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 effects of manipulating the cognitive complexity of tasks along +/- few elements and the time limits on l2 learners writing performance. to conduct the study, 60 iranian efl learners with two levels of proficiency, low and high intermediate, were selected and assigned to three groups based on the time devoted to task completion. the participants performed both a simp...

due to lack of knowledge management system in the organization of technical and vocational university of iran (tvuni) and losing good employees because of retirement and substitution causes huge amount of costs to replace the similar expertise. there is no any suitable system in the tvuni to store, to document, and to distribute knowledge. based on the university’s features such as it has diffe...

a simple, rapid and low-cost scanner spectroscopy method for the glucose determination by utilizing glucose oxidase and cdte/tga quantum dots as chromoionophore has been described. the detection was based on the combination of the glucose enzymatic reaction and the quenching effect of h2o2 on the cdte quantum dots (qds) photoluminescence.in this study glucose was determined by utilizing glucose...

implicit and unobserved errors and vulnerabilities issues usually arise in cryptographic protocols and especially in authentication protocols. this may enable an attacker to make serious damages to the desired system, such as having the access to or changing secret documents, interfering in bank transactions, having access to users’ accounts, or may be having the control all over the syste...

some researches made in the field of agency problem issue, deal with the role of control systems regarding owners and managers. in this research the relationship between the two control mechanisms, namely the voluntary disclosure (external control mechanism) and outside directors (internal control mechanism), which are reductive of agency problems, has been studied. for this reason, a sample ...

this exploratory study aimed to investigate a possible relationship between learners’ beliefs about language learning and one of their personality traits; that is,locus of control (loc). both variables, beliefs and locus of control, are assumed to influence the language learning process. the internal control index (ici) and the beliefs about language learning inventory (balli) were administered...

in new management approaches, in the organizations with inflexible structure, existing of red tapes and interruptions caused by limitations and also non-compliance with environmental changes, create demotivation among staff. with regard to the influence of job motivational potential and its relationship to the type of organizational structure( enabling and dissuasive), the goal of this research...

abstract biometric access control is an automatic system that intelligently provides the access of special actions to predefined individuals. it may use one or more unique features of humans, like fingerprint, iris, gesture, 2d and 3d face images. 2d face image is one of the important features with useful and reliable information for recognition of individuals and systems based on this ...

the present study aimed to investigate representation of discourse markers and metadiscourse markers in conversations and readings of general elt coursebook series used in the language centers of iran. to this aim, four elt coursebooks popularly taught in language centers of this country were analyzed based on fung and carter’s (2007) framework regarding discourse markers and hyland’s (2005) fr...