Navegando por Assunto "Probabilidade"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Densidade crítica no modelo de percolação em rede de Bethe não-homogênea
(Sociedade Brasileira de Matemática Aplicada e Computacional, 2015-08) TAVARES, Héliton Ribeiro; SOUZA, Raimundo Nonato Carneiro de; TAVARES, Maria Regina Madruga; FARIAS, Valcir Joao da Cunha
In this work we deal with an inhomogeneous Bethe lattice percolation model where the probability of an edge in level n is open changes according as n. This model can be appropriate to the case where the media changes its density in a systematic way, such as the proliferation of insects that depends on the temperature and humidity, which fluctuates between day and night. We consider the case where the density p(·) follows a function of the distance l(.) from the origin, given by a sinusoid function p(·) = p + (1 - p)|sin(l(.))|. For this model we present results of Monte-Carlo simulation showing the behavior of the probability of percolation with a second-order phase transition, but we present too a formal proof that the density is non trivial, with the mathematical expression to compute the percolation threshold.
Acesso aberto (Open Access)
Otimização e análise de risco da capacidade portuária da bacia amazônica, quanto ao crescimento da demanda de grãos e ao porte dos navios
(Universidade Federal do Pará, 2022-06-03) MORAES NETO, Luciano Pinto de; MORAES, Hito Braga de; http://lattes.cnpq.br/5044859479302394; https://orcid.org/0000-0003-0214-0587
Maritime transport in recent years has brought about a great change in ports around the world due to the advancement of technology which allowed the construction of increasingly larger vessels to reduce freight and transport more cargo. Aware of this reality, this work develops an assessment of port terminals in the Amazon basin, using queuing theory combined with risk analysis and optimization to evaluate port capacity in the face of future grain demands for the region, given that with the advance technology, larger ships are being manufactured and capable of transporting large amounts of cargo, with this advance, the existing ports need to adapt their infrastructure according to the new trends in shipbuilding. In this dissertation, data was collected of movement of cargo and capacity of the existing port terminals in the Amazon region with a focus on long-haul export terminals. A model was developed using the queuing theory to gauge the capacity of terminals and the productivity of ships for use in the @RISK platform, which uses optimization combined with risk analysis, generating distribution and tornado graphs, enabling the analysis of the terminals. help in decision-making on the performance of terminals and ships in an integrated manner. The research allows, through generated simulations, the analysis of various scenarios for the movement of grain from these terminals and the impact that larger ships will bring to the region's port infrastructure. Considering that the estimated movement of terminals in the Amazon basin for 2030 is approximately 60 million tons, where it was observed that the terminals are not prepared to achieve this stipulated target if they do not invest in their development.
Acesso aberto (Open Access)
Uma proposta para ensinar os conceitos da análise combinatória e de probabilidade: uma aplicação do uso da história da matemática, como organizador prévio, e dos mapas conceituais
(Universidade Federal do Pará, 2005-04-01) BOGA NETO, Francisco Rodrigues; ESPÍRITO SANTO, Adilson Oliveira do; http://lattes.cnpq.br/5870609258842071
We discussed, in this work, a proposal of use of the history of the mathematics, as previous organizer, for the teaching of the combination analysis and of the probability. That use of the history of the mathematics has as objective to develop the knowledge subsumers, presents in the students' cognitive structure, so that it can happen, in a significant way, the learning of the concepts of those topics of the mathematics, and that they will be taught, in a more detailed way, later on, through the conceptual maps. It is worth to stand out that, the previous organizers' of the content use, as well as the theory of the conceptual maps, they have theoretical justification in the works on significant learning, of the educational psychologist David P. Ausubel.