Optimisation of the parameters of an extended defect model applied to non-amorphizing implants

In this paper, we present the optimisation of the parameters of a physical model of the kinetics of extended defects and applied the model with the optimised parameters to non-amorphizing implants. The model describes the small clusters, the {113} defects and the dislocation loops. In the first part, we determine the formation energies of the small clusters, the fault energy of the {113} defects, their Burgers vector and the self-diffusivity of silicon using TEM measurements and extractions of the supersaturation from the spreading of boron marker layers in low-dose implanted silicon. The improvements of the simulations are presented for the fitted experiments and for other wafers annealed at intermediate temperatures. In the second part, we increase the dose and energy of the non-amorphizing implant, leading to the transformation of {113} defects into dislocation loops. The predictions obtained with the optimised model are shown to be in agreement with the measurements. (c) 2005 Elsevier B.V. All rights reserved

Ancillary qubit spectroscopy of cavity (circuit) QED vacua

We investigate theoretically how the spectroscopy of an ancillary qubit can probe cavity (circuit) QED ground states containing photons. We consider three classes of systems (Dicke, Tavis-Cummings and Hopfield-like models), where non-trivial vacua are the result of ultrastrong coupling between N two-level systems and a single-mode bosonic field. An ancillary qubit detuned with respect to the boson frequency is shown to reveal distinct spectral signatures depending on the type of vacua. In particular, the Lamb shift of the ancilla is sensitive to both ground state photon population and correlations. Back-action of the ancilla on the cavity ground state is investigated, taking into account the dissipation via a consistent master equation for the ultrastrong coupling regime. The conditions for high-fidelity measurements are determined

Perturbation of matrices and non-negative rank with a view toward statistical models

In this paper we study how perturbing a matrix changes its non-negative rank. We prove that the non-negative rank is upper-semicontinuos and we describe some special families of perturbations. We show how our results relate to Statistics in terms of the study of Maximum Likelihood Estimation for mixture models.Comment: 13 pages, 3 figures. A theorem has been rewritten, and some improvements in the presentations have been implemente

Last-mile delivery in favelas: an explanatory study with Brazilian Companies

In urban logistics, the last-mile delivery from warehouse to the consumer's home has become more and more challenging with the continuous growth of urbanization, particularly in developing countries when addressing the logistical difficulties of distributing products in low-income population. This work presents an approach how companies distribute products within brazilian Favelas. Delivering products in these scenarios are not an easy task, high concentration of households without formal urbanization imposes hurdles to find and access to specific location added to the high number of cargo stolen, leads to lot of obstacles in this last mile operations. The company’s strategies are found by matching product type with Favela type in quadrants in the Conditions Decision Matrix. The results showed an emergent proposed model from data based on theory that helps to understand the last-mile delivery in Favelas having the risk as the moderator factor of logistics performance. The paper highlights that companies do not change information, practices neither synergies between their distribution models as well as do not relate to communities in, for example, social actions, in the vast majority of cases. It concludes by mapping the practical strategies applicable for the companies in the last-mil

Análise das estratégias de efeito no filme Koyaanisqatsi

In this essay, we try to figure out, based on Wilson Gomes’s filmanalysis methodology and on the musical minimalistic theory, which are the cognitive, sensorial, and emotional elements that are composed in the effect production strategies in the experimental film Koyaanisqatsi (Godfrey Reggio, USA, 1982)

A new method to measure galaxy bias

We present a new approach for modelling galaxy/halo bias that utilizes the full non-linear information contained in the moments of the matter density field, which we derive using a set of numerical simulations. Although our method is general, we perform a case study based on the local Eulerian bias scheme truncated to second order. Using 200 N-body simulations covering a total comoving volume of 675 h-3 Gpc3, we measure several two- and three-point statistics of the halo distribution to unprecedented accuracy. We use the bias model to fit the halo-halo power spectrum, the halo-matter cross-spectrum and the corresponding three bispectra for wavenumbers in the range 0.04 ≲ k ≲ 0.12 h Mpc-1. We find that the constraints on the bias parameters obtained using the full non-linear information differ significantly from those derived using standard perturbation theory at leading order. Hence, neglecting the full non-linear information leads to biased results for this particular scale range. We also test the validity of the second-order Eulerian local biasing scheme by comparing the parameter constraints derived from different statistics. Analysis of the halo-matter cross-correlation coefficients defined for the two- and three-point statistics reveals further inconsistencies contained in the second-order Eulerian bias scheme, suggesting it is too simple a model to describe halo bias with high accuracy

Modelling large-scale halo bias using the bispectrum

We study the relation between the density distribution of tracers for large-scale structure and the underlying matter distribution - commonly termed bias - in the Λ cold dark matter framework. In particular, we examine the validity of the local model of biasing at quadratic order in the matter density. This model is characterized by parameters b1 and b2. Using an ensemble of N-body simulations, we apply several statistical methods to estimate the parameters. We measure halo and matter fluctuations smoothed on various scales. We find that, whilst the fits are reasonably good, the parameters vary with smoothing scale. We argue that, for real-space measurements, owing to the mixing of wavemodes, no smoothing scale can be found for which the parameters are independent of smoothing. However, this is not the case in Fourier space. We measure halo and halo-mass power spectra and from these construct estimates of the effective large-scale bias as a guide for b1. We measure the configuration dependence of the halo bispectra Bhhh and reduced bispectra Qhhh for very large-scale k-space triangles. From these data, we constrain b1 and b2, taking into account the full bispectrum covariance matrix. Using the lowest order perturbation theory, we find that for Bhhh the best-fitting parameters are in reasonable agreement with one another as the triangle scale is varied, although the fits become poor as smaller scales are included. The same is true for Qhhh. The best-fitting values were found to depend on the discreteness correction. This led us to consider halo-mass cross-bispectra. The results from these statistics supported our earlier findings. We then developed a test to explore whether the inconsistency in the recovered bias parameters could be attributed to missing higher order corrections in the models. We prove that low-order expansions are not sufficiently accurate to model the data, even on scales k1∼ 0.04 h Mpc−1. If robust inferences concerning bias are to be drawn from future galaxy surveys, then accurate models for the full non-linear bispectrum and trispectrum will be essentia