in this thesis our aim is to construct vector field in r3 for which the corresponding one-dimensional maps have certain discontinuities. two kinds of vector fields are considered, the first the lorenz vector field, and the second originally introced here. the latter have chaotic behavior and motivate a class of one-parameter families of maps which have positive lyapunov exponents for an open in...

in this thesis, we consider a mathematical model of cancer with completely unknown parameters. we study the stability of critical points which are biologically admissible. then we consider a control on the system and introduce situations at which solutions are attracted to critical points and so the cancer disease has auto healing. the lyapunov stability method is used for estimating the un...

abstract: one of the most visited & important spaces in different countries by tourist are urban areas. the old tehran which major part is located in district 12 is historical showcase of the capital, but, its hiidden cultural attraction is not used as it should be. this thesis occasionally engage in studying the efficacy of correct installation of travel guide boards in welfare & easily acc...

the frame semantic theory is a nascent approach in the area of translation studies which goes beyond the linguistic barriers and helps us to incorporate cognitive and cultural factors to the study of translation. based on rojos analytical model (2002b), which centered in the frames or knowledge structures activated in the text, the present research explores the various translation problems that...

abstract:‎ literature is said beautiful words of poetry or prose that excites reader’s or listener’s feel. certainly, to ‎be effective, such a text should have certain characteristics. the four elements of the literature: thought, ‎imagination, emotion and style make a text to be literary and effective. emotion and imagination are ‎specific elements of literary texts, while thought and style a...

plagiarism in esl/efl learning contexts has been established as a dynamic and multi-layered phenomenon and has become a topic engaging many researchers in a heated debate in recent years. comparisons of student-generated texts with their source texts have shown that students rely on source texts in their writings and copying is a major strategy used by both l1 and l2 writers. in our country a...

abstract: postmethod is a newly developed pedagogy which as an alternative to method rejects the notion of good or bad methods and the concept of best method that can be generalized and appropriate for all contexts. instead, it treats each context as unique and one of a kind which cant be compared with other cases. this study is a postmethod-oriented one which investigates whether and how far t...

fuzzy logic has been developed over the past three decades into a widely applied techinque in classification and control engineering. today fuzzy logic control is one of the most important applications of fuzzy set theory and specially fuzzy logic. there are two general approachs for using of fuzzy control, software and hardware. integrated circuits as a solution for hardware realization are us...

the construct of self-efficacy has received increasing attention in research over the past two decades. many studies have been carried out 1.3 significance of the study this study has pedagogical implications since improving students’ self- efficacy and autonomy is important for promoting actual performance on classroom academic tasks. in academic settings, it has been shown that self-effi...

nanotechnology is a general term which is related with field of all advanced science term that generally predicates with all modern technologies which consider nanoscales. improvement in the quality of products by adding some nanoparticles and study of their behavior in the presence of these nanoparticles have been obtained in many researches. on the other hand numerous demands for sowing ...