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showing 10 items of 4526 documents

Computationally efficient dynamical analysis of optically driven injection-locked GaAs FET oscillators

1995

A computer-aided simulation technique for the dynamical analysis of a class of GaAs FET optically-driven injection-locked oscillators (ODILO's) is presented. By combining a measurement-derived nonlinear model of the illuminated transistor with a phasor-domain analysis method, a first-approximation - but phenomenologically complete - differential model of the synchronized oscillator is derived. Since amplitude and phase of waveform evolutions are directly addressed and evaluated in a stroboscopic-time scale, the calculation of the transient response to modulated input signals can be done in a more user-friendly and computationally efficient manner than possible through conventional time-doma…

AmplitudelawComputer scienceTransistorBandwidth (signal processing)Electronic engineeringNonlinear opticsOptical computingWaveformFigure of meritTransient responselaw.invention25th European Microwave Conference, 1995
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Computer simulations for bioequivalence trials: Selection of analyte in BCS class II and IV drugs with first-pass metabolism, two metabolic pathways …

2018

A semi-physiological two compartment pharmacokinetic model with two active metabolites (primary (PM) and secondary metabolites (SM)) with saturable and non-saturable pre-systemic efflux transporter, intestinal and hepatic metabolism has been developed. The aim of this work is to explore in several scenarios which analyte (parent drug or any of the metabolites) is the most sensitive to changes in drug product performance (i.e. differences in in vivo dissolution) and to make recommendations based on the simulations outcome. A total of 128 scenarios (2 Biopharmaceutics Classification System (BCS) drug types, 2 levels of KM Pgp, in 4 metabolic scenarios at 2 dose levels in 4 quality levels of t…

AnalyteCmaxPharmaceutical ScienceAdministration Oral02 engineering and technologyEquivalence Trials as TopicPharmacologyBioequivalence030226 pharmacology & pharmacyModels Biological03 medical and health sciencesFirst pass effect0302 clinical medicinePharmacokineticsHumansComputer SimulationPharmacokineticsIntestinal MucosaBiotransformationChemistryMembrane Transport Proteins021001 nanoscience & nanotechnologyBiopharmaceutics Classification SystemNONMEMNonlinear DynamicsPharmaceutical PreparationsSolubilityTherapeutic EquivalencyResearch DesignArea Under CurveLinear Models0210 nano-technologyMonte Carlo MethodDrug metabolismEuropean journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences
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Data for: Analytical induced force solution in conducting cylindrical bodies and rings due to a rotating finite permanent magnet

2019

Implementation of analytical current density solution in numerical calculations using Wolfram Mathematica software. THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOVE

Analytical MethodComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATIONComputer Science::Mathematical SoftwareComputer Science::Software EngineeringElectromagneticsComputer Science::Symbolic ComputationInterdisciplinary sciencesOtherNonlinear Sciences::Cellular Automata and Lattice Gases
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Effect of sodium to barium substitution on the space charge implementation in thermally poled glasses for nonlinear optical applications

2009

Thermally poled niobium borophosphate glasses in the system 0.55(0.95-y) NaPO{sub 3}+y/2 Ba(PO{sub 3}){sub 2}+0.05Na{sub 2}B{sub 4}O{sub 7})+0.45Nb{sub 2}O{sub 5} were investigated for second order optical nonlinear (SON) properties. Bulk glasses were studied by Raman spectroscopy, thermal analysis, optical and dielectric measurements. The sodium to barium substitution does not lead to significant changes in optical properties, crystallization of glasses and coordination environment of polarizable niobium atoms. However, the ionic conductivity decreases drastically with the increase of barium concentration. Secondary ion mass spectroscopy has been used to determine the element distribution …

Analytical chemistryNiobiumchemistry.chemical_element02 engineering and technologyDielectric01 natural sciencesSpace chargeInorganic Chemistrysymbols.namesakeIonic conductivity0103 physical sciencesMaterials ChemistryPhysical and Theoretical Chemistry010302 applied physicsThermal polingSecond-harmonic generationNonlinear opticsBarium[CHIM.MATE]Chemical Sciences/Material chemistrySecond harmonic generation021001 nanoscience & nanotechnologyCondensed Matter PhysicsSpace chargeElectronic Optical and Magnetic MaterialschemistryBorophosphate glasses[ CHIM.MATE ] Chemical Sciences/Material chemistryContent (measure theory)Ceramics and Compositessymbols0210 nano-technologyRaman spectroscopy
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Angular Pseudomomentum Theory for the Generalized Nonlinear Schr\"{o}dinger Equation in Discrete Rotational Symmetry Media

2009

We develop a complete mathematical theory for the symmetrical solutions of the generalized nonlinear Schr\"odinger equation based on the new concept of angular pseudomomentum. We consider the symmetric solitons of a generalized nonlinear Schr\"odinger equation with a nonlinearity depending on the modulus of the field. We provide a rigorous proof of a set of mathematical results justifying that these solitons can be classified according to the irreducible representations of a discrete group. Then we extend this theory to non-stationary solutions and study the relationship between angular momentum and pseudomomentum. We illustrate these theoretical results with numerical examples. Finally, we…

