Anomaly Detection

Operational, Uncertainty-Aware, and Reliable Anomaly Detection

Anomaly detection methods aim to identify examples that do not follow the expected behavior. For various reasons, anomaly detection is typically tackled by using unsupervised approaches that assign real-valued anomaly scores based on various …

Unsupervised Anomaly Detection with Rejection @ NeurIPS23

Anomaly detection aims at detecting unexpected behaviours in the data. Because anomaly detection is usually an unsupervised task, traditional anomaly detectors learn a decision boundary by employing heuristics based on intuitions, which are hard to …

Learning from Positive and Unlabeled Multi-Instance Bags in Anomaly Detection @ KDD23

In the multi-instance learning (MIL) setting instances are grouped together into bags. Labels are provided only for the bags and not on the level of individual instances. A positive bag label means that at least one instance inside the bag is …

Estimating the Contamination Factor’s Distribution in Unsupervised Anomaly Detection @ ICML23

Anomaly detection methods identify examples that do not follow the expected behaviour, typically in an unsupervised fashion, by assigning real-valued anomaly scores to the examples based on various heuristics. These scores need to be transformed into …

How to Allocate your Label Budget? Choosing between Active Learning and Learning to Reject in Anomaly Detection @ AAAI23

Anomaly detection attempts at finding examples that deviate from the expected behaviour. Usually, anomaly detection is tackled from an unsupervised perspective because anomalous labels are rare and difficult to acquire. However, the lack of labels …

Transferring the Contamination Factor between Anomaly Detection Domains by Shape Similarity @ AAAI22

Anomaly detection attempts to find examples in a dataset that do not conform to the expected behavior. Algorithms for this task assign an anomaly score to each example representing its degree of anomalousness. Setting a threshold on the anomaly …

Quantifying the Confidence of Anomaly Detectors in Their Example-Wise Predictions @ Polito

Class Prior Estimation in Active Positive and Unlabeled Learning @ IJCAI20

Estimating the proportion of positive examples (i.e., the class prior) from positive and unlabeled (PU) data is an important task that facilitates learning a classifier from such data. In this paper, we explore how to tackle this problem when the …

A Ranking Stability Measure for Quantifying the Robustness of Anomaly Detection Methods @ ECML20

Anomaly detection attempts to learn models from data that can detect anomalous examples in the data. However, naturally occurring variations in the data impact the model that is learned and thus which examples it will predict to be anomalies. …

Quantifying the Confidence of Anomaly Detectors in Their Example-Wise Predictions @ ECML20

Anomaly detection focuses on identifying examples in the data that somehow deviate from what is expected or typical. Algorithms for this task usually assign a score to each example that represents how anomalous the example is. Then, a threshold on …