Group-theoretical methods are used to enumerate the structures of ordered perovskites, in which 1:2 and 1:3 ordering of B and B' cations is considered in combination with the ubiquitous BX6 (or B'X6) octahedral tilting. The cation ordering on the B-cation site is described by irreducible representations of the Pm3 m space group of the cubic aristotype: Lambda1 (k = 1/3,1/3,1/3) for the cation o...

In another article we associated a dynamical system to a non-properly ordered Bratteli diagram. In this article we describe how to compute the K−group K 0 of the dynamical system in terms of the Bratteli diagram. In the case of properly ordered Bratteli diagrams this description coincides with what is already known, namely the so-called dimension group of the Bratteli diagram. The new ordered g...

We discuss about the generalized $F$-contraction mappings in partially ordered metric spaces. For this, we first introduce the notion of ordered weakly $F$-contraction mapping. We also present some fixed point results about this type of mapping in partially ordered metric spaces. Next, we introduce the notion of $acute{mathrm{C}}$iri$acute{mathrm{c}}$ type generalized ordered weakly $F$-contrac...

in this paper, we introduce the concept of semihyperring $(r,+,cdot)$ together with a suitable partial order $le$. moreover, we introduce and study hyperideals in ordered semihyperrings. simple ordered semihyperrings are defined and its characterizations are obtained. finally, we study some properties of quasi-simple and $b$-simple ordered semihyperrings.

Group paging can simultaneously activate hundreds of user equipments (UEs) using a single paging message. Upon receiving the group paging message, all UEs should immediately transmit their paging response messages through the random access channels (RACHs). Simultaneous channel access from a huge group of UEs may result in severe collisions of the RACHs during a very short period of time. In th...

this study was designed to investigate the effect of grammar and vocabulary pre-teaching, as two types of pre-reading activities, on the iranian efl learners’ reading comprehension from a schema–theoretic perspective. the sample consisted of 90 female students studying at pre-university centers of isfahan.  the subjects were randomly divided into three equal-in-number groups. they participated ...

PURPOSE The purpose of this study was to evaluate the contribution of group therapy to the improvement of self-esteem, anger, stress coping and communication of those who were violent in to family. METHODS The research design was a one-group- pretest-posttest design in quasi-experimental research, and the period of this study was from March to October, 2005. Participants were 14 offenders who...

We define and study a notion of ring of formal power series with exponents in a cyclically ordered group. Such a ring is a quotient of various subrings of classical formal power series rings. It carries a two variable valuation function. In the particular case where the cyclically ordered group is actually totally ordered, our notion of formal power series is equivalent to the classical one in ...

1. Ordered groups. Suppose T is a simply ordered set and for each 7 in T let Ry be an additive group. Consider the set H = H(T, Ry) of all vectors ( • • • , ry, ■ • • ) for which ry is in Ry and almost every r"< is zero (i.e., the set of 7's for which ry^0 is inversely well ordered). H is a group w.r.t. (with respect to) vector addition, called the T-sum of the Ry. It the Ry are ordered groups ...

Let E be a computably enumerable (c.e.) equivalence relation on the set ω of natural numbers. We say that the quotient set ω/E (or equivalently, the relation E) realizes a linearly ordered set L if there exists a c.e. relation E respecting E such that the induced structure (ω/E;E) is isomorphic to L. Thus, one can consider the class of all linearly ordered sets that are realized by ω/E; formall...