We develop a transformation based on morphological filters
that measures the contrast of image texture. This ransforma
tion is proportional to texture contrast, but insensitive to its specific type. Though the transformation provides a high response in textured areas, it suppresses individual high contrast features that stand apart from textured areas. It can serve as an effective texture descriptor for unsupervised or supervised segmentation of textured regions, provides high accuracy of localization and does not involve heavy computations. The method is robust to variations of illumination and works on
different types of images without needing to be tuned. The only parameter is a scale related parameter. We illustrate the use of the proposed method on satellite and aerial images.
This dissertation investigates patterns and changes in young people’s labor market entry and their early career establishment processes in France since the 1990s when globalization and the related rise in employment flexibility started to increase. Due to the high-quality data available for France, it was possible to investigate this issue empirically at great depth and from different perspectives. As a result, a variety of findings merge to form a picture of youths in transition. The longitudinal data were collected retrospectively on a monthly basis and covered the first three to five years after leaving the educational or apprenticeship system. The sample size consists of more than 60,000 young people. The data was analyzed using techniques of event history modelling. The main part of the dissertation features a conceptual chapter explaining the theoretical background as well as an introduction to three empirical studies. The first empirical study focuses on general patterns and changes of young people’s labor market entry and early career establishment processes since the 1990s. The second empirical study is a detailed investigation of the situation of young migrants in the French labor market. The large sample size permits representative analyses of several migrant groups (interethnic differentiation) and first- versus second-generation migrants (intraethnic differentiation). The aim is to detect whether young migrants with the same human capital, i.e. identical educational certificates and social backgrounds, as their French counterparts have the same opportunities in the French labor market or whether they are particularly disadvantaged by labor market flexibilization measures and confronted with practices of labor market discrimination. The third empirical study addresses the role of vocational training in France. France has a long tradition of general diplomas rather than a dual system, like in Germany. This makes it particularly interesting to analyze the outcomes of the vocational training reforms in times of increasing labor market flexibilization