Institution
Brown University
Education•Providence, Rhode Island, United States•
About: Brown University is a education organization based out in Providence, Rhode Island, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 35778 authors who have published 90896 publications receiving 4471489 citations. The organization is also known as: brown.edu & Brown.
Papers published on a yearly basis
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TL;DR: In this article, a finite element methodology for the analysis of problems requiring the simultaneous resolution of continuum and atomistic length scales-and associated deformation processes-in a unified manner is presented.
Abstract: We develop a method which permits the analysis of problems requiring the simultaneous resolution of continuum and atomistic length scales-and associated deformation processes-in a unified manner. A finite element methodology furnishes a continuum statement of the problem of interest and provides the requisite multiple-scale analysis capability by adaptively refining the mesh near lattice defects and other highly energetic regions. The method differs from conventional finite element analyses in that interatomic interactions are incorporated into the model through a crystal calculation based on the local state of deformation. This procedure endows the model with crucial properties, such as slip invariance, which enable the emergence of dislocations and other lattice defects. We assess the accuracy of the theory in the atomistic limit by way of three examples: a stacking fault on the (111) plane, and edge dislocations residing on (111) and (100) planes of an aluminium single crystal. The method correctly predicts the splitting of the (111) edge dislocation into Shockley partials. The computed separation of these partials is consistent with results obtained by direct atomistic simulations. The method predicts no splitting of the Al Lomer dislocation, in keeping with observation and the results of direct atomistic simulation. In both cases, the core structures are found to be in good agreement with direct lattice statics calculations, which attests to the accuracy of the method at the atomistic scale.
1,487 citations
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TL;DR: Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activite (OMEGA) instrument on the European Space Agency's Mars Express spacecraft provides new information on Mars' geological and climatic history.
Abstract: Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activite (OMEGA) instrument on the European Space Agency's Mars Express spacecraft provides new information on Mars' geological and climatic history. Phyllosilicates formed by aqueous alteration very early in the planet's history (the "phyllocian" era) are found in the oldest terrains; sulfates were formed in a second era (the "theiikian" era) in an acidic environment. Beginning about 3.5 billion years ago, the last era (the "siderikian") is dominated by the formation of anhydrous ferric oxides in a slow superficial weathering, without liquid water playing a major role across the planet.
1,480 citations
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TL;DR: It is shown that the Gumbel-Softmax estimator outperforms state-of-the-art gradient estimators on structured output prediction and unsupervised generative modeling tasks with categorical latent variables, and enables large speedups on semi-supervised classification.
Abstract: Categorical variables are a natural choice for representing discrete structure in the world. However, stochastic neural networks rarely use categorical latent variables due to the inability to backpropagate through samples. In this work, we present an efficient gradient estimator that replaces the non-differentiable sample from a categorical distribution with a differentiable sample from a novel Gumbel-Softmax distribution. This distribution has the essential property that it can be smoothly annealed into a categorical distribution. We show that our Gumbel-Softmax estimator outperforms state-of-the-art gradient estimators on structured output prediction and unsupervised generative modeling tasks with categorical latent variables, and enables large speedups on semi-supervised classification.
1,476 citations
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TL;DR: In this paper, the angular power spectra derived from the seven-year maps and discuss the cosmological conclusions that can be inferred from WMAP data alone are presented. But the results are limited to the case of L 2.
Abstract: The WMAP mission has produced sky maps from seven years of observations at L2. We present the angular power spectra derived from the seven-year maps and discuss the cosmological conclusions that can be inferred from WMAP data alone. With the seven-year data, the temperature (TT) spectrum measurement has a signal-to-noise ratio per multipole that exceeds unity for l 2.7(95%CL). Also, using WMAP data alone, the primordial helium mass fraction is found to be Y He = 0.28+0.14 ?0.15, and with data from higher-resolution cosmic microwave background experiments included, we now establish the existence of pre-stellar helium at >3?. These new WMAP measurements provide important tests of big bang cosmology.
1,462 citations
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TL;DR: The results support the use of the Balance Scale in these groups and show strong internal consistency within the same rater at two points in time.
Abstract: The objective of this study was to assess the reliability of the Balance Scale. Subjects were chosen from a larger group of 113 elderly residents and 70 stroke patients participating in a psychometric study. Elderly residents were examined at baseline, and at 3, 6 and 9 months, and the stroke patients were evaluated at 2, 4, 6 and 12 weeks post onset. The Cronbach's alphas at each evaluation were greater than 0.83 and 0.97 for the elderly residents and stroke patients respectively, showing strong internal consistency. To assess inter-rater reliability, therapists treating 35 stroke patients were asked to administer the Balance Scale within 24 hours of the independent evaluator. Similarly, caregivers at the Residence were asked to test the elderly residents within one week of the independent evaluator. To assess intra-rater reliability, 18 residents and 6 stroke patients were assessed one week apart by the same rater. The agreement between raters was excellent (ICC = 0.98) as was the consistency within the same rater at two points in time (ICC = 0.97). The results support the use of the Balance Scale in these groups.
1,460 citations
Authors
Showing all 36143 results
Name | H-index | Papers | Citations |
---|---|---|---|
Walter C. Willett | 334 | 2399 | 413322 |
Robert Langer | 281 | 2324 | 326306 |
Robert M. Califf | 196 | 1561 | 167961 |
Eric J. Topol | 193 | 1373 | 151025 |
Joan Massagué | 189 | 408 | 149951 |
Joseph Biederman | 179 | 1012 | 117440 |
Gonçalo R. Abecasis | 179 | 595 | 230323 |
James F. Sallis | 169 | 825 | 144836 |
Steven N. Blair | 165 | 879 | 132929 |
Charles M. Lieber | 165 | 521 | 132811 |
J. S. Lange | 160 | 2083 | 145919 |
Christopher J. O'Donnell | 159 | 869 | 126278 |
Charles M. Perou | 156 | 573 | 202951 |
David J. Mooney | 156 | 695 | 94172 |
Richard J. Davidson | 156 | 602 | 91414 |