The U(1) phase transition on toroidal and spherical lattices

We have studied the properties of the phase transition in the U(1) compact pure gauge model paying special atention to the influence of the topology of the boundary conditions. From the behavior of the energy cumulants and the observation of an effective \nu -> 1/d on toroidal and spherical lattices, we conclude that the transition is first order.Comment: LATTICE98(gauge

Free fermionic propagators on a lattice

A method used recently to obtain a formalism for classical fields with non-local actions preserving chiral symmetry and uniqueness of fermion fields yields a discrete version of Huygens' principle with free discrete propagators that recover their continuum forms in certain limit.Comment: LaTex document, 13 pages, 1 figure. Minor changes, two references adde

First order signatures in 4D pure compact U(1) gauge theory with toroidal and spherical topologies

We study the pure compact U(1) gauge theory with the extended Wilson action (\beta, \gamma couplings) by finite size scaling techniques, in lattices ranging from L=6 to L=24 in the region of \gamma <= 0 with toroidal and spherical topologies. The phase transition presents a double peak structure which survives in the thermodynamical limit in the torus. In the sphere the evidence support the idea of a weaker, but still first order, phase transition. For negative values of gamma the transition becomes weaker and larger lattices are needed to find its asymptotic behaviour. Along the transient region the behaviour is the typical one of a weak first order transition for both topologies, with a region where 1/d < nu < 0.5, which becomes nu compatible with 1/d when larger lattices are used.Comment: Some references added; changes in the text mainly wording. To appear in Phys. Lett.

Apollo experience report: Lunar module electrical power subsystem

The design and development of the electrical power subsystem for the lunar module are discussed. The initial requirements, the concepts used to design the subsystem, and the testing program are explained. Specific problems and the modifications or compromises (or both) imposed for resolution are detailed. The flight performance of the subsystem is described, and recommendations pertaining to power specifications for future space applications are made

Building Adaptive Basis Functions with a Continuous SOM

This paper introduces CSOM, a distributed version of the Self-Organizing Map network capable of generating maps similar to those created with the original algorithm. Due to the continuous nature of the mapping, CSOM outperforms the traditional SOM algorithm in function approximation tasks. System performance is illustrated with three examples

Lattice calculations on the spectrum of Dirac and Dirac-K\"ahler operators

We present a matrix technique to obtain the spectrum and the analytical index of some elliptic operators defined on compact Riemannian manifolds. The method uses matrix representations of the derivative which yield exact values for the derivative of a trigonometric polynomial. These matrices can be used to find the exact spectrum of an elliptic operator in particular cases and in general, to give insight into the properties of the solution of the spectral problem. As examples, the analytical index and the eigenvalues of the Dirac operator on the torus and on the sphere are obtained and as an application of this technique, the spectrum of the Dirac-Kahler operator on the sphere is explored.Comment: 11 page

Impact of the commercial fishery on the population of bait shrimp (Penaeus spp.) in Biscayne Bay, 1986

Monthly population size of bait shrimp in the Bay was estimated from December 1984 to July 1985. Growth rates for male and female P. duorarum showed that pink shrimp exhibit a mean residence time in the nursery area (Biscayne Bay) of approximately 21 weeks. Monthly mortality rates were determined for each sex of pink shrimp. It was estimated that 23% and 26% of the male and female monthly population size, respectively, was absorbed by both the fishery and ecosystem monthly. Monthly proportion of the standing stock expected to die exclusively through fishing was 6.5% and 6.0% for males and females respectively. Estimates of emigration rates showed that approximately 4.0% of the population was lost from the Bay system each month. This surplus production was about 50% of the average monthly catch by the fleet. Fishing mortality represents only 8 - 9% of the losses to the shrimp population. The biggest source of loss is emigration, suggesting that most shrimp beyond the size at recruitment (to the fishery) are not utilized for food while in the Bay. Thus, it appears that the direct impact of the fishery on the bait shrimp population is relatively small. (PDF contains 46 pages

Building Adaptive Basis Functions with a Continuous Self-Organizing Map

This paper introduces CSOM, a continuous version of the Self-Organizing Map (SOM). The CSOM network generates maps similar to those created with the original SOM algorithm but, due to the continuous nature of the mapping, CSOM outperforms the SOM on function approximation tasks. CSOM integrates self-organization and smooth prediction into a single process. This is a departure from previous work that required two training phases, one to self-organize a map using the SOM algorithm, and another to learn a smooth approximation of a function. System performance is illustrated with three examples.Office of Naval Research (N00014-95-10409, N00014-95-0657