CP - rang of completely positive matrix

V magistrskem delu je obravnavan problem določitve cp-ranga dane popolnoma pozitivne matrike. Uvodoma so opisane osnovne lastnosti pozitivno semidefinitnih matrik in predstavljeni so konveksni stožci evklidskega prostora V. V osrednjem delu se osredotočimo na popolnoma pozitivne matrike. Matrika A je popolnoma pozitivna, če jo lahko zapišemo kot A=BB^{T} za neko nenegativno matriko B. Dokažemo osnovne lastnosti popolnoma pozitivnih matrik ter definiramo diagonalno dominantne in primerjalne matrike. Delo zaključimo z obravnavo problema določitve cp-ranga popolnoma pozitivne matrike. Obravnavamo primer za matrike manjše velikosti ter določimo zgornjo mejo za cp-rang matrike danega ranga in matrike dane velikosti. In the master thesis the problem of determining the cp-rank of a given completely positive matrix is discussed. In the introduction the basic properties of positive semidefinite matrices are described and convex cones in euclidean space V are presented. In the main part we focus on completely positive matrices. Matrix A is completely positive if it can be decomposed as A=BB^{T}, where B is a nonnegative matrix. We prove the basic properties of totally positive matrices and define diagonally dominant and comparative matrix. The thesis is concluded with a discussion of a problem of determining the cp-rank of a completely positive matrix. We consider a case of a matrix of a smaller size and set an upper bound for cp-rank matrix of a given rank and a matrix of a given order.