Search results for "9(39)"
showing 10 items of 677 documents
The reliability of spanish and german electricity forward prices. Databases and price discovery process
2021
Given the existence of different databases from different sources that offer information on forward electricity prices, the need to compare them arises to guarantee that research results and trading decisions based on them are not sensitive to the database used. We worked with forward electricity prices traded over the counter, closest month to maturity, covering the period from 2010 to 2016 for the Spanish over the counter (OTC) market, and from 2008 to 2016 for the German OTC market. The goal of this paper was to test whether there were significant discrepancies between the price series provided by two of the main agencies of financial information (Thomson Reuters and Bloomberg), as well …
Effective Hamiltonians in Nonrelativistic Quantum Electrodynamics
2021
In this paper, we consider some second-order effective Hamiltonians describing the interaction of the quantum electromagnetic field with atoms or molecules in the nonrelativistic limit. Our procedure is valid only for off-energy-shell processes, specifically virtual processes such as those relevant for ground-state energy shifts and dispersion van der Waals and Casimir-Polder interactions, while on-energy-shell processes are excluded. These effective Hamiltonians allow for a considerable simplification of the calculation of radiative energy shifts, dispersion, and Casimir-Polder interactions, including in the presence of boundary conditions. They can also provide clear physical insights int…
Stieltjes Differential Inclusions with Periodic Boundary Conditions without Upper Semicontinuity
2021
We are studying first order differential inclusions with periodic boundary conditions where the Stieltjes derivative with respect to a left-continuous non-decreasing function replaces the classical derivative. The involved set-valued mapping is not assumed to have compact and convex values, nor to be upper semicontinuous concerning the second argument everywhere, as in other related works. A condition involving the contingent derivative relative to the non-decreasing function (recently introduced and applied to initial value problems by R.L. Pouso, I.M. Marquez Albes, and J. Rodriguez-Lopez) is imposed on the set where the upper semicontinuity and the assumption to have compact convex value…
Statistical properties of general Markov dynamical sources: applications to information theory
2004
In \textitDynamical sources in information theory: fundamental intervals and word prefixes, B. Vallée studies statistical properties of words generated by dynamical sources. This is done using generalized Ruelle operators. The aim of this article is to generalize sources for which the results hold. First, we avoid the use of Grotendieck theory and Fredholm determinants, this allows dynamical sources that cannot be extended to a complex disk or that are not analytic. Second, we consider Markov sources: the language generated by the source over an alphabet \textbfM is not necessarily \textbfM^*.
The laicism in the Ilnd Republic. The vi I I about historic layman
2013
This work is focussed to the study of Laicism, an aspect of the teaching policy during the IInd Republic in Spain. Particularly, its devopment in the teachers training is proposed, in spite of the opposition and controversial that this poposal has raised.
Optimal control in models with conductive‐radiative heat transfer
2003
In this paper an optimal control problem for the elliptic boundary value problem with nonlocal boundary conditions is considered. It is shown that the weak solutions of the boundary value problem depend smoothly on the control parameter and that the cost functional of the optimal control problem is Frechet differentiable with respect to the control parameter. Optimalus valdymas modeliuose su laidžiu-radioaktyviu šilumos pernešimu Santrauka Darbe nagrinejamas nelokalaus kraštinio uždavinio optimalaus valdymo uždavinys. Parodyta, kad silpnasis kraštinio uždavinio sprendinys tolydžiai priklauso nuo valdomojo parametro, taigi, optimalaus valdymo tikslo funkcija yra diferencijuojama Freše prasme…
Profesores y estudiantes en la guerra civil española (1936-1939)
2011
Situación de profesores y estudiantes en la guerra civil española.
Revista de educación
2016
Los datos estadísticos suponen un elemento de gran relevancia para analizar la realidad educativa, independientemente de que esta sea, presente, pasada, global o parcial. Pese a su indudable trascendencia, los estudios de la denominada historia de la estadística escolar en España son muy escasos, especialmente los enmarcados en el siglo XX. El objetivo de este artículo es analizar los datos estadísticos referidos al bachillerato español en el periodo comprendido entre 1930 y 1970, haciendo especial hincapié en la presentación de la información, sus cambios y las razones que los motivaron. Para ello hemos efectuado, en primer término, una profunda revisión de las fuentes estadísticas disponi…
Revista complutense de educación
2019
espanolLa ensenanza secundaria espanola sufrio un notable cambio en la decada de 1950. Se produjo la ruptura efectiva del modelo de ensenanza dual, al permitir a chicos y chicas de familias obreras y de escasos ingresos accedieran al bachillerato, lo que les estaba practicamente vetado hasta entonces. Las autoridades educativas otorgaron tanta importancia a esa politica que tuvo denominacion especifica: la extension de la ensenanza media. Este trabajo se centra en el analisis del discurso que apoyo y explicito tal politica. Para ello se han localizado declaraciones y tomas de posicion de los principales responsables del ministerio de educacion que conformaron el discurso oficial que impulso…
A posteriori error identities for nonlinear variational problems
2015
A posteriori error estimation methods are usually developed in the context of upper and lower bounds of errors. In this paper, we are concerned with a posteriori analysis in terms of identities, i.e., we deduce error relations, which holds as equalities. We discuss a general form of error identities for a wide class of convex variational problems. The left hand sides of these identities can be considered as certain measures of errors (expressed in terms of primal/dual solutions and respective approximations) while the right hand sides contain only known approximations. Finally, we consider several examples and show that in some simple cases these identities lead to generalized forms of the …