Convergence of level sets in fractional Laplacian regularization

The use of the fractional Laplacian in image denoising and regularization of inverse problems has enjoyed a recent surge in popularity, since for discontinuous functions it can behave less aggressively than methods based on $H^1$ norms, while being linear and computable with fast spectral numerical methods. In this work, we examine denoising and linear inverse problems regularized with fractional Laplacian in the vanishing noise and regularization parameter regime. The clean data is assumed piecewise constant in the first case, and continuous and satisfying a source condition in the second. In these settings, we prove results of convergence of level set boundaries with respect to Hausdorff distance, and additionally convergence rates in the case of denoising and indicatrix clean data. The main technical tool for this purpose is a family of barriers constructed by Savin and Valdinoci for studying the fractional Allen-Cahn equation. To help put these fractional methods in context, comparisons with the total variation and classical Laplacian are provided throughout.Comment: 33 pages, 1 figur

Reynolds number and Shallow Depth Sloshing

The dependence on the Reynolds number of shallow depth sloshing flows inside rectangular tanks subjected to forced harmonic motion is studied in this paper with weakly compressible SPH. We are interested in assessing the in fluenceof viscous effects on the dynamics of shallow depth sloshing flows by using an SPH solver and by comparing with a Navier-Stokes level-set solver results. The goal of trying to model these viscous flows is compromised by the resolution requested due to their Reynolds number, if boundary layer effects are to be modeled. The convenience and feasibility of the implementation of free-slip and no-slip boundary conditions is also discusse

Biomimetic flow fields for proton exchange membrane fuel cells: A review of design trends

Bipolar Plate design is one of the most active research fields in Polymer Electrolyte Membrane Fuel Cells (PEMFCs) development. Bipolar Plates are key components for ensuring an appropriate water management within the cell, preventing flooding and enhancing the cell operation at high current densities. This work presents a literature review covering bipolar plate designs based on nature or biological structures such as fractals, leaves or lungs. Biological inspiration comes from the fact that fluid distribution systems found in plants and animals such as leaves, blood vessels, or lungs perform their functions (mostly the same functions that are required for bipolar plates) with a remarkable efficiency, after millions of years of natural evolution. Such biomimetic designs have been explored to date with success, but it is generally acknowledged that biomimetic designs have not yet achieved their full potential. Many biomimetic designs have been derived using computer simulation tools, in particular Computational Fluid Dynamics (CFD) so that the use of CFD is included in the review. A detailed review including performance benchmarking, time line evolution, challenges and proposals, as well as manufacturing issues is discussed.Ministerio de Ciencia, Innovación y Universidades ENE2017-91159-EXPMinisterio de Economía y Competitividad UNSE15-CE296

Understanding the Influence of Rendering Parameters in Synthetic Datasets for Neural Semantic Segmentation Tasks

Cursos e Congresos , C-155[Abstract] Deep neural networks are well known for demanding large amounts of training data, motivating the appearance of multiple synthetic datasets covering multiple domains. However, synthetic datasets have not yet outperformed real data for autonomous driving applications, particularly for semantic segmentation tasks. Thus, a deeper comprehension about how the parameters involved in synthetic data generation could help in creating better synthetic datasets. This work provides a summary review of prior research covering how image noise, camera noise and rendering photorealism could affect learning tasks. Furthermore, we presents novel experiments aimed at advancing our understanding around generating synthetic data for autonomous driving neural networks aimed at semantic segmentationXunta de Galicia; ED431F 2021/11This work has been supported by the Spanish Ministry of Science and Innovation (AEI/PID2020-115734RB-C22). We also want to acknowledge Side Effects Software Inc. for their support to this work. J.A. Iglesias-Guitian also acknowledges the UDC-Inditex InTalent programme, the Ministry of Science and Innovation (AEI/RYC2018-025385-I) and Xunta de Galicia (ED431F 2021/11). CITIC is funded by the Xunta de Galicia through the collaboration agreement between the Consellería de Cultura, Educación, Formación Profesional e Universidades and the Galician universities for the reinforcement of the research centres of the Galician University System (CIGUS

