326 research outputs found
On Some Geometric Properties of Slice Regular Functions of a Quaternion Variable
The goal of this paper is to introduce and study some geometric properties of
slice regular functions of quaternion variable like univalence, subordination,
starlikeness, convexity and spirallikeness in the unit ball. We prove a number
of results, among which an Area-type Theorem, Rogosinski inequality, and a
Bieberbach-de Branges Theorem for a subclass of slice regular functions. We
also discuss some geometric and algebraic interpretations of our results in
terms of maps from to itself. As a tool for subordination we
define a suitable notion of composition of slice regular functions which is of
independent interest
Fantastic Weights and How to Find Them: Where to Prune in Dynamic Sparse Training
Dynamic Sparse Training (DST) is a rapidly evolving area of research that
seeks to optimize the sparse initialization of a neural network by adapting its
topology during training. It has been shown that under specific conditions, DST
is able to outperform dense models. The key components of this framework are
the pruning and growing criteria, which are repeatedly applied during the
training process to adjust the network's sparse connectivity. While the growing
criterion's impact on DST performance is relatively well studied, the influence
of the pruning criterion remains overlooked. To address this issue, we design
and perform an extensive empirical analysis of various pruning criteria to
better understand their impact on the dynamics of DST solutions. Surprisingly,
we find that most of the studied methods yield similar results. The differences
become more significant in the low-density regime, where the best performance
is predominantly given by the simplest technique: magnitude-based pruning. The
code is provided at https://github.com/alooow/fantastic_weights_paperComment: NeurIPS 202
OBSERVATIONS ON THE STRUCTURE, DYNAMICS AND ABBREVIATION OF ENTOMOFAUNE COLLECTED FROM CERTAIN AGRICULTURAL CROPS
The remarks were made in 2016 in the fruit tree, pear, peach, vine plantations, corn crops and cabbage crops, in two stations, stationary Vasile Adamachi, Iasi Iasi county and Ezereni farm in the Miroslava, Iasi County. The purpose of the paper was to compare the entomofauna by a number of different agricultural and field cultures, different as well as agroecosystem technology and conditions.The material was collected using the entomological filet, from June until September inclusive.The collected material was cleaned of vegetal remains and was then prepared for identification at species level. The analysis of the collected material shows that the samples collected belong to the Hexapoda Class, with several insect orders and the Arachnida Class, the Aranea order and the Acari order. Most of them belong to the Insecta class. The orders to which the species are collected are: Coleoptera, Heteroptera, Hymenoptera, Diptera, all of the Hexapoda class. As regards the abundance entomofauna, cultures, it is found that the wheat had been collected the multiple copies (69) followed by the growing of maize (39) and then planting vine (29) and plantations apple (24)
On the validity of nonlinear Alfvén resonance in space plasmas
Aims. In the approximation of linear dissipative magnetohydrodynamics (MHD), it can be shown that driven MHD waves in magnetic plasmas with high Reynolds number exhibit a near resonant behaviour if the frequency of the wave becomes equal to the local Alfvén (or slow) frequency of a magnetic surface. This behaviour is confined to a thin region, known as the dissipative layer, which embraces the resonant magnetic surface. Although driven MHD waves have small dimensionless amplitude far away from the resonant surface, this near-resonant behaviour in the dissipative layer may cause a breakdown of linear theory. Our aim is to study the nonlinear effects in Alfvén dissipative layer
Methods. In the present paper, the method of simplified matched asymptotic expansions developed for nonlinear slow resonant waves is used to describe nonlinear effects inside the Alfvén dissipative layer.
Results. The nonlinear corrections to resonant waves in the Alfvén dissipative layer are derived, and it is proved that at the Alfvén resonance (with isotropic/anisotropic dissipation) wave dynamics can be described by the linear theory with great accuracy
Fantastic Weights and How to Find Them: Where to Prune in Dynamic Sparse Training
peer reviewedDynamic Sparse Training (DST) is a rapidly evolving area of research that
seeks to optimize the sparse initialization of a neural network by adapting its
topology during training. It has been shown that under specific conditions, DST
is able to outperform dense models. The key components of this framework are
the pruning and growing criteria, which are repeatedly applied during the
training process to adjust the network's sparse connectivity. While the growing
criterion's impact on DST performance is relatively well studied, the influence
of the pruning criterion remains overlooked. To address this issue, we design
and perform an extensive empirical analysis of various pruning criteria to
better understand their impact on the dynamics of DST solutions. Surprisingly,
we find that most of the studied methods yield similar results. The differences
become more significant in the low-density regime, where the best performance
is predominantly given by the simplest technique: magnitude-based pruning. The
code is provided at https://github.com/alooow/fantastic_weights_paper9. Industry, innovation and infrastructur
Fostering Transnational Research, Innovation and Education Through an International Europe and Africa Collaboration Project
publishedVersionPeer reviewe
A Monte Carlo comparison between template-based and Wiener-filter CMB dipole estimators
We review and compare two different CMB dipole estimators discussed in the
literature, and assess their performances through Monte Carlo simulations. The
first method amounts to simple template regression with partial sky data, while
the second method is an optimal Wiener filter (or Gibbs sampling)
implementation. The main difference between the two methods is that the latter
approach takes into account correlations with higher-order CMB temperature
fluctuations that arise from non-orthogonal spherical harmonics on an
incomplete sky, which for recent CMB data sets (such as Planck) is the dominant
source of uncertainty. For an accepted sky fraction of 81% and an angular CMB
power spectrum corresponding to the best-fit Planck 2018 CDM model, we
find that the uncertainty on the recovered dipole amplitude is about six times
smaller for the Wiener filter approach than for the template approach,
corresponding to 0.5 and 3K, respectively. Similar relative differences
are found for the corresponding directional parameters and other sky fractions.
We note that the Wiener filter algorithm is generally applicable to any dipole
estimation problem on an incomplete sky, as long as a statistical and
computationally tractable model is available for the unmasked higher-order
fluctuations. The methodology described in this paper forms the numerical basis
for the most recent determination of the CMB solar dipole from Planck, as
summarized by arXiv:2007.04997.Comment: 8 pages, 10 figures, submitted to A&
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