391 research outputs found
On the equivalence of stochastic completeness, Liouville and Khas'minskii condition in linear and nonlinear setting
Set in Riemannian enviroment, the aim of this paper is to present and discuss
some equivalent characterizations of the Liouville property relative to special
operators, in some sense modeled after the p-Laplacian with potential. In
particular, we discuss the equivalence between the Lioville property and the
Khas'minskii condition, i.e. the existence of an exhaustion functions which is
also a supersolution for the operator outside a compact set. This generalizes a
previous result obtained by one of the authors and answers to a question in
"Aspects of potential theory, linear and nonlinear" by Pigola, Rigoli and
Setti.Comment: 34 pages. The pasting lemma has been improved to fix a technical
problem in the main theorem. Final version, to appear on Trans. Amer. Math.
So
High Temperature Transformations in a Steel-TiCN Cermet
The influence of the carbon content on the microstructure, phase transformation and hardness of an iron-based cermet is studied. The cermet is constituted by a high-alloyed steel as matrix, and TiCN particles (50 vol.%) as reinforcement. The material is produced by conventional powder metallurgy techniques, that is, uniaxial pressing and sintering, and the carbon content is varied from 0 wt.% to 1 wt.%. The aim of the research is the understanding of the transformations undergone by the material with increasing C amounts when temperature is increased. For this purpose, the cermet is studied by mechanical spectroscopy (MS) and differential thermal analysis (DTA) and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and hardness measurements. The equilibrium phase diagram calculated by ThermoCalc software contributes to explain the differences found on phase transformations with respect to the C content of the cermet.The authors would like to acknowledge the financial support from the Spanish Ministry of Science and Innovation through the R&D Project MAT2009-14448-C02 and Regional Government of Madrid through the program ESTRUMAT-CM (Ref. S2009/MAT-1585)Publicad
All-for-One and One-For-All: Deep learning-based feature fusion for Synthetic Speech Detection
Recent advances in deep learning and computer vision have made the synthesis
and counterfeiting of multimedia content more accessible than ever, leading to
possible threats and dangers from malicious users. In the audio field, we are
witnessing the growth of speech deepfake generation techniques, which solicit
the development of synthetic speech detection algorithms to counter possible
mischievous uses such as frauds or identity thefts. In this paper, we consider
three different feature sets proposed in the literature for the synthetic
speech detection task and present a model that fuses them, achieving overall
better performances with respect to the state-of-the-art solutions. The system
was tested on different scenarios and datasets to prove its robustness to
anti-forensic attacks and its generalization capabilities.Comment: Accepted at ECML-PKDD 2023 Workshop "Deep Learning and Multimedia
Forensics. Combating fake media and misinformation
Sclerostin and Insulin Resistance in Prediabetes: Evidence of a Cross Talk Between Bone and Glucose Metabolism
A gene mutation of the Wnt/β-catenin signaling cascade is present in rare patients with the insulin resistance syndrome. Sclerostin is a circulating peptide inhibiting Wnt/β-catenin signaling. Our aims were to evaluate serum sclerostin in subjects with prediabetes and to analyze its relationship with insulin resistance and β-cell function
Grain boundary relaxation in yellow gold bi-crystals
The mechanical loss spectrum of a yellow gold bi-crystal is presented and analyzed in detail. The relaxation strength is monitored as a function of several geometrical parameters such as sample width, length and thickness. It is found that the relaxation strength is proportional to the GB density (the inverse width), whereas it depends linearly on the sample thickness. The experimental findings are compared to finite elements (FE) simulations, where the material can glide frictionless along the grain boundary. The simulations show the same dependencies as the mechanical loss measurements. The relaxation peak in the loss spectrum can be interpreted as due to GB sliding accommodated by the elastic deformation of the grains. (C) 2015 Elsevier B.V. All rights reserved
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