Estudo das propriedades e robustez da rede de transporte público de São Paulo

Abstract

Version original. Complex systems are characteristic by having an internal network representing the structural relationship between its elements and a natural way to interpret this interaction is through a graph. In this work, the urban public transport system of São Paulo is reinterpreted as a coupled (bus and subway) complex network, bypassing operational details and focusing on connectivity. Using the empirically generated graph, a statistical characterisation is made by network metrics where different radius values are used to group nearby stops and stations that were disconnected before. That can be interpreted as a public policy tool, representing the user's willingness to get around the nearest point to access transportation. This process has shown that increasing this willingness generates great reduction in the distance and in the number of jumps between buses, trains and subways lines to achieve all the network destinations. An exploratory model is used to test the robustness of the network by randomly, deterministically and preferentially targeting the stops and service lines. According to the grouping radius, aka willingness, different fragmentation values were obtained under attack simulations. These findings support two main characteristics observed in such networks literature: they have a high degree of robustness to random failures, but are vulnerable to targeted attacks.

Produtividade e qualidade de frutos do maracujazeiro-amarelo submetido à poda de ramos produtivos

“…A poda de formação ou condução da planta tem por finalidade proporcionar uma estrutura de ramos adequados, com uma distribuição equilibrada destes, havendo o arejamento e iluminação convenientes (Sousa, 2005). Segundo as Normas Técnicas para a Produção Integrada de Maracujá (Brasil, 2005), é obrigatório conduzir a planta de forma a equilibrar a atividade vegetativa e a produção, propiciando boa distribuição dos ramos de modo a facilitar os tratos culturais e permitir maior insolação dos ramos produtivos.…”