Title : A Comparative Study of State-of-the-Art Machine Learning Algorithms for Predictive Maintenance

Presenter Luis Pedro Silvestrin
Abstract Predictive maintenance strives to maximize the availability of engineering systems. Over the last decade, machine learning has started to play a pivotal role in the domain to predict failures in machines and thus contribute to predictive maintenance. Ample approaches have been proposed to exploit machine learning based on sensory data obtained from engineering systems. Traditionally, these were based on feature engineering from the data followed by the application of a traditional machine learning algorithm. Recently, also deep learning approaches that are able to extract the features automatically have been utilized (including LSTMs and Convolutional Neural Networks), showing promising results. However, deep learning approaches need a substantial amount of data to be effective. Also, novel developments in deep learning architectures for time series have not been applied to predictive maintenance so far. In this paper, we compare a variety of different traditional machine learning and deep learning approaches to a representative (and modestly sized) predictive maintenance dataset and study their differences. In the deep learning approaches we include a novel approach that has not been tested for predictive maintenance yet: the temporal convolutional neural network. We compare the approaches over different sizes of the training dataset. The results show that, when the data is scarce, the temporal convolutional network performs better than the common deep learning approaches applied to predictive maintenance. However, it does not beat the more traditional feature engineering based approaches.

Title : Making Decisions over Contextual Ontologies

Presenter Erman Acar
Abstract Various probabilistic description logics (DLs) have been proposed for dealing with the uncertainty endemic to many domain knowledge representation scenarios. A particular class of such formalisms focuses on representing knowledge that is certain, but holds only in some uncertain contexts. In this paper, we consider an extension of those formalisms that allows an agent to influence the choice of the context and minimise its subjective cost. This is achieved through a combination of the light-weight DL EL and influence diagrams, a graphical model for representing decision situations, and their potential costs, under uncertainty. This is a joint work with Rafael Penaloza and Livia Predoiu.