Strongly nonlinear second order differential inclusions with generalized boundary conditions

In this paper, we study second order differential inclusions in with a maximal monotone term and generalized boundary conditions. The nonlinear differential operator need not be necessary homogeneous and incorporates as a special case the one-dimensional p-Laplacian. The generalized boundary conditions incorporate as special cases well-known problems such as the Dirichlet (Picard), Neumann and periodic problems. As application to the proven results we obtain existence theorems for both “convex” and “nonconvex” problems when the maximal monotone term A is defined everywhere and when not (case of variational inequalities).     

A nontrivial solution of mountain-pass type for a hemivariational inequality

We consider a class of noncoercive hemivariational inequalities involving the p-Laplacian. Our goal is to obtain the existence of a nontrivial solution. Using the mountain-pass theorem for locally Lipschitz functionals we obtain the desired result.     

A weak nonsmooth palais-smale condition and coercivity

In this paper we show that a generally nonsmooth locally Lipschitz function which satisfies the nonsmooth C-condition (nonsmooth Cerami condition) and is bounded from below, is coercive. The Cerami condition is a weak form of the well-known Palais-Smale condition, which suffices to prove minimax principles.     

Positive solutions for nonlinear singular superlinear elliptic equations

Positivity - We consider a nonlinear nonparametric elliptic Dirichlet problem driven by the p-Laplacian and reaction containing a singular term and a $$(p-1)$$ -superlinear perturbation. Using...     

Private labels and retail assortment planning: a differential evolution approach

Despite the longstanding recognition of the importance of product assortment planning (PAP), existing literature has failed to provide satisfactory solutions to a great deal of problems that reside in this area of research. The issue of optimal assortment planning in the retail sector becomes even more important in periods of economic crisis, as retailers must adapt their product portfolios to new evolving patterns of consumer buying behaviour and reduced levels of consumer’s purchasing power. Private labels (PLs) typically experience significant growth in times of recession, due to their low prices, and the reduced disposable income of households. In this direction, the present paper introduces differential evolution to assist retailers in adapting their product portfolios in periods of economic recession and facilitate strategic PAP decisions, related to (a) optimal variety of PL product categories, (b) optimal service level of PL merchandise within a product category, and hence, (c) optimal balance between PLs and National Brands in a retailer’s product portfolio. The interrelated issue of assortment adaptation across different store formats is also considered. Economic recessions contribute to the prolonged upward evolution in PL share, and hence, our mechanism facilitates decisions that are nowadays more important than ever before. The proposed mechanism is illustrated through an implementation to an empirical dataset derived from a random sample of 1928 consumers who participated in a large-scale computer assisted telephone survey during the current economic crisis period.     

Positive solutions for singular p(z)$p(z)$-equations

We consider a Dirichlet problem driven by the anisotropic p-Laplacian, with a reaction having the competing effects of a singular term and a parametric superlinear perturbation. We prove a bifurcation-type theorem describing the changes of the set of positive solutions as the parameter varies. We also prove the existence of minimal positive solutions.     

Geographic characterization of Greek wine by inductively coupled plasma–mass spectrometry macroelemental analysis

Abstract

Studying wine mineral profile has been proven as a valuable tool in geographical origin discrimination and authenticity for both producers and consumers. Adulteration of wines, in terms of geographical origin or variety, is considered a major topic of extensive research. Traceability and authenticity of wines have been previously studied on the basis of typical mineral element patterns by means of chemometric methods. In this context, analytical methods were developed for the determination of mineral elements in wines by inductively coupled plasma–mass spectrometry. This study aimed at classifying selected varietal Greek wines from various regions by employing instrumental analysis. Preliminary data of wine mineral content enabled for the classification of samples according to geographical origin and variety. However, further work is required in order to draw more valid conclusions and to obtain a detailed map of the mineral element content of Greek wines according to their geographical origin and/or variety.