48,872 research outputs found
Comparing Deep Recurrent Networks Based on the MAE Random Sampling, a First Approach
Recurrent neural networks have demonstrated to be good at tackling prediction problems, however due to their high sensitivity to
hyper-parameter configuration, finding an appropriate network is a tough task. Automatic hyper-parameter optimization methods have emerged to find the most suitable configuration to a given problem, but these methods are not generally adopted because of their high computational cost. Therefore, in this study we extend the MAE random sampling, a low-cost method to compare single-hidden layer architectures, to multiple-hidden-layer ones. We validate empirically our proposal and show that it is possible to predict and compare the expected performance of an hyper-parameter configuration in a low-cost way.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
This research was partially funded by Ministerio de Economı́a, Industria y Competitividad, Gobierno de España, and European Regional Development Fund grant numbers TIN2016-81766-REDT (http://cirti.es) and TIN2017-88213-R (http://6city.lcc.uma.es)
Energy rating of a water pumping station using multivariate analysis
Among water management policies, the preservation and the saving of energy demand in water supply and treatment systems play key roles. When focusing on energy, the customary metric to determine the performance of water supply systems is linked to the definition of component-based energy indicators. This approach is unfit to account for interactions occurring among system elements or between the system and its environment. On the other hand, the development of information technology has led to the availability of increasing large amount of data, typically gathered from distributed sensor networks in so-called smart grids. In this context, data intensive methodologies address the possibility of using complex network modeling approaches, and advocate the issues related to the interpretation and analysis of large amount of data produced by smart sensor networks.
In this perspective, the present work aims to use data intensive techniques in the energy analysis of a water management network.
The purpose is to provide new metrics for the energy rating of the system and to be able to provide insights into the dynamics of its operations. The study applies neural network as a tool to predict energy demand, when using flowrate and vibration data as predictor variables
Random Neural Networks and Optimisation
In this thesis we introduce new models and learning algorithms for the Random
Neural Network (RNN), and we develop RNN-based and other approaches for the
solution of emergency management optimisation problems.
With respect to RNN developments, two novel supervised learning algorithms are
proposed. The first, is a gradient descent algorithm for an RNN extension model
that we have introduced, the RNN with synchronised interactions (RNNSI), which
was inspired from the synchronised firing activity observed in brain neural circuits.
The second algorithm is based on modelling the signal-flow equations in RNN as a
nonnegative least squares (NNLS) problem. NNLS is solved using a limited-memory
quasi-Newton algorithm specifically designed for the RNN case.
Regarding the investigation of emergency management optimisation problems,
we examine combinatorial assignment problems that require fast, distributed and
close to optimal solution, under information uncertainty. We consider three different
problems with the above characteristics associated with the assignment of
emergency units to incidents with injured civilians (AEUI), the assignment of assets
to tasks under execution uncertainty (ATAU), and the deployment of a robotic
network to establish communication with trapped civilians (DRNCTC).
AEUI is solved by training an RNN tool with instances of the optimisation problem
and then using the trained RNN for decision making; training is achieved using
the developed learning algorithms. For the solution of ATAU problem, we introduce
two different approaches. The first is based on mapping parameters of the
optimisation problem to RNN parameters, and the second on solving a sequence of
minimum cost flow problems on appropriately constructed networks with estimated
arc costs. For the exact solution of DRNCTC problem, we develop a mixed-integer
linear programming formulation, which is based on network flows. Finally, we design
and implement distributed heuristic algorithms for the deployment of robots
when the civilian locations are known or uncertain
CloudScan - A configuration-free invoice analysis system using recurrent neural networks
We present CloudScan; an invoice analysis system that requires zero
configuration or upfront annotation. In contrast to previous work, CloudScan
does not rely on templates of invoice layout, instead it learns a single global
model of invoices that naturally generalizes to unseen invoice layouts. The
model is trained using data automatically extracted from end-user provided
feedback. This automatic training data extraction removes the requirement for
users to annotate the data precisely. We describe a recurrent neural network
model that can capture long range context and compare it to a baseline logistic
regression model corresponding to the current CloudScan production system. We
train and evaluate the system on 8 important fields using a dataset of 326,471
invoices. The recurrent neural network and baseline model achieve 0.891 and
0.887 average F1 scores respectively on seen invoice layouts. For the harder
task of unseen invoice layouts, the recurrent neural network model outperforms
the baseline with 0.840 average F1 compared to 0.788.Comment: Presented at ICDAR 201
Sampling Frequency Evaluation on Recurrent Neural Networks Architectures for IoT Real-time Fall Detection Devices
Falls are one of the most frequent causes of injuries in elderly people. Wearable Fall Detection Systems
provided a ubiquitous tool for monitoring and alert when these events happen. Recurrent Neural Networks
(RNN) are algorithms that demonstrates a great accuracy in some problems analyzing sequential inputs, such
as temporal signal values. However, their computational complexity are an obstacle for the implementation
in IoT devices. This work shows a performance analysis of a set of RNN architectures when trained with
data obtained using different sampling frequencies. These architectures were trained to detect both fall and
fall hazards by using accelerometers and were tested with 10-fold cross validation, using the F1-score metric.
The results obtained show that sampling with a frequency of 25Hz does not affect the effectiveness, based
on the F1-score, which implies a substantial increase in the performance in terms of computational cost. The
architectures with two RNN layers and without a first dense layer had slightly better results than the smallest
architectures. In future works, the best architectures obtained will be integrated in an IoT solution to determine
the effectiveness empirically.Ministerio de Economía y Competitividad TEC2016-77785-
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