In this paper, some properties of the periodic shadowing are presented. It is shown that a homeomorphism has the periodic shadowing property if and only if so does every lift of it to the universal covering space. Also, it is proved that continuous mappings on a compact metric space with the periodic shadowing and the average shadowing property also have the shadowing property and then are chao...

With the release of SPARQL 1.1 in 2013 property paths were introduced, which make it possible to describe queries that do not explicitly define the length of the path that is traversed within an RDF graph. Already existing RDF stores were adapted to support property paths. In order to give an insight on how well the current implementations of property paths in RDF stores work, we introduce a be...

Detectability is a basic property of dynamic systems: when it holds one can use the observed output signal produced by a system to reconstruct its current state. In this paper, we consider properties of this type in the framework of discrete event systems modeled by Petri nets (a.k.a. place/transition nets). We first study weak detectability and weak approximate detectability. The former implie...

Several min-max relations in graph theory can be expressed in the framework of the Erdős– Pósa property. Typically, this property reveals a connection between packing and covering problems on graphs. We describe some recent techniques for proving this property that are related to tree-like decompositions. We also provide an unified presentation of the current state of the art on this topic.