Results 121 to 130 of about 666,240 (259)
A goodness‐of‐fit test for regression models with discrete outcomes
Canadian Journal of Statistics, EarlyView.Abstract Regression models are often used to analyze discrete outcomes, but classical goodness‐of‐fit tests such as those based on the deviance or Pearson's statistic can be misleading or have little power in this context. To address this issue, we propose a new test, inspired by the work of Czado et al.
Lu Yang +2 more
wiley +1 more source
Quaternions and Clifford Algebras
, 2022 Quaternions are a type of hypercomplex numbers. Unit quaternions, which describe rotations, were called versors by Hamilton. The concept of versor can be generalized as the product of invertible vectors in the Clifford algebra. Clifford algebras are also named geometric algebras, when referring to the subset of nondegenerate Clifford algebras ...
openaire +3 more sources
A partial envelope approach for modelling multivariate spatial‐temporal data
Canadian Journal of Statistics, EarlyView.Abstract In the new era of big data, modelling multivariate spatial‐temporal data is a challenging task due to both the high dimensionality of the features and complex associations among the responses across different locations and time points.
Reisa Widjaja +3 more
wiley +1 more source
Algebras and quaternion defect groups. I
Mathematische Annalen, 1988 The structure of blocks with cyclic defect groups was determined by R. Brauer and E. C. Dade. The author has recently been able to achieve a similar goal for blocks with dihedral, semidihedral or (generalized) quaternion defect groups. The papers under review contain her results for the (generalized) quaternion case.
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Self‐Similar Blowup for the Cubic Schrödinger Equation
Communications on Pure and Applied Mathematics, EarlyView.ABSTRACT We give a rigorous proof for the existence of a finite‐energy, self‐similar solution to the focusing cubic Schrödinger equation in three spatial dimensions. The proof is computer‐assisted and relies on a fixed point argument that shows the existence of a solution in the vicinity of a numerically constructed approximation.
Roland Donninger, Birgit Schörkhuber
wiley +1 more source
Invariant Measure and Universality of the 2D Yang–Mills Langevin Dynamic
Communications on Pure and Applied Mathematics, EarlyView.ABSTRACT We prove that the Yang–Mills (YM) measure for the trivial principal bundle over the two‐dimensional torus, with any connected, compact structure group, is invariant for the associated renormalised Langevin dynamic. Our argument relies on a combination of regularity structures, lattice gauge‐fixing and Bourgain's method for invariant measures ...
Ilya Chevyrev, Hao Shen
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Corporate Social Responsibility and Environmental Management, EarlyView.ABSTRACT Sustainability‐oriented collaborations are inter‐organisational arrangements where the competencies of multiple companies are pooled together to tackle environmental challenges. These collaborations differ from traditional strategic alliances in that they tackle complex goals amidst greater uncertainties that extend beyond economic performance,
Vittorio Maria Garibbo +3 more
wiley +1 more source
Kinetic Contribution to the Arbitrary Order Odd Frequency Moments of the Dynamic Structure Factor
Contributions to Plasma Physics, EarlyView.ABSTRACT An exact expression is derived for the kinetic contribution to the odd (arbitrary order) frequency moments of the dynamic structure factor via a finite summation that features averages of even (all lower orders) powers of the momentum over the exact momentum distribution.
Panagiotis Tolias +2 more
wiley +1 more source
Study on fracture parameter calibration and failure characteristics of rock with hole and crack
Deep Underground Science and Engineering, EarlyView.The SIF and plastic zone equations for a single hole and crack have been derived. The model's failure state leads to the identification of four types of cracks. The plastic zone increases with increased brittleness and decreased crack length. Abstract Cracks within the surrounding rock of roadways significantly affect their stability and failure ...
Shaochi Peng, Wensong Wang
wiley +1 more source
Forces in MechanicsThis paper presents a new co-rotational shell element based on quaternion algebra as a means of parameterizing large rotations. The co-rotational framework is suitable for beam or shell elements and has been extensively studied in the literature.
Stéphane Grange, David Bertrand
doaj +1 more source