in this paper, sufficient conditions are investigated for the existence of periodic (not necessarily positive) solutions for nonlinear several time delay population system with feedback control. nonlinear system affected by an periodic external source is studied. existence of a control variable provides  the extension of  some previous results obtained in other studies. we give a illustrative e...

ad hoc networks are multi-hop wireless networks without a pre-installed infrastructure. such networks are widely used in military applications and in emergency situations as they permit the establishment of a communication network at very short notice with a very low cost. video is very sensitive for packet loss and wireless ad-hoc networks are error prone due to node mobility and weak links. h...

the main challenge of a search engine is ranking web documents to provide the best response to a user`s query. despite the huge number of the extracted results for user`s query, only a small number of the first results are examined by users; therefore, the insertion of the related results in the first ranks is of great importance. in this paper, a ranking algorithm based on the reinforcement le...

this paper presents a theoretical approach to implementation of the “multi-realization of nonlinear mimo systems”. this method aims to find state-variable realization for a set of systems, sharing as many parameters as possible. in this paper a special nonlinear multi-realization problem, namely the multi-realization of feedback linearizable nonlinear systems is considered and an algorithm for ...

background: functional electrical stimulation (fes) is the most commonly used system for restoring functions after spinal cord injury (sci). objective: in this study we investigated feedback pid and feedforward-feedback p-pid controllers for regulating the elbow joint angle. methods: the controllers were tuned based on a nonlinear muculoskeletal model containing two links, one joint with one de...

a major problem in information retrieval is the difficulty to define the information needs of user and on the other hand, when user offers your query there is a vast amount of information to retrieval. different methods , therefore, have been suggested for query expansion which concerned with reconfiguring of query by increasing efficiency and improving the criterion accuracy in the information...

the bulk of research within the interactionist framework seems to be consensually pointing to the beneficial effects of interaction in sla. however, few studies have investigated the role of training in providing and perceiving interactional feedback, especially among young learners. this study probed the effects of training prior to engagement in interaction in case of young learners acquiring...

natural vibration analysis of plates represents an important issue in engineering applications. in this paper, a new and simplify method for vibration analysis of circular and rectangular plates is presented. the design of an effective robust controller, which consistently attenuates transverse vibration of the plate caused by an external disturbance force, is given. the dynamics of the plate i...

The Research was aimed at finding out the effects of the implementation of writing feedback techniques and students’ writing anxiety on students’ writing ablity. Experimental method of 3x2 factorial design was employed in the research. There were three experimental groups of students who were taught by using teacher feedback, peer feedback and the combination of peer and teacher feedback writin...