An existence theorem for G-structure preserving affine immersions

We prove an existence result for local and global G-structure preserving affine immersions between affine manifolds. Several examples are discussed in the context of Riemannian and semi-Riemannian geometry, including the case of isometric immersions into Lie groups endowed with a left-invariant metric, and the case of isometric immersions into products of space forms.

A note on an application of Arrow's theorem: sufficient conditions for Lucas' inflation and welfare

Bellman's methods for dynamic optimization constitute the present mainstream in economics. However, some results associated with optimal controI can be particularly usefuI in certain problems. The purpose of this note is presenting such an example. The value function derived in Lucas' (2000) shopping-time economy in Infiation and Welfare need not be concave, leading this author to develop numerical analyses to determine if consumer utility is in fact maximized along the balanced path constructed from the first order conditions. We use Arrow's generalization of Mangasarian's results in optimal control theory and develop sufficient conditions for the problem. The analytical conclusions and the previous numerical results are compatible .

Value-for-money e geração de valor público na atuação das organizações sociais de saúde : contribuições para o governo do estado de São Paulo

O fato de que o Estado brasileiro deve, de acordo com sua Carta Magna, garantir o direito de seus cidadãos à saúde não significa, necessariamente, que a provisão destes serviços tem de ser feita diretamente pelo poder público. As parcerias com organizações sociais, previstas na Lei Federal 9.637/1998 e regulamentadas pelos Contratos de Gestão, pretendem oferecer uma alternativa à eficiência, agilidade e flexibilidade na assistência à saúde. Entretanto, a estrutura dos contratos de gestão com Organizações Sociais de Saúde (OSS), elaborada com a pactuação de metas e indicadores de desempenho, não pode ser considerada, isoladamente, como fator garantidor da prestação adequada de tais serviços públicos. É fundamental considerar neste contexto os arranjos organizados pelo poder público para assegurar que os serviços oferecidos representam o que, de fato, os cidadãos consideram valor. O presente trabalho tem como objeto as parcerias com OSS no âmbito do governo do estado de São Paulo. As entrevistas realizadas e as pesquisas empreendidas na confecção deste estudo revelam que, caso se pretenda trabalhar com estas parcerias sob uma perspectiva de value-for-money e geração de valor público, faz-se necessário aprimorar os mecanismos de escuta aos cidadãos, os arranjos de governança colaborativa entre entes federados, o alinhamento com órgãos de controle e, sobretudo, qualificar a capacidade organizacional do Estado e das OSS, por meio da revisão das metas e indicadores dispostos nos contratos de gestão.

Joint dynamic probabilistic constraints with projected linear decision rules

We consider multistage stochastic linear optimization problems combining joint dynamic probabilistic constraints with hard constraints. We develop a method for projecting decision rules onto hard constraints of wait-and-see type. We establish the relation between the original (in nite dimensional) problem and approximating problems working with projections from di erent subclasses of decision policies. Considering the subclass of linear decision rules and a generalized linear model for the underlying stochastic process with noises that are Gaussian or truncated Gaussian, we show that the value and gradient of the objective and constraint functions of the approximating problems can be computed analytically.

