957 research outputs found
Manga: o produtor pergunta, a Embrapa responde.
No full textClassificação e descrição botânica; Variedades; Clima e solo; Propagação; Instalação do pomar; Adubação e calagem; Irrigação; Fertirrigação; Podas; Florescimento e frutificação; Monitoramento e controle de pragas; Monitoramento e controle de doenças; Colheita e pós-colheita; Processamento; Comercialização.Ana Lúcia Borges; Antônia Fonseca de Jesus Magalhães; Antônio Souza do Nascimento; Aristoteles Pires de Matos; Carlos Estevão Leite Cardoso; Clóvis Oliveira de Almeida; Eugênio Ferreira Coelho; Fernanda Vidigal Duarte Souza; Hermes Peixoto Santos Filho; Janay Almeida dos Santos-Serejo; Laerte Scanavaca Júnior; Manoel Teixeira de Castro Neto; Marcelo do Amaral Santana; Márcio Eduardo Canto Pereira; Nelson Fonseca; Rossana Catie Bueno de Godoy.
Projeto Minibibliotecas
Representing Roomates' Preferences with Symmetric Utilities
Get PDFIn the context of the stable roommates problem, it is shown that acyclicity of preferences is equivalent to the existence of symmetric utility functions, i.e. the utility of agent i when matched with j is the same as j 's utility when matched with i .
Out-Of-The_Money Monte Carlo Simulation Option Pricing: the join use of Importance Sampling and Descriptive Sampling
Get PDFAs in any Monte Carlo application, simulation option valuation produces imprecise estimates. In such an application, Descriptive Sampling (DS) has proven to be a powerful Variance Reduction Technique. However, this performance deteriorates as the probability of exercising an option decreases. In the case of out of the money options, the solution is to use Importance Sampling (IS). Following this track, the joint use of IS and DS is deserving of attention. Here, we evaluate and compare the benefits of using standard IS method with the joint use of IS and DS. We also investigate the influence of the problem dimensionality in the variance reduction achieved. Although the combination IS+DS showed gains over the standard IS implementation, the benefits in the case of out-of-the-money options were mainly due to the IS effect. On the other hand, the problem dimensionality did not affect the gains. Possible reasons for such results are discussed.
Building Confidence Intervals with Block Bootstraps for the Variance Ratio Test of Predictability
Get PDFThis paper compares different versions of the multiple variance ratio test based on bootstrap techniques for the construction of empirical distributions. It also analyzes the crucial issue of selecting optimal block sizes when block bootstrap procedures are used, by applying the methods developed by Hall et al. (1995) and by Politis and White (2004). By comparing the results of the different methods using Monte Carlo simulations, we conclude that methodologies using block bootstrap methods present better performance for the construction of empirical distributions of the variance ratio test. Moreover, the results are highly sensitive to methods employed to test the null hypothesis of random walk.
As cosmovisões pessimistas de Schopenhauer e Augusto dos Anjos
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão.O objetivo da dissertação é o de comparar as obras do filósofo alemão Arthur Schopenhauer e do poeta brasileiro Augusto dos Anjos, explorando os assuntos relativos ao pessimismo existente nelas. Eu mostro que os seguintes tópicos estão presentes na produção de ambos os autores: Schopenhauer e Augusto dos Anjos defendem que a dor é um importante constituinte do mundo, sendo perene; que a vida oscila, tal qual um pêndulo, entre o tédio e o sofrimento; que a natureza humana é malévola; que é pelo amor, pelo sexo e perpetuação da espécie que se prolonga o sofrimento humano no mundo; que a salvação e bem-aventurança só é possível através do ascetismo, do encontro com o nada
The Effect of Bid-Ask Prices on Brazilian Options Implied Volatility: A Case Study of Telemar Call Options
Get PDFAlthough not explicitly reported, option traders on the Bovespa exchange pay an implicit bid-ask spread on each trade. Reported transaction prices that comprise the databases previously used to study the Brazilian options markets do not reflect actual option values at the time of the trades, but actual values plus (for purchases) or minus (for sales) the bid-ask spread. We use a chooser American option model to estimate Telemar call options bid-ask spreads, and to create a database of spread-adjusted trade prices. We find that the bid-ask spreads explain several previously reported puzzles regarding asset price volatility.
