Multi-robot search and rescue: A potential field based approach

This paper describes two implementations of a potential field sharing multi-robot system which we term as pessimistic and optimistic. Unlike other multirobot systems in which coordination is designed explicitly, it is an emergent property of our system. The robots perform no reasoning and are purely reactive in nature. We extend our previous work in simulated search and rescue where there was only one target to the search for multiple targets. As in our previous work the sharing systems with six or more robots outperformed the equivalent non-sharing system. We conclude that potential field sharing has a positive impact on robots involved in a search and rescue problem

A definition for the covalent and ionic bond index in a molecule

Formulae for hermitian operators representing covalent, ionic, and total bond indices are derived. The eigenstates of these operators come in pairs, and can be considered as bonding, anti-bonding and lone-pair orbitals. The form of these operators is derived by generalising the rule that the bond order be defined as the net number of bonding electron pairs. The percentage of covalency and ionicity of a chemical bond may be obtained, and bond indices can also be defined between groups of atoms. The calculation of the bond indices depends only on the electron density operator, and certain projection operators used to represent each atom in the molecule. Bond indices are presented for a series of first and second row hydrides and fluorides, hydrocarbons, a metal complex, a Diels–Alder reaction and a dissociative reaction. In general the agreement between the bond indices is in accord with chemical intuition. The bond indices are shown to be stable to basis set expansion