Výsledky vyhledávání - "Abdelkhalek, Fatma"

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Causal Vector Autoregression Enhanced with Covariance and Order Selection

Autor: Bolla, Marianna, Ye, Dongze, Wang, Haoyu, Ma, Renyuan, Frappier, Valentin, Thompson, William, Donner, Catherine, Baranyi, Máté, Abdelkhalek, Fatma

A causal vector autoregressive (CVAR) model is introduced for weakly stationary multivariate processes, combining a recursive directed graphical model for the contemporaneous components and a vector autoregressive model longitudinally. Block Cholesky

Externí odkaz: http://arxiv.org/abs/2211.14203

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Regularity based spectral clustering and mapping the Fiedler-carpet

Autor: Bolla, Marianna, Winstein, Vilas, You, Tao, Seidl, Frank, Abdelkhalek, Fatma

Spectral clustering is discussed from many perspectives, by extending it to rectangular arrays and discrepancy minimization too. Near optimal clusters are obtained with singular value decomposition and with the weighted $k$-means algorithm. In case o

Externí odkaz: http://arxiv.org/abs/2112.10637

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Akademický článek

Regularity-based spectral clustering and mapping the Fiedler-carpet

Autor: Bolla Marianna, Winstein Vilas, You Tao, Seidl Frank, Abdelkhalek Fatma

Publikováno v: Special Matrices, Vol 10, Iss 1, Pp 394-416 (2022)

We discuss spectral clustering from a variety of perspectives that include extending techniques to rectangular arrays, considering the problem of discrepancy minimization, and applying the methods to directed graphs. Near-optimal clusters can be obta

Externí odkaz: https://doaj.org/article/00496577c17b43de9cb7bf677621358d

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Akademický článek

Two-way associations between relationship quality and uptake of couples health screening including HIV testing and counselling together: quantitative analysis of a couples cohort in rural South Africa.

Autor: Abdelkhalek, Fatma, Joseph, Phillip, DeRose, Laurie, Olamijuwon, Emmanuel, Dladla, Pumla, Ngubane, Thulani, Hosegood, Victoria, van Rooyen, Heidi, van Heerden, Alastair, McGrath, Nuala

Publikováno v: AIDS Care; 2024 Suppl 1, Vol. 36, p187-200, 14p

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Akademický článek

Block circulant matrices and the spectra of multivariate stationary sequences

Autor: Bolla Marianna, Szabados Tamás, Baranyi Máté, Abdelkhalek Fatma

Publikováno v: Special Matrices, Vol 9, Iss 1, Pp 36-51 (2021)

Given a weakly stationary, multivariate time series with absolutely summable autocovariances, asymptotic relation is proved between the eigenvalues of the block Toeplitz matrix of the first n autocovariances and the union of spectra of the spectral d

Externí odkaz: https://doaj.org/article/cf640f32dbd34ec2a419efbb29348dfe

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