884 research outputs found
REflex: Flexible Framework for Relation Extraction in Multiple Domains
Systematic comparison of methods for relation extraction (RE) is difficult
because many experiments in the field are not described precisely enough to be
completely reproducible and many papers fail to report ablation studies that
would highlight the relative contributions of their various combined
techniques. In this work, we build a unifying framework for RE, applying this
on three highly used datasets (from the general, biomedical and clinical
domains) with the ability to be extendable to new datasets. By performing a
systematic exploration of modeling, pre-processing and training methodologies,
we find that choices of pre-processing are a large contributor performance and
that omission of such information can further hinder fair comparison. Other
insights from our exploration allow us to provide recommendations for future
research in this area.Comment: accepted by BioNLP 2019 at the Association of Computation Linguistics
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Computational Bounds for Doing Harmonic Analysis on Permutation Modules of Finite Groups
We develop an approach to finding upper bounds for the number of arithmetic
operations necessary for doing harmonic analysis on permutation modules of
finite groups. The approach takes advantage of the intrinsic orbital structure
of permutation modules, and it uses the multiplicities of irreducible
submodules within individual orbital spaces to express the resulting
computational bounds. We conclude by showing that these bounds are surprisingly
small when dealing with certain permutation modules arising from the action of
the symmetric group on tabloids.Comment: 19 page
Emulating Natural Disturbances for Declining Late- Successional Species: A Case Study of the Consequences for Cerulean Warblers (Setophaga cerulea)
Forest cover in the eastern United States has increased over the past century and while some late-successional species have benefited from this process as expected, others have experienced population declines. These declines may be in part related to contemporary reductions in small-scale forest interior disturbances such as fire, windthrow, and treefalls. To mitigate the negative impacts of disturbance alteration and suppression on some late-successional species, strategies that emulate natural disturbance regimes are often advocated, but large-scale evaluations of these practices are rare. Here, we assessed the consequences of experimental disturbance (using partial timber harvest) on a severely declining late-successional species, the cerulean warbler (Setophaga cerulea), across the core of its breeding range in the Appalachian Mountains. We measured numerical (density), physiological (body condition), and demographic (age structure and reproduction) responses to three levels of disturbance and explored the potential impacts of disturbance on source-sink dynamics. Breeding densities of warblers increased one to four years after all canopy disturbances (vs. controls) and males occupying territories on treatment plots were in better condition than those on control plots. However, these beneficial effects of disturbance did not correspond to improvements in reproduction; nest success was lower on all treatment plots than on control plots in the southern region and marginally lower on light disturbance plots in the northern region. Our data suggest that only habitats in the southern region acted as sources, and interior disturbances in this region have the potential to create ecological traps at a local scale, but sources when viewed at broader scales. Thus, cerulean warblers would likely benefit from management that strikes a landscape-level balance between emulating natural disturbances in order to attract individuals into areas where current structure is inappropriate, and limiting anthropogenic disturbance in forests that already possess appropriate structural attributes in order to maintain maximum productivity
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