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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Algumas importantes constantes em matematica

Alves, Alessandro Ferreira 02 March 1999 (has links)
Orientador: Jose Plinio de Oliveira Santos / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-07-24T16:17:59Z (GMT). No. of bitstreams: 1 Alves_AlessandroFerreira_M.pdf: 1073554 bytes, checksum: 53e0c50b7fca0350e8be2d1c6f74d4c0 (MD5) Previous issue date: 1999 / Resumo: Neste trabalho são estudadas algumas constantes numéricas importantes, tais como 7r, e e a constante de Euler que aparecem amplamente em todos os ramos da matemática, bem como suas principais características e propriedades, dentre elas irracionalidade e transcendência. / Abstract: In this dissertation we study some important mathematical constants such as 11", e and Euler's constant that appear in almost all branches of mathematics. Special attention is given for the transcendence and irrationality of them. / Mestrado / Mestre em Matemática
2

Essays on imprecise representation of uncertainty considering evidence theory and FUZZY

SILVA, Lucimário Gois de Oliveira 21 December 2016 (has links)
Submitted by Alice Araujo (alice.caraujo@ufpe.br) on 2018-05-04T17:50:41Z No. of bitstreams: 1 TESE Lucimário Gois de Oliveira Silva.pdf: 1773160 bytes, checksum: 544f69e8bf9e030500afed15f5669888 (MD5) / Made available in DSpace on 2018-05-04T17:50:41Z (GMT). No. of bitstreams: 1 TESE Lucimário Gois de Oliveira Silva.pdf: 1773160 bytes, checksum: 544f69e8bf9e030500afed15f5669888 (MD5) Previous issue date: 2016-12-21 / This paper contains the compendium of three articles on the representation of uncertainty. The two first ones deal with the classical theory of evidence or Dempster - Shafer theory. In these articles, the classification of conflict in the theory of evidence is approached, since bodies of evidence with high level of conflict lead to counterintuitive results when the Dempster Rule of Combination is used. In the first article, the conflict classification is made from class profiles by using the ELECTRE TRI method. In the second article, the classification is made from reference alternatives of each conflict class, the classification of conflict having been obtained through the outranking flow of the PROMETHEE method among the reference alternatives and the alternatives to be classified. In both articles, the parameters of the two methods are obtained by means of disaggregation approaches where the parameters are generated from alternatives pre-classified in conflict in the first article and reference alternatives in the second. Finally, the third article deals with the financial analysis in the development of a new product where a real options model is added by using dynamic programming, the modeling of uncertainty through FUZZY triangular numbers. Thus, in this model it is possible to consider the different types of uncertainty contained in the development of new products. / Este trabalho contém o compêndio de três artigos sobre representação da incerteza. Os dois primeiros artigos tratam sobre a clássica teoria da evidência ou teoria Dempster - Shafer. Nesses artigos, é abordada a classificação do conflito na teoria da evidência, uma vez que corpos de evidência com alto teor de conflito conduzem a resultados contra intuitivos quando a regra de Dempster é utilizada. No primeiro artigo, a classificação do conflito é feita a partir de perfis de classe, utilizando o método ELECTRE TRI. No segundo artigo, a classificação é feita a partir de alternativas referência de cada classe de conflito, sendo a classificação do conflito obtida por meio do fluxo de sobreclassificação do método PROMETHEE entre as alternativas de referência e as alternativas a serem classificadas. Em ambos os artigos, os parâmetros dos dois métodos são obtidos por meio de abordagens de desagregação onde os parâmetros são gerados a partir de alternativas pré-classificadas em conflito no primeiro artigo e alternativas referência no segundo artigo. Por último, o terceiro artigo trata da análise financeira no desenvolvimento de um novo produto onde é agregado um modelo de opções reais, que utiliza programação dinâmica, a modelagem da incerteza através de números triangulares FUZZY. Assim, nesse modelo é possível considerar os diferentes tipos de incerteza que estão contidos no desenvolvimento de novos produtos.
3

Evaluation of Nitration/Anammox process by bacterial activity tests.

Mika, Anna January 2015 (has links)
Partial Nitritation/Anammox process (deammonification process), by which occurs oxidation of ammonium to nitrogen gas by autotrophic bacteria in anaerobic conditions, considered to be cost-effective and environmentally friendly method of nitrogen removal. Present research work focuses on achieving a high nitrogen removal degree, thanks to Anammox bacteria, while providing the best performance of the ongoing process. Integrated fixed-film activated sludge (IFAS) reactor was supplied with the main stream of the wastewater after UASB reactor, characterized by low concentration of nitrogen and organic matter. The bacteria ability to accommodate, were tested in the biofilm and in the activated sludge, depending on the different stages in which the process were being conducted. Batch test, such as Specific Anammox Activity (SAA), Nitrate Uptake Rate (NUR) and Oxygen Uptake Rate (OUR), were used for the evaluation of activity of various groups of bacteria. On the basis of laboratory analysis verified the values obtained from the batch tests. It was determined that a high degree of nitrogen removal (92% of NH4-N) was achieved thanks to the dominant activity of the Anammox bacteria, with low participation of other groups of bacteria. It was also proved, that Anammox bacteria activity were overwhelming in the biofilm. Dominant role of Ammonium Oxidizing Bacteria (AOB) was associated with high activity of Anammox bacteria, which together satisfyingly out-competed Nitrite Oxidizing Bacteria (NOB) and heterotrophic bacteria. It has been shown that Anammox bacteria quickly adapt to the new conditions and they are able to assume a dominant role, even in the case of inoculation of the reactor with the sludge from SBR. This allows conclude, that in the case of operational problems, the reactor can be supplied from another source, in order not to inhibit the process.

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