GPS Based Design of the Local Clock Control System based on the Optimally Unbiased Moving Average Filter

In this paper we made the simulation steering of the local clock t'ime errors with simple moving average (MA), optimally unbiased moving average (OMA), the two and three-state Kalman filters. The references signal (precise time) was suministred by GPS. In this task we have two important activities, estimating and the error control, so the,principal parameter in this study is the root mean square error (RMSE) of steering. When steering the GPS-based time error in the local clock with four filters, we found out that, of the filter with the same time constant, the optimally unbiased MA filter desmostred the steering error between the two and three state Kalman filter.Universidad de Guanajuat

Angra Neutrino Project: status and plans

We present the status and plans of the Angra Project, a new nuclear reactor neutrino oscillation experiment, proposed to be built in Brazil at the Angra dos Reis nuclear reactor complex. This experiment is aimed to measure theta_13, the last unknown of the three neutrino mixing angles. Combining a high luminosity design, very low background from cosmic rays and careful control of systematic errors at the 1% level, we propose a high sensitivity multi-detector experiment, able to reach a sensitivity to antineutrino disappearance down to sin^2(2*theta_13) = 0.006 in a three years running period, improving present limits constrained by the CHOOZ experiment by more than an order of magnitude.Comment: 2 pages, 1 figure, talk presented by J.C. Anjos ([email protected]) at NuFact05, 21-26 June 2005, Frascati, Ital

Frontera tecnológica y eficiencia técnica sectorial en México: un análisis envolvente de datos

Esta investigación tiene como objetivo determinar la frontera tecnológica y la eficiencia técnica sectorial de México. La metodología empleada es el Data Envelopment Analysis. Los resultados muestran, en primer lugar, que los sectores relacionados con la agricultura, minería, manufacturas, servicios financieros, profesionales y corporativos, son totalmente eficientes bajo rendimientos variables a escala mientras que bajo rendimientos constantes se excluye el sector 11; la media de eficiencia es de 0.71 bajo rendimientos variables y 0.64 bajo rendimientos constantes a escala, por lo que existe la posibilidad de mejorar el output en aproximadamente un 30% haciendo mejor uso del capital y el empleo.This research aims to determine the technological frontier and technical sectorial efficiency in Mexico. The methodology is based on Data Envelopment Analysis. The results show, first, that the sectors related to agriculture, mining, manufacturing, financial services, professional and corporative, are fully efficient under variable returns to scale while under constant returns excluding the sector 11. The average efficiency is 0.71 under variable returns and 0.64 under constant returns to scale, so there is the possibility of improving the output by about 30% doing better use of capital and employment

Analytic and geometric properties of photoinduced effects in noncentrosymmetric crystals: photovoltaic current and optical rectification

An original dispersion relation between the stationary coherent nonlinear optical responses by current and polarisation is obtained. The dispersion relation provides a new complimentary tool that can be employed to study light-induced charge transport models and facilitate experimental data analysis. It is shown that the origin of the coherent current and the dc-polarisation induced in a noncentrosymmetric crystal under illumination is related to the theory of the Berry phase and can be represented in terms of the renormalised geometric potentials. This renormalisation originates from the extra phase difference acquired by a carrier in the light field on the quantum transition between the electronic bands. The gauge invariance of the corresponding expressions for the current and the polarisation is demonstrated.Comment: 7 page

Experimental constraints on a dark matter origin for the DAMA annual modulation effect

A claim for evidence of dark matter interactions in the DAMA experiment has been recently reinforced. We employ a new type of germanium detector to conclusively rule out a standard isothermal galactic halo of Weakly Interacting Massive Particles (WIMPs) as the explanation for the annual modulation effect leading to the claim. Bounds are similarly imposed on a suggestion that dark pseudoscalars mightlead to the effect. We describe the sensitivity to light dark matter particles achievable with our device, in particular to Next-to-Minimal Supersymmetric Model candidates.Comment: v4: introduces recent results from arXiv:0807.3279 and arXiv:0807.2926. Sensitivity to pseudoscalars is revised in light of the first. Discussion on the subject adde

Results from a Search for Light-Mass Dark Matter with a P-type Point Contact Germanium Detector

We report on several features present in the energy spectrum from an ultra low-noise germanium detector operated at 2,100 m.w.e. By implementing a new technique able to reject surface events, a number of cosmogenic peaks can be observed for the first time. We discuss several possible causes for an irreducible excess of bulk-like events below 3 keVee, including a dark matter candidate common to the DAMA/LIBRA annual modulation effect, the hint of a signal in CDMS, and phenomenological predictions. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.Comment: 4 pages, 4 figures. v2: submitted version. Minimal changes in wording, one reference adde