Robust constrained model predictive control based on parameter-dependent Lyapunov functions

The problem of robust constrained model predictive control (MPC) of systems with polytopic uncertainties is considered in this paper. New sufficient conditions for the existence of parameter-dependent Lyapunov functions are proposed in terms of linear matrix inequalities (LMIs), which will reduce the conservativeness resulting from using a single Lyapunov function. At each sampling instant, the corresponding parameter-dependent Lyapunov function is an upper bound for a worst-case objective function, which can be minimized using the LMI convex optimization approach. Based on the solution of optimization at each sampling instant, the corresponding state feedback controller is designed, which can guarantee that the resulting closed-loop system is robustly asymptotically stable. In addition, the feedback controller will meet the specifications for systems with input or output constraints, for all admissible time-varying parameter uncertainties. Numerical examples are presented to demonstrate the effectiveness of the proposed techniques

Seleção de genótipos de feijão-caupi tipo comercial Canapu no semiárido piauiense.

O feijão-caupi ou feijão-de-corda (Vigna unguiculata L. Walp.) é a espécie de feijão de maior importância socioeconômica nas regiões Norte e Nordeste do Brasil. Na cultura, o tipo comercial de grão mais cultivado no semiárido piauiense é o Canapu. Este trabalho teve como objetivo avaliar e selecionar genótipos de feijão-caupi tipo comercial Canapu com potencial para o mercado do semiárido piauiense. Foram avaliados 20 genótipos de feijão-caupi em quatro municípios do semiárido piauiense, em delineamento de blocos casualizados, com quatro repetições. Foram mensurados os seguintes caracteres: número de dias para o início da floração, valor de cultivo, comprimento de vagem, número de grãos por vagem, peso de 100 grãos, produtividade de grãos e índice de grãos. Foram realizadas análises de variância e comparação entre médias para todos os caracteres, e adaptabilidade e estabilidade da produtividade de grãos. Foi observada variabilidade para a maioria dos caracteres, exceto para o número de grãos por vagem e o índice de grãos, e comportamento diferencial dos genótipos frente às variações ambientais de locais. As cultivares Canapuzinho, Canapuzinho-2 e Paulistinha apresentam superioridade para precocidade, adaptabilidade e estabilidade da produtividade de grãos e potencial para o mercado do feijão-caupi tipo comercial Canapu no semiárido piauiense.bitstream/item/83192/1/Boletim-99-Selecao-Genotipos-Caupi.pd

Spin, gravity, and inertia

The gravitational effects in the relativistic quantum mechanics are investigated. The exact Foldy-Wouthuysen transformation is constructed for the Dirac particle coupled to the static spacetime metric. As a direct application, we analyze the non-relativistic limit of the theory. The new term describing the specific spin (gravitational moment) interaction effect is recovered in the Hamiltonian. The comparison of the true gravitational coupling with the purely inertial case demonstrates that the spin relativistic effects do not violate the equivalence principle for the Dirac fermions.Comment: Revtex, 12 pages, no figures, accepted in Phys. Rev. Let

Energy spectra, wavefunctions and quantum diffusion for quasiperiodic systems

We study energy spectra, eigenstates and quantum diffusion for one- and two-dimensional quasiperiodic tight-binding models. As our one-dimensional model system we choose the silver mean or `octonacci' chain. The two-dimensional labyrinth tiling, which is related to the octagonal tiling, is derived from a product of two octonacci chains. This makes it possible to treat rather large systems numerically. For the octonacci chain, one finds singular continuous energy spectra and critical eigenstates which is the typical behaviour for one-dimensional Schr"odinger operators based on substitution sequences. The energy spectra for the labyrinth tiling can, depending on the strength of the quasiperiodic modulation, be either band-like or fractal-like. However, the eigenstates are multifractal. The temporal spreading of a wavepacket is described in terms of the autocorrelation function C(t) and the mean square displacement d(t). In all cases, we observe power laws for C(t) and d(t) with exponents -delta and beta, respectively. For the octonacci chain, 0<delta<1, whereas for the labyrinth tiling a crossover is observed from delta=1 to 0<delta<1 with increasing modulation strength. Corresponding to the multifractal eigenstates, we obtain anomalous diffusion with 0<beta<1 for both systems. Moreover, we find that the behaviour of C(t) and d(t) is independent of the shape and the location of the initial wavepacket. We use our results to check several relations between the diffusion exponent beta and the fractal dimensions of energy spectra and eigenstates that were proposed in the literature.Comment: 24 pages, REVTeX, 10 PostScript figures included, major revision, new results adde

Holographic Superconductors with Power-Maxwell field

With the Sturm-Liouville analytical and numerical methods, we investigate the behaviors of the holographic superconductors by introducing a complex charged scalar field coupled with a Power-Maxwell field in the background of $d$-dimensional Schwarzschild AdS black hole. We note that the Power-Maxwell field takes the special asymptotical solution near boundary which is different from all known cases. We find that the larger power parameter $q$ for the Power-Maxwell field makes it harder for the scalar hair to be condensated. We also find that, for different $q$, the critical exponent of the system is still 1/2, which seems to be an universal property for various nonlinear electrodynamics if the scalar field takes the form of this paper.Comment: 14 pages, 1 figure, and 2 table

Noncommutative Inflation and the CMB Multipoles

The first year results of WMAP tentatively indicate running of the spectral index as well as a deficit of power in the low multipoles in the CMB spectrum. The former can be rather easily understood in the noncommutative inflation model, and the latter, as we shall show in this paper, still appears to be an anomaly, even though the noncommutative inflation model already suppresses the low multipoles to a certain degree. By fitting the power spectrum, we determine the string scale to be $l_s\sim 4\times 10^{-29}$cm.Comment: 11 pages, 4 figures, harvmac; v2: references adde

Molecular modeling and inhibitory activity of cowpea cystatin against bean bruchid pests.

Made available in DSpace on 2018-06-06T01:01:49Z (GMT). No. of bitstreams: 1 ID278851.pdf: 325253 bytes, checksum: 9561dcac2d70f9704f44dd57019d07c0 (MD5) Previous issue date: 2007-01-16bitstream/item/178117/1/ID-27885-1.pd

Caracterização e análise financeira de um consórcio agroflorestal com cupuaçu, pupunha, copaíba e andiroba: BR SAF RO 02.

O objetivo deste trabalho é descrever o sistema, registrar os coeficientes técnicos e apresentar uma análise financeira de um consórcio agroflorestal com 14 anos, implantado e conduzido por agrossilvicultores do projeto Reca (Rondônia)