3,636 research outputs found
Topological Excitations in the Thirring model
The quantization of the massless Thirring model in the light-cone using
functional methods is considered. The need to compactify the coordinate
in the light-cone spacetime implies that the quantum effective action for
left-handed fermions contains excitations similar to abelian instantons
produced by composite of left-handed fermions. Right-handed fermions don't have
a similar effective action. Thus, quantum mechanically, chiral symmetry must be
broken as a result of the topological excitations. The conserved charge
associated to the topological states is quantized. Different cases with only
fermionic excitations or bosonic excitations or both can occur depending on the
boundary conditions and the value of the coupling.Comment: title changed, one reference added, accepted in Phys. Lett.
From supply chains to demand networks. Agents in retailing: the electrical bazaar
A paradigm shift is taking place in logistics. The focus is changing from operational effectiveness to adaptation. Supply Chains will develop into networks that will adapt to consumer demand in almost real time. Time to market, capacity of adaptation and enrichment of customer experience seem to be the key elements of this new paradigm. In this environment emerging technologies like RFID (Radio Frequency ID), Intelligent Products and the Internet, are triggering a reconsideration of methods, procedures and goals. We present a Multiagent System framework specialized in retail that addresses these changes with the use of rational agents and takes advantages of the new market opportunities. Like in an old bazaar, agents able to learn, cooperate, take advantage of gossip and distinguish between collaborators and competitors, have the ability to adapt, learn and react to a changing environment better than any other structure. Keywords: Supply Chains, Distributed Artificial Intelligence, Multiagent System.Postprint (published version
Materials pre-romans trobats en la confluĂšncia de la riera d'Agell, el camĂ del Mig i el pont de l'autopista A-19 (Cabrera de Mar)
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