Fatores associados à efetividade da doação de órgãos e tecidos para transplantes

The transplantation of organs and tissues presents itself as an important therapeutic option, both from a medical standpoint, the social or economic. Thus, the identification of variables that can interfere in the effectiveness of organs and tissues donation for transplantation needs to be investigated adequately, because it stands before increasing index of chronic and degenerative diseases in the population, what makes the waiting list for transplantation grow disproportionately and patients come to death without the opportunity of realization the treatment due to a lack of donors. In this context, has defined as objective of this study evaluate the factors associated with the effectiveness of organs and tissues donation for transplantation. It is a evaluative research, quantitative, prospective, with longitudinal design, developed at Central of Catchment, Notification and organ donation for transplant, Organ Procurement Organization and in six accredited hospitals to collect and transplantation of organs and tissues, in Natal/RN, between august 2010 and february 2011, after the approval of the Research Ethics Committee, under No. 414/10 and CAAE 007.0.294.000-10. The probabilistic sample without replacement was composed of 65 potential donors. It was used as an instrument of data collection a structured script non-participant observation of checklist type. Data were analyzed using descriptive statistics and presented in tables, charts, graphs and figures. For this, was used Microsoft Excel 2007 and statistical program SPSS version 20.0. To check the level of significance was chosen by applying the chi-square test (χ2) and Mann Whitney and caselas for less than five, it is considered the Fisher exact test. It was adopted as the significance level p-value <0.05. Among the surveyed it was observed that most of the individuals were male (50,8%), in the age group 45 years (53,8%), mean age of 42,3 years, minimum 5 and maximum 73 years (± 17,32 years). Single / widowers / divorced (56,9%), with up to completed elementary school (60,0%) in the exercise of professional activity (86,2%), catholic (83,1%) and residents in metropolitan region of Natal (52,3%). Was obtained donation effectiveness of 27,7%. There was no statistical significance between structure and effectiveness of the donation, but were observed inadequacies in physical resources (36,9%), materials (30,8%), organizational structure (29,2%) and human resources (18,5%). In the process, the maintenance phase (p= 0.004), diagnosis of brain death (p= 0.032), family interview (p≤ 0.001) and documentation (p= 0.001) presented statistical significance with effectiveness. Thus, it is accepts the alternative hypothesis of the study, in which is evidenced that the adequacy of the factors related to structure and process is associated to effectiveness of organs and tissues donation for transplantation. In this way, the effectiveness of organ and tissue donation ends in an essential way the rapidity and accuracy with which the donation process is conducted, requiring appropriate structure, with appropriate physical and material resources and skilled human resources to optimize the reduction of time and the suffering of those waiting for an organ or tissue transplant queued in Brazil

Análise da precipitação no semi-árido potiguar

The semiarid rainfall regime is northeastern Brazil is highly variable. Climate processes associated with rainfall are complex and their effects may represent extreme situations of drought or floods, which can have adverse effects on society and the environment. The regional economy has a significant agricultural component, which is strongly influenced by weather conditions. Maximum precipitation analysis is traditionally performed using the intensity-duration-frequency (IDF) probabilistic approach. Results from such analysis are typically used in engineering projects involving hydraulic structures such as drainage network systems and road structures. On the other hand, precipitation data analysis may require the adoption of some kind of event identification criteria. The minimum inter-event duration (IMEE) is one of the most used criteria. This study aims to analyze the effect of the IMEE on the obtained rain event properties. For this purpose, a nine-year precipitation time series (2002- 2011) was used. This data was obtained from an automatic raingauge station, installed in an environmentally protected area, Ecological Seridó Station. The results showed that adopted IMEE values has an important effect on the number of events, duration, event height, mean rainfall rate and mean inter-event duration. Furthermore, a higher occurrence of extreme events was observed for small IMEE values. Most events showed average rainfall intensity higher than 2 mm.h-1 regardless of IMEE. The storm coefficient of advance was, in most cases, within the first quartile of the event, regardless of the IMEE value. Time series analysis using partial time series made it possible to adjust the IDF equations to local characteristics

Mean motion resonances and the stability of a circumbinary disk in a triple stellar system

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Economic-statistical design of the (X)over-bar chart used to control a wandering process mean using genetic algorithm

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Analysis of the electrical conductivity in milking fractions as a mean for detecting and characterizing mastitis in goats

The aim of the work was to study the effect of milking fraction on electrical conductivity of milk (EC) to improve its use in dairy goat mastitis detection using automatic EC measurements during milking. The experiment was carried out on a group of 84 Murciano-Granadina goats (28 primiparous and 56 multiparous). Goats were in the fourth month of lactation. A linear mixed model was used to analyse the relationship between EC or somatic cell count (SCC) of gland milk and parity, mammary gland health status, analysed fraction (first 100 mL=F-1; machine milk=F-2; and stripping milk=F-3) and their first order interactions. Additionally, the mastitis detection characteristics (sensitivity, specificity, positive predictive value and negative predictive value) of SCC and EC were studied at different thresholds.All factors considered were significant for EC and SCC. EC decreased significantly as milking progressed (from F-1 to F-3) in both healthy and infected glands. EC was not significantly different between healthy and infected glands in F-1 and F-2 fractions, but EC of healthy glands (5.01 mS/cm) was significantly lower than in infected glands (5.03 mS/cm) at F-3.Mastitis detection characteristics of EC did not differ amongst studied fractions. The small significant difference of EC between healthy and infected glands obtained in F-3 fraction did not yield better sensitivity results compared to F-1 and F-2. The best EC mastitis detection characteristics were obtained at 5.20 mS/cm threshold (sensitivity of 70% and specificity of 50%). The best SCC mastitis detection characteristics were obtained at 300,000 cells/mL threshold and F-3 fraction (sensitivity of 85% and specificity of 65%).It was concluded that mastitis detection characteristics of EC were similar in the three milking fractions analysed, being slightly better for SCC in F-3 fraction. As shown in previous studies, there are no factors other than the mammary gland health status that affect milk EC and should be considered in the algorithms for mastitis detection to improve the results. (C) 2012 Elsevier B.V. All rights reserved.

