4,140 research outputs found

    A Computational Approach for Designing Tiger Corridors in India

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    Wildlife corridors are components of landscapes, which facilitate the movement of organisms and processes between intact habitat areas, and thus provide connectivity between the habitats within the landscapes. Corridors are thus regions within a given landscape that connect fragmented habitat patches within the landscape. The major concern of designing corridors as a conservation strategy is primarily to counter, and to the extent possible, mitigate the effects of habitat fragmentation and loss on the biodiversity of the landscape, as well as support continuance of land use for essential local and global economic activities in the region of reference. In this paper, we use game theory, graph theory, membership functions and chain code algorithm to model and design a set of wildlife corridors with tiger (Panthera tigris tigris) as the focal species. We identify the parameters which would affect the tiger population in a landscape complex and using the presence of these identified parameters construct a graph using the habitat patches supporting tiger presence in the landscape complex as vertices and the possible paths between them as edges. The passage of tigers through the possible paths have been modelled as an Assurance game, with tigers as an individual player. The game is played recursively as the tiger passes through each grid considered for the model. The iteration causes the tiger to choose the most suitable path signifying the emergence of adaptability. As a formal explanation of the game, we model this interaction of tiger with the parameters as deterministic finite automata, whose transition function is obtained by the game payoff.Comment: 12 pages, 5 figures, 6 tables, NGCT conference 201

    SciTech News Volume 71, No. 2 (2017)

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    Columns and Reports From the Editor 3 Division News Science-Technology Division 5 Chemistry Division 8 Engineering Division 9 Aerospace Section of the Engineering Division 12 Architecture, Building Engineering, Construction and Design Section of the Engineering Division 14 Reviews Sci-Tech Book News Reviews 16 Advertisements IEEE

    Dirichlet belief networks for topic structure learning

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    Recently, considerable research effort has been devoted to developing deep architectures for topic models to learn topic structures. Although several deep models have been proposed to learn better topic proportions of documents, how to leverage the benefits of deep structures for learning word distributions of topics has not yet been rigorously studied. Here we propose a new multi-layer generative process on word distributions of topics, where each layer consists of a set of topics and each topic is drawn from a mixture of the topics of the layer above. As the topics in all layers can be directly interpreted by words, the proposed model is able to discover interpretable topic hierarchies. As a self-contained module, our model can be flexibly adapted to different kinds of topic models to improve their modelling accuracy and interpretability. Extensive experiments on text corpora demonstrate the advantages of the proposed model.Comment: accepted in NIPS 201

    How much Mathematics does Economy Need? ...Or... Some Brief Epistemological Excursions into the Mathematics located on the border with Social Sciences

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    In our paper we try to answer to the epistemological question how much mathematics does economy need.economics, economy, mathematics, epistemology

    Use of RNA secondary structure for evolutionary relationships : investigating RNase P and RNase MRP : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Genetics at Massey University, New Zealand

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    Bioinformatics is applied here to examine whether RNA secondary structure data can reflect distant evolutionary relationships. This is important when there is little confidence in sequence data such as when looking at the evolution of RNase MRP (MRP). RNase P (P) and RNase MRP (MRP) are ribonucleoproteins (RNPs) that are involved in RNA processing and due to functional and secondary structure similarities, are thought to be evolutionary related. P activity is found in all cells, and fits the criteria for inclusion in the RNA world (Jeffares et al. 1998). MRP is found only in eukaryotes with essential functions in both the nucleus and mitochondria. The RNA components of P and MRP (pRNA and mrpRNA) cannot be aligned with any certainty, which leads to a lack of confidence in any phylogenetic trees constructed from them. If MRP evolved from P only in eukaryotes then it is an exception to the general process of the transfer of catalytic activity from RNA, to ribonucleoproteins, to proteins (Jeffares et al. 1998). An alternative possibility that MRP evolved with P in the RNA world (and has since been lost from all but the eukaryotes) is raised and examined. Quantitative comparisons of the pRNA and mrpRNA biological secondary structures have found that the third possibility of an organellar origin of MRP is unlikely Results show that biological secondary structure can be used in the evaluation of an evolutionary relatedness between MRP and P and may be extended to other catalytic RNA molecules. Although there are many protein families, this may be the first evidence of the existence of a family of RNA molecules, although it would be a very small family. Secondary structures derived with folding programs from pRNA and mrpRNA sequences are examined for use in the characterisation of catalytic RNA sequences. The high AT content in organellar genomes may hinder the identification of their catalytic RNA sequences. A search strategy is developed here to address this problem and is used to identify putative pRNA sequences in the chloroplast genomes of four green plants. A maize chloroplast pRNA-like sequence is examined in more detail and shows many characteristics seen in known pRNA sequences. Folding programs show some potential for the characterisation of possible catalytic RNA sequences with only a small bias in the results due to sequence length and AT content

    READUP BUILDUP. Thync - instant α-readings

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