Trading Safety Versus Performance: Rapid Deployment of Robotic Swarms with Robust Performance Constraints

In this paper we consider a stochastic deployment problem, where a robotic swarm is tasked with the objective of positioning at least one robot at each of a set of pre-assigned targets while meeting a temporal deadline. Travel times and failure rates are stochastic but related, inasmuch as failure rates increase with speed. To maximize chances of success while meeting the deadline, a control strategy has therefore to balance safety and performance. Our approach is to cast the problem within the theory of constrained Markov Decision Processes, whereby we seek to compute policies that maximize the probability of successful deployment while ensuring that the expected duration of the task is bounded by a given deadline. To account for uncertainties in the problem parameters, we consider a robust formulation and we propose efficient solution algorithms, which are of independent interest. Numerical experiments confirming our theoretical results are presented and discussed

Food Environment, Built Environment, and Women\u27s BMI: Evidence from Erie County, New York

The authors present the results of a neighborhood-scaled exploratory study that tests the association of the food environment and the built environment with women’s body mass index (BMI) in Erie County, New York. The proximity of women’s homes to a supermarket relative to a convenience store is associated with lower BMI. A diverse land use mix in a neighborhood is positively associated with women’s BMI, especially when restaurants dominate nonresidential land use. The article offers suggestions for how food environments may be improved using planning strategies

Manual of tropical bryology

Bryophytes belong to the oldest land plants. They existed already in the Palaeozoic 300 mio years ago in forms which were hardly different from the extant species. They remained relatively unchanged with relatively low evolution rates (and are thus often called a „conservative“ plant group), but could successfully establish themselves in an always varying environment from Devonian swamps to Permian forests, Mesozoic deserts and as epiphytes in Tertiary rainforests. They are not eaten by snails or insects, and are resistant against fungi and bacteria