8,820 research outputs found
From the Schwarzschild Anti de Sitter Black Hole to the Conformal Field Theory
The emergence of the quantum gravitational effects in a very high energy
regime necessitates some corrections to the thermodynamics of Black holes. In
this letter, we investigate a possible modification to the thermodynamics of
Schwarzschild anti de Sitter (SAdS) black holes due to rainbow gravity model.
Using the correspondence between a dimensional SAdS black hole and a
conformal filed theory in -dimensional spacetime, one may find the
corrections to the Cardy-Verlinde formula from the modified thermodynamics of
the black hole. Furthermore, we show that the corrected Cardy-Verlinde formula
can also be derived by redefining the Virasoro operator and the central charge
Sequence to Sequence Learning for Query Expansion
Using sequence to sequence algorithms for query expansion has not been
explored yet in Information Retrieval literature nor in Question-Answering's.
We tried to fill this gap in the literature with a custom Query Expansion
engine trained and tested on open datasets. Starting from open datasets, we
built a Query Expansion training set using sentence-embeddings-based Keyword
Extraction. We therefore assessed the ability of the Sequence to Sequence
neural networks to capture expanding relations in the words embeddings' space.Comment: 8 pages, 2 figures, AAAI-19 Student Abstract and Poster Progra
Adaptive Behaviours and Occupancy Patterns in UK Primary Schools: Impacts on Comfort and Indoor Quality
To improve the quality of school environment and reach state of comfort, it's important that teachers and students take appropriate personal and environmental adaptive behaviours. Studies on adaptive behaviours are mainly focused on adults, especially in residential and office buildings while children's adaptive behaviours at schools are not largely studied. This paper has investigated adaptive behaviours, influential factors and their impact on comfort and indoor quality by doing field studies in 4 primary schools and 15 classrooms in Coventry, UK during July, September, October and November 2017 through observations, subjective and objective measurements. The results are derived from observations on around 400 students aged 9-11 and from more than 600 surveys. Results illustrate that students usually take personal adaptive behaviours after or before breaks, and the number of these behaviours increases during warmer seasons and in afternoon sessions. Students' decisions over appropriate clothing level is related to time of year, however, 27% of students could improve their thermal vote by taking off or taking on jumpers/cardigans. Some environmental adaptive behaviours like door operation are less related to climatic factors, however, window operation is correlated to indoor temperature (R =0.29) and outdoor temperature (R =0.35). Observations show that around 80% of all environmental adaptive behaviours are done by teachers, teacher assistants or on their request, which can provide conditions that are not comfortable for children. Therefore, it is important to facilitate adaptive behaviour of children to improve their comfort level
Environment of The Gamma-Ray Burst GRB971214 : A Giant H II Region surrounded by A Galactic Supershell
Among a number of gamma ray bursts whose host galaxies are known, GRB971214
stands out for its high redshift and the Ly emission line
having a P-Cygni type profile, which is interpreted to be a direct consequence
of the expanding supershell. From a profile fitting analysis we estimate the
expansion velocity of the supershell v_{exp} = 1500\kms and the neutral
column density N_{HI}=10^{20}\cm^{-2}. The redshift of the host
galaxy proposed by Kulkarni et al. (1998) has been revised to be from
our profile analysis. The observed Ly profile is fitted well by a
Gaussian curve, which yields the Ly luminosity
L_{Ly\alpha}=(1.8\pm0.8)\times10^{42}\ergs \s^{-1}. Assuming that the photon
source is a giant H II region, we deduce the electron number density in the H
II region n_e=(40\pm10) ({R \over {100 \pc}})^{-1.5}\cm^{-3}, which
corresponds to the illumination by about O5 stars. We estimate the
star-formation rate to be R_{SF} = (7\pm3){\rm M}_\odot\yr^{-1} with the
internal and the Galactic extinction corrected. The theory on the evolution of
supernova remnants is used to propose that the supershell is at the adiabatic
phase, with its radius R = 18 E_{53}^{1/2} \pc, its age $t = 4.7\times10^3\
E_{53}^{1/2} \yrsn_1 = 5.4\
E_{53}^{-1/2}\cm^{-3}E_{53}= E/10^{53}\ergsE_k=7.3\times10^{52} E_{53} \ergs$.
These values are consistent with the hypothesis that the supershell is the
remnant of a gamma ray burst.Comment: 5 papges, 3 figures, Accepted for publication in Astrophysical
Journal Letter
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