Maximization and minimization problems of the principle eigenvalue for divergence form second order elliptic operators with Dirichlet boundary condition are considered. The principal eigen map such is introduced some basic properties this map, including continuity, concavity, differentiability respect to parameter in diffusibility matrix, established. For maximization problem, admissible contro...

for calculation of the displacements of points in micro geodesy networks, it is essential to discover stable and unstable points. without knowing stable points, calculated displacements are due to datum deficiency. in this case, calculated displacements are not valid. there are two methods to discover stable and unstable points: a-congruency robust method b- l1 norm minimization in this study t...

return maximization or risk minimization is goal in portfolio optimization based on mean variance theory. the structure of correlation matrices and individual variance of each asset are two main factors in optimization with risk minimization object. it’s necessary to use appropriate variance and correlation coefficient for time series with clustering volatilities feature, too. in this research,...

this study was conducted to determine timeliness costs in using machinery and their effects on farmers’ revenues. in addition, optimum cropping pattern was compared with the existing one assuming removal of timeliness cost. for the purpose of the study, mixed integer and linear programming methods were used. the study was conduced in marvdasht region in southern iran. the data were collected th...

in most industrial zones, electric energy is one of the most important energy sources. since electrical motors are the main energy consumers of industrial factories, consumption optimization in these motors can be considered as a main option related to energy saving. one very effective way to reduce the consumption of these equipment is to use a motor speed controllers or drives. since the loss...

this study aims to minimize the total cost of a four-echelon supply chain including suppliers, an assembler, distributers, and retailers. the total cost consists of purchasing raw materials from the suppliers by the assembler, assembling the final product, materials transportation from the suppliers to the assembler, product transportation from the assembler to the distributors, product transpo...

We examine the NFA minimization problem in terms of atomic NFA’s, that is, NFA’s in which the right language of every state is a union of atoms, where the atoms of a regular language are non-empty intersections of complemented and uncomplemented left quotients of the language. We characterize all reduced atomic NFA’s of a given language, that is, those NFA’s that have no equivalent states. Usin...