Progressive Simplification of Polygonal Curves

Simplifying polygonal curves at different levels of detail is an important problem with many applications. Existing geometric optimization algorithms are only capable of minimizing the complexity of a simplified curve for a single level of detail. We present an $O(n^3m)$-time algorithm that takes a polygonal curve of n vertices and produces a set of consistent simplifications for m scales while minimizing the cumulative simplification complexity. This algorithm is compatible with distance measures such as the Hausdorff, the Fr\'echet and area-based distances, and enables simplification for continuous scaling in $O(n^5)$ time. To speed up this algorithm in practice, we present new techniques for constructing and representing so-called shortcut graphs. Experimental evaluation of these techniques on trajectory data reveals a significant improvement of using shortcut graphs for progressive and non-progressive curve simplification, both in terms of running time and memory usage.Comment: 20 pages, 20 figure

Mark Rein•Hagen’s Foundational Influence on 21st Century Vampiric Media

Mark Rein•Hagen’s role-playing game Vampire: The Masquerade, set in the World of Darkness shared universe, is foundational to the 21st Century vampire. We aim to, through the cultural analysis of how ideas have been transferred from this role-playing game to other media, clearly demonstrate Mark Rein•Hagen’s cultural historical significance

Weakly coupled, antiparallel, totally asymmetric simple exclusion processes

We study a system composed of two parallel totally asymmetric simple exclusion processes with open boundaries, where the particles move in the two lanes in opposite directions and are allowed to jump to the other lane with rates inversely proportional to the length of the system. Stationary density profiles are determined and the phase diagram of the model is constructed in the hydrodynamic limit, by solving the differential equations describing the steady state of the system, analytically for vanishing total current and numerically for nonzero total current. The system possesses phases with a localized shock in the density profile in one of the lanes, similarly to exclusion processes endowed with nonconserving kinetics in the bulk. Besides, the system undergoes a discontinuous phase transition, where coherently moving delocalized shocks emerge in both lanes and the fluctuation of the global density is described by an unbiased random walk. This phenomenon is analogous to the phase coexistence observed at the coexistence line of the totally asymmetric simple exclusion process, however, as a consequence of the interaction between lanes, the density profiles are deformed and in the case of asymmetric lane change, the motion of the shocks is confined to a limited domain.Comment: 14 pages, 15 figures, to appear in Phys. Rev.

Introducing the "religious minorities at risk" dataset

Religion has been taking an increasingly contentious character worldwide. Deprivation, grievances and protest by religious groups seems to be on the rise. Previous research has shown that the marginalization of ethnic groups can contribute significantly to violent conflict. However, we know little about religious groups as existing research has lacked the necessary fine-grained data. This paper introduces the "Religious Minorities at Risk" dataset comprising data on 771 religious minorities worldwide for the period between 2000 and 2014. The dataset contains pertinent worldwide information on relevant characteristics of these minorities, especially those that may explain their motivation and capability to mobilize. Such characteristics include objective deprivation in religious, economic and political terms as well as corresponding subjective grievances and intensities. The dataset also includes group-related features and structural variables that arguably influence minorities' capability to mobilize. Moreover, while previous studies have focussed exclusively on violence, we now have more information available on the exact character of mobilization enabling scholars to distinguish between peaceful and violent forms of mobilization