Methods for estimating the upcrossings index: improvements and comparison

The upcrossings index 0≤η≤1, as a measure of the degree of local dependence in the upcrossings of a high level by a stationary process, plays, together with the extremal index θ, an important role in extreme events modelling. For stationary processes, verifying a long range dependence condition, upcrossings of high thresholds in different blocks can be assumed asymptotically independent and therefore blocks estimators for the upcrossings index can be easily constructed using disjoint blocks. In this paper we focus on the estimation of the upcrossings index via the blocks method and properties such as consistency and asymptotic normality are studied. Besides this new estimation approach for this parameter, we also enlarge its family of runs estimators and improve estimation within this class by providing an empirical way of checking local dependence conditions that control the clustering of upcrossings. We compare the performance of a range of different estimators for η and illustrate the methods using simulated data and financial data.info:eu-repo/semantics/publishedVersio

The effect of a home-based, gamified stability skills intervention on 4-5-year-old children's physical and cognitive outcomes:A pilot study

Background: Stability skills (e.g., static/dynamic balance) are a precursor for other movement skill development (e.g., jumping, catching). However, young children consistently demonstrate low stability and movement skill ability. There is therefore a need to develop effective strategies to improve stability skills in early childhood. Aim: To pilot the effect of a home-based gamified stability skills intervention on 4-5-year-old children's physical skills, self-perceptions and cognitions. Methods: One-hundred-and-eleven 4-5-year-old children participated from three schools. Two schools were allocated into the intervention group (n = 66 children, 33 boys) and one to the control group (n = 45 children, 25 boys). Stability, fundamental movement skills, perceived motor competence, and cognition were assessed at baseline and at post-intervention. The intervention group was given a booklet detailing the 12-week gamified stability skill intervention. The control group participated in their usual weekly activities. Results: A series of ANCOVAs controlling for baseline values demonstrated significantly higher stability skills (F(1,93) = 24.79, p &lt; 0.001, partial η2 = 0.212), fundamental movement skills (F(1,94) = 15.5, p = &lt; 0.001, partial η2 = 0.139), perceived motor competence (F(1,96) = 5.48, p = 0.021, partial η2 = 0.054) and cognition (F(1,96) = 15.5, p = &lt; 0.001, partial η2 = 0.139) at post-test for the intervention versus control groups. Discussion: This study demonstrates that a home-based, gamified, stability skills intervention enhances stability skills, fundamental movement skills, perceived motor competence and cognition in children aged 4-5-years old.</p

Positivity Bias in Customer Satisfaction Ratings

Customer ratings are valuable sources to understand their satisfaction and are critical for designing better customer experiences and recommendations. The majority of customers, however, do not respond to rating surveys, which makes the result less representative. To understand overall satisfaction, this paper aims to investigate how likely customers without responses had satisfactory experiences compared to those respondents. To infer customer satisfaction of such unlabeled sessions, we propose models using recurrent neural networks (RNNs) that learn continuous representations of unstructured text conversation. By analyzing online chat logs of over 170,000 sessions from Samsung's customer service department, we make a novel finding that while labeled sessions contributed by a small fraction of customers received overwhelmingly positive reviews, the majority of unlabeled sessions would have received lower ratings by customers. The data analytics presented in this paper not only have practical implications for helping detect dissatisfied customers on live chat services but also make theoretical contributions on discovering the level of biases in online rating platforms.Comment: This paper will be presented at WWW'18 conferenc

