due to the limiting workspace of parallel manipulator and regarding to finding the trajectory planning of singularity free at workspace is difficult, so finding a best solution that can develop a technique to determine the singularity-free zones in the workspace of parallel manipulators is highly important. in this thesis a simple and new technique are presented to determine the maximal singula...

abstract the present study was conducted to investigate the effect of using model essays on the development of writing proficiency of iranian pre-intermediate efl learners. to fulfill the purpose of the study, 55 pre- intermediate learners of parsa language institute were chosen by means of administering proficiency test. based on the results of the pretest, two matched groups, one as the expe...

adolescents and young adults and their problems is an issue whose importance is obvious to anyone because youth are the founders of our countrys future and requires proper planning to be on leisure. given the importance of leisure,this study to investigate needs assessment and planning how adolescents and young adults spend their leisure time in urban of case study of high school girls and boys...

there are two major theories of measurement in psychometrics: classical test theory (ctt) and item-response theory (irt). despite its widespread and long use, ctt has a number of shortcomings, which make it problematic to be used for practical and theoretical purposes. irt tries to solve these shortcomings, and provide better and more dependable answers. one of the applications of irt is the as...

according to webster and wind (1972) and anderson et al (1987), “organizational buying is a complex process and involves many people from different functional areas, multiple goals and potentially conflicting decision criteria. moreover, the customers of today are also more knowledgeable and selective when making their purchasing decisions. since a key to organizational survival is the retentio...

an investigation into oral interaction in language classes: a conversation analytic point of view the aim of this thesis is to analyze the interaction between language teachers and students in english language institutes. this work is done in the context of yasuj city. learning another language, which is in most cases english, involves many variables. one of these variables is the linguistic...

abstract: in the paper of black and scholes (1973) a closed form solution for the price of a european option is derived . as extension to the black and scholes model with constant volatility, option pricing model with time varying volatility have been suggested within the frame work of generalized autoregressive conditional heteroskedasticity (garch) . these processes can explain a number of em...

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...

the study reflected in this thesis aims at finding out relationships between critical thinking (ct), and the reading sections of tofel and ielts tests. the study tries to find any relationships between the ct ability of students and their performance on reading tests of tofel and academic ielts. however, no research has ever been conducted to investigate the relationship between ct and the read...

abstract: advertisements are the most accessible type of authentic materials, and this is one reason why they are used more and more in english teaching classes. for this cause, studies in the field of advertisements are very widespread nowadays. for pun is one aspect which makes advertisements more interesting, it is used more than before in advertisements. use of puns makes an advertisement m...