the space now known as complete erdos space ec was introduced by paul erdos in 1940 as the closed subspace of the hilbert space ?2 consisting of all vectors such that every coordinate is in the convergent sequence {0} ? { 1 n : n ? n}. in a solution to a problem posed by lex g. oversteegen we present simple and useful topological characterizations of ec. as an application we determine the ...

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...

nowadays,tourism industry considered as one of the main sources of income of a country.unfortunately and despite of owning plenty of cultural historical and natural attractions, iran has not reached to a proper position in this field. besides, the historical cities of a country are considered as the income resource and national wealth of it. qazvin with a rich cultural precedent, have suitable ...

the present study was an attempt to compare the effect of peer metalinguistic corrective feedback on elementary and intermediate efl learners speaking ability to see which level benefits more from this type of feedback. to this end, 117 female efl learners at grade 3, al-zahra high school in kermanshah, iran were non-randomly chosen. the homogeneity of the participants was attained through a pi...

abstract type-ii fuzzy logic has shown its superiority over traditional fuzzy logic when dealing with uncertainty. type-ii fuzzy logic controllers are however newer and more promising approaches that have been recently applied to various fields due to their significant contribution especially when the noise (as an important instance of uncertainty) emerges. during the design of type- i fuz...

it is not possible to understand developments of a country’s culture and civilization without knowing his believes and myths. whether it is north or south, east or west, planes or mountains, sahara or deserts, here in iran every corner includes valuable and precious treasures which are known all over the world, and cultural – historical objects which are found here adorn all well known museums...

rested on sociocultural theory (sct), this study attempted to examine the effect of written corrective feedback (wcf) followed by producing written languaging on developing writing accuracy over new tasks. to this aim, two intact iranian efl classes at the low-intermediate level were randomly assigned to two experimental groups: direct (n = 25) and indirect (n = 25). both groups wrote on a numb...

the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...

seismic retrofit strategies have been developed in the past few decades following the introduction of new seismic provisions and the availability of advanced materials and methods. it can be observed that new approaches to deal with more lateral forces are more innovative and more energy absorbent. in line with this, there is a growing trend toward the use of steel shear walls as a system with ...

abstract this research is about a longitudinal case study of english morpheme acquisition by a persian speaking child l2 learner of english (2 .9-3).the goal of this research has been discovery of the child ‘s ability in acquiring of english morphemes in a persian context while only one person (the child’ s father)has been talking to her.this child has also been exposed to english languag...