Absorption of nutrients by grapevine under field conditions

From a well fertilized 7 years-old vineyard var. 'Niagara Rosada' (Vinis labrusca L. X Vitis vinifera L.). situated on an Entisol at country of Jundiaí, SP, Brazil, plants were harvested every fifteen days up to 150 days. The plants were divided into: terminal and basal leaves, terminal and basal shoots, and canes, as well grapes. The plant material was analysed by conventional methods for B, Cu, Fe, Mn and Zn. The research was conducted in order: a. to obtain data on the absorption and distribution of the nutrients by the grapevine; b. to obtain data on the exportation of nutrients by the shoots and by the grapes. Conclusions: The leaves present always a higher concentration in nutrients than the other parts of the plant. The leaves, shoots and grapes present different concentrations of the nutrients during the year. The maximum absorption by the leaves, shoots and grapes in mg per plant was observed at the following age (days): The grapevine exported by shoots (pruned) and by grapes the following quantities of nutrients in mg per plant: A vineyeard of 5,000 plants per hectare contains the following quantitites of nutrients: B = 145.45 g.; Cu = 33.60 g.; Fe = 588.85 g.; Mn = 4,093,35 g.; Za = 373.30 g.Ensaio foi conduzido com viderias da cultivar 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifera L.) com 7 anos de idade, no município de Jundiaí, SP, (23°12' de latitude sul e 46°33' de longitude oeste e 715 m de altitude), situadas sobre um Regossolo unidade Currupira, com os objetivos de: (1) determinar as quantidades de nutrientes absorvidos pela videira nos diferentes estádios de desenvolvimento; (2) avaliar a exportação de nutrientes pela cultura durante um ciclo vegetativo. Após a brotação da videira, foram realizadas 17 coletas quinzenais de material. Foram coletadas e separadas as folhas das partes terminal e basal, sarmentos das partes terminal e basal e cachos. No material coletado foram determinados os teores de micronutrientes, com exceção do molibdênio e cloro. Curvas representativas das concentraçoes dos nutrientes nas partes da planta, em função da idade, foram obtidas a partir dos dados calculados através de equações de regressão. Pelos pontos de máximo estimaram-se as quantidades máximas de nutrientes extraídos. Concluiu-se que: - A concentração dos nutrientes é sempre maior nas folhas do que nos sarmentos e existem diferenças nas concentrações de nutrientes das folhas, sarmentos e cachos, em função da idade. - Os acúmulos máximos de nutrientes nas folhas, sarmentos e cachos ocorrem nas seguintes idades: - A exportação de nutrientes em mg por planta pelos cachos e sarmentos removidos pelas colheitas e poda é a seguinte

Acúmulo de nitrogênio, fósforo, potássio, cálcio, magnésio e enxofre pela videira (Vitis labrusca L. X Vitis vinifera L.) cv. 'Niágara rosada', durante um ciclo vegetativo

Plant material from a well fertilized 7 years-old vineyard var. 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifera L.), situated on an Entisol at country of Jundiai, SP, Brazil, was harvested every fifteen days up to 150 days. The plants were divided into: terminal and basal leaves, terminal and basal shoots, and canes, as well grapes. The plant material was analysed by conventional methods for N, P, K, Ca, Mg, S. The research was conducted in order: a. to obtain information on the accumulation of dry matter, during a period of one year; b. to obtain data on the absorption and distribuition of the nutrients by the grapevine; c. to obtain data on the exportation of nutrients by the shoots and by the grapes. Conclusions : The maximum accumulation of the dry matter took place at the age of 148 days. The leaves present always a higher concentration in nutrients than the other parts of the plant. The leaves, shoots and grapes present different concentration of the nutrients during the year. The maximun absorption by the leaves, shoots and grapes in mg per plant was observed at the following age (days): The grapevine exported by shoots (pruned) and by grapes the following quantities of nutrients in mg per plant: A vineyeard of 5.000 plants per hectare content the following quantities of nutrients: N: 90.85 kg; P:28.40 kg; K: 97.60 kg; Ca: 41.20 kg; Mg: 8.10 kg; S: 9.30 kg.Ensaio foi conduzido com videiras de cultivar 'Niagara Rosada' (Vitis labrusca L. X Vitis vinifeva L.) com 7 anos de idade, no município de Jundiaí, SP (23°12' de latitude sul e 46º33' de longitude oeste e 715 m de altitude), situadas sobre um Regossolo unidade Currupira, com os objetivos de: (1) analisar o crescimento (produção de materia seca); (2) determinar as quantidades de nutrientes absorvidos pela videira nos diferentes estádios de desenvolvimento e (3) avaliar a exportação de nutrientes pela cultura durante o ciclo vegetativo. Após a brotação da videira, foram realizadas 17 coletas quinzenais de material. Foram coletadas e separadas as folhas das partes terminal e basal, sarmentos das partes terminal e basal e cachos. No material coletado foram determinados os teores de N, P, K, Ca, Mg e S. Curvas representativas dos acúmulos de matéria seca e das concentrações dos nutrientes nas partes da planta, em função da idade, foram obtidas a partir dos dados calculados através de equações de regressão. Pelos pontos de máximo estimaram-se a produção maxima de matéria seca e as quantidades de nutrientes extraídos. Conclui-se que: . A produção maxima de materia seca ocorre aos 148 dias. . A concentração dos nutrientes é sempre maior nas folhas do que nos sarmentos e existem diferenças nas concentrações de nutrientes das folhas, sarmentos e cachos, em função da idade. . Os acúmulos máximos de nutrientes nas folhas, sarmentos e cachos ocorrem nas seguintes idades

