this thesis basically deals with the well-known notion of the bear-invariant of groups, which is the generalization of the schur multiplier of groups. in chapter two, section 2.1, we present an explicit formula for the bear-invariant of a direct product of cyclic groups with respect to nc, c>1. also in section 2.2, we caculate the baer-invatiant of a nilpotent product of cyclic groups wuth resp...

chapter one is devotod to collect some notion and background informations, which are needed in the next chapters. it also contains some important statements which will be proved in a more general context later in this thesis. in chapter two, we show that if the marginal factor-group is of order np1...pk,n>1, then we obtain a bound for the order of the verbal subgroup. also a bound for the bear-...

in chapter 1, charactrizations of fragmentability, which are obtained by namioka (37), ribarska (45) and kenderov-moors (32), are given. also the connection between fragmentability and its variants and other topics in banach spaces such as analytic space, the radone-nikodym property, differentiability of convex functions, kadec renorming are discussed. in chapter 2, we use game characterization...

nowadays in trade and economic issues, prediction is proposed as the most important branch of science. existence of effective variables, caused various sectors of the economic and business executives to prefer having mechanisms which can be used in their decisions. in recent years, several advances have led to various challenges in the science of forecasting. economical managers in various fi...

in chapter one we will describe definitions and preliminary results to provide the global context of our own results to be presented in detail in the subsequent chapters in chapter two we consider degree-one maps of the circle and we study their rotation set. our main result in this chapter says that if the map is topologically mixing then its rotation interval is nontrivial (that is, not reduc...

in the first chapter we study the necessary background of structure of commutators of operators and show what the commutator of two operators on a separable hilbert space looks like. in the second chapter we study basic property of jb and jb-algebras, jc and jc-algebras. the purpose of this chapter is to describe derivations of reversible jc-algebras in term of derivations of b (h) which are we...

abstract:assume that y is a banach space such that r(y ) ? 2, where r(.) is garc?a-falset’s coefficient. and x is a banach space which can be continuously embedded in y . we prove that x can be renormed to satisfy the weak fixed point property (w-fpp). on the other hand, assume that k is a scattered compact topological space such that k(!) = ? ; and c(k) is the space of all real continuous ...

we have devided the thesis in to five chapters. the first recollects facts from purely algebraic theory of jordan algebras and also basic properties of jb and jb* - algebras which are needed in the sequel. in the second chapter we extend to jb* - algebras, a classical result due to cleveland [8]. this result shows shows the weakness of jb* - norm topology on a jb* - algebera. in chapter three, ...

insurers have in the past few decades faced longevity risks - the risk that annuitants survive more than expected - and therefore need a new approach to manage this new risk. in this dissertation we survey methods that hedge longevity risks. these methods use securitization to manage risk, so using modern financial and insurance pricing models, especially wang transform and actuarial concepts, ...

abstract: in this thesis, we focus to class of convex optimization problem whose objective function is given as a linear function and a convex function of a linear transformation of the decision variables and whose feasible region is a polytope. we show that there exists an optimal solution to this class of problems on a face of the constraint polytope of feasible region. based on this, we dev...