collaborators

8 papers

cs.LG2026

RECAST: Model Reconstruction via Counterfactual-Aware Wasserstein Geometry under Limited Data

Xuan Zhao, Lena Krieger, Zhuo Cao +3

Counterfactual explanations (CFs) help understand machine learning models by identifying minimal input changes that would lead to alternative model outcomes. Recent work demonstrat…

cs.AI2026

Residual-Space Evolutionary Optimization via Flow-based Generative Models

Zhuo Cao, Lena Krieger, Fernanda Nader +3

Data editing with generative methods typically requires differentiable objectives and gradient-based search. However, these assumptions break down in flow-based settings, where edi…

cs.LG2026

Counterfactual Transport Flows for Offline Conservative Trajectory Refinement

Lena Krieger, Xuan Zhao, Zhuo Cao +3

Offline reinforcement learning (RL) offers a path to policy improvement from logged data alone, using historical returns or other measurable outcomes as world feedback. A key diffi…

cs.LG2026

ExDBSCAN: Explaining DBSCAN with Counterfactual Reasoning -- Additional Material

Pernille Matthews, Lena Krieger, Tommaso Amico +3

Clustering is an unsupervised technique for grouping data points by similarity. While explainability methods exist for supervised machine learning, they are not directly applicable…

cs.LG2026

DCFO: Density-Based Counterfactuals for Outliers -- Additional Material

Tommaso Amico, Pernille Matthews, Lena Krieger +2

Outlier detection identifies data points that significantly deviate from the majority of the data distribution. Explaining outliers is crucial for understanding the underlying fact…

cs.LG2025

Internal Evaluation of Density-Based Clusterings with Noise

Anna Beer, Lena Krieger, Pascal Weber +3

Being able to evaluate the quality of a clustering result even in the absence of ground truth cluster labels is fundamental for research in data mining. However, most cluster valid…