Germinação E Reindução Da Tolerância à Dessecação Em Sementes De Senna Multijuga (rich.) Irwin Et Barn

The aims of this study were to verify the effects of different tests in the overcoming dormancy, excellent germination terms, as light and temperature, and the possibility of re-induction of desiccation tolerance in Senna multijuga seeds. We evaluated two tests for overcoming dormancy: immersion in water with an initial temperature of 100ºC (hot water) and immersion in water at a constant temperature at 100ºC for 20 seconds (boiling water), both treatments followed by rest out of the heating for 24 hours. For the germination test, we evaluated 25ºC, 30ºC (constant) and 20-30ºC (alternate), in the presence and absence of light. For the re-induction of desiccation tolerance, we selected seeds germinated with 1, 2, 3 and 4mm of radicle length. We submitted the germinated seeds to the follow treatments: no incubation, incubation in polyethylene glycol (PEG6000) at the -1,4, -1,7 and -2,0MPa; incubation in PEG -1,4MPa + ABA at the concentrations of 1, 10 and 100μM. The tests followed a completely randomized design (DIC) using 4 repetitions of 25 seeds. The overcoming dormancy using hot water provided the best germination (65%). The Senna multijuga seeds are not photoblastic required, but in light conditions the germination was higher. We observed the resumption of the radicle growth in germinated seeds of up to 3mm length. © 2016, Universidade Federal de Santa Maria. All rights reserved.2641133114

Computing the first eigenpair of the p-Laplacian via inverse iteration of sublinear supersolutions

We introduce an iterative method for computing the first eigenpair $(\lambda_{p},e_{p})$ for the $p$-Laplacian operator with homogeneous Dirichlet data as the limit of $(\mu_{q,}u_{q})$ as $q\rightarrow p^{-}$, where $u_{q}$ is the positive solution of the sublinear Lane-Emden equation $-\Delta_{p}u_{q}=\mu_{q}u_{q}^{q-1}$ with same boundary data. The method is shown to work for any smooth, bounded domain. Solutions to the Lane-Emden problem are obtained through inverse iteration of a super-solution which is derived from the solution to the torsional creep problem. Convergence of $u_{q}$ to $e_{p}$ is in the $C^{1}$-norm and the rate of convergence of $\mu_{q}$ to $\lambda_{p}$ is at least $O(p-q)$. Numerical evidence is presented.Comment: Section 5 was rewritten. Jed Brown was added as autho

TOMATE PARA INDÚSTRIA ESTRATÉGIAS SUSTENTÁVEIS NO COMBATE A TUTA ABSOLUTA

O objetivo deste estudo foi desenvolver um sistema de apoio à decisão com base no acompanhamento técnico dos inimigos da cultura e na construção de mapas de risco para as principais zonas de produção. Outros objetivos foram o estabelecimento de uma metodologia de observação e avaliação, nomeadamente métodos expeditos de estimativa do risco, estabelecimento de regras de tomada de decisão e o estudo da bioecologia da espécie em tomate para indústria no Ribatejo. Os resultados deste projeto são uma contribuição para o uso sustentável dos produtos fitofarmacêuticos e, consequentemente, para uma maior ecoeficiência, conservação da biodiversidade e garantia de qualidade e segurança alimentar do produto final