Anisotropy analysis of pressed point processes

This paper introduces methods for the detection of anisotropies which are caused by compression of regular 3D point patterns. Isotropy tests based on directional summary statistics and estimators for the compression factor are developed. Using simulated data, the dependence of the power of these methods on the intensity, the degree of regularity, and the compression strength is studied. Finally, our methods are applied to the point patterns of centers of air pores extracted from tomographic images of ice cores. This way the presence of anisotropies in the ice caused by the compression of the ice sheet and an increase of their strength with increasing depth are shown.     

Timing, Sequencing, and Quantum of Life Course Events: A Machine Learning Approach

In this paper we discuss and apply machine learning techniques, using ideas from a core research area in the artificial intelligence literature to analyse simultaneously timing, sequencing, and quantum of life course events from a comparative perspective. We outline the need for techniques which allow the adoption of a holistic approach to life course analysis, illustrating the specific case of the transition to adulthood. We briefly introduce machine learning algorithms to build decision trees and rule sets and then apply such algorithms to delineate the key features which distinguish Austrian and Italian pathways to adulthood, using Fertility and Family Survey data. The key role of sequencing and synchronization between events emerges clearly from the analysis. Billari F.C., Fürnkranz J., et Prskawetz A., 2006. Calendrier, séquence et intensitédes événements du cycle de vie : une application des techniques d’apprentissage par machine. Revue Européenne de Démographie, 22: 37–65     

Truthful Equilibria in Dynamic Bayesian Games

This paper characterizes an equilibrium payoff subset for dynamic Bayesian games as discounting vanishes. Monitoring is imperfect, transitions may depend on actions, types may be correlated, and values may be interdependent. The focus is on equilibria in which players report truthfully. The characterization generalizes that for repeated games, reducing the analysis to static Bayesian games with transfers. With independent private values, the restriction to truthful equilibria is without loss, except for the punishment level: if players withhold their information during punishment‐like phases, a folk theorem obtains.     

Zweite Konferenz der Japanischen Arbeitsgemeinschaft für deutsche Soziologie

Ohne Zusammenfassung     

Freundschaftsnetzwerke in den neuen Bundesländern

Social networks were a very important component of the society of the GDR. This suggests a study of these networks — especially friendship networks — in Germany’s new federal states. Ego-centered friendship networks in the present, as well as for the final days of the GDR, are analysed with network-analytic methods. The 83 participants of the examination were selected via snowball sampling. The results are not homogenous. Some impressively document how people reacted to the circumstances in the GDR, while others do not show any difference to studies from the old German federal states. Some further results show that changes have taken place.     

Are transformational and laissez-faire leadership related to state anxiety among subordinates? A two-wave prospective study of forward and reverse associations

ABSTRACT

The aim of this study was to determine the direction of associations between perceived leadership styles of an immediate leader and state anxiety among subordinates using time-lagged data from a large and heterogeneous probability sample of Norwegian employees. It was hypothesised that high levels of transformational leadership would be associated with a decrease, whereas high levels of laissez-faire leadership would be associated with an increase, in subsequent levels of anxiety. Reciprocal associations were also expected in that higher levels of anxiety were hypothesised to be related to subsequent increase in reports of laissez-faire, and decrease in reported exposure to transformational leadership. The sample comprised 1149 Norwegian employees. The design was a two-wave full panel study with a six-month time interval between the baseline and follow-up assessments. Contrary to hypotheses, neither transformational nor laissez-faire leadership were significantly related to subsequent levels of state anxiety. In support of hypotheses, baseline low levels of state anxiety were associated with reporting the immediate leader as less transformational and more laissez-faire six months later. In conclusion, the findings challenge theoretical models that explain leadership as a one-way superior–subordinate influence process.