Giant monopole resonance and nuclear compression modulus for 40Ca and 16O

Using a collective potential derived on the basis of the Generator Coordinate Method with Skyrme interactions we obtain values for the compression modulus of 40Ca which are in good agreement with a recently obtained experimental value. Calculated values for the compression modulus for 16O are also given. The procedure involved in the derivation of the collective potential is briefly reviewed and discussed.Comment: 14 pages, no figures, two tables, REVTE

Run-Time Selection of Coordination Mechanisms in Multi-Agent Systems

This paper presents a framework that enables autonomous agents to dynamically select the mechanism they employ in order to coordinate their inter-related activities. Adopting this framework means coordination mechanisms move from the realm of being imposed upon the system at design time, to something that the agents select at run-time in order to fit their prevailing circumstances and their current coordination needs. Empirical analysis is used to evaluate the effect of various design alternatives for the agent's decision making mechanisms and for the coordination mechanisms themselves

Risk preferences estimation for small raspberry producers in the Bio-Bio Region, Chile

Toledo, R (reprint author), Ctr Reg Invest Quilamapu, Inst Invest Agropecuarias, Casilla 426, Chillan, ChileDecisions are strongly influenced by Ask and Ask preferences or decision makes; however, in Chile there are few studies in Me agricultural sector focused on this topic. The present paper analyzes the risk preferences of small producers or raspberries (Win idaeus L.) and the production function associated with their production system in the Bio-Bio Region of Chile. Under a mean-variance approach, the estimation procedure uses a flexible utility Function to incorporate a variety of risk preference alternatives. Three different estimation procedures were used: Least Squares Estimation, Seemingly Unrelated Regression and Full Information Maximum Likelihood, which revealed Me same Conclusions. Results showed that small farmers are risk averse (gamma=0.104) and present increasing relative and absolute aversion to risk (theta =0.099 < 1 and theta < gamma, respectively). The hypotheses of risk neutrality (gamma = 0) and constant absolute risk aversion (theta = 1) were rejected with 94% and 99% confidence, respectively. The chosen function of production is the Cobb Douglas type, because A presents a better adjustment, and the relevant factors are fertilizer quantity per hectare, the experience of the producer and the planted area. This Function presents decreasing returns to scale, then beta(2)+beta(3)+beta(4) is equal to 0.18. The hypothesis of constant returns to scale is rejected with 99%, confidence

Stern-Gerlach Entanglement in Spinor Bose-Einstein Condensates

Entanglement of spin and position variables produced by spatially inhomogeneous magnetic fields of Stern-Gerlach type acting on spinor Bose-Einstein condensates may lead to interference effects at the level of one-boson densities. A model is worked out for these effects which is amenable to analytical calculation for gaussian shaped condensates. The resulting interference effects are sensitive to the spin polarization properties of the condensate.Comment: 9 pages, 2 figure