The Linac Coherent Light Source (LCLS) will be the world’s first x-ray free-electron laser (FEL). To ensure the vitality of FEL lasing, a longitudinal feedback system is required together with other diagnostics. In this paper, we study the possibility of using Coherent Synchrotron Radiation (CSR) from the chicane as a diagnostic tool for bunch length feedback. Studies show that CSR is a good ca...

100-200 MeV range ERL driven high gain FEL oscillators generating few cycle short, high intensity midIR pulses with tens of MHz repetition rates might become attractive tools in various strong field applications. In a recent study a mode-locked, coupled FEL oscillator scheme has been presented to generate multi-mJ level, ultra-short (<10 cycles) output pulses tunable within the entire IR region...

In this study, the virtual reality (VR) proprioception rehabilitation system was developed for stroke patients to use proprioception feedback in upper limb rehabilitation by blocking visual feedback. To evaluate its therapeutic effect, 10 stroke patients (onset>3 month) trained proprioception feedback rehabilitation for one week and visual feedback rehabilitation for another week in random orde...

in this study, a new adaptive controller is proposed for position control of pneumatic systems. difficulties associated with the mathematical model of the system in addition to the instability caused by pulse width modulation (pwm) in the learning-based controllers using gradient descent, motivate the development of a new approach for pwm pneumatics. in this study, two modified feedback error l...

The temporal structure of the storage-ring free-electron laser at Elettra shows high sensitivity to electron-beam instabilities. In fact, even small beam perturbations may affect the FEL dynamics and periodically switch off the laser. In order to improve the FEL operation and performance, different and complementary feedback systems have been activated. This paper reports on their beneficial ef...

Feedback instruction is a proven modality for the alteration of motion patterns. There are no existing data on the contribution of strength training, when combined with feedback instruction, to the altering of lower extremity biomechanics. Thus the purpose of the current study was comparison of strength training  program with external and internal focus of attention strategies on kinetic and fu...

the present study-both qualitative and quantitative--explored fifty efl learners’ preferences for receiving error feedback on different grammatical units as well as their beliefs about teacher feedback strategies. the study also examined the effect of the students’ level of writing ability on their views about the importance of teacher feedback on different error types. data was gathered throug...

there is no doubt that augmented feedback has an important role in improvinglearning. however, it is the content of the feedback which is challenging. the aimof the present study was to examine the effect of feedback on successful versusunsuccessful trials on simple and complex tracking tasks. for this purpose, 48undergraduate right-handed male and female students of hakim sabzevari teachertrai...