Brown University

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.

SUN database: Large-scale scene recognition from abbey to zoo

Abstract: Scene categorization is a fundamental problem in computer vision However, scene understanding research has been constrained by the limited scope of currently-used databases which do not capture the full variety of scene categories Whereas standard databases for object categorization contain hundreds of different classes of objects, the largest available dataset of scene categories contains only 15 classes In this paper we propose the extensive Scene UNderstanding (SUN) database that contains 899 categories and 130,519 images We use 397 well-sampled categories to evaluate numerous state-of-the-art algorithms for scene recognition and establish new bounds of performance We measure human scene classification performance on the SUN database and compare this with computational methods Additionally, we study a finer-grained scene representation to detect scenes embedded inside of larger scenes

Nanoscale thermal transport

Abstract: Rapid progress in the synthesis and processing of materials with structure on nanometer length scales has created a demand for greater scientific understanding of thermal transport in nanoscale devices, individual nanostructures, and nanostructured materials. This review emphasizes developments in experiment, theory, and computation that have occurred in the past ten years and summarizes the present status of the field. Interfaces between materials become increasingly important on small length scales. The thermal conductance of many solid–solid interfaces have been studied experimentally but the range of observed interface properties is much smaller than predicted by simple theory. Classical molecular dynamics simulations are emerging as a powerful tool for calculations of thermal conductance and phonon scattering, and may provide for a lively interplay of experiment and theory in the near term. Fundamental issues remain concerning the correct definitions of temperature in nonequilibrium nanoscale systems. Modern Si microelectronics are now firmly in the nanoscale regime—experiments have demonstrated that the close proximity of interfaces and the extremely small volume of heat dissipation strongly modifies thermal transport, thereby aggravating problems of thermal management. Microelectronic devices are too large to yield to atomic-level simulation in the foreseeable future and, therefore, calculations of thermal transport must rely on solutions of the Boltzmann transport equation; microscopic phonon scattering rates needed for predictive models are, even for Si, poorly known. Low-dimensional nanostructures, such as carbon nanotubes, are predicted to have novel transport properties; the first quantitative experiments of the thermal conductivity of nanotubes have recently been achieved using microfabricated measurement systems. Nanoscale porosity decreases the permittivity of amorphous dielectrics but porosity also strongly decreases the thermal conductivity. The promise of improved thermoelectric materials and problems of thermal management of optoelectronic devices have stimulated extensive studies of semiconductor superlattices; agreement between experiment and theory is generally poor. Advances in measurement methods, e.g., the 3ω method, time-domain thermoreflectance, sources of coherent phonons, microfabricated test structures, and the scanning thermal microscope, are enabling new capabilities for nanoscale thermal metrology.

Path dependence in historical sociology

Abstract: Cet article cherche a determiner a quels types d'evenements historiques s'applique l'analyse de path dependence. Selon l'A., il s'agit de sequences historiques au sein desquelles des evenements contingents mettent en mouvement des modeles institutionnels ou des chaines d'evenements ayant des proprietes deterministes. L'identification de la path dependence implique a la fois de relier un resultat a une serie d'evenements et de montrer en quoi ces evenements sont eux-memes des occurences contingentes ne pouvant etre expliquees par des conditions historiques prealables. Ces sequences historiques sont generalement de deux types : les sequences a auto-renforcement et les sequences reactives