at ...
Mei Zhang, Boutaïeb Dahhou, Ze-Tao Li
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Efficient Algebraic Method for Testing the Invertibility of Finite State Machines
Computation, 2023 The emergence of new embedded system technologies, such as IoT, requires the design of new lightweight cryptosystems to meet different hardware restrictions.
Zineb Lotfi +2 more
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Co-EP-Ness and EP-Ness Involving the Inverse along an Element
Mathematics, 2023 Let a,d be two elements in rings and a∥d be the inverse of a along d. When a∥d exists, we obtain several characterizations for the invertibility of aa∥d−a∥da, which is related to the invertibility of elements expressed by certain functions of a,d and ...
Honglin Zou, Dijana Mosić, Huihui Zhu
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Diagonal dominance and invertibility of matrices
Special Matrices, 2023 A weakly diagonally dominant matrix may or may not be invertible. We characterize, in terms of combinatorial structure and sign pattern when such a matrix is invertible, which is the common case. Examples are given.
Johnson Charles Royal +2 more
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Right-Sided Invertibility of Binomial Functional Operators and Graded Dichotomy
Современная математика: Фундаментальные направления, 2021 In this paper, we consider the right-sided invertibility problem for binomial functional operators. It is known that such operators are invertible iff there exists dichotomy of solutions of the homogeneous equation.
A. B. Antonevich
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On generalized inverses of regular elements in an arbitrary semiring
上海师范大学学报. 自然科学版, 2018 In this paper, we investigate the generalized invertibility for regular elements in an arbitrary semiring. We give some sufficient conditions for the existence of a special kind of {1,2} inverse of a regular element a in an arbitrary semiring and give ...
Israr Ali Khan, Wang Qingwen
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Invertibility properties of matrix wiener‐hopf plus Hankel integral operators
Mathematical Modelling and Analysis, 2008 We consider matrix Wiener‐Hopf plus Hankel operators acting between Lebesgue spaces on the real line with Fourier symbols presenting some even properties (which in particular include unitary matrix‐valued functions), and also with Fourier symbols which ...
Giorgi Bogveradze, Luís P. Castro
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