Genetic control programs for scrapie in sheep build on solid knowledge of how susceptibility to scrapie is modulated by the prion protein genotype at the level of an individual sheep. In order to satisfactorily analyze the effectivity of control programs at the population level, insight is needed at the flock level, i.e., how the grouping of sheep in flocks affects the population-level transmis...

Let K be a quadratic cone of PG(3, q) with vertex v. A flock F of K is a partition of K"[v] into q conics. If all planes containing the elements of the flock F share a common line, then F is called linear. Given a flock F there is a standard construction of a generalized quadrangle Q(F) associated with F ([19]), which is classical if and only if F is a linear flock. Article ID jcta.1998.2933, a...

Many different animals, including birds and fish, exhibit a collective behavior known as flocking. Flocking behavior is believed by biologists to emerge from relatively simple local control rules utilized by each individual in a flock. Specifically, each individual adjusts its behavior based on the behaviors of its closest neighbors. In our work we consider the possibility of adding a small set...

In this paper, we study the closed pattern mining problem for a class of spatio-temporal patterns, called closed (k, r)-flock patterns in trajectory databases. A (k, r)-flock pattern (Gudmundsson and van Kreveld, 2006) represents a set of moving objects traveling close each other within radius r during time period of length k. Based on the notion of the envelope for a flock pattern, we introduc...

Scrapie control in Great Britain (GB) was originally based on the National Scrapie Plan's Ram Genotyping scheme aimed at reducing the susceptibility of the national flock. The current official strategy to control scrapie in the national flock involves culling susceptible genotypes in individual, known affected flocks (compulsory scrapie flock scheme or CSFS). However, the recent development of ...

Flocking is a fascinating collective behavior exhibited by many different animals including birds and fish. As understood by biologists, the overall flocking behavior emerges from relatively simple local control rules by which each individual adjusts its own trajectory based on those of its closest neighbors. We consider the possibility of adding a small set of influencing agents, that are unde...

The problem of herding a flock of birds is posed in a graph theoretic framework. A novel algorithm, called the n-wavefront algorithm, is developed for enabling a single unmanned aerial vehicle to herd a flock of birds to a desired point. The technique is applied to the problem of diverting a flock of birds approaching an airport away from a protected zone around the airport. The n-wavefront alg...

Five species of Cyprinodon in Laguna Chichancanab, Yucatan, Mexico comprise a young species flock whose ecology and evolution has not been thoroughly studied, but whose existence is threatened with extinction. Species flocks evolve in isolated areas where predators and competitors are absent. Since the description of the Chichancanab flock, Oreochromis mossambicus, a species introduced into the...

We study monomial flocks of quadratic cones of PG(3, q), with emphasis on the case where the flock is semifield, providing some nonexistence and some uniqueness results. In addition, we give a computer-free proof of the existence of the sporadic semifield flock of the quadratic cone of PG(3, 35) (and hence of the sporadic translation ovoid of Q(4, 35)), and relate that flock to the sporadic sim...

This paper presents a distributed coordination methodology for multi-robot systems, based on nearest-neighbor interactions. Among many interesting tasks that may be performed using swarm robots, we propose a biologically-inspired control law for a shepherding task, whereby a group of external agents drives another group of agents to a desired location. First, we generated sheep-like robots that...