Search results for "force"
showing 10 items of 3423 documents
Realizing Undelayed N-step TD prediction with neural networks
2010
There exist various techniques to extend reinforcement learning algorithms, e.g., eligibility traces and planning. In this paper, an approach is proposed, which combines several extension techniques, such as using eligibility-like traces, using approximators as value functions and exploiting the model of the environment. The obtained method, ‘Undelayed n-step TD prediction’ (TD-P), has produced competitive results when put in conditions of not fully observable environment.
Comparative Study of the Mechanical Unfolding Pathways of α- and β-Peptides
2015
Using molecular simulations, we analyze the unfolding pathways of various peptides. We compare the mechanical unfolding of a β-alanine's octamer (β-HAla8) and an α-alanine's decamer (α-Ala10). Using force-probe molecular-dynamics simulations, to induce unfolding, we show that the 3(14)-helix formed by β-HAla8 is mechanically more stable than the α-helix formed by α-Ala10, although both structures are stabilized by six hydrogen bonds. Additionally, computations of the potential of mean force validate this result and show that also the thermal stability of the 3(14)-helix is higher. It is demonstrated that β-HAla8 unfolds in a two-step fashion with a stable intermediate. This is contrasted wi…
Dynamical Casimir-Polder forces
2011
We consider the dynamical Casimir-Polder force on an atom placed near an infinite conducting wall. The system is initially in a non equilibrium configuration such as a bare or a partially dressed state, and its time evolution is considered as well as the time dependence of the atom-wall Casimir-Polder interaction. A possible scheme to generate experimentally the initial partially dressed state and to detect the dynamical Casimir-Polder force is discussed.
Dynamical Casimir-Polder interaction between an atom and a real surface
2014
We discuss the dynamical (i.e. time-dependent) Casimir-Polder force between a neutral atom and a real surface of arbitrary material, under non-equilibrium conditions. More specifically, we consider a polarisable neutral atom placed near a surface with arbitrary dielectric properties and we investigate the dynamical dressing and the consequent dynamical Casimir-Polder potential after the non-adiabatic (sudden) change of parameters involved in the atom-field coupling, such as the atomic transition frequency or the transition dipole moment. Using time-dependent perturbation theory and the matter-assisted field approach, we discuss how the physical properties of the real surface can influence t…
Application of a non linear local analysis method for the problem of mixed convection instability
2007
Abstract We consider the problem of laminar mixed convection flow between parallel, vertical and uniformly heated plates where the governing dimensionless parameters are the Prandtl, Rayleigh and Reynolds numbers. Using the method based on the centre manifold theorem which was derived from the general theory of dynamical systems, we reduce a three-dimensional simplified model of ordinary differential amplitude equations emanating from the original Navier-Stokes system of the problem in the vicinity of a trivial stationary solution. We have found that when the forcing parameter, the Rayleigh number, increases beyond the critical value Ra s , the stationary solution is a pitchfork bifurcation…
Quality evaluation of grapes for mechanical harvest using vis NIR spectroscopy
2019
Mechanical harvest of grapes is one of the operations that mostly influence the quality of the future wine. The shaking frequency of the harvesting machine is usually adjusted on the basis of the grape berry characteristics in order to limit grape juice production that is a potential cause of uncontrolled fermentations. These evaluations usually require time, personnel and laboratory analyses. The introduction of a vis NIR system to rapidly and reliably evaluate the berry properties in field before mechanical harvest could be a good alternative. The aim of this study was to evaluate the feasibility of applying vis NIR spectroscopy as a non-destructive technique on grapes cv. Syrah and Chard…
Ligand-Based Charge-Transfer Luminescence in Ionic Cyclometalated Iridium(III) Complexes Bearing a Pyrene-Functionalized Bipyridine Ligand: A Joint T…
2012
Two new heteroleptic iridium(III) complexes [Ir(ppy)(2)(pyr(2)bpy)][PF(6)] ([1a][PF(6)]) and [Ir(dfppy)(2)(pyr(2)bpy)][PF(6)] ([2a][PF(6)]), where Hppy = 2-phenylpyridine, Hdfppy = 2-(3,5-difluorophenyl)pyridine, and pyr(2)bpy = 5,5'-bis(pyren-1-yl)-2,2'-bipyridine, have been synthesized and fully characterized. The single-crystal structures of pyr(2)bpy and the complexes 4{[1a][PF(6)]}·2CH(2)Cl(2)·9H(2)O and [2a][PF(6)]·0.25CH(2)Cl(2)·H(2)O have been determined. The effect of the pyrene substituents on the electronic properties is investigated through a comprehensive photophysical and theoretical study on the two complexes in comparison to reference complexes without substituents on the an…
The thin and medium filters of the EPIC camera on-board XMM-Newton: measured performance after more than 15 years of operation
2016
After more than 15 years of operation of the EPIC camera on board the XMM-Newton X-ray observatory, we have reviewed the status of its Thin and Medium filters. We have selected a set of Thin and Medium back-up filters among those still available in the EPIC consortium and have started a program to investigate their status by different laboratory measurements including: UV/VIS transmission, Raman scattering, X-Ray Photoelectron Spectroscopy, and Atomic Force Microscopy. Furthermore, we have investigated the status of the EPIC flight filters by performing an analysis of the optical loading in the PN offset maps to gauge variations in the optical and UV transmission. We both investigated repea…
Appeal against the Decision on the Application for a Declaration on enforceability. Procedure to Contest the Decision Given on Appeal. Refusal or Rev…
2016
Lo scritto è un commento agli articoli da 50 a 58 del Regolamento n. 650 del 2012 del Parlamento Europeo e del Consiglio del 4 luglio 2012, relativo alla competenza, alla legge applicabile, al riconoscimento e all’esecuzione delle decisioni e all’accettazione e all’esecuzione degli atti pubblici in materia di successioni e alla creazione di un certificato successorio europeo. Lo scritto affronta i temi relativi alla impugnazione avverso la decisione emessa in seguito alla istanza per il riconoscimento delle sentenze e dei provvedimenti stranieri nelle materie oggetto del regolamento; il procedimento per impugnare le sentenza emesse in seguito all'appello; il rifiuto o la revoca del riconosc…
EUROASPIRE IV: A European Society of Cardiology survey on the lifestyle, risk factor and therapeutic management of coronary patients from 24 European…
2016
AIMS: To determine whether the Joint European Societies guidelines on cardiovascular prevention are being followed in everyday clinical practice of secondary prevention and to describe the lifestyle, risk factor and therapeutic management of coronary patients across Europe. METHODS AND RESULTS: EUROASPIRE IV was a cross-sectional study undertaken at 78 centres from 24 European countries. Patients <80 years with coronary disease who had coronary artery bypass graft, percutaneous coronary intervention or an acute coronary syndrome were identified from hospital records and interviewed and examined ≥ 6 months later. A total of 16,426 medical records were reviewed and 7998 patients (24.4% female…