Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher.
Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?
Some links on this page may take you to non-federal websites. Their policies may differ from this site.
-
null (Ed.)We introduce a new inverse modeling method to interactively design crowd animations. Few works focus on providing succinct high-level and large-scale crowd motion modeling. Our methodology is to read in real or virtual agent trajectory data and automatically infer a set of parameterized crowd motion models. Then, components of the motion models can be mixed, matched, and altered enabling rapidly producing new crowd motions. Our results show novel animations using real-world data, using synthetic data, and imitating real-world scenarios. Moreover, by combining our method with our interactive crowd trajectory sketching tool, we can create complex spatio-temporal crowd animations in about a minute.more » « less
-
null (Ed.)We introduce a novel tool for designing a swarming behavior model for a set of virtual agents to automatically capture an initially unknown indoor architectural environment. Our key idea is to use an output-driven optimization to create targeted swarming behavior. The input to our model is a simple rectangular proxy of the target area and desired acquisition indicator values. The final outputs are the parameters for a swarming behavior model that is autonomous and decentralized, uses only local exploration, and is robust to agent failure. We show and compare the swarming performance in several simulated environments of up to several hundred square meters, 100 agents, and under various conditions.more » « less
-
more » « less
Premise Apetaly is widespread across distantly related lineages of flowering plants and is associated with abiotic (or self‐) pollination. It is particularly prevalent in the carnation family, and the cosmopolitan genus
Stellaria contains many lineages that are hypothesized to have lost petals from showy petalous ancestors. But the pollination biology of apetalous species ofStellaria remains unclear.Methods Using a substantial species‐level sampling (~92% of known taxonomic diversity), we describe the pattern of petal evolution within
Stellaria using ancestral character state reconstructions. To help shed light on the reproductive biology of apetalousStellaria , we conducted a field experiment at an alpine tundra site in the southern Rocky Mountains to test whether an apetalous species (S. irrigua ) exhibits higher levels of selfing than a sympatric, showy petalous congener (S. longipes ).Results Analyses indicated that the ancestor of
Stellaria was likely showy petalous and that repeated, parallel reductions of petals occurred in clades across much of the world, with uncommon reversal back to showy petals. Field experiments supported high rates of selfing in the apetalous species and high rates of outcrossing in the petalous species.Conclusions Petal loss is rampant across major clades of
Stellaria and is potentially linked with self‐pollination worldwide. Self‐pollination occurs within the buds inS. irrigua , and high propensities for this and other forms of selfing known in many other taxa of arctic‐alpine habitats may reflect erratic availability of pollinators.
