The R-Tree and variant indexes have been used for multidimensional indexing since 1984 and applied to temporal data since 1994. Despite this, there are few functional implementations of the index that can be applied directly to the temporal data. This paper explores the use of the index for temporal subsequence searches and identifies two implications that must be considered so the index can be...

Multi-temporal sets of ERS-1/2 SAR interferometric (InSAR) phase have been evaluated at several test sites in Europe for tree height estimation. Atmospheric artefacts affected a large number of image pairs. These were generally well compensated in case of large-scale artefacts over small forests, whereas for large forests their effect could only be assessed. Hence, the amount of pairs utilizabl...

Timed computation tree logic (Tctl) extends Ctl by allowing timing constraints on the temporal operators. The semantics of Tctl is deened on a dense tree. The satissability of Tctl-formulae is undecidable even if the structures are restricted to dense trees obtained from timed graphs. According to the known results there are two possible causes of such undecidability: the denseness of the under...

The need for efficient access and management of time dependent data in modern database applications is well recognised and researched. Existing access methods are mostly derived from the family of spatial R-tree indexing techniques. These techniques are particularly not suitable to handle data involving open ended intervals, which are common in temporal databases. This is due to overlapping bet...

A new class of directed trees is introduced. formula for the group inverse matrices associated with any tree belonging to this obtained. This answers affirmatively, a conjecture Catral et al., class.

We study the dynamical behaviour of weighted shifts defined on sequence spaces a directed tree. In particular, we characterize their boundedness as well when they are hypercyclic, weakly mixing and mixing.

Linan Jiang, Betty Salzberg College of Comp. Sc., Northeastern Univ. Boston, MA 02115 flinan, [email protected] David Lomet Microsoft Research One Microsoft Way Bldg 9 Redmond, WA 98052 [email protected] Manuel Barrena y Universidad de Extremadura C aceres, Spain [email protected] Abstract Temporal databases assume a single line of time evolution. In other words, they support timeevolving d...

Aggregate computation, such as selecting the minimum attribute value of a relation, is expensive, especially in a temporal database. We describe the basic techniques behind computing aggregates in conventional databases and show that these techniques are not efficient when applied to temporal databases. We examine the problem of computing constant intervals (intervals of time for which the aggr...