the main objective in sampling is to select a sample from a population in order to estimate some unknown population parameter, usually a total or a mean of some interesting variable. a simple way to take a sample of size n is to let all the possible samples have the same probability of being selected. this is called simple random sampling and then all units have the same probability of being ch...

within the components of communicative competence, a special emphasis is put on the “rules of politeness,” specifically the politeness strategies (brown and levinson, 1978) that speakers deploy when performing the request speech act. this is because the degree of imposition that making a request places upon one’s interlocutor(s) has been seen to be influenced by several factors among which, as ...

in this thesis, ‎‎using‎‎ ‎concept‎s‎ ‎of‎ ‎wavelet‎s‎ ‎theory ‎‎‎som‎e‎ ‎methods‎‎ ‎of‎ ‎th‎e ‎solving‎‎ ‎optimal‎‎ ‎‎con‎tr‎ol‎ problems ‎(ocps)‎‎. ‎g‎overned by time-delay systems is investigated. ‎th‎is‎ thesis contains ‎tw‎o parts. ‎‎first, the method of obtaining ‎o‎f ‎the‎ ‎‎ocps‎ in time delay systems by linear legendre multiwavelets is ‎ ‎presented‎.‎‎‎‎ the main advantage of the meth...

the rationale behind the present study is that particular learning strategies produce more effective results when applied together. the present study tried to investigate the efficiency of the semantic-context strategy alone with a technique called, keyword method. to clarify the point, the current study seeked to find answer to the following question: are the keyword and semantic-context metho...

abstract the purpose of this study is twofold: on the one hand, it is intended to see what kind of noticing-the –gap activity (teacher generated vs. learner generated) is more efficient in teaching l2 grammar in classroom language learning. on the other hand, it is an attempt to determine which approach of the noticing-the-gap- activity is more effective in the long- term retention of grammar...

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...

the treatment of in completely formed pulpless teeth has presented considrable problems. these teeth have wide open apexes and the walls of the root canal diverge toward the apical tissues. mechanical preparation cannot be done in the normal manner beacause of the large initial size and the taper of apical part of the canal , a mechanical stop cannot be produced at the apex of the canal and , t...

in this study reference as one of the five cohesive devices in the achievement of textuality in english and persian narrative/descripitive written texts is focused on and analysed . to do so , the theoretical framework elaborated by halliday and hasan (1976) and its version adapted by the writer to match the sub-types of reference in farsi are applied to the analysis of reference in english and...

the issue of curriculum and syllabus evaluation and revision has been in center of attention right from when curriculum came into attention of educational institutions. thus everywhere in the world in educational institutions curricula and syllabi are evaluated and revised based on the goals, the needs, existing content, etc.. in iran any curriculum is designed in a committee of specialists and...

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...