A Time-Periodic Lyapunov Approach for Motion Planning of Controllable Driftless Systems on SU(n)

For a right-invariant and controllable driftless system on SU(n), we consider a time-periodic reference trajectory along which the linearized control system generates su(n): such trajectories always exist and constitute the basic ingredient of Coron's Return Method. The open-loop controls that we propose, which rely on a left-invariant tracking error dynamics and on a fidelity-like Lyapunov function, are determined from a finite number of left-translations of the tracking error and they assure global asymptotic convergence towards the periodic reference trajectory. The role of these translations is to avoid being trapped in the critical region of this Lyapunov-like function. The convergence proof relies on a periodic version of LaSalle's invariance principle and the control values are determined by numerical integration of the dynamics of the system. Simulations illustrate the obtained controls for $n=4$ and the generation of the C--NOT quantum gate.Comment: Submitte

Classical and quantum wormholes in a flat Λ\Lambda-decaying cosmology

We study the classical and quantum wormholes for a flat {\it Euclidean} Friedmann-Robertson-Walker metric with a perfect fluid including an ordinary matter source plus a source playing the role of dark energy (decaying cosmological term). It is shown that classical wormholes exist for this model and the quantum version of such wormholes are consistent with the Hawking-Page conjecture for quantum wormholes as solutions of the Wheeler-DeWitt equation.Comment: 8 pages, 4 figures, accepted for publication in IJT

Cuidados no vinhedo que antecedem à colheita, para obtenção de uva de qualidade.

bitstream/item/140428/1/cuidados-no-vinhedo-que-antecedem.pd

Campaign Advertising and Election Outcomes: Quasi-Natural Experiment Evidence from Gubernatorial Elections in Brazil

Whether campaign advertising influences election outcomes is an open question; a paradox given the amount spent on campaigning in general and TV advertising in particular. We argue that such “absence of documentation” is due to the focus of the empirical literature on the United States, in which the allocation of campaign spending and advertising is decentralized. We explore a quasinatural experiment that enables us to mitigate the omitted variables and reverse causality problems caused by decentralized allocation. In Brazil, gubernatorial elections work in a two-round system. In the first round, candidates’ TV time shares are determined by their coalitions’ share of seats in the National Parliament. In the second round, TV time is split equally between the first-round winner and runner-up. Using differences between rounds as a source of variation, we find a large causal effect of TV advertising on election outcomes.TV Advertising; Campaign Spending; Election Outcomes; Endogeneity; Quasi-Natural Experiments

Rastreabilidade na etapa indústria da Produção Integrada de Uva para Processamento.

O propósito deste trabalho é apresentar os pontos chaves identificados junto a três vinícolas da Serra Gaúcha no processo de validação do Caderno do Estabelecimento Vinícola (CEV), na safra 2013/2014, abordando os pontos cruciais para a rastreabilidade

Estudo de retenção de carotenoides totais em híbridos de mandioca cozida.

O consumo culinário das raízes de mandioca é bastante generalizado em todo o mundo, sendo que a forma de processamento mais utilizada na América Latina e África é o cozimento. As raízes de mandioca ainda podem ser integradas a pratos mais complexos. O melhoramento e a seleção de matérias primas de origem vegetal com altos conteúdos de micronutrientes vêm sendo realizada nos países em desenvolvimento com a finalidade de minimizar carências nutricionais