A class of cubic Rauzy Fractals

In this paper, we study arithmetical and topological properties for a class of Rauzy fractals ${\mathcal R}_a$ given by the polynomial $x^3- ax^2+x-1$ where $a \geq 2$ is an integer. In particular, we prove the number of neighbors of ${\mathcal R}_a$ in the periodic tiling is equal to $8$. We also give explicitly an automaton that generates the boundary of ${\mathcal R}_a$. As a consequence, we prove that ${\mathcal R}_2$ is homeomorphic to a topological disk

A Multivariate Training Technique with Event Reweighting

An event reweighting technique incorporated in multivariate training algorithm has been developed and tested using the Artificial Neural Networks (ANN) and Boosted Decision Trees (BDT). The event reweighting training are compared to that of the conventional equal event weighting based on the ANN and the BDT performance. The comparison is performed in the context of the physics analysis of the ATLAS experiment at the Large Hadron Collider (LHC), which will explore the fundamental nature of matter and the basic forces that shape our universe. We demonstrate that the event reweighting technique provides an unbiased method of multivariate training for event pattern recognition.Comment: 20 pages, 8 figure

Nonparametric models of financial leverage decisions

This paper investigates the properties of nonparametric decision tree models in the analysis of financial leverage decisions. This approach presents two appealing features: the relationship between leverage ratios and the explanatory variables is not predetermined but is derived according to information provided by the data, and the models respect the bounded and fractional nature of leverage ratios. The analysis shows that tree models suggest relationships between explanatory variables and the relative amount of issued debt that parametric models fail to capture. Furthermore, the significant relationships found by tree models are in most cases in accordance with the effects predicted by the pecking-order theory. The results also show that two-part tree models can accommodate better the distinct effects of explanatory variables on the decision to issue debt and on the amount of debt issued by firms that do resort to debt.Capital structure, Fractional regression, Decision trees, Two-part models

Performance of extended space-time coding techniques for MIMO MC-CDMA systems

In this paper we consider a transmission system based on MC-CDMA, where signal spreading is performed entirely in the frequency domain. An extended spacetime coding technique, the Double Alamouti, is evaluated considering a MIMO channel. This assessment is made against standard Alamouti coding, for two different Tx/Rx antenna schemes (2x1 and 2x2). Numerical results, attained through system model simulations, are presented for performance evaluation under realistic scenarios considering some typical system impairments. These results show that in practical systems significant improvements can be achieved by using the Double Alamouti coding scheme

Sensing UMTS bands using cyclostationary features and cooperation between opportunistic terminals

The Opportunistic Radio (OR) concept relies on the cognitive features of the OR terminals, namely the ability to adapt its transmitter parameters, based upon interaction with the RF environment in which it operates. An OR system operates in licensed frequency bands, exploiting opportunities and operating with a lower priority regarding the licensed system, implementing a spectrum pool mechanism. The most important constraint is that the OR network should always avoid harmful interference with the licensed system, therefore it should reliably detect licensed signals in the used band in order to avoid interfering with the licensed owner of that band. Given the importance of UMTS systems in current wireless communications, this paper is focused on 3G bands and addresses the problem of sensing weak UMTS signals. The proposed sensing algorithm exploits the cyclostationary features of UMTS signals and the cooperation between multiple OR terminals clustered in the OR network

Recomendações técnicas para o cultivo do milho no Meio-Norte do Brasil: safra 2003/2004.

bitstream/item/131490/1/Circular-39-Recomendacoes-Tecnicas-para-o-Cultivo-do-milho.PD

Entropic Gravity, Phase-Space Noncommutativity and the Equivalence Principle

We generalize E. Verlinde's entropic gravity reasoning to a phase-space noncommutativity set-up. This allow us to impose a bound on the product of the noncommutative parameters based on the Equivalence Principle. The key feature of our analysis is an effective Planck's constant that naturally arises when accounting for the noncommutative features of the phase-space.Comment: 12 pages. Version to appear at the Classical and Quantum Gravit

Analysis of communication opportunities in UMTS cellular networks

A scenario based on an UMTS TDD opportunistic cellular system that operates over UMTS FDD licensed cellular networks is considered. Therefore a simulation tool was developed for the analysis and assessment of UMTS TDD opportunistic radio system in a coexistence environment with UMTS FDD primary cellular networks. The communication presents the scenario considered, the main features of the simulation tool, discusses and proposes metrics to evaluate the communication opportunities in UMTS FDD primary cellular networks, and presents numerical simulation results. These show that a moderate number of UMTS FDD available frequencies and a reasonable UMTS TDD opportunistic radio transmission power will allow the deployment of UMTS TDD opportunistic radio networks in a coexistence environment with existing licensed systems

Efeitos de tratamentos pré-germinativos e germinativos em sementes de Liquidambar styraciflua l. coletadas em Quedas do Iguaçu, PR.

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