This technical note addresses the distributed fixed-time consensus protocol design problem for multi-agent systems with general linear dynamics over directed communication graphs. By using motion planning approaches, a class of distributed fixed-time consensus algorithms are developed, which rely only on the sampling information at some sampling instants. For linear multi-agent systems, the pro...

We present a new approach for determining consistency of temporal constraint networks based on Allen's interval-based framework All83]. The temporal network is rst translated into a clausal theory in propositional logic Men64], whose satissability is then determined using an anytime family of tractable rea-soners Dal96]. Anytime reasoners are complete reasoners that provide partial answers even...

A directed path graph is the intersection graph of a family of directed subpaths of a directed tree. A rooted path graph is the intersection graph of a family of directed subpaths of a rooted tree. Rooted path graphs are directed path graphs. Several characterizations are known for directed path graphs: one by forbidden induced subgraphs and one by forbidden asteroids. It is an open problem to ...

by TOLGA BOZKAYA This thesis proposes index structures for efficient evaluation of temporal queries in temporal databases and similarity based queries in multimedia databases. To support temporal operators and to increase the efficiency of temporal queries, indexing based on temporal attributes is required. A temporal database can support two notions of time. Valid time is the time when a data ...

In general the problem of finding a miminum spanning tree for a weighted directed graph is difficult but solvable. There are a lot of differences between problems for directed and undirected graphs, therefore the algorithms for undirected graphs cannot usually be applied to the directed case. In this paper we examine the kind of weights such that the problems are equivalent and a minimum spanni...

In this paper, we study the problem of compressing a data structure (e.g. tree, undirected and directed graphs) in an eecient way while keeping a similar structure in the compressed form. To date, there has been no proven optimal algorithm for this problem. We use the idea of building LZW tree in LZW compression to compress a binary tree generated by a stationary ergodic source in an optimal ma...

In this paper we extend the standard attack tree model by introducing temporal order to the attacker’s decision making process. This will allow us to model the attacker’s behaviour more accurately, since this way it is possible to study his actions related to dropping some of the elementary attacks due to them becoming obsolete based on the previous success/failure results. We propose an effici...

In its full generality, a time domain can be defined as a set of temporal individuals connected by a set of temporal relations. Different choices for the temporal individuals and/or the temporal relations give rise to different temporal ontologies. In the database context, the most common temporal ontology takes time instants (equivalently, points or moments) as the temporal individuals and a l...

Given a digraph D, the Minimum Leaf Out-Branching problem (MinLOB) is the problem of finding in D an out-branching with the minimum possible number of leaves, i.e., vertices of out-degree 0. Gutin, Razgon and Kim (2008) proved that MinLOB is polynomial time solvable for acyclic digraphs which are exactly the digraphs of directed path-width (DAG-width, directed tree-width, respectively) 0. We in...