Mechanisms of peer interactions between native and non-native students: rejection or integration?

This paper focuses on mechanisms of “peer interactions” among native and non-native students. We present a theoretical framework based on Lazear (2001) education production model and on the “sub-cultural” sociological theory and we test the theoretical predictions exploiting a dataset of Italian junior high school. Results show that non-native school share has small and negative impacts on Language test scores of natives’ peers, while it does not significantly affect Math test scores. The negative effects to natives’ attainment are concentrated in schools characterized by low levels of non-natives’ isolation or where non-natives’ school share is above 10%.Peer effects, native and non-native students, social interactions

Exact design solutions for photodiode transimpedance amplifiers based on FET input OP-AMPs

We calculate the transfer function of an optical receiver composed by a photodiode and a FET input operational amplifier as a current to voltage converter. According to the theory of low-pass filters, the receiver bandwidth and quality factor are here analytically evaluated, proposing design solutions and their related sensitivity to eventual parameter fluctuations. We exemplify the combined action of photodetection and filtering comparing the analytical expression with full numerical SPICE simulations

MIMO precoding for filter bank modulation systems based on PSVD

In this paper we consider the design of a linearly precoded MIMO transceiver based on filter bank (FB) modulation for transmission over broadband frequency selective fading channels. The modulation FB is capable of lowering the channel dispersion at sub-channel level. Nevertheless, the sub-channels experience some level of inter-symbol interference. Therefore, the pre-coder and the equalizer are designed exploiting the polynomial singular value decomposition (PSVD). In particular, we consider two types of FB system. The first system deploys maximal frequency confined pulses and it is referred to as filtered multitone (FMT) modulation, while the second uses maximal time confined pulses with rectangular impulse response, i.e., it corresponds to the conventional orthogonal frequency division multiplexing (OFDM) system. We compare the performance of the considered systems in terms of capacity over typical WLAN channels, showing that PSVD precoding with FMT can outperform the performance of precoded OFDM in the two-bytwo antenna case especially for moderate to low SNRs