384 research outputs found
Half-quadratic transportation problems
We present a primal--dual memory efficient algorithm for solving a relaxed
version of the general transportation problem. Our approach approximates the
original cost function with a differentiable one that is solved as a sequence
of weighted quadratic transportation problems. The new formulation allows us to
solve differentiable, non-- convex transportation problems
GAMIX-VAE: A VAE with Gaussian Mixture Based Posterior
Variational Autoencoders (VAEs) have become a cornerstone in generative
modeling and representation learning within machine learning. This paper
explores a nuanced aspect of VAEs, focusing on interpreting the Kullback
Leibler (KL) Divergence, a critical component within the Evidence Lower Bound
(ELBO) that governs the trade-off between reconstruction accuracy and
regularization. While the KL Divergence enforces alignment between latent
variable distributions and a prior imposing a structure on the overall latent
space but leaves individual variable distributions unconstrained. The proposed
method redefines the ELBO with a mixture of Gaussians for the posterior
probability, introduces a regularization term to prevent variance collapse, and
employs a PatchGAN discriminator to enhance texture realism. Implementation
details involve ResNetV2 architectures for both the Encoder and Decoder. The
experiments demonstrate the ability to generate realistic faces, offering a
promising solution for enhancing VAE based generative models.Comment: 5 pages, 3 figure
Attentive VQ-VAE
We present a novel approach to enhance the capabilities of VQ-VAE models
through the integration of a Residual Encoder and a Residual Pixel Attention
layer, named Attentive Residual Encoder (AREN). The objective of our research
is to improve the performance of VQ-VAE while maintaining practical parameter
levels. The AREN encoder is designed to operate effectively at multiple levels,
accommodating diverse architectural complexities. The key innovation is the
integration of an inter-pixel auto-attention mechanism into the AREN encoder.
This approach allows us to efficiently capture and utilize contextual
information across latent vectors. Additionally, our models uses additional
encoding levels to further enhance the model's representational power. Our
attention layer employs a minimal parameter approach, ensuring that latent
vectors are modified only when pertinent information from other pixels is
available. Experimental results demonstrate that our proposed modifications
lead to significant improvements in data representation and generation, making
VQ-VAEs even more suitable for a wide range of applications as the presented.Comment: 5 pages, 4 figures, 2 table2, 1 pseudo-cod
Spatial Interpolation contribution to noise maps uncertainty
Noise maps results are usually presented as contour graphs or isophone curves, which describe the sound levels as functions of spatial location. These maps are added to Geographic Information Systems (GIS), allowing sound level evaluation as a function of the continuous coordinates x and y, for a given height above ground. Although the outcome of the system is a continuous variable, the calculations that allow its evaluation are obtained in discrete points that form a calculation grid, which is created by the application of spatial sampling techniques. Using spatial interpolation tools, values are assigned to the locations in which measures or calculations have not been performed. The application of sampling and interpolation techniques (the type of grid, its density, the interpolation algorithms…) contributes to the uncertainty of the results. This paper describes a calculation method to quantify the uncertainty associated to the spatial sampling and interpolation process. We also propose a revision of the classical meaning of noise mapping uncertainty, taking into account the final application of the results
Divorcio por causal de separación de hecho y la pérdida de la sociedad de gananciales en la ciudad de Abancay
La investigación tuvo como objetivo determinar la incidencia del divorciopor causal de separación de hecho en la perdida de la sociedad de gananciales en la ciudad de Abancay. Se utilizó para alcanzar dicho objetivo el tipo explicativo y un diseño expost - facto, asimismo la población objeto estuvo constituida por 345 Jueces de Familia y litigantes especializados. Al calcular el tamaño de la muestra se trabajó finalmente con 182 personas.The research aimed to determine the incidence of divorce due to de facto
separation in the loss of the community of acquisitions in the city of
Abancay The descriptive method and a non-experimental design were
used to achieve this objective, and the target population was composed of
345 Family Judges and specialized litigants. When calculating the sample
size, we finally worked with 182 people
Influence of the hydrodynamic size and ζ potential of manganese ferrite nanozymes as peroxidase‒mimicking catalysts at ph 4 in different buffers
Peroxidase-mimicking activity of manganese ferrite nanoparticles was studied, based on the oxidation of TMB (3,3’,5,5’-tetramethylbenzidine) by H2O2 at pH 4 using acetate and citrate buffers. The aim of this study was to examine this reaction not only by enzymology (Michaelis-Menten kinetics model) but also by surface science methods of heterogeneous catalysis. Nanoparticles were characterized by different techniques to determine their phase composition, surface area, surface composition, surface charge, pH at the point of zero charge, magnetization, mean size, and morphology. Results show that the nanozymes are coated with buffer anions that form a shell around them. In addition, the hydrodynamic size and ζ potential of the nanoparticles under reaction conditions play an important role in the proposed Fenton-type oxidation mechanism. A greater amount of Mn ions than Fe ions leaches from the nanozymes during TMB oxidation, likely because Fe is better protected than Mn by the buffer coating the outer surface of the nanoparticles. This shortcoming must be addressed when applying these nanomaterials.Operative Program, and Junta de Andalucía FEDER 2014-2020
(Projects FEDER-UJA-138062
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