Search results for "Mathematica"

Onset of Convection in an Inclined Anisotropic Porous Layer with Internal Heat Generation

2019

The onset of convection in an inclined porous layer which is heated internally by a uniform distribution of heat sources is considered. We investigate the combined effects of inclination, anisotropy and internal heat generation on the linear instability of the basic parallel flow. When the Rayleigh number is sufficiently large, instability occurs and a convective motion is set up. It turns out that the preferred motion at convection onset depends quite strongly on the anisotropy ratio, &xi

Quasilinear Dirichlet Problems with Degenerated p-Laplacian and Convection Term

2021

The paper develops a sub-supersolution approach for quasilinear elliptic equations driven by degenerated p-Laplacian and containing a convection term. The presence of the degenerated operator forces a substantial change to the functional setting of previous works. The existence and location of solutions through a sub-supersolution is established. The abstract result is applied to find nontrivial, nonnegative and bounded solutions.

La matriz de análisis de políticas con datos eficientes: evaluación de la rentabilidad del cultivo del arroz

2008

This paper combines policy analysis matrix and data envelopment analysis techniques to model the analysis of profitability from farming. Policy analysis matrices are computed for a sample of rice growers located in the wetland of the Albufera (Eastern Spain) under observed conventional and profit-efficient farming conditions. While conventional analysis points to a lack of profitability, farmers are shown to make positive profits at private and social prices when data reflecting efficiency adjustments are used in the analysis. The main conclusion is that the usefulness of the policy analysis matrix might be substantially enhanced by simulating profitability after efficiency-improving manage…

On the number of singularities, zero curvature points and vertices of a simple convex space curve

1995

We prove a generalization of the 4 vertex theorem forC3 closed simple convex space curves including singular and zero curvature points.

Constrained control of a nonlinear two point boundary value problem, I

1994

In this paper we consider an optimal control problem for a nonlinear second order ordinary differential equation with integral constraints. A necessary optimality condition in form of the Pontryagin minimum principle is derived. The proof is based on McShane-variations of the optimal control, a thorough study of their behaviour in dependence of some denning parameters, a generalized Green formula for second order ordinary differential equations with measurable coefficients and certain tools of convex analysis.

On the Euler-Lagrange inequality of a convex variational integral in Orlicz spaces

1987

Fixed point theory for almost convex functions

1998

Traditionally, metric fixed point theory has sought classes of spaces in which a given type of mapping (nonexpansive, assymptotically or generalized nonexpansive, uniformly Lipschitz, etc.) from a nonempty weakly compact convex set into itself always has a fixed point. In some situations the class of space is determined by the application while there is some degree of freedom in constructing the map to be used. With this in mind we seek to relax the conditions on the space by considering more restrictive types of mappings.

Convex Duality in Stochastic Optimization and Mathematical Finance

2011

This paper proposes a general duality framework for the problem of minimizing a convex integral functional over a space of stochastic processes adapted to a given filtration. The framework unifies many well-known duality frameworks from operations research and mathematical finance. The unification allows the extension of some useful techniques from these two fields to a much wider class of problems. In particular, combining certain finite-dimensional techniques from convex analysis with measure theoretic techniques from mathematical finance, we are able to close the duality gap in some situations where traditional topological arguments fail.

Selected Topics from Functional and Convex Analysis

2003

Non absolutely convergent integrals of functions taking values in a locally convex space

2006

Properties of McShane and Kurzweil-Henstock integrable functions taking values in a locally convex space are considered and the relations with other integrals are studied. A convergence theorem for the Kurzweil-Henstock integral is given