Variational Inequality Approach to Stochastic Nash Equilibrium Problems with an Application to Cournot Oligopoly

In this note we investigate stochastic Nash equilibrium problems by means of monotone variational inequalities in probabilistic Lebesgue spaces. We apply our approach to a class of oligopolistic market equilibrium problems where the data are known through their probability distributions.Comment: 19 pages, 2 table

Random Variational Inequalities with Applications to Equilibrium Problems under Uncertainty

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A Variational Inequality Approach to a Class of Environmental Equilibrium Problems

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Identification Of A Parameter in Fourth-Order Partial Differential Equations By An Equation Error Approach

The objective of this short note is to employ an equation error approach to identify a variable parameter in fourth-order partial differential equations. Existence and convergence results are given for the optimization problem emerging from the equation error formulation. Finite element based numerical experiments show the effectiveness of the proposed framework

WebSocket Integration in Django

Nowadays Web technologies have become more common as they improve the work of astronomers by easing, for example, the monitoring and analysing of data. The Django Python framework is one of the most widely used libraries for developing Web applications as it offers several advantages. However, the necessity of continuously deal with data in real time, such as tracking atmospheric parameters, analysing the evolution of the light curve during a transient event, displaying inline vector graphics for interactive plots and representation, has constantly grown in Astronomy and Astrophysics, and this has naturally involved in new challenges. Nevertheless the WebSocket protocol represents the best option to manage real-time data, but it is not supported by Django natively. This report provides an overview of the WebSocket protocol and advances the integration of a WebSocket server as a loosely coupled service within a Django application by illustrating a simple and non-invasive methodology, within a proof-of-concept using open source software, which avoid switching to new deployment architectures, with all its consequences. Such proposed technique can be applied to any generic scenarios, such as done for the TMSS project included in the report as use case example

Toward porting Astrophysics Visual Analytics Services to the European Open Science Cloud

The European Open Science Cloud (EOSC) aims to create a federated environment for hosting and processing research data to support science in all disciplines without geographical boundaries, such that data, software, methods and publications can be shared as part of an Open Science community of practice. This work presents the ongoing activities related to the implementation of visual analytics services, integrated into EOSC, towards addressing the diverse astrophysics user communities needs. These services rely on visualisation to manage the data life cycle process under FAIR principles, integrating data processing for imaging and multidimensional map creation and mosaicing, and applying machine learning techniques for detection of structures in large scale multidimensional maps

The Gaia AVU-GSR parallel solver: preliminary porting with OpenACC parallelization language of a LSQR-based application in perspective of exascale systems

The Gaia Astrometric Verification Unit-Global Sphere Reconstruction (AVU-GSR) Parallel Solver aims to find the positions and the proper motions for ~10^8 stars in our galaxy, besides the attitude and the instrumental settings of the Gaia satellite, and the global parameter of the post Newtonian formalism. To find these parameters, the code solves a system of linear equations, × = , where the coefficient matrix is large, containing ~10^11 x 10^8 elements, and sparse. The system of equations is solved with a customized implementation of the iterative preconditioned (PC)-LSQR algorithm and is parallelized on the CPU with MPI+OpenMP, where the computation related to different horizontal portions of the coefficient matrix is assigned to different MPI processes and it is further parallelized on the OpenMP threads. To improve the code performance, we explored the feasibility of a porting of this application on a GPU environment, by replacing the OpenMP directives with the OpenACC correspondent ones. In this preliminary porting, the ~95% of the data is copied from the host (CPU) to the device (GPU) before the entire cycle of iterations, making the code compute bound rather than data-transfers bound. The OpenACC code accelerates of a factor of ~1.5 compared to the OpenMP code. The OpenACC application runs on multiple GPUs and it was tested on the CINECA SuperComputer Marconi100, with 4 V100 GPUs per node having 16 GB of memory each. A following porting, where the OpenACC language is replaced with CUDA, was performed, optimizing the preliminary porting with OpenACC. The CUDA code has just been put into production on Marconi100 and we plan to run it on the future pre-exascale platform Leonardo of CINECA, with 4 next-generation A100 GPUs per node

Electron structure, Zitterbewegung, and the new non-linear Dirac-like equation

The recent literature shows a renewed interest, with various independent approaches, in the classical theories for spin. Considering the possible interest of those results, at least for the electron case, we purpose in this paper to explore their physical and mathematical meaning, by the natural and powerful language of Clifford algebras (which, incidentally, will allow us to unify those different approaches). In such theories, the ordinary electron is in general associated to the mean motion of a point-like "constituent" Q, whose trajectory is a cylindrical helix. We find, in particular, that the object Q obeys a new, non-linear Dirac-like equation, such that --when averaging over an internal cycle (which corresponds to linearization)-- it transforms into the ordinary Dirac equation (valid for the electron as a whole).Comment: LaTeX; 19 pages; this is a corrected version of work appeared partly in Hadronic J. 18 (1995) 97 and partly in Phys.Lett. B318 (1993) 48

Global urban environmental change drives adaptation in white clover

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale