| 1. |
- Andersson, Mattias, et al.
(författare)
-
Reporting leadership patterns among trajectories
- 2007
-
Ingår i: Proceedings of the 2007 ACM symposium on Applied computing. - ACM Press. - 1-59593-480-4 ; s. 3-7
-
Konferensbidrag (refereegranskat)abstract
- Widespread availability of location aware devices (such as GPS receivers) promotes capture of detailed movement trajectories of people, animals, vehicles and other moving objects, opening new options for a better understanding of the processes involved. In this paper we investigate spatio-temporal movement patterns in large tracking data sets. We present a natural definition of the pattern 'one object is leading others', and discuss how such leadership patterns can be computed from a group of moving entities. The proposed definition is based on behavioural patterns discussed in the behavioural ecology literature. We also present several algorithms for computing the pattern, and they are analysed both theoretically and experimentally.
|
|
| 2. |
- Andersson, Mattias, et al.
(författare)
-
Restricted mesh simplification using edge contractions
- 2006
-
Ingår i: Computing and combinatorics / Lecture notes in computer science. - Springer. - 0302-9743. - 978-3-540-36925-7 ; 4112, s. 196-204
-
Konferensbidrag (refereegranskat)abstract
- We consider the problem of simplifying a triangle mesh using edge contractions, under the restriction that the resulting vertices must be a subset of the input set. That is, contraction of an edge must be made onto one of its adjacent vertices. In order to maintain a high number of contractible edges under this restriction, a small modification of the mesh around the edge to be contracted is allowed. Such a contraction is denoted a 2-step contraction. Given m "important" points or edges it is shown that a simplification hierarchy of size O(n) and depth O(log(n/m)) may be constructed in O(n) time. Further, for many edges not even 2-step contractions may be enough, and thus, the concept is generalized to k-step contractions.
|
|
