San Dimas
Time-Warping Recurrent Neural Networks for Transfer Learning
Dynamical systems describe how a physical system evolves over time. Physical processes can evolve faster or slower in different environmental conditions. We use time-warping as rescaling the time in a model of a physical system. This thesis proposes a new method of transfer learning for Recurrent Neural Networks (RNNs) based on time-warping. We prove that for a class of linear, first-order differential equations known as time lag models, an LSTM can approximate these systems with any desired accuracy, and the model can be time-warped while maintaining the approximation accuracy. The Time-Warping method of transfer learning is then evaluated in an applied problem on predicting fuel moisture content (FMC), an important concept in wildfire modeling. An RNN with LSTM recurrent layers is pretrained on fuels with a characteristic time scale of 10 hours, where there are large quantities of data available for training. The RNN is then modified with transfer learning to generate predictions for fuels with characteristic time scales of 1 hour, 100 hours, and 1000 hours. The Time-Warping method is evaluated against several known methods of transfer learning. The Time-Warping method produces predictions with an accuracy level comparable to the established methods, despite modifying only a small fraction of the parameters that the other methods modify.
The Excellent Evolution of 'Bill and Ted Face the Music'
Time travel becomes a family affair in Bill and Ted Face the Music, the long-awaited third film in the popular Bill and Ted comedy franchise. Fans won't be disappointed: the film is most excellent, capturing that same breezy, chaotic, let's-just-have-fun-with-this madcap magic of its predecessors. This story originally appeared on Ars Technica, a trusted source for technology news, tech policy analysis, reviews, and more. Ars is owned by WIRED's parent company, Condé Nast. "We were trying to pay some homage to the original two [films] while making it feel like it was contemporary," Parisot told Ars about how he approached bringing the Bill and Ted franchise into the 21st century.