Who Invests in Training if Contracts are Temporary? - Empirical Evidence for Germany Using Selection Correction

This study deals with the effect of fixed-term contracts on work-related training. Though previous studies found a negative effect of fixed-term contracts on the participation in training, from the theoretical point of view it is not clear whether workers with fixed-term contracts receive less or more training, compared to workers with permanent contracts. In addition to the existing strand of literature, we especially distinguish between employer- and employee-financed training in order to allow for diverging investment patterns of worker and firm. Using data from the German Socio-Economic Panel (GSOEP), we estimate a bivariate probit model to control for selection effects that may arise from unobservable factors, affecting both participation in training and holding fixed-term contracts. Finding negative effects for employer-sponsored, as well as for employee-sponsored training, leads us to conclude that workers with fixed-term contracts do not compensate for lower firm investments.training, fixed-term contracts, bivariate probit model

Modelling a Dune Field

We present a model to describe the collective motion of barchan dunes in a field. Our model is able to reproduce the observation that a typical dune stays confined within a stripe. We also obtain some of the pattern structures which ressemble those observed from aerial photos which we do analyse and compare with the specific field of La\^ayounne.Comment: 15 pages, 13 figure

Calculation of the separation streamlines of barchans and transverse dunes

We use FLUENT to calculate the wind profile over barchans and transverse dunes. The form of the streamlines of flow separation at the lee side of the dunes is determined for a symmetric barchan dune in three dimensions, and for the height profile of a measured transverse dune field in the Len\c{c}\'ois Maranhenses.Comment: 6 pages including 5 figures. Proceedings of PSIS 200

A lower bound for the kk-multicolored sum-free problem in Zmn\mathbb{Z}^n_m

In this paper, we give a lower bound for the maximum size of a $k$-colored sum-free set in $\mathbb{Z}_m^n$, where $k\geq 3$ and $m\geq 2$ are fixed and $n$ tends to infinity. If $m$ is a prime power, this lower bound matches (up to lower order terms) the previously known upper bound for the maximum size of a $k$-colored sum-free set in $\mathbb{Z}_m^n$. This generalizes a result of Kleinberg-Sawin-Speyer for the case $k=3$ and as part of our proof we also generalize a result by Pebody that was used in the work of Kleinberg-Sawin-Speyer. Both of these generalizations require several key new ideas