15 resultados para Probability and Statistics

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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The Brazilian relief, predominantly composed by small mountains and plateaus, contributed to formation of rivers with high amount of falls. With exception to North-eastern Brazil, the climate of this country are rainy, which contributes to maintain water flows high. These elements are essential to a high hydroelectric potential, contributing to the choice of hydroelectric power plants as the main technology of electricity generation in Brazil. Though this is a renewable source, whose utilized resource is free, dams must to be established which generates a high environmental and social impact. The objective of this study is to evaluate the impact caused by these dams through the use of environmental indexes. These indexes are ratio formed by installed power with dam area of a hydro power plant, and ratio formed by firm power with this dam area. In this study, the greatest media values were found in South, Southeast, and Northeast regions respectively, and the smallest media values were found in North and Mid-West regions, respectively. The greatest encountered media indexes were also found in dams established in the 1950s. In the last six decades, the smallest indexes were registered by darns established in the 1980s. These indexes could be utilized as important instruments for environmental impact assessments, and could enable a dam to be established that depletes an ecosystem as less as possible.

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This article presents an exercise in meta-comprehension of what has been researched on teaching probability and statistics in Brazil. This research was based on the work on this subject presented in the third International Symposium for Research in Mathematics Education (III SIPEM). Articles were selected from the proceedings of the event analyzed hermeneuticly according to the procedures of phenomenology. We observed no evidence of clustering of research on this topic in terms of region or institutions, and we also emphasize that research on the teaching of Probability and Statistics needs to advance toward a theoretical discussion that transcends the subjects being studied and makes broader and deeper links between theory and practice. Findings also indicate that this sub-area of research in mathematics education is in the process of constituting itself.

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The aim of this research is to analyze, in a comparative way, by category of grade, some indicators used by Coordination for the Improvement of Higher Education Personnel (CAPES) in evaluating the performance of Graduate Programs in Mathematics in Brazil, for the triennium 2007-2009, in order to contribute to understanding of the complex methodology involved in triennial evaluations of graduate programs. Based on the indicators present in the Comparative Worksheet of Triennial Assessment, Area Mathematics / Probability and Statistics, from 2007 to 2009, present at CAPES Portal, contingency tables were built for the 26 graduate programs in Mathematics, presenting each indicator and the program concepts. Overall, there was a trend of association of all indicators analyzed and the concept obtained, with older and larger programs with better grades in the assessment. Also, with the exception of journal articles Qualis B5, the article average per professor grows as grows the program grade.

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The objectives of this article are to provide a short history of dentistry and dental education in Brazil and to analyze the nature of its development to date. The databases consulted are those provided by the Brazilian Federal Council of Dentistry, Brazilian Ministry of Health, Brazilian Ministry of Education, National Institute of Studies and Educational Research Anisio Teixeira, and Brazilian Institute of Geography and Statistics. Formal dental education in Brazil started in the late nineteenth century with the creation of courses annexed to existing schools of medicine in Rio de Janeiro and Bahia. Today, there are 191 institutions of higher education nationwide granting degrees in dentistry (137 private [71.7 percent] and fifty-four public [28.3 percent]), with a total of 17,157 student positions offered annually. These schools graduate around 10,000 professionals per year-one of the highest rates in the world. Both the distribution of schools of dentistry and of dentists varies among the regions of the country, with the greatest concentrations in major metropolitan centers with high population density, resulting in limited coverage in the more deprived regions. A review of epidemiological data for oral health and distribution of dentists in Brazil indicates that there is a lack of systematic planning for the allocation of the dental workforce and a lack of consideration of regional needs in the development of dental training programs in Brazil today.

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Portuguese chestnut (Castanea sativa) is used for forest products, raw nuts and processed flour, paste, and candy. We studied the influence on germination efficiency of seed with and without partial tegument removal combined with different substrate composition (coconut fiber, pine compost and vermiculite) at São Paulo State University, Campus of Botucatu, São Paulo, Brazil. Randomized blocks were used in a factorial scheme 3x2 (three substrates x two seed types) consisting of six treatments with five replications (twelve seeds). Seeds were sowed in expanded polystyrene trays, with 72 cells, and maintained at 25 C under controlled environment. Rate, time elapsed and speed of seed germination was submitted to ANOVA and the average compared using Tukey's 5% test of probability and curves adjusted based on Gompertz regression. Coconut fiber or vermiculite associated with seed without partial tegument removal showed the highest germination rate, and coconut fiber with or without partial tegument removal displayed the fastest speed of seed germination.

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The measurement of the mixing angle theta(13), sign of Deltam(13)(2), and the CP or T violating phase delta is fraught with ambiguities in neutrino oscillation. In this paper we give an analytic treatment of the paramater degeneracies associated with measuring the nu(mu)-->nu(e) probability and its CP and/or T conjugates. For CP violation, we give explicit solutions to allow us to obtain the regions where there exist twofold and fourfold degeneracies. We calculate the fractional differences, (Deltatheta/(θ) over bar), between the allowed solutions which may be used to compare with the expected sensitivities of the experiments. For T violation we show that there is always a complete degeneracy between solutions with positive and negative Deltam(13)(2) which arises due to a symmetry and cannot be removed by observing one neutrino oscillation probability and its T conjugate. Thus there is always a fourfold parameter degeneracy apart from exceptional points. Explicit solutions are also given and the fractional differences are computed. The biprobability CP/T trajectory diagrams are extensively used to illuminate the nature of the degeneracies.

