11,814 research outputs found
Holographic entanglement entropy in insulator/superconductor transition with Born-Infeld electrodynamics
We investigate the holographic entanglement entropy in the
insulator/superconductor phase transition for the Born-Infeld electrodynamics
with full backreaction in five-dimensional AdS soliton spacetime. We note that
the holographic entanglement entropy is a good probe to study the properties of
the phase transition, and the Born-Infeld factor has no effect on the
critical chemical potential . We find that both in the half space and
the belt one, the non-monotonic behavior of the entanglement entropy versus the
chemical potential is a general property, and the entanglement entropy
increases with the increase of the Born-Infeld factor in the superconductor
phase. Particularly, there exists confinement/deconfinement phase transition in
the strip geometry and the critical width is dependent of the
Born-Infeld parameter.Comment: 17 pages, 6 figures, accepted for publication in JHEP. arXiv admin
note: text overlap with arXiv:1203.6620 by other author
Holographic entanglement entropy in metal/superconductor phase transition with Born-Infeld electrodynamics
We investigate the holographic entanglement entropy in the
metal/superconductor phase transition for the Born-Infeld electrodynamics with
full backreaction and note that the entropy is a good probe to study the
properties of the phase transition. For the operator , we
find that the entanglement entropy decreases (or increases) with the increase
of the Born-Infeld parameter $b$ in the metal (or superconducting) phase. For
the operator , we observe that, with the increase of the
Born-Infeld parameter, the entanglement entropy in the metal phase decreases
monotonously but the entropy in the superconducting phase first increases and
forms a peak at some threshold , then decreases continuously. Moreover,
the value of becomes smaller as the width of the subsystem
decreases.Comment: 12 pages, 5 figures. arXiv admin note: text overlap with
arXiv:1404.1659 by other author
Local spatiotemporal modeling of house prices: a mixed model approach
The real estate market has long provided an active application area for spatial–temporal modeling and analysis and it is well known that house prices tend to be not only spatially but also temporally correlated. In the spatial dimension, nearby properties tend to have similar values because they share similar characteristics, but house prices tend to vary over space due to differences in these characteristics. In the temporal dimension, current house prices tend to be based on property values from previous years and in the spatial–temporal dimension, the properties on which current prices are based tend to be in close spatial proximity. To date, however, most research on house prices has adopted either a spatial perspective or a temporal one; relatively little effort has been devoted to situations where both spatial and temporal effects coexist. Using ten years of house price data in Fife, Scotland (2003–2012), this research applies a mixed model approach, semiparametric geographically weighted regression (GWR), to explore, model, and analyze the spatiotemporal variations in the relationships between house prices and associated determinants. The study demonstrates that the mixed modeling technique provides better results than standard approaches to predicting house prices by accounting for spatiotemporal relationships at both global and local scales
Place, time and experience: barriers to universalization of institutional child delivery in rural Mozambique
CONTEXT: Although institutional coverage of childbirth is increasing in the developing world, a substantial minority of births in rural Mozambique still occur outside of health facilities. Identifying the remaining barriers to safe professional delivery services can aid in achieving universal coverage. METHODS: Survey data collected in 2009 from 1,373 women in Gaza, Mozambique, were used in combination with spatial, meteorological and health facility data to examine patterns in place of delivery. Geographic information system–based visualization and mapping and exploratory spatial data analysis were used to outline the spatial distribution of home deliveries. Multilevel logistic regression models were constructed to identify associations between individual, spatial and other characteristics and whether women's most recent delivery took place at home. RESULTS: Spatial analysis revealed high- and low-prevalence clusters of home births. In multivariate analyses, women with a higher number of clinics within 10 kilometers of their home had a reduced likelihood of home delivery, but those living closer to urban centers had an increased likelihood. Giving birth during the rainy, high agricultural season was positively associated with home delivery, while household wealth was negatively associated with home birth. No associations were evident for measures of exposure to and experience with health institutions. CONCLUSIONS: The results suggest the need for a comprehensive approach to expansion of professional delivery services. Such an approach should complement measures facilitating physical access to health institutions for residents of harder-to-reach areas with community-based interventions aimed at improving rural women's living conditions and opportunities, while also taking into account seasonal and other variables
Exploring spatiotemporal dynamics of urban fires: A case of Nanjing, China
Urban fire occurs within the built environment, usually involving casualties and economic losses, and affects individuals and socioeconomic activities in the surrounding neighborhoods. A good understanding of the spatiotemporal dynamics of fire incidents can offer insights into potential determinants of various fire events, therefore enabling better fire risk estimation which can assist with future allocation of prevention resources and strategic planning of mitigation programs. Using a twelve-year (2002–2013) dataset containing the urban fire events in Nanjing, China, this research explores the spatiotemporal dynamics of urban fires using a range of exploratory spatial data analysis (ESDA) approaches. Of particular interest here are the fire incidents involving residential properties and local facilities due to their relatively higher occurrence frequencies. The results indicate that the overall amount of urban fires has greatly increased in the last decade and the spatiotemporal distribution of fire events varies among different incident types. The identified spatiotemporal patterns of urban fires in Nanjing can be linked to the urban development strategies and how they have been reflected in reality in recent years
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