for a given riemannian manifold (m,g),it is an interesting question to study the existence of a conformal diffemorphism (also called as a conformal transformation) f : m ! m such that the metric g? = fg has one of the following properties: (i)(m; g?) has constant scalar curvature. (ii)(m; g?) is an einstein manifold.

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...

chapter two presents three m-admissible function algebras ab, bd, and sl, to construct the universal abelian, band, and semilattice compactifications, respectively. the main results are (11.3), (12.3), and (12.4). some inclusion relationships between these function algebras and the other well-known ones, presented in section 8, are made via the devico of compactifications. chpter three is about...

abstract tasks nowadays are at the center of attention in sla research. task types is one of the critical issues in this regard, their effectiveness and suitability to any particular context, their characteristics and the result they yield are among some of these issues. on the other hand, discourse markers (dms) have been very much investigated and their effectiveness in conveying the meaning...

the current study examined iranian undergraduate efl students’ willingness to communicate with regard to their vocabulary knowledge. in general, participants were somewhat willing to communicate in english. the total mean score of 730 university students’ perception of willing to communicate was 83.53 out of 135. results, regarding four parts of willingness to communicate, revealed that part...

to teach english adequately, qualified teachers are needed. unfortunately, there are still teachers who are teaching english without an academic degree in tefl. it is necessary for teachers to have a major in english to have subject knowledge, but it is not sufficient. teachers need to have an understanding of the social, cultural, moral, ethical, and pedagogical issues of education and practic...

this study purported to compare and contrast the use of self-mention and evidentials as two mtadiscourse features in opinion columns of persian and english newspapers. the theoretical basis of this study is the idea that metadiscourse features vary across cultural boundaries. for this purpose, 150 persian and 150 english opinion columns were collected based on three factors of topic, audience a...

the following null hypothesis was proposed: h : there is no significant difference between the use of semantically or communicatively translates scientific texts. to test the null hypothesis, a number of procedures were taken first, two passages were selected form soyrcebooks of food and nutrition industry and gardening deciplines. each, in turn, was following by a number of comprehension quest...

teachers beliefs have usually been left unattended in the realm of educational research in iranian context. one of those beliefs which seems to impact teachers performance in the classroom is their sense of self-efficacy, which refers to teachers belief in their ability to enhance student achievement and in bringing about positive learning outcomes. the present study aimed to investigate the pr...

امروزه تخمین حرکت بلوک در تصاویر بر اساس روش هایی که تمام جزئیات را شامل می شوند، تبدیل به یک مبحث فراگیر در شاخه ی پردازش تصویر گشته است. چرا که از جمله ی روش هایی به حساب می آید که باعث فشردگی و کاهش حجم داده های تصویری می گردد. جهت تحقّق این هدف، الگوریتم های متفاوتی ارائه شده اند. الگوریتم های جستجوی محلی، جستجوی پیشگویانه و... که با توجه به نیاز مسأله انتخاب و مورد استفاده قرار می گیرند، از...