On natural thinking

This article presents figures which show that environmental education is part of the curriculum for different subjects in West German schools. Criticism is made in the following areas: still too little time is used for environmental education; a lack of innovation in using new methods; a lack of adequate scope for teachers to shape their own teaching in a non‐disciplinary, action‐ and situation‐oriented way.     

Adaptive synchronization of unknown heterogeneous agents: An adaptive virtual model reference approach

This work deals with state synchronization of heterogeneous linear agents with unknown dynamics. The problem is solved by formulating the synchronization problem as a special model reference adaptive control where each agent tries to converge to the model defined by its neighbors. For those agents that do not know the reference signal that drives the flock, a fictitious reference is estimated in place of the actual one: the estimation of such reference is distributed and requires measurements from neighbors. By using a matching condition assumption, which is imposed so that the agents can converge to the same behavior, the fictitious reference estimation leads to adaptive laws for the feedback and the coupling gains arising from distributed matching conditions. In addition, the coupling connection is not scalar as in most literature, but possibly vector-valued. The proposed approach is applicable to heterogeneous agents with arbitrarily large matched uncertainties. A Lyapunov-based approach is derived to show analytically asymptotic convergence of the synchronization error: robustification in the presence of bounded errors or unknown (constant) leader input is also discussed. Finally, a motivational example is presented in the context of Cooperative Adaptive Cruise Control and numerical examples are provided to demonstrate the effectiveness of the proposed method.     

Non-market effects of education on crime: Evidence from Italian regions

This paper studies the non-market effects of education on crime using a panel dataset for the 20 Italian regions over the period 1980–1995. Our empirical results suggest that education reduces crime over and above its effect through labour market opportunities (employment rate and wage rate). Because of the absence of a credible instrumental variable for education for Italy, our empirical strategy is to include in our econometric specification region fixed effect, year fixed effects and region-specific time trends together with an extensive set of socioeconomic and deterrence variables. Our results are robust to model specification, changes in the typology of crimes and finally, to alternative definitions of education.