Friday, August 3rd, 2018

1:00 p.m.

DeBartolo Hall Room 102

 

Skyler Speakman

Research Scientist at IBM Research - Africa

 

 S.-Speakman-Headshot.png - 464.04 kB

Pattern Detection on Hidden Layers of Neural Networks

The motivating theme for this work is to view neural nets as data-generating systems and then detect patterns in that generated data with the overall goal of increasing the explainability of the models . One approach to this problem is to identify anomalous subsets of neurons that have higher-than-expected activations. The subset scanning approach to anomalous pattern detection has been applied in multiple domains including disease outbreak detection, crime prediction, detecting the spread of water contaminants, customs monitoring, network intrusion detection, and bias detection in criminal sentencing. [Event & Pattern Detection Lab https://epdlab.heinz.cmu.edu/]. This is the first work to apply subset scanning techniques to data generated within neural networks. A majority of work in deep learning has focused on identifying and encouraging a highly-activated single neuron in the ‘output layer’ of neural networks (usually denoting a class probability). Pattern detection through subset scanning identifies groups of highly-activated neurons in the hidden layers in order to detect and identify patterns not visible from any individual neuron activity alone. A promising application of this methodology is detecting and characterizing adversarial noise that has been added to images in order to 'trick' neural networks into misclassification. We will present early results in this domain and then follow up with many exciting extensions to continue the work.

About Skyler Speakman

Skyler Speakman is a Research Scientist at IBM Research -- Africa.  His projects use data science to impact the lives of millions of people on the continent.  He believes that data collected through phones and drones will fundamentally change service delivery and African development in the next decade.  Skyler completed a Ph.D. in Information Systems at Carnegie Mellon University as well as a M.S. in Machine Learning.  He also holds masters in Mathematics, Statistics, and Public Policy.  He lives in Nairobi, Kenya with his wife and two young sons.