Search results for "NLO"
showing 10 items of 285 documents
Finite-Element Formulation of a Nonlocal Hereditary Fractional-Order Timoshenko Beam
2017
AbstractA mechanically-based nonlocal Timoshenko beam model, recently proposed by the authors, hinges on the assumption that nonlocal effects can be modeled as elastic long-range volume forces and moments mutually exerted by nonadjacent beam segments, which contribute to the equilibrium of any beam segment along with the classical local stress resultants. Long-range volume forces/moments linearly depend on the product of the volumes of the interacting beam segments, and on pure deformation modes of the beam, through attenuation functions governing the space decay of nonlocal effects. This paper investigates the response of this nonlocal beam model when viscoelastic long-range interactions a…
Strain gradient plasticity, strengthening effects and plastic limit analysis
2010
Abstract Within the framework of isotropic strain gradient plasticity, a rate-independent constitutive model exhibiting size dependent hardening is formulated and discussed with particular concern to its strengthening behavior. The latter is modelled as a (fictitious) isotropic hardening featured by a potential which is a positively degree-one homogeneous function of the effective plastic strain and its gradient. This potential leads to a strengthening law in which the strengthening stress, i.e. the increase of the plastically undeformed material initial yield stress, is related to the effective plastic strain through a second order PDE and related higher order boundary conditions. The plas…
Collaborative Content Downloading in VANETs with Fuzzy Comprehensive Evaluation
2019
Vehicle collaborative content downloading has become a hotspot in current vehicular ad-hoc network (VANET) research. However, in reality, the highly dynamic nature of VANET makes users lose resources easily, and the transmission of invalid segment data also wastes valuable bandwidth and storage of the users&rsquo
Mathematical modeling of a vehicle crash test based on elasto-plastic unloading scenarios of spring-mass models
2011
Published version of an article in the journal: The International Journal of Advanced Manufacturing Technology. Also available from the publisher on SpringerLink: htp://dx.doi.org/10.1007/s00170-010-3056-x This paper investigates the usability of spring which exhibit nonlinear force-deflection characteristic in the area of mathematical modeling of vehicle crash. We present a method which allows us to obtain parameters of the spring-mass model basing on the full-scale experimental data analysis. Since vehicle collision is a dynamic event, it involves such phenomena as rebound and energy dissipation. Three different spring unloading scenarios (elastic, plastic, and elasto-plastic) are covered…
Pressure Dependence of the Band Gaps and Charge Densities in Si
1994
The empirical local and nonlocal pseudopotentials of Si which can describe the electronic energy structure over a wide energy range of more than 20 eV from the bottom of the valence band is determined for different pressures. The nonlocality of the potential is described by the Gaussian model. The predictions for the linear and quadratic pressure coefficients are consistent with the experiment. The valence charge densities of Si under high pressure are studied. The forbidden X-ray factor F(222) is very stable under pressure and changes by less than 3% under volume changes of the order of 5%.
Anomaly Detection from Network Logs Using Diffusion Maps
2011
The goal of this study is to detect anomalous queries from network logs using a dimensionality reduction framework. The fequencies of 2-grams in queries are extracted to a feature matrix. Dimensionality reduction is done by applying diffusion maps. The method is adaptive and thus does not need training before analysis. We tested the method with data that includes normal and intrusive traffic to a web server. This approach finds all intrusions in the dataset. peerReviewed
Academic Workload, Workaholism e benessere individuale: uno studio esplorativo su effetti e conseguenze del sovraccarico lavorativo in accademia
2016
La cosiddetta "dipendenza da lavoro" sembra essere uno stato sempre più diffuso all'interno delle professioni ad alta responsabilità: sebbene essa sia in qualche modo giustificata, in quanto approvata socialmente e culturalmente, non va dimenticato che essa è pur sempre una situazione in grado, a lungo termine, di produrre stati di malessere diffusi nelle persone che ne sono coinvolte. Tale condizione di continuo e persistente stato di impegno professionale è tipico di coloro i quali lavorano presso strutture accademiche: esiste un interessante filone di ricerca che ha esplorato il persistente aumento di richieste lavorative che affligge il mondo accademico occidentale, e che sovrappone ad …
Constrained differential inclusions with nonlocal initial conditions
2017
International audience; We show existence for the perturbed sweeping process with nonlocal initial conditions under very general hypotheses. Periodic, anti-periodic, mean value and multipoints conditions are included in this study. We give abstract results for differential inclusions with nonlocal initial conditions through bounding functions and tangential conditions. Some applications to differential complementarity systems and to vector hysteresis are given.
NLO properties of polythiophenes galvanostatically electrodeposited on ITO glasses
2008
International audience; A study of nonlinear optical properties of ClO4-doped polythiophenes, galvanostatically electrodeposited on ITO glasses, was carried out using second and third harmonic generation measurements. The effect of the oxidation state of the polymeric films was studied by comparing the nonlinear optical response of oxidised and reduced polythiophenes. Reduced polymeric films show higher values of the second and third order susceptibilities and a lower absorbance in respect to the oxidised ones. The morphology of the polythiophene films was studied by scanning electron and atomic force microscopes.
L’humour français et anglais, entre recherche et pratique : Comment joindre les deux (quatre) bouts ?
2013
International audience