We consider a weighted eigenvalue problem for the Dirichlet laplacian in smooth bounded domain Ω⊂RN, where bang–bang weight equals positive constant m¯ on ball B⊂Ω and negative −m̲ Ω∖B. The corresponding principal provides threshold to detect persistence/extinction of species whose evolution is described by heterogeneous Fisher–KPP equation population dynamics. In particular, we study minimizati...

Cost reduction is one of the methods applied for improving the productivity of organizations. In productivity literature, particularly in nonparametric methods, cost reduction related methods are regarded as input oriented models. This paper presents a Supply Chain Management (SCM) model in which purchasing iron ore and coke from different resources, along with production and distribution of st...

We develop a procedure for the integration of balance equations in terms displacements orthotropic bodies with certain restrictions imposed on elastic moduli material. The components vector are expressed two functions, one which satisfies equation second order, while fourth-order equation. An algorithm is proposed solving boundary-value problems an rectangular prism. based separation principal ...