The emergence of the LBS services (Location Based Services) creates the need for indoor and outdoor positioning. Indoor environments refer to environments inside buildings, and outdoor environments refer to urban environments (streets). Indoor localization poses a true challenge for classical positioning systems. Indeed, radio propagation in indoor environments is affected by several factors particularly multipath, shadowing, cross-correlations, receiver mobility, interference... Urban environments are also challenging environments where multipaths problems are even more pronounced. This paper aims at analyzing such environments in the frame of a state of the art of the GPS acquisition environment.

Abstract:The United States electric power infrastructure is in an urgent need of renovation. The recent incidents of major power outages in the city of Long Beach, Los Angeles, Simi Valley, San Diego, and San Francisco have drawn attention to the unreliability of California's electric power system. President Obama discusses America's aging power infrastructure and California Public Utilities Commission calls for a comprehensive review of the causes of the recent power outages. This report explores GIS (geographic information systems) and their aim to identify a correlation between the power plants age and the power outages in the state of California. Utilizing ArcMap OLS (ordinary least squares) modeling tool, data analysis shows no correlation between the power outages and the infrastructure age.