Speculative Attacks on Debts and Optimum Currency Area: A Welfare Analysis
Get PDFResorting to an extension of the debt crisis model of Cole and Kehoe (JIE 1996), we evaluate financial aspects of an optimum currency area. Our focus is to appraise the welfare of a country, which belongs to a monetary union and might suffer a speculative attack on its public debt. A default may be avoided by an inflation tax on common-currency debt, but this decision depends on majority voting and have costs associated with it. Moreover, the model considers symmetry between national and central governments' decisions about inflation and also describes the loss in international bankers' confidence towards one country being passed on to another. One of our results is that, for a country with low weight in the voting system, common-currency regime is superior in terms of expected welfare to dollarization and may be a better choice than the local-currency one, as the central bank under the latter regime undergoes some political influence from its government.
Interdependence and Contagion: an Analysis of Information Transmission in Latin America's Stock Markets
Get PDFThis paper brings evidences about the hypotheses of financial crisis contagion over Latin American stock markets in the 90's using a multivariate GARCH model. Beside the traditional volatility structure, we added a leverage term like GJR framework in order to avoid problems due to the use of conditional correlation as a measure of relationship between stock markets. The results show the existence of contagion only during the Asian (1997) and the Russian (1998) crises. The consequences of the Brazilian crisis (1999) can be identified as a result of interdependence among Latin American markets, while the crises of Mexico (1994) and Argentina (2001) show a specific mechanism of propagation. This result raises questions about the "contagion" and "interdependence" concepts' adequacy for the analysis of information transmission among stock markets.
Jogos de linguagem matemáticos de mulheres rendeiras de Florianópolis
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Educação Científica e Tecnológica, Florianópolis, 2014.Este estudo tem como objetivo descrever e analisar alguns jogos de linguagem matemáticos praticados por mulheres rendeiras de Florianópolis, mais especificamente as que vivem no bairro Praia do Forte, no norte da ilha de Santa Catarina. A intenção, ao descrever e analisar os jogos de linguagem envolvidos na "prática de fazer renda", foi o de apontar as especificidades em relação a gramática e as regras que os compõem, bem como as semelhanças de família existentes com os jogos de linguagem presentes na forma de vida escolar, para, a partir disso, buscar possíveis desdobramentos para a Educação Matemática. A metodologia empregada na pesquisa é de inspiração etnográfica e utiliza-se de observações diretas, entrevistas semiestruturadas, diário de campo, fotos e filmagem. As ferramentas teóricas que servem para compor a análise advêm da Etnomatemática em suas interlocuções com os filósofos Ludwig Wittgenstein, em sua segunda fase caracterizada pela obra "Investigações Filosóficas", e Michel Foucault. Os jogos de linguagem matemáticos evidenciados sinalizam um modelo de racionalidade que está amalgamado a forma de vida ao qual pertencem, evidenciando, dessa forma, uma maneira particular de matematizar. A partir disso, essa dissertação, problematizou a maneira como vem sendo discutida a finalidade e o modo como vem sendo utilizados esses saberes na forma de vida escolar, pois é possível inferir que a tentativa de inseri-los na forma de vida escolar, que conta com suas especificidades, encontrará algumas dificuldades, pois os jogos de linguagem matemáticos de mulheres rendeiras tem suas significações construídas a partir dessa forma de vida.Abstract : This study aims to describe and analyze some mathematical language games practiced by lace maker women from Florianópolis, more specifically the ones who live in Praia do Forte district, on the south side of Santa Catarina Island. The intention, on describing and analyzing the language games involved on the "lace making practice", was to point out the specificities in relation to the grammar and the rules which they contain, as well as the existing family similarities with the language games present on the way of school life, then, from that, search for plausible developments for the Mathematical Education. The methodology applied on the research is from an ethnographic inspiration and uses direct observations, semi-structured interviews, field diary, photos and filming. The theoretical tools which assist to make up the analysis come from the Ethnomathematics on its interlocutions with the philosophers Ludwig Wittgenstein, on his second phase characterized by the work "Philosophical Investigations", and Michel Foucault. The outlined mathematical language games indicate a rationality model which is amalgamated to the way of life it belongs to, outlining, this way a particular way of mathematizing. Starting from that, this dissertation, problematized the way how the purpose has been discussed and the way how this knowledge has been used on the form of school life, because it is possible to infer that the attempt to insert it on the form of school life, what counts on its specificities, will find out some difficulties, because the mathematical language games from the lace maker women have their meanings built up from this way of life
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