به طور کلی در فرآیندهای مارکوف ارگودیک دو بعدی یافتن فرم بسته توزیع ایستا، تنها برای حالات خیلی خاص امکان پذیر است. با توجه به این مشکل و نیز با توجه به اهمیت توزیع ایستا، بررسی و مطالعه رفتار مجانبی توزیع ایستای این فرآیندها مورد توجه قرار گرفته است. زنجیر قدم زدن تصادفی دو بعدی که در برخی متون به آن، فرآیند qbd دو طرفه نیز می گویند، یکی از این فرآیندها است. یک فرآیند qbd زمان گسسته یک زنجیر م...

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...

among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...

the purpose of this study is to investigate the relationships between teachers’ immediacy behaviors and iranian students’ willingness to talk in english classes. analysis of the results from willingness to talk scale represents a relatively high level of willingness to talk in english classrooms among iranian language learners. the total mean score of students’ willingness to talk was 66.3 ou...

abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...

let g=(v,e) be a graph with vertex set v and edge set e.for two vertices u,v of g ,the closed interval i[u,v] ,consists of u,v and all vertices lying in some u-v geodesic in g.if s is a set of vertices of g then i[s]is the union of all sets i[u,v]for u,v ? s. if i[s]=v(g) , then s is a geodetic set for g.the geodetic number g(g) is the minimum cardinality of geodetic set.the maximum cardinalit...

there are many approaches for solving variety combinatorial optimization problems (np-compelete) that devided to exact solutions and approximate solutions. exact methods can only be used for very small size instances due to their expontional search space. for real-world problems, we have to employ approximate methods such as evolutionary algorithms (eas) that find a near-optimal solution in a r...

in this thesis, at first we investigate the bounded inverse theorem on fuzzy normed linear spaces and study the set of all compact operators on these spaces. then we introduce the notions of fuzzy boundedness and investigate a new norm operators and the relationship between continuity and boundedness. and, we show that the space of all fuzzy bounded operators is complete. finally, we define...

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...

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...