Semi-parametric geolocation estimation in NLOS environments

The position of a stationary target can be determined using triangulation in combination with time of arrival measurements at several sensors. In urban environments, none-line-of-sight (NLOS) propagation leads to biased time estimation and thus to inaccurate position estimates. Here, a semi-parametric approach is proposed to mitigate the effects of NLOS propagation. The degree of contamination by NLOS components in the observations, which result in asymmetric noise statistics, is determined and incorporated into the estimator. The proposed method is adequate for environments where the NLOS error plays a dominant role and outperforms previous approaches that assume a symmetric noise statistic.

Does attendance affect grade? An analysis of first year economics students in Ireland

This paper examines the relationship between attendance and grade, controlling for other factors, in first year economics courses in University College Cork. Determinants of both class attendance and grade are specified and estimated. We find that attendance is low, at least by comparison with US evidence. Hours worked and travel time are among the factors affecting class attendance. Class attendance, and especially tutorial attendance has a positive and diminishing marginal effect on grade, while hours worked in a part-time job have a significant negative effect on grade.