pK determination. A mean field, Poisson-Boltzmann approach

A model describing dissociation of monoprotonic acid and a method for the determination of its pK value are presented. The model is based on a mean field approximation. The Poisson-Boltzmann equation, adopting spherical symmetry, is numerically solved, and the solution of its linearized form is written. By use of the pH values of a dilution experiment of galacturonic acid as the entry data, the proposed method allowed estimation of the value of pK = 3.25 at a temperature of 25 degrees C. Values for the complex dimensions and dissociation degree are calculated using experimental pH values for solution concentration values ranging from 0.1 to 60 mM. The present analysis leads to the conclusion that the Poisson-Boltzmann equation or its linear form is equally suited for the description of such systems.

On the value function for nonautonomous optimal control problems with infinite horizon

In this paper we consider nonautonomous optimal control problems of infinite horizon type, whose control actions are given by L-1-functions. We verify that the value function is locally Lipschitz. The equivalence between dynamic programming inequalities and Hamilton-Jacobi-Bellman (HJB) inequalities for proximal sub (super) gradients is proven. Using this result we show that the value function is a Dini solution of the HJB equation. We obtain a verification result for the class of Dini sub-solutions of the HJB equation and also prove a minimax property of the value function with respect to the sets of Dini semi-solutions of the HJB equation. We introduce the concept of viscosity solutions of the HJB equation in infinite horizon and prove the equivalence between this and the concept of Dini solutions. In the Appendix we provide an existence theorem. (c) 2006 Elsevier B.V. All rights reserved.

Synthetic control chart for monitoring the pprocess mean and variance

In this article, we consider the synthetic control chart with two-stage sampling (SyTS chart) to control the process mean and variance. During the first stage, one item of the sample is inspected; if its value X, is close to the target value of the process mean, then the sampling is interrupted. Otherwise, the sampling goes on to the second stage, where the remaining items are inspected and the statistic T = Sigma [x(i) - mu(0) + xi sigma(0)](2) is computed taking into account all items of the sample. The design parameter is function of X-1. When the statistic T is larger than a specified value, the sample is classified as nonconforming. According to the synthetic procedure, the signal is based on Conforming Run Length (CRL). The CRL is the number of samples taken from the process since the previous nonconforming sample until the occurrence of the next nonconforming sample. If the CRL is sufficiently small, then a signal is generated. A comparative study shows that the SyTS chart and the joint X and S charts with double sampling are very similar in performance. However, from the practical viewpoint, the SyTS chart is more convenient to administer than the joint charts.

X charts with supplementary samples to control the mean and variance

A standard X chart for controlling a process takes regular individual observations, for instance every half hour. This article proposes a modification of the X chart that allows one to take supplementary samples. The supplementary sample is taken (and the (X) over bar and R values computed) when the current value of X falls outside the control limits. With the supplementary sample, the signal of out-of-control is given by an (X) over bar value outside the (X) over bar chart's control limits or an R value outside the R chart's control limit. The proposed chart is designed to hold the supplementary sample frequency, during the in-control period, as low as 5% or less. In this context, the practitioner might prefer to verify an out-of-control condition by simply comparing the (X) over bar and R values with the control limits. In other words, without plotting the (X) over bar and R points. The X chart with supplementary samples has two major advantages when compared with the standard (X) over bar and A charts: (a) the user will be plotting X values instead of (X) over bar and R values; (b) the shifts in the process mean and/or changes in the process variance are detected faster.

Monitoring the process mean and variance using a synthetic control chart with two-stage testing

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mean-field description of collapsing and exploding Bose-Einstein condensates

Numerical simulations based on the time-dependent mean-field Gross-Pitaevskii equation was performed to explain the dynamics of collapsing and exploding Bose-Einstein condensates (BEC) of 85Rb atoms. The atomic interaction was manipulated by an external magnetic field via a Feshbach resonance. On changing the scattering length of atomic interaction from a positive to a large negative value, the condensate collapsed and ejected atoms via explosion.