2,265 research outputs found

    Online Construction of Wavelet Trees

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    The wavelet tree (WT) is a flexible and efficient data structure for representing character strings in succinct space, while allowing for fast generalised rank, select and access operations. As such, they play an important role in modern text indexing methods. However, despite their popularity, not many algorithms have been published concerning their construction. In particular, while the WT is capable of representing a sequence of length n over an alphabet of size m in nlg m+o(nlg m) bits, much more space is typically used for its construction. Here we propose an O(nlg m)-time online method for the construction of the WT, requiring no prior knowledge about the input alphabet. The proposed algorithm is conceptually simpler than other state-of-the-art methods, while having comparable time performance and being more space-efficient in practice, since it performs just one pass over the input text and uses little extra space other than for the structure itself, as shown both theoretically and empirically

    Primeira ocorrência de Pachycheles riisei (Crustacea, Porcellanidae) no Atol das Rocas Brasil

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    The present work redescribes Pachycheles riisei based on material from intertidal lagoons at Rocas Atoll, Brazil. This is the first record of P. riisei for Rocas Atoll, species previously found from Florida, Caribbean Sea, and Brazil (Paraíba to São Paulo, Fernando de Noronha and Trindade Isl.).O presente estudo redescreve Pachycheles riisei com base no material coletado em poças de maré no Atol das Rocas, Brasil. Este é o primeiro registro de P. riisei para o Atol das Rocas, espécies anteriormente encontrada na Florida, Mar do Caribe e Brazil (Paraíba to São Paulo, Fernando de Noronha and Trindade Island)

    Decomposition of stochastic flows with automorphism of subbundles component

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    We show that given a GG-structure PP on a differentiable manifold MM, if the group G(M)G(M) of automorphisms of PP is big enough, then there exists the quotient of an stochastic flows phitphi_t by G(M)G(M), in the sense that ϕt=ξtρt\phi_t = \xi_t \circ \rho_t where ξtG(M)\xi_t \in G(M), the remainder ρt\rho_t has derivative which is vertical but transversal to the fibre of PP. This geometrical context generalizes previous results where MM is a Riemannian manifold and ϕt\phi_t is decomposed with an isometric component, see Liao \cite{Liao1} and Ruffino \cite{Ruffino}, which in our context corresponds to the particular case of an SO(n)-structure on MM.Comment: To appear in Stochastics and Dynamics, 201

    Foraging Behaviour and Herbage Intake in the Favourable Tropics/Subtropics

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    Key points 1. Herbage intake by animals grazing tropical/sub-tropical pastures is directly related to bite mass, as it is for those grazing temperate pastures. 2. Where these swards have low proportions of stem and dead material (controlled swards), herbage intake follows a similar pattern to that of temperate pasture species, but leaf characteristics, such as lamina length play an important role and influence the short-term rate of intake. 3. Sward structural characteristics and behavioural factors are relatively more important than nutritional factors in terms of herbage intake regulation. The feeding value of the herbage produced is potentially adequate to sustain high levels of beef cattle performance under controlled sward conditions, but relatively limited for dairy cows, since nutrient concentration in the forage is not optimal for high levels of daily milk yield. 4. Sward targets for attaining production objectives are now a feasible management practice on tropical pastures and should be evaluated further

    Foraging Behaviour and Herbage Intake in the Favourable Tropics/Sub-Tropics

    Get PDF
    Herbage intake by animals grazing tropical/sub-tropical pastures is directly related to bite mass, as it is for those grazing temperate pastures. Where these swards have low proportions of stem and dead material (controlled swards), herbage intake follows a similar pattern to that of temperate pasture species, but leaf characteristics, such as lamina length play an important role and influence the short-term rate of intake. Sward structural characteristics and behavioural factors are relatively more important than nutritional factors in terms of herbage intake regulation. The feeding value of the herbage produced is potentially adequate to sustain high levels of beef cattle performance under controlled sward conditions, but relatively limited for dairy cows, since nutrient concentration in the forage is not optimal for high levels of daily milk yield. Sward targets for attaining production objectives are now a feasible management practice on tropical pastures and should be evaluated further

    Validation of a simplified model for the design of masonry infilled frames

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    The design of masonry infills is an issue that has attracted the attention of several researchers in the past, both from the experimental and analytical points of view. Nevertheless, the results are often questionable due to the large variability of masonry properties, the limited number of tests carried out and the large number of influencing factors. This paper addresses this limitation by using numerical analysis as a simulation of an experimental laboratory, and by performing a sensitivity analysis about the influence of the different influence factors. The modelling approach has been validated using the experimental results of two masonry walls subjected to horizontal loading. The parametric study subsequently carried out allowed to propose a strut-and-tie model that provides a novel simplified expression for the failure of infill walls belonging to frames subjected to horizontal loading. The proposed model is compared with other models available in the literature exhibiting superior performance and constituting a simple and versatile tool for design.CAPES.UFV

    Ação "in vitro”do fenil-borato de mercúrio (phb) sobre fungos

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