Jamming and percolation of linear k -mers on honeycomb lattices

Numerical simulations and finite-size scaling analysis have been performed to study the jamming and percolation behavior of elongated objects deposited on two-dimensional honeycomb lattices. The depositing particle is modeled as a linear array of length k (so-called k -mer), maximizing the distance between first and last monomers in the chain. The separation between k -mer units is equal to the lattice constant. Hence, k sites are occupied by a k -mer when adsorbed onto the surface. The adsorption process starts with an initial configuration, where all lattice sites are empty. Then, the sites are occupied following a random sequential adsorption mechanism. The process finishes when the jamming state is reached and no more objects can be deposited due to the absence of empty site clusters of appropriate size and shape. Jamming coverage θ j , k and percolation threshold θ c , k were determined for a wide range of values of k ( 2 ≤ k ≤ 128 ). The obtained results shows that ( i ) θ j , k is a decreasing function with increasing k , being θ j , k → ∞ = 0.6007 ( 6 ) the limit value for infinitely long k -mers; and ( i i ) θ c , k has a strong dependence on k . It decreases in the range 2 ≤ k < 48 , goes through a minimum around k = 48 , and increases smoothly from k = 48 up to the largest studied value of k = 128 . Finally, the precise determination of the critical exponents ν , β , and γ indicates that the model belongs to the same universality class as 2D standard percolation regardless of the value of k considered.Fil: Iglesias Panuska, G. A.. Universidad Nacional de San Luis; ArgentinaFil: Centres, Paulo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

Catalytic applications of magnetic nanoparticles functionalized using iridium N-heterocyclic carbene complexes

synthetic modular methodology allows the preparation of catalytic materials based on magnetic nanoparticles with iridium N-heterocyclic carbene (NHC) complexes. Imidazolium salts containing a ketone/aldehyde as a pendant functional group are the key species prepared. The condensation reaction of the Cp*IrNHC–CHO compound with magnetic nanoparticles containing amine groups on the surface yields the covalent anchoring of the iridium complex to the surface of the magnetite. The catalytic properties have been evaluated in transfer hydrogenation. The iridium complexes and the material are active in the reduction of ketones using isopropanol as the solvent and hydrogen donor. The catalytic results reveal that the catalytic activity of the material and the molecular complex are equivalent. We have not observed any change in activity due to the support. The recyclability properties of the magnetic material have been evaluated. The results show that the catalyst activity is maintained for two runs. This work describes a simple methodology for anchoring molecular complexes on the surface of magnetic nanoparticles.We thank the financial support from the Ministerio de Cienciave Innovación of Spain (CTQ2011-24055/BQU). We thank the ‘Generalitat Valenciana’ for a fellowship (S. Sabater). The authors are grateful to the ‘Serveis Centrals d’Instrumentació Científica (SCIC)’ of the Universitat Jaume I

Clinical pharmacology facing the real-world setting: Pharmacovigilance, pharmacoepidemiology and the economic evaluation of drugs

Adverse drug reaction; Effectiveness; PharmacoeconomicsReacció adversa als fàrmacs; Eficàcia; FarmacoeconomiaReacción adversa a medicamentos; Eficacia; FarmacoeconomíaTraditionally, clinical pharmacology has focused its activities on drug-organism interaction, from an individual or collective perspective. Drug efficacy assessment by performing randomized clinical trials and analysis of drug use in clinical practice by carrying out drug utilization studies have also been other areas of interest. From now on, Clinical pharmacology should move from the analysis of the drug-individual interaction to the analysis of the drug-individual-society interaction. It should also analyze the clinical and economic consequences of the use of drugs in the conditions of normal clinical practice, beyond clinical trials. The current exponential technological development that facilitates the analysis of real-life data offers us a golden opportunity to move to all these other areas of interest. This review describes the role that clinical pharmacology has played at the beginning and during the evolution of pharmacovigilance, pharmacoepidemiology and economic drug evaluations in Spain. In addition, the challenges that clinical pharmacology is going to face in the following years in these three areas are going to be outlined too

All for One, and One for All: UrbanSyn Dataset, the third Musketeer of Synthetic Driving Scenes

We introduce UrbanSyn, a photorealistic dataset acquired through semi-procedurally generated synthetic urban driving scenarios. Developed using high-quality geometry and materials, UrbanSyn provides pixel-level ground truth, including depth, semantic segmentation, and instance segmentation with object bounding boxes and occlusion degree. It complements GTAV and Synscapes datasets to form what we coin as the 'Three Musketeers'. We demonstrate the value of the Three Musketeers in unsupervised domain adaptation for image semantic segmentation. Results on real-world datasets, Cityscapes, Mapillary Vistas, and BDD100K, establish new benchmarks, largely attributed to UrbanSyn. We make UrbanSyn openly and freely accessible (www.urbansyn.org).Comment: The UrbanSyn Dataset is available in http://urbansyn.org