A worker checks the radiation level inside the control room of reactor No 4, where the Chornobyl disaster happened in 1986. A worker checks the radiation level inside the control room of reactor No 4, where the Chornobyl disaster happened in 1986. In February 2025, a cheap Russian drone tore through Chornobyl's confinement shelter. Workers warn the site of the world's worst nuclear accident is not safe yet The dosimeter clipped to your chest ticks faster the moment you step off the designated path inside the Chornobyl nuclear power plant. Step back, and it slows again - an invisible line between clean ground and contamination.

'Animals are traumatised too': Pet rescuers under fire in Ukraine On a morning in February, animal shelter staff were getting changed for their shift when a Russian drone slammed into the centre of their compound in the frontline Ukrainian city of Zaporizhzhia. The steel door at the entrance probably saved their lives. More than a dozen animals sheltering at Give a Paw, Friend were not so lucky. It was terrifying, to put it mildly, says the group's head Iryna Didur. Residents rushed to help clean up the rubble and catch the animals that had escaped in terror.

Strong mixed-integer programming formulations for trained neural networks.

We study the problem of reward shaping to accelerate the training process of a reinforcement learning agent. Existing works have considered a number of different reward shaping formulations; however, they either require external domain knowledge or fail in environments with extremely sparse rewards. In this paper, we propose a novel framework, Exploration-Guided Reward Shaping (EXPLORS), that operates in a fully self-supervised manner and can accelerate an agent's learning even in sparse-reward environments. The key idea of EXPLORS is to learn an intrinsic reward function in combination with exploration-based bonuses to maximize the agent's utility w.r.t.

We study the problem of reward shaping to accelerate the training process of a reinforcement learning agent. Existing works have considered a number of different reward shaping formulations; however, they either require external domain knowledge or fail in environments with extremely sparse rewards. In this paper, we propose a novel framework, Exploration-Guided Reward Shaping (EXPLORS), that operates in a fully self-supervised manner and can accelerate an agent's learning even in sparse-reward environments. The key idea of EXPLORS is to learn an intrinsic reward function in combination with exploration-based bonuses to maximize the agent's utility w.r.t.

Given an unsupervised outlier detection task on a new dataset, how can we automatically select a good outlier detection algorithm and its hyperparameter(s) (collectively called a model)? In this work, we tackle the unsupervised outlier model selection (UOMS) problem, and propose METAOD, a principled, data-driven approach to UOMS based on meta-learning. The UOMS problem is notoriously challenging, as compared to model selection for classification and clustering, since (i) model evaluation is infeasible due to the lack of hold-out data with labels, and (ii) model comparison is infeasible due to the lack of a universal objective function. METAOD capitalizes on the performances of a large body of detection models on historical outlier detection benchmark datasets, and carries over this prior experience to automatically select an effective model to be employed on a new dataset without any labels, model evaluations or model comparisons. To capture task similarity within our meta-learning framework, we introduce specialized metafeatures that quantify outlying characteristics of a dataset. Extensive experiments show that selecting a model by METAOD significantly outperforms no model selection (e.g.