Search results for "DOMAIN"

The Oblivion of Demography in Sustainability’s Studies

2017

[RESUMEN] A lo largo de la historia del Homo sapiens, su número se ha mantenido muy reducido y hubo que esperar a principios del siglo XIX para que alcanzara los mil millones. Se inició entonces un rápido crecimiento y durante el siglo XX la población mundial casi se cuadriplicó, superando los 6000 millones, lo que llevó a estudiar, con lógica preocupación, los posibles efectos de esta explosión demográfica sobre el conjunto de la biosfera y sobre la propia especie humana. Hoy, sin embargo, cuando se han sobrepasado los 7500 millones y la población mundial sigue aumentando en unos 80 millones cada año, la problemática demográfica ha dejado de tener una presencia relevante en los estudios y …

Discrete frequency models for inventory management – an introduction

2001

Abstract The paper deals with the problem of devising a periodic replenishment policy when orders must be periodic, but only a given, discrete set of order frequencies can be used. The multi-item, instantaneous replenishment case with known demand is studied. In particular, staggering policies somehow arranging replenishments not to come at the same time instants are considered. The paper is composed of three parts: first, a taxonomy of several versions of the discrete frequency problem is proposed, according to different elements; in the second part, a general mixed integer programming model is proposed which is able to capture the peculiarities of the whole spectrum of this kind of proble…

A note on comparative downside risk aversion

2005

International audience; We provide comparative global conditions for downside risk aversion, which are similar to the ones studied by Ross for risk aversion. We define a coefficient of downside risk aversion, and study its local properties.

Ciencia de la sostenibilidad: un nuevo campo de conocimientos al que la química y la educación química están contribuyendo

2013

Los dominios de conocimiento más diversos contribuyen actualmente al tratamiento de problemas socioambientales. Se han publicado muchos artículos y libros en los campos de Química Verde, Ecología Industrial, Ingeniería Ambiental, Economía Verde (baja en carbono), Educación Ambiental, etc. Pero hace poco se entendió que estas contribuciones son insuficientes y que necesitamos una Ciencia de Sostenibilidad que los integra a todos. Este documento estudia el surgimiento de este nuevo campo de conocimiento e investigación, cuyo objetivo explícito es contribuir a la transición a una sociedad sostenible. The most diverse knowledge domains are currently contributing to the treatment of socio-enviro…

Electromagnetic Form Factors in the Time Like Domain

2008

The electromagnetic form factors in the time like domain can be accessed by the reaction p ¯ p → e + e − or its time inversed process. Despite a long standing experimental effort to determine these form factors, the precision in the knowledge of the ratio | G E | / | G M | ist still very poor in the time like domain. All world data suffer from limited statistics and therefore have used the hypothesis of | G E | = | G M | in order to extract a value for | G M | . While there is no theory argument for this hypothesis, recent JLAB data from polarisation transfer in elastic electron scattering show, that this hypothesis does not hold. Only a few data points allow the determination of | G E | / …

Elastoplastic analysis by the multidomain Symmetric Boundary Element Method

2009

The behavior of the 180° domain walls in disordered dielectrics like KTaO3 : Li and KTaO3 : Nb

2003

We calculate the structure of 180° domain wall in disordered ferroelectrics with random site electric dipoles (i.e. those like K 1-x Li x TaO 3 , KTa 1-x Nb x O 3 , where Li + or Nb 5+ are off-center ions forming impurity dipoles). The calculation is performed on the base of the free energy functional of disordered dielectrics derived earlier [M. D. Glinchuk et al., Phase Transit., 2003 (to be published)] within the framework of a random field method. We obtain the domain wall thickness as a function of impurity dipole concentration n and temperature T. It is shown that in disordered ferroelectrics the domain wall is usually broader than in their ordered counterparts. The thickness increase…

CNN based Gearbox Fault Diagnosis and Interpretation of Learning Features

2021

Machine learning based fault diagnosis schemes have been intensively proposed to deal with faults diagnosis of rotating machineries such as gearboxes, bearings, and electric motors. However, most of the machine learning algorithms used in fault diagnosis are pattern recognition tools, which can classify given data into two or more classes. The underlined physical phenomena in fault diagnosis are not directly interpretable in machine learning schemes, thus it is usually called black/gray box models. In this study, convolutional neural networks (CNN) machine learning algorithm is proposed to classify gearbox faults, and the learning features of the CNN filters are visualized to understand the…

An Advanced Numerical Model in Solving Thin-Wire Integral Equations by Using Semi-Orthogonal Compactly Supported Spline Wavelets

2003

Abstract—In this paper, the semi-orthogonal compactly sup- ported spline wavelets are used as basis functions for the efficient solution of the thin-wire electric field integral equation (EFIE) in frequency domain. The method of moments (MoM) is used via the Galerkin procedure. Conventional MoM directly applied to the EFIE, leads to dense matrix which often becomes computation- ally intractable when large-scale problems are approached. To overcome these difficulties, wavelets can be used as a basis set so obtaining the generation of a sparse matrix; this is due to the local supports and the vanishing moments properties of the wavelets. In the paper, this technique is applied to analyze elec…

An inverse problem for the fractional Schrödinger equation in a magnetic field

2020

This paper shows global uniqueness in an inverse problem for a fractional magnetic Schrodinger equation (FMSE): an unknown electromagnetic field in a bounded domain is uniquely determined up to a natural gauge by infinitely many measurements of solutions taken in arbitrary open subsets of the exterior. The proof is based on Alessandrini's identity and the Runge approximation property, thus generalizing some previous works on the fractional Laplacian. Moreover, we show with a simple model that the FMSE relates to a long jump random walk with weights.