This paper is concerned with the maintenance of rigid formations of mobile autonomous agents. A key element in all future multi-agent systems will be the role of sensor and communication networks as an integral part of coordination. Network topologies are critically important for autonomous systems involving mobile underwater, ground and air vehicles and for sensor networks. This paper focuses ...

A set of structural cohesiveness issues raised in control of autonomous multi-vehicle formations is analysed, using a recently developed theoretical framework of graph rigidity and persistence. The general characteristics of rigid and persistent formations and some operational criteria to check the rigidity and persistence of a given formation from the aspect of their use in cohesive motion of ...

Even since pioneering work of Levine and Athans and Melzer and Kuo, control of vehicular formations has been a topic of active research. In spite of its apparent simplicity, this problem poses significant engineering challenges, and it has often inspired theoretical developments. In this article, we view vehicular formations as a particular instance of dynamical systems over networks and summar...

In this paper, a systematic way of maintaining rigidity in case of vehicle removals in formations for coordinating mobile autonomous vehicles with limited communication/sensing links is presented. The main concern is the minimal rearrangement of links in such a way that the links that have not been removed are preserved as they are, and the minimum number of new links are created in the formati...

The treatment of word formations has until recently been a neglected topic in natural language AI research. This paper proposes a multilayered approach to word formation which treats derivatives and compounds on several different levels of processing within a natural language dialogue system. Analysis and generation strategies being developed for the dialogue system HAM-ANS are described. Ident...

The rapid growth in natural gas consumption has increased the need for gas storage, in particular in the form of injection into depleted reservoirs. Also, CO2 sequestration into the depleted reservoirs has attracted a large attention recently. However, it is important to ensure that the injection pressure is maintained below a certain limit to avoid unsealing the cap rock or reactivation of any...

The ergastoplasm (granular endoplasmic reticulum) of parotid acinous cells of the mouse is described with special emphasis on unusual forms of this membranous system. In the majority of the acinous cells the ergastoplasm appeared in sections to consist of a large number of separate flattened cisternae. In some acinous cells, however, the ergastoplasm was disposed as a very small number of large...