12,555 research outputs found
Bridging the Gap between Probabilistic and Deterministic Models: A Simulation Study on a Variational Bayes Predictive Coding Recurrent Neural Network Model
The current paper proposes a novel variational Bayes predictive coding RNN
model, which can learn to generate fluctuated temporal patterns from exemplars.
The model learns to maximize the lower bound of the weighted sum of the
regularization and reconstruction error terms. We examined how this weighting
can affect development of different types of information processing while
learning fluctuated temporal patterns. Simulation results show that strong
weighting of the reconstruction term causes the development of deterministic
chaos for imitating the randomness observed in target sequences, while strong
weighting of the regularization term causes the development of stochastic
dynamics imitating probabilistic processes observed in targets. Moreover,
results indicate that the most generalized learning emerges between these two
extremes. The paper concludes with implications in terms of the underlying
neuronal mechanisms for autism spectrum disorder and for free action.Comment: This paper is accepted the 24th International Conference On Neural
Information Processing (ICONIP 2017). The previous submission to arXiv is
replaced by this version because there was an error in Equation
New findings on the prototypical Of?p stars
In recent years several in-depth investigations of the three Galactic Of?p
stars were undertaken. These multiwavelength studies revealed the peculiar
properties of these objects (in the X-rays as well as in the optical): magnetic
fields, periodic line profile variations, recurrent photometric changes.
However, many questions remain unsolved. To clarify some of the properties of
the Of?p stars, we have continued their monitoring. A new XMM observation and
two new optical datasets were obtained. Additional information for the
prototypical Of?p trio has been found. HD108 has now reached its quiescent,
minimum-emission state, for the first time in 50--60yrs. The echelle spectra of
HD148937 confirm the presence of the 7d variations in the Balmer lines and
reveal similar periodic variations (though of lower amplitudes) in the HeI5876
and HeII4686 lines, underlining its similarities with the other two
prototypical Of?p stars. The new XMM observation of HD191612 was taken at the
same phase in the line modulation cycle but at a different orbital phase as
previous data. It clearly shows that the X-ray emission of HD191612 is
modulated by the 538d period and not the orbital period of 1542d - it is thus
not of colliding-wind origin and the phenomenon responsible for the optical
changes appears also at work in the high-energy domain. There are however
problems: our MHD simulations of the wind magnetic confinement predict both a
harder X-ray flux of a much larger strength than what is observed (the modeled
DEM peaks at 30-40MK, whereas the observed one peaks at 2MK) and narrow lines
(hot gas moving with velocities of 100--200km/s, whereras the observed FWHM is
~2000km/s).Comment: 10 pages, 8 figures (2 in jpg), accepted for publication by A&
Large Margin Neural Language Model
We propose a large margin criterion for training neural language models.
Conventionally, neural language models are trained by minimizing perplexity
(PPL) on grammatical sentences. However, we demonstrate that PPL may not be the
best metric to optimize in some tasks, and further propose a large margin
formulation. The proposed method aims to enlarge the margin between the "good"
and "bad" sentences in a task-specific sense. It is trained end-to-end and can
be widely applied to tasks that involve re-scoring of generated text. Compared
with minimum-PPL training, our method gains up to 1.1 WER reduction for speech
recognition and 1.0 BLEU increase for machine translation.Comment: 9 pages. Accepted as a long paper in EMNLP201
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