Nonsmooth continuous-time optimization problems: Sufficient conditions

We discuss sufficient conditions of optimality for nonsmooth continuous-time nonlinear optimization problems under generalized convexity assumptions. These include both first-order and second-order criteria. (C) 1998 Academic Press.

On the solution of mathematical programming problems with equilibrium constraints

Mathematical programming problems with equilibrium constraints (MPEC) are nonlinear programming problems where the constraints have a form that is analogous to first-order optimality conditions of constrained optimization. We prove that, under reasonable sufficient conditions, stationary points of the sum of squares of the constraints are feasible points of the MPEC. In usual formulations of MPEC all the feasible points are nonregular in the sense that they do not satisfy the Mangasarian-Fromovitz constraint qualification of nonlinear programming. Therefore, all the feasible points satisfy the classical Fritz-John necessary optimality conditions. In principle, this can cause serious difficulties for nonlinear programming algorithms applied to MPEC. However, we show that most feasible points do not satisfy a recently introduced stronger optimality condition for nonlinear programming. This is the reason why, in general, nonlinear programming algorithms are successful when applied to MPEC.

Necessary and sufficient condition for generalized passivity, passification and application to multivariable adaptive systems

Recently, a generalized passivity concept for linear multivariable systems was obtained which allows circumventing the restrictiveness of the usual passivity concept. The latter is associated with the classical SPR (Strictly Positive Real) condition whereas the new concept of passivity is associated with the so called WSPR condition and its advantage in multivariable systems is that it does not require a restrictive symmetry condition of SPR systems. As a result, it allows the design of multivariable adaptive control that, unlike some existing factorization approaches, does not imply in additional overparameterization of the adaptive controller. In this paper, we complete a previously established WSPR sufficient condition and prove that it is also necessary. We also propose some methods of passification by either premultiplying the system output tracking error vector or the system input vector by an adequate passifying matrix multiplier, so that the resulting input/output transfer function becomes WSPR. The efficiency of our proposals are illustrated by simulation utilizing a well known robotics adaptive visual servoing problem. © 2011 IFAC.

A new sufficient condition for optimal impulsive control problems

In this article we introduce the concept of MP-pseudoinvexity for general nonlinear impulsive optimal control problems whose dynamics are specified by measure driven control equations. This is a general paradigm in that, both the absolutely continuous and singular components of the dynamics depend on both the state and the control variables. The key result consists in showing the sufficiency for optimality of the MP-pseudoinvexity. It is proved that, if this property holds, then every process satisfying the maximum principle is an optimal one. This result is obtained in the context of a proper solution concept that will be presented and discussed. © 2012 IEEE.

Estratégias para produção de mudas de tomateiro utilizando paclobutrazol

The modern tomato production, either for fruit table production or for processing, has required quality seedlings, able to withstand environmental adversities after planting and maintaining the standard genotype productive. The aim of this study was to evaluate the effect of three concentrations of PBZ (0, 50 and 100 mg L-1) and two methods of application (seed treatment and watering seedlings) on seedling emergence and seedling production of tomato growth indeterminate. We adopted a completely randomized in a 2x3 factorial scheme with four replications. We evaluated the seedling emergence, the rate of speed of emergence, seedling height and diameter of hypocotyl and their absolute growth rate (TCA), leaf area, dry weight of shoots, roots and total, and reason leaf area (RAF). Results were subjected to analysis of variance and the mean levels of the factor methods of application compared by Tukey test at 5% and the mean levels of the factor concentrations subjected to regression analysis. The application of paclobutrazol via seedlings watering did not affect seedling emergence, significantly reduced the rate of seedling growth and, consequently, the size of the seedlings without affecting the diameter of hypocotyl, plus allow accumulation of dry roots. A concentration of 50 mg L-1 was shown to be sufficient to obtain seedlings more compact, subject to leaf area, the application via watering, beyond allowing an increase of about 37% in dry weight of roots.

Propriedades físico-mecânicas de painéis particulados de Eucalyptus saligna e casca de noz macadâmia

Pós-graduação em Engenharia Mecânica - FEG

Fatores sócio-demográficos e antecedentes obstétricos relacionados à sífilis na gestação em uma amostra de gestantes do Distrito Federal

Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB

Determinação de indicadores de eficiência e racionalidade energética na produção de etanol com a aplicação da lógica fuzzy

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Single CpG island methylation is not sufficient to maintain the silenced expression of CASPASE-8 apoptosis-related gene among women with epithelial ovarian cancer

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinants of bird species richness, endemism, and island network roles in Wallacea and the West Indies: is geography sufficient or does current and historical climate matter?

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diverse urban plantings managed with sufficient resource availability can increase plant productivity and arthropod diversity

Buildings structures and surfaces are explicitly being used to grow plants, and these "urban plantings" are generally designed for aesthetic value. Urban plantings also have the potential to contribute significant "ecological values" by increasing urban habitat for animals such as arthropods and by increasing plant productivity. In this study, we evaluated how the provision of these additional ecological values is affected by plant species richness; the availability of essential resources for plants, such as water, light, space; and soil characteristics. We sampled 33 plantings located on the exterior of three buildings in the urban center of Brisbane, Australia (subtropical climatic region) over 2, 6 week sampling periods characterized by different temperature and rainfall conditions. Plant cover was estimated as a surrogate for productivity as destructive sampling of biomass was not possible. We measured weekly light levels (photosynthetically active radiation), plant CO2 assimilation, soil CO2 efflux, and arthropod diversity. Differences in plant cover were best explained by a three-way interaction of plant species richness, management water regime and sampling period. As the richness of plant species increased in a planter, productivity and total arthropod richness also increased significantly likely due to greater habitat heterogeneity and quality. Overall we found urban plantings can provide additional ecological values if essential resources are maintained within a planter such as water, light and soil temperature. Diverse urban plantings that are managed with these principles in mind can contribute to the attraction of diverse arthropod communities, and lead to increased plant productivity within a dense urban context.

Root morphology and phosphorus uptake by potato cultivars grown under deficient and sufficient phosphorus supply

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A dual control mechanism synchronizes riboflavin and sulphur metabolism in Bacillus subtilis

Flavin mononucleotide (FMN) riboswitches are genetic elements, which in many bacteria control genes responsible for biosynthesis and/or transport of riboflavin (rib genes). Cytoplasmic riboflavin is rapidly and almost completely converted to FMN by flavokinases. When cytoplasmic levels of FMN are sufficient (high levels), FMN binding to FMN riboswitches leads to a reduction of rib gene expression. We report here that the protein RibR counteracts the FMN-induced turn-off activities of both FMN riboswitches in Bacillus subtilis, allowing rib gene expression even in the presence of high levels of FMN. The reason for this secondary metabolic control by RibR is to couple sulfur metabolism with riboflavin metabolism.

Dinâmica de corpos lúteos em protocolos com redução da dose de FSH na superovulação em ovelhas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)