1,074 research outputs found
The brightness distribution of IRC +10216 at 11 microns
The brightness distribution of IRC +10216 at a wavelength of 11 microns was measured in detail using a spatial interferometer. This brightness distribution appears to have azimuthal symmetry; an upper limit of 1.1 may be set to the ellipticity at 11 microns if the object has a major axis oriented either along or perpendicular to the major axis of the optical image. The radial distribution shows both compact and extended emission. The extended component, which is due to thermal emission from circumstellar dust, contributes 91% of the total flux and has a 1/e diameter of 0.90 minutes. The tapered shape of this component is consistent with a l/r squared dust density dependence. The compact component is unresolved (less than 0.2 minutes in diameter) and represents emission from the central star seen through the circumstellar envelope
ADVISE: Symbolism and External Knowledge for Decoding Advertisements
In order to convey the most content in their limited space, advertisements
embed references to outside knowledge via symbolism. For example, a motorcycle
stands for adventure (a positive property the ad wants associated with the
product being sold), and a gun stands for danger (a negative property to
dissuade viewers from undesirable behaviors). We show how to use symbolic
references to better understand the meaning of an ad. We further show how
anchoring ad understanding in general-purpose object recognition and image
captioning improves results. We formulate the ad understanding task as matching
the ad image to human-generated statements that describe the action that the ad
prompts, and the rationale it provides for taking this action. Our proposed
method outperforms the state of the art on this task, and on an alternative
formulation of question-answering on ads. We show additional applications of
our learned representations for matching ads to slogans, and clustering ads
according to their topic, without extra training.Comment: To appear, Proceedings of the European Conference on Computer Vision
(ECCV
Stable and unstable regimes in Bose-Fermi mixture with attraction between components
A collapse of the trapped boson- fermion mixture with the attraction between
bosons and fermions is investigated in the framework of the effective
Hamiltonian for the Bose system. The properties of the Rb and K
mixture are analyzed quantitatively at . We find numerically solutions of
modified Gross- Pitaevskii equation which continuously go from stable to
unstable branch. We discuss the relation of the onset of collapse with
macroscopic properties of the system. A comparison with the case of a Bose
condensate of atomic system is given.Comment: 7 pages, 5 figure
Spatial heterodyne interferometry of VY Canis Major's, alpha Orionis, alpha Scorpii, and R leonis at 11 microns
Using the technique of heterodyne interferometry, measurements were made of the spatial distribution of 11 micron radiation from four late type stars. The circumstellar shells surrounding VY Canis Majoris, alpha Orionis, and alpha Scorpii were resolved, whereas that of R Leonis was only partially resolved at a fringe spacing of 0.4 sec
Scale-invariant temporal history (SITH): optimal slicing of the past in an uncertain world
In both the human brain and any general artificial intelligence (AI), a
representation of the past is necessary to predict the future. However, perfect
storage of all experiences is not possible. One possibility, utilized in many
applications, is to retain information about the past in a buffer. A limitation
of this approach is that although events in the buffer are represented with
perfect accuracy, the resources necessary to represent information at a
particular time scale go up rapidly. Here we present a neurally-plausible,
compressed, scale-free memory representation we call Scale-Invariant Temporal
History (SITH). This representation covers an exponentially large period of
time in the past at the cost of sacrificing temporal accuracy for events
further in the past. The form of this decay is scale-invariant and can be shown
to be optimal in that it is able to respond to worlds with a wide range of time
scales. We demonstrate the utility of this representation in learning to play a
simple video game. In this environment, SITH exhibits better learning
performance than a fixed-size buffer history representation. Whereas the buffer
performs well as long as the temporal dependencies can be represented within
the buffer, SITH performs well over a much larger range of time scales for the
same amount of resources. Finally, we discuss how the application of SITH,
along with other human-inspired models of cognition, could improve
reinforcement and machine learning algorithms in general.First author draf
Open defecation and childhood stunting in India: an ecological analysis of new data from 112 districts.
Poor sanitation remains a major public health concern linked to several important health outcomes; emerging evidence indicates a link to childhood stunting. In India over half of the population defecates in the open; the prevalence of stunting remains very high. Recently published data on levels of stunting in 112 districts of India provide an opportunity to explore the relationship between levels of open defecation and stunting within this population. We conducted an ecological regression analysis to assess the association between the prevalence of open defecation and stunting after adjustment for potential confounding factors. Data from the 2011 HUNGaMA survey was used for the outcome of interest, stunting; data from the 2011 Indian Census for the same districts was used for the exposure of interest, open defecation. After adjustment for various potential confounding factors--including socio-economic status, maternal education and calorie availability--a 10 percent increase in open defecation was associated with a 0.7 percentage point increase in both stunting and severe stunting. Differences in open defecation can statistically account for 35 to 55 percent of the average difference in stunting between districts identified as low-performing and high-performing in the HUNGaMA data. In addition, using a Monte Carlo simulation, we explored the effect on statistical power of the common practice of dichotomizing continuous height data into binary stunting indicators. Our simulation showed that dichotomization of height sacrifices statistical power, suggesting that our estimate of the association between open defecation and stunting may be a lower bound. Whilst our analysis is ecological and therefore vulnerable to residual confounding, these findings use the most recently collected large-scale data from India to add to a growing body of suggestive evidence for an effect of poor sanitation on human growth. New intervention studies, currently underway, may shed more light on this important issue
Properties of Nucleon Resonances by means of a Genetic Algorithm
We present an optimization scheme that employs a Genetic Algorithm (GA) to
determine the properties of low-lying nucleon excitations within a realistic
photo-pion production model based upon an effective Lagrangian. We show that
with this modern optimization technique it is possible to reliably assess the
parameters of the resonances and the associated error bars as well as to
identify weaknesses in the models. To illustrate the problems the optimization
process may encounter, we provide results obtained for the nucleon resonances
(1230) and (1700). The former can be easily isolated and thus
has been studied in depth, while the latter is not as well known
experimentally.Comment: 12 pages, 10 figures, 3 tables. Minor correction
Adaptive mutation using statistics mechanism for genetic algorithms
Copyright @ 2004 Springer-Verla
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