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This paper presents the overall methodology that has been used to encode both the Brazilian Portuguese WordNet (WordNet.Br) standard language-independent conceptual-semantic relations (hyponymy, co-hyponymy, meronymy, cause, and entailment) and the so-called cross-lingual conceptual-semantic relations between different wordnets. Accordingly, after contextualizing the project and outlining the current lexical database structure and statistics, it describes the WordNet.Br editing GUI that was designed to aid the linguist in carrying out the tasks of building synsets, selecting sample sentences from corpora, writing synset concept glosses, and encoding both language-independent conceptual-semantic relations and cross-lingual conceptual-semantic relations between WordNet.Br and Princeton WordNet © Springer-Verlag Berlin Heidelberg 2006.

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In order to contribute to the genetic breeding programs of buffaloes, this study aimed to determine the influence of environmental effects on the stayability (ST) of dairy female Murrah buffalo in the herd. Data from 1016 buffaloes were used. ST was defined as the ability of the female to remain in the herd for 1, 2, 3, 4, 5 or 6 years after the first calving. Environmental effects were studied by survival analysis, adjusted to the fixed effects of farm, year and season of birth, class of first-lactation milk yield and age at first calving. The data were analyzed using the LIFEREG procedure of the SAS program that fits parametric models to failure time data (culling or ST = 0), and estimates parameters by maximum likelihood estimation. Breeding farm, year of birth and first-lactation milk yield significantly influenced (P < 0.0001) the ST to the specific ages (1 to 6 years after the first calving). Buffaloes that were older at first calving presented higher probabilities of being culled 1 year after the first calving, without any effect on culling at older ages. Buffaloes with a higher milk yield at first calving presented a lower culling probability and remained for a longer period of time in the herd. The effects of breeding farm, year of birth and first-lactation milk yield should be included in models used for the analysis of ST in buffaloes. Copyright © The Animal Consortium 2010.

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The Brazilian Network for Continuous Monitoring of GNSS - RBMC is a national network of continuously operating reference GNSS stations. Since its establishment in December of 1996, it has been playing an essential role for the maintenance and user access of the fundamental geodetic frame in the country. In order to provide better services for RBMC, the Brazilian Institute of Geography and Statistics - IBGE and the National Institute of Colonization and Land Reform - INCRA are both partners involved in the National Geospatial Framework Project - PIGN. This paper provides an overview of the recent modernization phases the RBMC network has undergone highlighting its future steps. These steps involve the installation of new equipment, provide real time data from a group of core stations and compute real-time DGPS corrections, based on CDGPS (The real-time Canada-Wide DGPS Service) (The Real-Time Canada-Wide DGPS Service. http://www.cdgps.com/ 2009a). In addition to this, a post-mission Precise Point Positioning (PPP) service has been established based on the current Geodetic Survey Division of NRCan (CSRS-PPP) service. This service is operational since April 2009 and is in large use in the country. All activities mentioned before are based on a cooperation signed at the end of 2004 with the University of New Brunswick, supported by the Canadian International Development Agency and the Brazilian Cooperation Agency. The Geodetic Survey Division of NRCan is also participating in this modernization effort under the same project. This infrastructure of 66 GNSS stations, the real time, post processing services and the potentiality of providing Wide Area DGPS corrections in the future show that the RBMC system is comparable to those available in USA and Europe. © Springer-Verlag Berlin Heidelberg 2012.

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The self-assembly of short amino acid chains appears to be one of the most promising strategies for the fabrication of nanostructures. Their solubility in water and the possibility of chemical modification by targeting the amino or carboxyl terminus give peptide-based nanostructures several advantages over carbon nanotube nanostructures. However, because these systems are synthesized in aqueous solution, a deeper understanding is needed on the effects of water especially with respect to the electronic, structural and transport properties. In this work, the electronic properties of l-diphenylalanine nanotubes (FF-NTs) have been studied using the Self-Consistent Charge Density-Functional-based Tight-Binding method augmented with dispersion interaction. The presence of water molecules in the central hydrophilic channel and their interaction with the nanostructures are addressed. We demonstrate that the presence of water leads to significant changes in the electronic properties of these systems decreasing the band gap which can lead to an increase in the hopping probability and the conductivity. © the Owner Societies 2013.

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Pós-graduação em Ciências Biológicas (Farmacologia) - IBB

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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We analyze the relationship between innovation and firms' performance in Brazil using a comprehensive database that cross-references innovation information by PINTEC (Technological Innovation Research) of the IBGE (Brazilian Institute of Geography and Statistics) and financial information from Serasa and Gazeta Mercantil. Results from the structural equation modeling suggest that variables associating with investments in innovation, which are connected to the innovative effort of a company, do not explain financial performance significantly. (C) 2013 Elsevier Inc. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The grinding operation gives workpieces their final finish, minimizing surface roughness through the interaction between the abrasive grains of a tool (grinding wheel) and the workpiece. However, excessive grinding wheel wear due to friction renders the tool unsuitable for further use, thus requiring the dressing operation to remove and/or sharpen the cutting edges of the worn grains to render them reusable. The purpose of this study was to monitor the dressing operation using the acoustic emission (AE) signal and statistics derived from this signal, classifying the grinding wheel as sharp or dull by means of artificial neural networks. An aluminum oxide wheel installed on a surface grinding machine, a signal acquisition system, and a single-point dresser were used in the experiments. Tests were performed varying overlap ratios and dressing depths. The root mean square values and two additional statistics were calculated based on the raw AE data. A multilayer perceptron neural network was used with the Levenberg-Marquardt learning algorithm, whose inputs were the aforementioned statistics. The results indicate that this method was successful in classifying the conditions of the grinding wheel in the dressing process, identifying the tool as "sharp''(with cutting capacity) or "dull''(with loss of cutting capacity), thus reducing the time and cost of the operation and minimizing excessive removal of abrasive material from the grinding wheel.