ESA activities in space laser sounding and ranging

Laser remote sensing from space is undoubtedly one of the most promising means to obtain essential atmospheric and geophysical parameters on a global scale. Efforts including feasibility assessments, technology developments, and mission definition studies are in progress at the European Space Agency (ESA) to prepare for the prospective use of laser remote sensing systems in space. An overview of the programs under way is presented and the perspectives of laser remote sensing in the context of ESA's Long-Term European Space Plan are discussed

Small examples of non-constructible simplicial balls and spheres

We construct non-constructible simplicial $d$-spheres with $d+10$ vertices and non-constructible, non-realizable simplicial $d$-balls with $d+9$ vertices for $d\geq 3$.Comment: 9 pages, 3 figure

The Effects of Quotas on Vertical Intra-Industry Trade

A quota on foreign competition will generally lead to quality-upgrading (downgrading) of the low-quality (high-quality) firm, an increase in average quality, a reduction of quality differentiation, and a reduction of domestic consumer surplus, irrespective of whether the foreign firm produces higher or lower quality. Effects of a quota on industry profits and domestic welfare depend crucially on the direction of international vertical differentiation. If the foreign firm produces low quality, both firms' prices and profits rise but domestic welfare falls. This describes well some major effects of a Japanese VER in the US auto market and relevant empirical findings. If the foreign firm produces high quality, foreign profits will fall. Since domestic consumer surplus falls only unsubstantially, domestic profit gains lead to an increase of domestic welfare. --trade,quotas,vertical product differentiation,quality-dependent costs

Stellar theory for flag complexes

Refining a basic result of Alexander, we show that two flag simplicial complexes are piecewise linearly homeomorphic if and only if they can be connected by a sequence of flag complexes, each obtained from the previous one by either an edge subdivision or its inverse. For flag spheres we pose new conjectures on their combinatorial structure forced by their face numbers, analogous to the extremal examples in the upper and lower bound theorems for simplicial spheres. Furthermore, we show that our algorithm to test the conjectures searches through the entire space of flag PL spheres of any given dimension.Comment: 12 pages, 2 figures. Notation unified and presentation of proofs improve