Computational Multiscale Methods for Linear Poroelasticity with High Contrast

In this work, we employ the Constraint Energy Minimizing Generalized Multiscale Finite Element Method (CEM-GMsFEM) to solve the problem of linear heterogeneous poroelasticity with coefficients of high contrast. The proposed method makes use of the idea of energy minimization with suitable constraints in order to generate efficient basis functions for the displacement and the pressure. These basis functions are constructed by solving a class of local auxiliary optimization problems based on eigenfunctions containing local information on the heterogeneity. Techniques of oversampling are adapted to enhance the computational performance. Convergence of first order is shown and illustrated by a number of numerical tests.Comment: 14 pages, 9 figure

Aesthetic Highlight Detection in Movies Based on Synchronization of Spectators’ Reactions.

Detection of aesthetic highlights is a challenge for understanding the affective processes taking place during movie watching. In this paper we study spectators’ responses to movie aesthetic stimuli in a social context. Moreover, we look for uncovering the emotional component of aesthetic highlights in movies. Our assumption is that synchronized spectators’ physiological and behavioral reactions occur during these highlights because: (i) aesthetic choices of filmmakers are made to elicit specific emotional reactions (e.g. special effects, empathy and compassion toward a character, etc.) and (ii) watching a movie together causes spectators’ affective reactions to be synchronized through emotional contagion. We compare different approaches to estimation of synchronization among multiple spectators’ signals, such as pairwise, group and overall synchronization measures to detect aesthetic highlights in movies. The results show that the unsupervised architecture relying on synchronization measures is able to capture different properties of spectators’ synchronization and detect aesthetic highlights based on both spectators’ electrodermal and acceleration signals. We discover that pairwise synchronization measures perform the most accurately independently of the category of the highlights and movie genres. Moreover, we observe that electrodermal signals have more discriminative power than acceleration signals for highlight detection

The Discovery of an X-ray/UV Stellar Flare from the Late-K/Early-M Dwarf LMC 335

We report the discovery of an X-ray/UV stellar flare from the source LMC 335, captured by XMM-Newton in the field of the Large Magellanic Cloud. The flare event was recorded continuously in X-ray for its first 10 hours from the precursor to the late decay phases. The observed fluxes increased by more than two orders of magnitude at its peak in X-ray and at least one in the UV as compared to quiescence. The peak 0.1-7.0 keV X-ray flux is derived from the two-temperature APEC model to be ~(8.4 +/- 0.6) x 10^-12 erg cm-2 s-1. Combining astrometric information from multiple X-ray observations in the quiescent and flare states, we identify the NIR counterpart of LMC 335 as the 2MASS source J05414534-6921512. The NIR color relations and spectroscopic parallax characterize the source as a Galactic K7-M4 dwarf at a foreground distance of (100 - 264) pc, implying a total energy output of the entire event of ~(0.4 - 2.9) x 10^35 erg. This report comprises detailed analyses of this late-K / early-M dwarf flare event that has the longest time coverage yet reported in the literature. The flare decay can be modeled with two exponential components with timescales of ~28 min and ~4 hours, with a single component decay firmly ruled out. The X-ray spectra during flare can be described by two components, a dominant high temperature component of ~40-60MK and a low temperature component of ~10MK, with a flare loop length of about 1.1-1.3 stellar radius.Comment: 35 pages, 6 figures, 5 tables, accepted for publication in Ap

INJURY INCIDENCE, DISTRIBUTION, AND SEVERITY DURING A MARATHON TRAINING SEASON AND THE IMPLICATIONS

Marathon runners and their coaches are concerned about the potential for injury during an individual season. No published studies of running injuries address this training season as a meaningful entity. This study reports the incidence of injury and the distribution of injuries for runners (n=75) on two established marathon training teams during an individual season. An injury was defined as affecting seven consecutive days or three consecutive workouts. The incidence/risks of overuse injuries, for marathon runners in a single season were found to be: anterior knee pain (20%), iliotibial band syndrome (29%), plantar fasciitis (1%), Achilles tendonitis (9%) shin splints (16%) and stress fractures (4%). This risk, overall injury distribution, severity and length of longest run prior to presentation of injury are of interest to runners, coaches and biomechanists

Thin accretion disks onto brane world black holes

The braneworld description of our universe entails a large extra dimension and a fundamental scale of gravity that might be lower by several orders of magnitude as compared to the Planck scale. An interesting consequence of the braneworld scenario is in the nature of the vacuum solutions of the brane gravitational field equations, with properties quite distinct as compared to the standard black hole solutions of general relativity. One possibility of observationally discriminating between different types of black holes is the study of the emission properties of the accretion disks. In the present paper we obtain the energy flux, the emission spectrum and accretion efficiency from the accretion disks around several classes of static and rotating brane world black holes, and we compare them to the general relativistic case. Particular signatures can appear in the electromagnetic spectrum, thus leading to the possibility of directly testing extra-dimensional physical models by using astrophysical observations of the emission spectra from accretion disks.Comment: 37 pages, 14 figures, accepted for publication in PR