WAVELET BASED NONLINEAR SEPARATION OF IMAGES

This work addresses a real-life problem corresponding to the separation of the nonlinear mixture of images which arises when we scan a paper document and the image from the back page shows through. The proposed solution consists of a non-iterative procedure that is based on two simple observations: (1) the high frequency content of images is sparse, and (2) the image printed on each side of the paper appears more strongly in the mixture acquired from that side than in the mixture acquired from the opposite side. These ideas had already been used in the context of nonlinear denoising source separation (DSS). However, in that method the degree of separation achieved by applying these ideas was relatively weak, and the separation had to be improved by iterating within the DSS scheme. In this paper the application of these ideas is improved by changing the competition function and the wavelet transform that is used. These improvements allow us to achieve a good separation in one shot, without the need to integrate the process into an iterative DSS scheme. The resulting separation process is both nonlinear and non-local. We present experimental results that show that the method achieves a good separation quality

Spin(7)-manifolds in compactifications to four dimensions

We describe off-shell $\mathcal{N}=1$ M-theory compactifications down to four dimensions in terms of eight-dimensional manifolds equipped with a topological $Spin(7)$-structure. Motivated by the exceptionally generalized geometry formulation of M-theory compactifications, we consider an eight-dimensional manifold $\mathcal{M}_{8}$ equipped with a particular set of tensors $\mathfrak{S}$ that allow to naturally embed in $\mathcal{M}_{8}$ a family of $G_{2}$-structure seven-dimensional manifolds as the leaves of a codimension-one foliation. Under a different set of assumptions, $\mathfrak{S}$ allows to make $\mathcal{M}_{8}$ into a principal $S^{1}$ bundle, which is equipped with a topological $Spin(7)$-structure if the base is equipped with a topological $G_{2}$-structure. We also show that $\mathfrak{S}$ can be naturally used to describe regular as well as a singular elliptic fibrations on $\mathcal{M}_{8}$, which may be relevant for F-theory applications, and prove several mathematical results concerning the relation between topological $G_{2}$-structures in seven dimensions and topological $Spin(7)$-structures in eight dimensions.Comment: 50 pages. We have included Proposition 6.4 about elliptic fibrations in relation to a pair of vector fields. We have also included Remark 5.13, thanks to an internal communication by Dominic Joyce. Discussion about the relation of singular foliations and D7-branes include

National Policies to Attract FDI in R&D: An Assessment of Brazil and Selected Countries

This paper is part of a project based on a broad data collection of policies in selected countries, with a special focus on the attraction of foreign R&D investments. The purpose of the research is to contribute to effective policy-making, capable of fostering multinational corporations? (MNCs) investments in Brazil. In this context, the paper aims at identifying and examining the main policies to attract MNC technological activities in China, India, Ireland, Israel, Singapore, and Taiwan, in order to illustrate successful experiences and, based on them, to analyse the Brazilian case. The experiences and, based on them, to analyse the Brazilian case. The international experiences are analysed bearing in mind that foreign direct investment (FDI) attraction policies are part of industrial and development policies, and should not be assessed or used in isolation. ...industrial policy, technology, foreign direct investment, MNC R&D activites

THE USE OF BUDGETS IN FORECASTING THE ACTIVITY OF THE FIRM

The firm’s activity is recommended to develop in a permanent equilibrium between incomes and expenses. In the actual stage of transition of Romanian economy, the firms can not maintain this equilibrium because the expenses determined by the achievement of production overtake the level of the incomes obtained from the selling of production even when certain branches of activity are subsidized from the public budget. In these conditions, finding the methods that allow the sizing and control of the equilibrium relation between expenses and incomes represents a problem with which the firm’s management confronts. From this point of view the budget can become an instrument of correlation and especially of turning to good account the relation between incomes and expenses. Budgeting becomes a systematic economic practice that assumes the development of a process of formal assignment of financial resources that aim at the achievement of some established objectives for the future periods.budget, budgeting, forecasting, management by using budgets, expenditure budget, budget holders, manufacturing costs.

The Unusual Super-Luminous Supernovae SN 2011kl and ASASSN-15lh

Two recently discovered very luminous supernovae (SNe) present stimulating cases to explore the extents of the available theoretical models. SN 2011kl represents the first detection of a supernova explosion associated with an ultra-long duration gamma ray burst. ASASSN-15lh was even claimed as the most luminous SN ever discovered, challenging the scenarios so far proposed for stellar explosions. Here we use our radiation hydrodynamics code in order to simulate magnetar powered SNe. To avoid explicitly assuming neutron star properties we adopt the magnetar luminosity and spin-down timescale as free parameters of the model. We find that the light curve (LC) of SN 2011kl is consistent with a magnetar power source, as previously proposed, but we note that some amount of 56^Ni (> 0.08 M_sun) is necessary to explain the low contrast between the LC peak and tail. For the case of ASASSN-15lh we find physically plausible magnetar parameters that reproduce the overall shape of the LC provided the progenitor mass is relatively large (a mass of the ejecta approx 6 M_sun). The ejecta hydrodynamics of this event is dominated by the magnetar input, while the effect is more moderate for SN 2011kl. We conclude that a magnetar model may be used for the interpretation of these events and that the hydrodynamic modeling is necessary to derive the properties of powerful magnetars and their progenitors.Comment: Accepted by Astrophysical Journal Letters, 5 pages, 5 figure

Multiscale Fractal Descriptors Applied to Nanoscale Images

This work proposes the application of fractal descriptors to the analysis of nanoscale materials under different experimental conditions. We obtain descriptors for images from the sample applying a multiscale transform to the calculation of fractal dimension of a surface map of such image. Particularly, we have used the}Bouligand-Minkowski fractal dimension. We applied these descriptors to discriminate between two titanium oxide films prepared under different experimental conditions. Results demonstrate the discrimination power of proposed descriptors in such kind of application

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