a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...

‏‎this study investigated the effect of prior knowledge on the listening comprehension performance of fl learners. twenty students, male and female, drawn from the two intact groups of the senior and junior english language and literature majors were chosen as the participants of this study . the two groups were then randomly assigned into the experimental and control group. the experimental gr...

the purpose of this study was to investigate the effect of task repetition on accuracy of iranian efl learners ’speaking ability. in order to achieve this purpose, a null hypothesis was developed: there is no statistically significant difference between accuracy speaking ability in iranian efl learners by use of task repetition. ; of course i should mention that, beside this null hypothesis, an...

in order to examine the ecological conditions and characteristics of fraxinus excelsior l. in the northern forests of iran 6 main areas as well as some miscellaneous ones , have been selected in the region respectively in : lomir2, shafaroud , park - e-noor , ahlam , alandan and noor.

abstract this study aimed at investigating the effect of bilingual teaching of cognate words (persian-english) on iranian upper intermediate efl learners’ knowledge of lexical development. for this purpose,100 subjects participated in this study out of which 40 learners were selected for this study and they were assigned into two groups, control and experimental. cross-language cognates (wor...

why some learners are willing to communicate in english, concurrently others are not, has been an intensive investigation in l2 education. willingness to communicate (wtc) proposed as initiating to communicate while given a choice has recently played a crucial role in l2 learning. it was hypothesized that wtc would be associated with language learning orientations (llos) as well as social suppo...

the present study was conducted to investigate the effect of implicit focus on form through input flooding and the effect of noticing, explicit focus on form on linguistic accuracy. to fulfill the purpose of the study, 86 iranian pre-intermediate efl learners of one of the language institutes were chosen by means of administering ket as the homogeneity test. these learners were pretested throug...

with the increasing population and the need for more food, as well as with the development of science and technology, human approach to unnatural and often chemical inputs to increase agricultural production has been a great expansion and problems such as increased cancers, chronic diseases has created environmental pollution. implementation of organic organic is a solution to these problems . ...

cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...