A first approach to model the low-frequency wave activity in the plasmasphere

International audienceA comprehensive empirical model of waves is developed in the objective to simulate wave-particle interactions involved in the loss and acceleration of radiation belt electrons. Three years of measured magnetic wave field components from the Plasma Wave Instrument on board the DE-1 satellite are used to model the amplitude spectral density of the magnetic wave field of each type of emission observed in the equatorial regions of the plasmasphere: VLF transmitter emissions, chorus emissions, plasmaspheric hiss emissions and equatorial emissions below ~ 200 Hz. Each model is a function of the wave frequency f , the MLT, L and Mlat parameters, and the Kp values. The performances of the plasmaspheric hiss and chorus models are tested on amplitude spectra recorded on board the OGO-5 and GEOS-1 satellites

Development and validation of the Online Student Connectedness Survey (OSCS)

With the growth of online courses and programs in higher education, considerable concerns emerge about student feelings of isolation and disconnectedness in the online learning environment. A research study was conducted to develop and validate an instrument that can be used to measure perceptions of connectedness of students enrolled in online programs or certification programs in higher education. The instrument consists of 25 items and has four scales: (a) community, (b) comfort, (c) facilitation, and (d) interaction and collaboration. One hundred and forty-six online learners who were enrolled in courses at a Turkish university completed the online questionnaire. Results of a factor and reliability analysis confirmed that the instrument is a valid and reliable measure of students’ perceived connectedness in an online certificate program

Low computational complexity mode division multiplexed OFDM transmission over 130 km of few mode fiber

We demonstrate 337.5-Gb/s MDM-8QAM-OFDM transmission over 130 km of FMF. This confirms that OFDM can significantly reduce the required DSP complexity to compensate for differential mode delay, a key step towards real-time MDM transmission

Multimode EDFA performance in mode-division multiplexed transmission systems

We report a detailed study on the system performance of a two-mode group EDFA. In particular we quantify how the gain spectrum and BER performance are affected by input signal and pump power as required in the execution of our ongoing MDM transmission experiments