Angular momentumRotational symmetryFOS: Physical sciencesMultidimensional discrete solitonsPattern Formation and Solitons (nlin.PS)01 natural sciences010305 fluids & plasmasSchrödinger equationsymbols.namesake0103 physical sciences010306 general physicsNonlinear Schrodinger equationNonlinear Sciences::Pattern Formation and SolitonsNonlinear Schrödinger equationMathematicsAngular pseudomomentumMathematical analysisFísicaStatistical and Nonlinear PhysicsCondensed Matter PhysicsNonlinear Sciences - Pattern Formation and SolitonsMathematical theoryCondensed Matter - Other Condensed MatterNonlinear systemClassical mechanicsIrreducible representationsymbolsDiscrete symmetry mediaSolitonMATEMATICA APLICADAOther Condensed Matter (cond-mat.other)
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Wulff shape characterizations in overdetermined anisotropic elliptic problems

2017

We study some overdetermined problems for possibly anisotropic degenerate elliptic PDEs, including the well-known Serrin's overdetermined problem, and we prove the corresponding Wulff shape characterizations by using some integral identities and just one pointwise inequality. Our techniques provide a somehow unified approach to this variety of problems.

Applied Mathematics010102 general mathematicsDegenerate energy levelsMathematical analysisMathematics::Analysis of PDEsElliptic pdesComputer Science::Numerical Analysis01 natural sciencesMathematics::Numerical Analysis010101 applied mathematicsOverdetermined systemMathematics - Analysis of PDEsNonlinear Sciences::Exactly Solvable and Integrable SystemsSettore MAT/05 - Analisi MatematicaOverdetermined problems. Finsler manifold. Wulff shapes. Torsion problem. CapacityFOS: MathematicsMathematics::Differential GeometryFinsler manifold0101 mathematicsAnisotropyAnalysisAnalysis of PDEs (math.AP)Mathematics
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Energy dissipative solutions to the Kobayashi-Warren-Carter system

2017

In this paper we study a variational system of two parabolic PDEs, called the Kobayashi-Warren-Carter system, which models the grain boundary motion in a polycrystal. The focus of the study is the existence of solutions to this system which dissipate the associated energy functional. We obtain existence of this type of solutions via a suitable approximation of the energy functional with Laplacians and an extra regularization of the weighted total variation term of the energy. As a byproduct of this result, we also prove some $\Gamma$-convergence results concerning weighted total variations and the corresponding time-dependent cases. Finally, the regularity obtained for the solutions togethe…

Applied Mathematics010102 general mathematicsGeneral Physics and AstronomyStatistical and Nonlinear Physics010103 numerical & computational mathematicsDissipation01 natural sciencesMathematics - Analysis of PDEs35K87 35R06 35K67Regularization (physics)FOS: MathematicsDissipative systemApplied mathematics0101 mathematicsMathematical PhysicsAnalysis of PDEs (math.AP)Energy functionalMathematics
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Almost Planar Homoclinic Loops in R3

1996

AbstractIn this paper we study homoclinic loops of vector fields in 3-dimensional space when the two principal eigenvalues are real of opposite sign, which we call almost planar. We are interested to have a theory for higher codimension bifurcations. Almost planar homoclinic loop bifurcations generically occur in two versions “non-twisted” and “twisted” loops. We consider high codimension homoclinic loop bifurcations under generic conditions. The generic condition forces the existence of a 2-dimensional topological invariant ring (non necessarily unique), which is a topological cylinder in the “non-twisted” case and a topological Möbius band in the “twisted” case. If the third eigenvalue is…

Applied Mathematics010102 general mathematicsMathematical analysisCodimensionFixed point01 natural sciences010101 applied mathematicsNonlinear Sciences::Chaotic Dynamicssymbols.namesakesymbolsHomoclinic bifurcationHomoclinic orbitMöbius strip0101 mathematicsInvariant (mathematics)Asymptotic expansionEigenvalues and eigenvectorsAnalysisMathematicsJournal of Differential Equations
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Stress concentration for closely located inclusions in nonlinear perfect conductivity problems

2019

We study the stress concentration, which is the gradient of the solution, when two smooth inclusions are closely located in a possibly anisotropic medium. The governing equation may be degenerate of $p-$Laplace type, with $1<p \leq N$. We prove optimal $L^\infty$ estimates for the blow-up of the gradient of the solution as the distance between the inclusions tends to zero.

Applied Mathematics010102 general mathematicsMathematical analysisDegenerate energy levelsZero (complex analysis)Perfect conductorAnalysiGradient blow-upType (model theory)Conductivity01 natural sciences010101 applied mathematicsNonlinear systemMathematics - Analysis of PDEsFOS: MathematicsFinsler p-Laplacian0101 mathematicsPerfect conductorAnisotropy35J25 35B44 35B50 (Primary) 35J62 78A48 58J60 (Secondary)AnalysisAnalysis of PDEs (math.AP)MathematicsStress concentration
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Oscillation criteria for even-order neutral differential equations

2016

Abstract We study oscillatory behavior of solutions to a class of even-order neutral differential equations relating oscillation of higher-order equations to that of a pair of associated first-order delay differential equations. As illustrated with two examples in the final part of the paper, our criteria improve a number of related results reported in the literature.

Applied Mathematics010102 general mathematicsMathematical analysisDelay differential equation01 natural sciences010101 applied mathematicsExamples of differential equationsStochastic partial differential equationNonlinear systemDistributed parameter systemSimultaneous equationsCollocation method0101 mathematicsDifferential algebraic equationMathematics
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