abstract: in this thesis, we focus to class of convex optimization problem whose objective function is given as a linear function and a convex function of a linear transformation of the decision variables and whose feasible region is a polytope. we show that there exists an optimal solution to this class of problems on a face of the constraint polytope of feasible region. based on this, we dev...

the present dissertation aims to investigate four-word lexical bundles in applied linguistics research articles by iranian and internationally-published writers. the aims of this study are two-fold: first of all, attempts have been made to create a comprehensive list of the most commonly used four-word lexical bundles categorized by their type and token frequency, their structural characteristi...

nowadays, air pollution is a global problem that has had significant growth by technology development, population growth andindustrial development. industrial development brought natural resources deterioration, more manufacturing products, and more environmental pollutants. if pollutant won’t be controlled, human-being and wildlife will face the critical risks. significant release and critical...

the present paper deals with criminal issues. for example, legal injunction on the necessity of returning a deposit has a legal nature and legal injunction on the punishment of those who breach the trust has a criminal nature. existing social issues are the basis of classification of some instances into the issue, some of which are based on variation and others on quality. therefore, the motiva...

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...

according to cheng (1999), in recent esl/efl literature, asian (especially east asian) learners of english as a foreign/second language have been arguably reported as reticent and passive learners. the most common allegations are that these students are reluctant to participate in classroom discourse; they are unwilling to give responses; they do not ask questions; and they are passive and over...

abstract while task-based instruction is considered as the most effective way to learn a language in the related literature, it is oversimplified on various grounds. different variables may affect how students are engaged with not only the language but also with the task itself. the present study was conducted to investigate language and task related engagement on the basis of the task typolog...

the present study reports an analysis of response articles in four different disciplines in the social sciences, i.e., linguistics, english for specific purposes (esp), accounting, and psychology. the study has three phases: micro analysis, macro analysis, and e-mail interview. the results of the micro analysis indicate that a three-level linguistic pattern is used by the writers in order to cr...

according to coates’s (2004, as cited in zhang, 2010) definition of "conversational dominance" (p.111), it refers to the phenomenon of a speaker dominating others in interaction. specifically, it means how a speaker makes use of certain strategies to get the floor and maintain the floor. thus, the amount of talk is the main measurement for the dominance of the conversation. whether a speaker do...

abstract listening is a key and main tool in second language skill and its development is of prime concern to teachers and learners. furthermore, the application of technology in language classrooms has become more commonplace in the last fifty years. computer and the internet have made foreign language materials easy to access and use. so, the present study is an attempt to examine the effec...