214 research outputs found
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 -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 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
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