Automatic ontology mapping for agent communication

Agent communication languages such as ACL and KQML provide a standard for agent communication. These languages enable an agent to specify the intention and the content of a message as well as the protocol, the language, and the ontology that are used. For the protocol and the language some standards are available and should be known by the communicating agents. The ontology used in a communication depends on the subject of the communication. Since the number of subjects is almost infinite and since the concepts used for a subject can be described by different ontologies, the development of generally accepted standards will take a long time. This lack of standardization, which hampers communication and collaboration between agents, is known as the interoperability problem. To overcome the interoperability problem, agents must be able to establish a mapping between their ontologies. This paper investigates a new approach to the interoperability problem. The proposed approach requires neither a correspondence between concepts used in the ontologies nor a correspondence between the structure of the ontologies. It only requires that some instances of the subject about which the agents try to communicate are known by both agents.economics of technology ;

Theoretical status of the top quark cross section

We discuss the most recent calculations of the top quark total cross section and transverse momentum distributions at the Tevatron and the LHC. These calculations include the soft-gluon corrections at next-to-next-to-leading order (NNLO). The soft NNLO corrections stabilize the scale dependence of the cross section.Comment: 4 pages, 2 figures, presented at DPF 2004, Riverside, California, August 26-31, 200

The bimodal initial mass function in the Orion Nebula Cloud

Due to its youth, proximity and richness the Orion Nebula Cloud (ONC) is an ideal testbed to obtain a comprehensive view on the Initial Mass Function (IMF) down to the planetary mass regime. Using the HAWK-I camera at the VLT, we have obtained an unprecedented deep and wide near-infrared JHK mosaic of the ONC (90% completeness at K~19.0mag, 22'x28). Applying the most recent isochrones and accounting for the contamination of background stars and galaxies, we find that ONC's IMF is bimodal with distinct peaks at about 0.25 and 0.025 M_sun separated by a pronounced dip at the hydrogen burning limit (0.08 M_sun), with a depth of about a factor 2-3 below the log-normal distribution. Apart from ~920 low-mass stars (M < 1.4 M_sun) the IMF contains ~760 brown dwarf (BD) candidates and ~160 isolated planetary mass object (IPMO) candidates with M > 0.005 M_sun, hence about ten times more substellar candidates than known before. The substellar IMF peak at 0.025 M_sun could be caused by BDs and IPMOs which have been ejected from multiple systems during the early star-formation process or from circumstellar disks.Comment: Accepted at MNRAS, 12 pages, 13 figures, 3 table

Atom-molecule collisions in an optically trapped gas

Cold inelastic collisions between confined cesium (Cs) atoms and Cs$\_2$ molecules are investigated inside a CO$\_2$ laser dipole trap. Inelastic atom-molecule collisions can be observed and measured with a rate coefficient of $\sim 2.5 \times 10^{-11}$cm$^3$ s$^{-1}$, mainly independent of the molecular ro-vibrational state populated. Lifetimes of purely atomic and molecular samples are essentially limited by rest gas collisions. The pure molecular trap lifetime ranges 0,3-1 s, four times smaller than the atomic one, as is also observed in a pure magnetic trap. We give an estimation of the inelastic molecule-molecule collision rate to be $\sim 10^{-11}$ cm$^{3}$ s$^{-1}$

Carbonation cell materials compatibility

Material test and evaluation program for compatibility of materials with alkaline and acid electrolyte environments of carbonation cell syste