This week we have Alexander G. Ororbia II from Penn State giving a talk on Friday March 23 at 10:30AM in room AA1360.

Want to meet with Alex? Fill out this Doodle and we'll find a spot!

This talk should present some new ideas that will really challenge us to never stop learning, so you should definitely come!
Michael

TITLE Adaptation in the Face of Evolving Distributions: Towards Continual Learning of Connectionist Architectures

KEYWORDS continual/lifelong/meta learning, optimization, biological-inspired RNN

ABSTRACT
It is a common statistical learning practice to build models on (very large) static datasets of identically and independently distributed samples. But what if the distribution to be learned is dynamic and samples are drawn from it over time? In this setting, these traditional learning approaches no longer directly apply. Motivated by this issue, we must look to continual, or lifelong learning, and the nature of systems that adapt themselves to such distributions. With the goal of creating robust and scalable continual learning systems, my work can be decomposed into two main threads: 1) creating architectures with longer-term memory and 2) developing better learning algorithms.

In this talk, I will focus on the second thread, specifically on my efforts in developing alternatives to back-propagation of errors. Specifically, I will present, Local Representation Alignment (LRA), a training procedure that is much less sensitive to bad initializations, does not require modifications to the network architecture, can be readily adapted to networks with highly nonlinear and discrete-valued activation functions and stochastic sampling operations, and can even train networks with various kinds of activation functions from zero initialization. Results on classification benchmarks will be discussed and recent results in the lifelong learning setting, where the model must learn across tasks, will be presented.

I will finally talk about my proposed neural architecture, the Temporal Neural Coding Network (TNCN), which builds on concepts from predictive coding, an important theory of the brain that has gained influence in cognitive science. Using the proposed Discrepancy Reduction learning procedure, which can be viewed as a special variation of LRA, the TNCN can learn from sequential data, such as videos or text documents. More importantly, initial results show promise that the TNCN can be competitive with models that learn using back-propagation through time--the popular, biologically implausible algorithm used to "unroll" and train recurrent neural networks.

BIO
Alex is currently a Ph.D. student at The Pennsylvania State University in Information Sciences & Technology. In 2013, he obtained his Bachelor of Science degree in Computer Science & Engineering at Bucknell University, minoring in Philosophy and Mathematics. The focus of his work is on lifelong learning--an important and challenging open problem in machine learning. He studies representation learning and draws inspiration from ideas in cognitive science and neuroscience. Alex's mission is to develop the learning procedures and architectures needed to create general-purpose, adaptive agents that can learn from data of multiple modalities and operate in messy, non-stationary environments.