Living with crime: spaces of risk for homeless young people

This paper reports on a study of victimization, offending and fear among homeless young people in Newcastle upon Tyne, England, which employed a participatory methodology. These young people live in marginal and often invisible spaces, yet are subject to a high degree of regulation which structures their experiences of risk. Their accounts demonstrate that an ‘either/or’ distinction which often structures understanding of offenders and victims, feared and fearful, and safe and dangerous spaces has led to their experiences being poorly represented. Homeless young people are often multiply positioned in relation to crime, an understanding which challenges the current political climate in Britain.     

A Map Overlay Error Model Based on Boundary Geometry

An error model for quantifying the magnitudes and variability of errors generated in the areas of polygons during spatial overlay of vector geographic information system layers is presented. Numerical simulation of polygon boundary displacements was used to propagate coordinate errors to spatial overlays. The model departs from most previous error models in that it incorporates spatial dependence of coordinate errors at the scale of the boundary segment. It can be readily adapted to match the scale of error–boundary interactions responsible for error generation on a given overlay. The area of error generated by overlay depends on the sinuosity of polygon boundaries, as well as the magnitude of the coordinate errors on the input layers. Asymmetry in boundary shape has relatively little effect on error generation. Overlay errors are affected by real differences in boundary positions on the input layers, as well as errors in the boundary positions. Real differences between input layers tend to compensate for much of the error generated by coordinate errors. Thus, the area of change measured on an overlay layer produced by the XOR overlay operation will be more accurate if the area of real change depicted on the overlay is large. The model presented here considers these interactions, making it especially useful for estimating errors studies of landscape change over time.     

Espace,temps et cognition

Revue de Synthèse - La cognition humaine paraît étroitement liée à la structure de l'espace et du temps relativement auxquels le corps, le geste,...