415 research outputs found
Global Patterns of Synchronization in Human Communications
Social media are transforming global communication and coordination. The data
derived from social media can reveal patterns of human behavior at all levels
and scales of society. Using geolocated Twitter data, we have quantified
collective behaviors across multiple scales, ranging from the commutes of
individuals, to the daily pulse of 50 major urban areas and global patterns of
human coordination. Human activity and mobility patterns manifest the synchrony
required for contingency of actions between individuals. Urban areas show
regular cycles of contraction and expansion that resembles heartbeats linked
primarily to social rather than natural cycles. Business hours and circadian
rhythms influence daily cycles of work, recreation, and sleep. Different urban
areas have characteristic signatures of daily collective activities. The
differences are consistent with a new emergent global synchrony that couples
behavior in distant regions across the world. A globally synchronized peak that
includes exchange of ideas and information across Europe, Africa, Asia and
Australasia. We propose a dynamical model to explain the emergence of global
synchrony in the context of increasing global communication and reproduce the
observed behavior. The collective patterns we observe show how social
interactions lead to interdependence of behavior manifest in the
synchronization of communication. The creation and maintenance of temporally
sensitive social relationships results in the emergence of complexity of the
larger scale behavior of the social system.Comment: 20 pages, 12 figures. arXiv admin note: substantial text overlap with
arXiv:1602.0621
Convex Decomposition of Indoor Scenes
We describe a method to parse a complex, cluttered indoor scene into
primitives which offer a parsimonious abstraction of scene structure. Our
primitives are simple convexes. Our method uses a learned regression procedure
to parse a scene into a fixed number of convexes from RGBD input, and can
optionally accept segmentations to improve the decomposition. The result is
then polished with a descent method which adjusts the convexes to produce a
very good fit, and greedily removes superfluous primitives. Because the entire
scene is parsed, we can evaluate using traditional depth, normal, and
segmentation error metrics. Our evaluation procedure demonstrates that the
error from our primitive representation is comparable to that of predicting
depth from a single image.Comment: 18 pages, 12 figure
Applying a Color Palette with Local Control using Diffusion Models
We demonstrate two novel editing procedures in the context of fantasy card
art. Palette transfer applies a specified reference palette to a given card.
For fantasy art, the desired change in palette can be very large, leading to
huge changes in the "look" of the art. We demonstrate that a pipeline of vector
quantization; matching; and "vector dequantization" (using a diffusion model)
produces successful extreme palette transfers. Segment control allows an artist
to move one or more image segments, and to optionally specify the desired color
of the result. The combination of these two types of edit yields valuable
workflows, including: move a segment, then recolor; recolor, then force some
segments to take a prescribed color. We demonstrate our methods on the
challenging Yu-Gi-Oh card art dataset.Comment: 11 pages, 8 figure
ESTIMATION OF FLAVONOID CONTENT, POLYPHENOLIC CONTENT AND ANTIOXIDANT POTENTIAL OF DIFFERENT PARTS OF ABRUS PRECATORIUS (L.)
Objective: Abrus precatorius (L.) is a tropical plant and is used in traditional medicine for treatment of a wide range of ailments. Lately, plants with medicinal properties have gained importance for their potential therapeutic use in diseases caused due free radicals. Hence, the present investigation was carried out to estimate the total phenolic and flavonoid content and free radical scavenging activity of fresh and dry parts of Abrus precatorius.Methods: Plant material was collected from Karnala forest of Maharashtra. Extracts of leaves, stem, root and seed (fresh and dry) were prepared using four different solvents i.e. Distilled water, Ethanol, Methanol and Acetone. Each extract was tested for total phenolic content, flavonoid content, and antioxidant activity (by FRAP, DPPHË™ and ABTSË™+assays), while phenolic compounds like Gallic acid, Catechol, Vanillin, Caffeic acid, p-Coumaric acid and Ferulic acid were detected and quantified using RP-HPLC.Results: Seeds showed highest phenolic content (8.99±0.27 mg GAE/g) and DPPHË™ radical scavenging activity (88.34±0.08 %) in methanolic extracts. The leaves had the highest flavonoid content (145.68±0.99 mg RE/g). The antioxidant potential was found to be the highest in seeds followed by root, leaves and stem. Methanol proved to be the best solvent for extraction of phenolics, flavonoid and antioxidants.Conclusion: This study substantiates the high antioxidant activity of different plant parts of A. precatorius. Therefore, it can be used as a source of natural antioxidants and used in drug formulations for treatment of diseases resulting from oxidative stress.Â
Variation in pediatric traumatic brain injury outcomes in the United States.
OBJECTIVE: To ascertain the degree of variation, by state of hospitalization, in outcomes associated with traumatic brain injury (TBI) in a pediatric population. DESIGN: A retrospective cohort study of pediatric patients admitted to a hospital with a TBI. SETTING: Hospitals from states in the United States that voluntarily participate in the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project. PARTICIPANTS: Pediatric (age ≤ 19 y) patients hospitalized for TBI (N=71,476) in the United States during 2001, 2004, 2007, and 2010. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Primary outcome was proportion of patients discharged to rehabilitation after an acute care hospitalization among alive discharges. The secondary outcome was inpatient mortality. RESULTS: The relative risk of discharge to inpatient rehabilitation varied by as much as 3-fold among the states, and the relative risk of inpatient mortality varied by as much as nearly 2-fold. In the United States, approximately 1981 patients could be discharged to inpatient rehabilitation care if the observed variation in outcomes was eliminated. CONCLUSIONS: There was significant variation between states in both rehabilitation discharge and inpatient mortality after adjusting for variables known to affect each outcome. Future efforts should be focused on identifying the cause of this state-to-state variation, its relationship to patient outcome, and standardizing treatment across the United States
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Improvement of Homogeneity and Adhesion of Diamond-Like Carbon Films on Copper Substrates
Electrodeposition method is used to deposit diamond-like carbon (DLC) films on copper substrates via anodic oxidation at low temperature. These films are characterized using Raman spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. Homogeneity of these films is studied using Raman spectroscopy and scanning electron microscopy. Scotch tape peel tests indicate adherent film on copper substrate. Carbon phase transformation is studied using thermal annealing experiments in conjunction with Raman spectroscopy and scanning electron microscopy. A cathodic electrochemical method is also studied to deposit diamond-like carbon films on copper substrates. However, films deposited by the cathodic route have poor adhesion and quality compared to anodically deposited films. It is also possible to grow diamond phase on copper substrates using acetylene in liquid ammonia via electrodeposition route. An electrochemical method is proposed for boron doping into DLC films
Blocks2World: Controlling Realistic Scenes with Editable Primitives
We present Blocks2World, a novel method for 3D scene rendering and editing
that leverages a two-step process: convex decomposition of images and
conditioned synthesis. Our technique begins by extracting 3D parallelepipeds
from various objects in a given scene using convex decomposition, thus
obtaining a primitive representation of the scene. These primitives are then
utilized to generate paired data through simple ray-traced depth maps. The next
stage involves training a conditioned model that learns to generate images from
the 2D-rendered convex primitives. This step establishes a direct mapping
between the 3D model and its 2D representation, effectively learning the
transition from a 3D model to an image. Once the model is fully trained, it
offers remarkable control over the synthesis of novel and edited scenes. This
is achieved by manipulating the primitives at test time, including translating
or adding them, thereby enabling a highly customizable scene rendering process.
Our method provides a fresh perspective on 3D scene rendering and editing,
offering control and flexibility. It opens up new avenues for research and
applications in the field, including authoring and data augmentation.Comment: 16 pages, 15 figure
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