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 ...

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...

We present a quantitative continuum theory of ‘‘flocking’’: the collective coherent motion of large numbers of self-propelled organisms. In agreement with everyday experience, our model predicts the existence of an ‘‘ordered phase’’ of flocks, in which all members of even an arbitrarily large flock move together with the same mean velocity ^vW &Þ0. This coherent motion of the flock is an exampl...

aedi-Visna is a viral disease of sheep caused by a lentivirus. It is characterized by progressive interstitial pneumonia or meningoencephalitis. Sometimes arthritis, ill-thrift and indurative mastitis are observed. The disease most often progresses slowly, but irreversibly. The disease occurs in all major sheep producing countries with the exception of Australia, New Zealand, and Finland. The i...

Flocking is a typical example of emergent collective behavior, where interactions between individuals produce collective patterns on the large scale. Here we show how a quantitative microscopic theory for directional ordering in a flock can be derived directly from field data. We construct the minimally structured (maximum entropy) model consistent with experimental correlations in large flocks...

The Cucker-Smale model for flocking or swarming of birds or insects is generalized to scenarios where a typical bird will be subject to a) a friction force term driving it to fly at optimal speed, b) a repulsive short range force to avoid collisions, c) an attractive “flocking” force computed from the birds seen by each bird inside its vision cone, and d) a “boundary” force which will entice bi...

Flocks are an important topic in the field of finite geometry, with many relations other objects interest. This paper is a contribution to difficult problem classifying flocks up projective equivalence. We complete classification quadratic cone PG ( 3 , q ) for ≤ 71 by showing computer that there exactly three 64 The had previously been discovered, and they linear flock, Subiaco flock Adelaide ...