Learning from label proportions (LLP) is a weakly supervised setting for classification in which unlabeled training instances are grouped into bags, and each bag is annotated with the proportion of each class occurring in that bag. Prior work on LLP has yet to establish a consistent learning procedure, nor does there exist a theoretically justified, general purpose training criterion. In this work we address these two issues by posing LLP in terms of mutual contamination models (MCMs), which have recently been applied successfully to study various other weak supervision settings. In the process, we establish several novel technical results for MCMs, including unbiased losses and generalization error bounds under non-iid sampling plans. We also point out the limitations of a common experimental setting for LLP, and propose a new one based on our MCM framework.
Detecting Traffic Incidents Using Persistence Diagrams
We introduce a novel methodology for anomaly detection in time-series data. The method uses persistence diagrams and bottleneck distances to identify anomalies. Specifically, we generate multiple predictors by randomly bagging the data (reference bags), then for each data point replacing the data point for a randomly chosen point in each bag (modified bags). The predictors then are the set of bottleneck distances for the reference/modified bag pairs. We prove the stability of the predictors as the number of bags increases. We apply our methodology to traffic data and measure the performance for identifying known incidents.
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Learning from label proportions (LLP) is a weakly supervised setting for classification in whichunlabeled training instances are grouped into bags, and each bag is annotated with the proportion ofeach class occurring in that bag. Prior work on LLP has yet to establish a consistent learning procedure,nor does there exist a theoretically justified, general purpose training criterion. In this work we addressthese two issues by posing LLP in terms of mutual contamination models (MCMs), which have recentlybeen applied successfully to study various other weak supervision settings. In the process, we establishseveral novel technical results for MCMs, including unbiased losses and generalization error bounds undernon-iid sampling plans. We also point out the limitations ofa common experimental setting for LLP,and propose a new one based on our MCM framework.
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