22,310 research outputs found
A Uniform Approximation for the Coherent State Propagator using a Conjugate Application of the Bargmann Representation
We propose a conjugate application of the Bargmann representation of quantum
mechanics. Applying the Maslov method to the semiclassical connection formula
between the two representations, we derive a uniform semiclassical
approximation for the coherent state propagator which is finite at phase space
caustics.Comment: 4 pages, 1 figur
Estado Confusional Agudo após Corticoterapia Inalada
Background: The connection between corticotherapy and neuropsychiatric symptoms is
widely known, being one of the first questions
we need to assess when presenting with first
episode psychiatric symptoms or confusional
state.
Aims: To date, data on cases related to inhaled
corticotherapy and neuropsychiatric effects is
scarce. In this paper we describe a rare case in
a young woman.
Methods: The clinical case presented led us
to try to understand the data published on the
subject in order to discuss it in greater length.
Results and Conclusions: We present and
discuss a 27-year-old patient’s case, with no
previous psychiatric disease, who was admitted to our Psychiatric ward after the onset of
severe acute behavioural disturbance characterized by aggressiveness, visual and auditory
hallucinatory activity, misidentification and
altered conscience status. It was later found
that seven days earlier she had been prescribed
inhaled corticotherapy for a minor respiratory
infection. A few days after corticotherapy withdrawal, the clinical symptoms improved significantly.info:eu-repo/semantics/publishedVersio
Relation between spectral changes and the presence of the lower kHz QPO in the neutron-star low-mass X-ray binary 4U 1636-53
We fitted the -keV spectrum of all the observations of the
neutron-star low-mass X-ray binary 4U 163653 taken with the {\it Rossi X-ray
Timing Explorer} using a model that includes a thermal Comptonisation
component. We found that in the low-hard state the power-law index of this
component, , gradually increases as the source moves in the
colour-colour diagram. When the source undergoes a transition from the hard to
the soft state drops abruptly; once the source is in the soft state
increases again and then decreases gradually as the source spectrum
softens further. The changes in , together with changes of the electron
temperature, reflect changes of the optical depth in the corona. The lower
kilohertz quasi-periodic oscillation (kHz QPO) in this source appears only in
observations during the transition from the hard to the soft state, when the
optical depth of the corona is high and changes depends strongly upon the
position of the source in the colour-colour diagram. Our results are consistent
with a scenario in which the lower kHz QPO reflects a global mode in the system
that results from the resonance between, the disc and/or the neutron-star
surface, and the Comptonising corona.Comment: 9 pages, 6 figures. Accepted for publication in MNRA
End-to-end multi-level dialog act recognition
The three-level dialog act annotation scheme of the DIHANA corpus poses a multi-level classification problem in which the bottom levels allow multiple or no labels for a single segment. We approach automatic dialog act recognition on the three levels using an end-to-end approach, in order to implicitly capture relations between them. Our deep neural network classifier uses a combination of word- and character-based segment representation approaches, together with a summary of the dialog history and information concerning speaker changes. We show that it is important to specialize the generic segment representation in order to capture the most relevant information for each level. On the other hand, the summary of the dialog history should combine information from the three levels to capture dependencies between them. Furthermore, the labels generated for each level help in the prediction of those of the lower levels. Overall, we achieve results which surpass those of our previous approach using the hierarchical combination of three independent per-level classifiers. Furthermore, the results even surpass the results achieved on the simplified version of the problem approached by previous studies, which neglected the multi-label nature of the bottom levels and only considered the label combinations present in the corpus.info:eu-repo/semantics/publishedVersio
A curiosity model for artificial agents
Curiosity is an inherent characteristic of the animal instinct, which stimulates the need to obtain further knowledge and leads to the exploration of the surrounding environment. In this document we present a computational curiosity model, which aims at simulating that kind of behavior on artificial agents. This model is influenced by the two main curiosity theories defended by psychologists – Curiosity Drive Theory and Optimal Arousal Model. By merging both theories, as well as aspects from other sources, we concluded that curiosity can be defined in terms of the agent’s personality, its level of arousal, and the interest of the object of curiosity. The interest factor is defined in terms of the importance of the object of curiosity to the agent’s goals, its novelty, and surprise. To assess the performance of the model in practice, we designed a scenario consisting of virtual agents exploring a tile-based world, where objects may exist. The performance of the model in this scenario was evaluated in incremental steps, each one introducing a new component to the model. Furthermore, in addition to empirical evaluation, the model was also subjected to evaluation by human observers. The results obtained from both sources show that our model is able to simulate curiosity on virtual agents and that each of the identified factors has its role in the simulation.info:eu-repo/semantics/acceptedVersio
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