Local reachability of two-dimensional (2D) positive systems, by means of positive scalar inputs, is addressed by means of a graph theoretic approach. Some results concerned with equivalent conditions for local reachability as well as upper and lower bounds on the reachability indices are provided.

This paper studies the reachability problem of the switched linear discrete singular (SLDS) systems. Under the condition that all subsystems are regular, the reachability of the SLDS systems is characterized based on a peculiar repeatedly introduced switching sequence. The necessary and sufficient conditions are obtained for the reachability of the SLDS systems.

The paper presents a new method for checking reachability properties of Timed Automata. The idea consists in on-the-fly verification of a property on a pseudo-bisimulating model generated by a modified partitioning algorithm. Pseudo-bisimulating models are often much smaller than forward-reachability graphs commonly used in reachability analysis. A theoretical description of the algorithm is su...

The primary function of a BGP speaking system is to exchange network reachability information with other BGP systems. This network reachability information includes information on the list of Autonomous Systems (ASs) that reachability information traverses. This information is sufficient to construct a graph of AS connectivity from which routing loops may be pruned and some policy decisions at ...

Graph-structured databases and related problems such as reachability query processing have been increasingly relevant to many applications such as XML databases, biological databases, social network analysis and the Semantic Web. To efficiently evaluate reachability queries on large graph-structured databases, there has been a host of recent research on graph indexing. To date, reachability ind...

Search using subgoal graphs is a recent preprocessing-based path-planning algorithm that can find shortest paths on 8neighbor grids several orders of magnitude faster than A*, while requiring little preprocessing time and memory overhead. In this paper, we first generalize the ideas behind subgoal graphs to a framework that can be specialized to different types of environments (represented as w...

We adapt hypergraph rewriting system to a generalization of Vector Addition Systems with States (VASS) that we call vector addition systems with pairs (VASP). We give rewriting systems and strategies, that allow us to obtain reachability equivalence results between some classes of VASP and VASS. Reachability for the later is well known be equivalent to reachability in Petri nets. VASP generaliz...

We investigate reachability in pushdown automata over infinite alphabets: machines with finite control, a finite collection of registers and pushdown stack. First we show that, despite the stack’s unbounded storage capacity, in terms of reachability/emptiness these machines can be faithfully represented by using only 3r elements of the infinite alphabet, where r is the number of registers. More...

We analyze the complexity of graph reachability queries on ST-graphs, defined as directed acyclic graphs (DAGs) obtained by merging the suffix tree of a given string and its suffix links. Using a simplified reachability labeling algorithm presented by Agrawal et al. (1989), we show that for a random string of length n, its ST-graph can be preprocessed in O(n log n) expected time and space to an...

We study variants of a recently introduced hybrid system model, called a Hierarchical Piecewise Constant Derivative (HPCD). These variants (loosely called Restricted HPCDs) form a class of natural models with similarities to many other well known hybrid system models in the literature such as Stopwatch Automata, Rectangular Automata and PCDs. We study the complexity of reachability and mortalit...