22 research outputs found
Random Hyper-parameter Search-Based Deep Neural Network for Power Consumption Forecasting
In this paper, we introduce a deep learning approach, based on feed-forward
neural networks, for big data time series forecasting with arbitrary prediction horizons.
We firstly propose a random search to tune the multiple hyper-parameters involved in
the method perfor-mance. There is a twofold objective for this search: firstly, to improve
the forecasts and, secondly, to decrease the learning time. Next, we pro-pose a procedure
based on moving averages to smooth the predictions obtained by the different models
considered for each value of the pre-diction horizon. We conduct a comprehensive
evaluation using a real-world dataset composed of electricity consumption in Spain,
evaluating accuracy and comparing the performance of the proposed deep learning with
a grid search and a random search without applying smoothing. Reported results show
that a random search produces competitive accu-racy results generating a smaller
number of models, and the smoothing process reduces the forecasting error.Ministerio de Economía y Competitividad TIN2017-88209-C2-1-
Coding Efficiency of Fly Motion Processing Is Set by Firing Rate, Not Firing Precision
To comprehend the principles underlying sensory information processing, it is important to understand how the nervous system deals with various sources of perturbation. Here, we analyze how the representation of motion information in the fly's nervous system changes with temperature and luminance. Although these two environmental variables have a considerable impact on the fly's nervous system, they do not impede the fly to behave suitably over a wide range of conditions. We recorded responses from a motion-sensitive neuron, the H1-cell, to a time-varying stimulus at many different combinations of temperature and luminance. We found that the mean firing rate, but not firing precision, changes with temperature, while both were affected by mean luminance. Because we also found that information rate and coding efficiency are mainly set by the mean firing rate, our results suggest that, in the face of environmental perturbations, the coding efficiency is improved by an increase in the mean firing rate, rather than by an increased firing precision