Finding Safe Zones of Markov Decision Processes Policies Lee Cohen Yishay Mansour Michal Moshkovitz TTI-Chicago Tel-Aviv University Bosch Center for AI Google Research
One notable exception to that is Safe RL which addresses the concept of safety. Traditional Safe RL focuses on finding the best policy that meets safety requirements, typically by either adjusting the objective to include the safety requirements and then optimizing for it, or incorporating additional safety constraints to the exploration. In both of these cases, the safety requirements should be pre-specified. Anomaly Detection is the problem of identifying patterns in data that are unexpected, i.e., anomalies (see, e.g., Chandola et al. (2009) for survey).
Adversarial Counterfactual Environment Model Learning
An accurate environment dynamics model is crucial for various downstream tasks in sequential decision-making, such as counterfactual prediction, off-policy evaluation, and offline reinforcement learning. Currently, these models were learned through empirical risk minimization (ERM) by step-wise fitting of historical transition data. This way was previously believed unreliable over long-horizon rollouts because of the compounding errors, which can lead to uncontrollable inaccuracies in predictions. In this paper, we find that the challenge extends beyond just longterm prediction errors: we reveal that even when planning with one step, learned dynamics models can also perform poorly due to the selection bias of behavior policies during data collection.
Appendix A Proofs of Formal Claims X M X, and measure P over sets in X M, we denote by () will be used to refer to the c-th coordinate of the output of a function X M X
By pretraining the model on domain-specific data, PubMED BERT is expected to have a better understanding of biomedical concepts, terminology, and language patterns compared to general domain models like BERT-base and BERT-large [95]. The main advantage of using PubMED BERT for biomedical text mining tasks is its domain-specific knowledge, which can lead to improved performance and more accurate results when fine-tuned on various downstream tasks, such as named entity recognition, relation extraction, document classification, and question answering. Since PubMED BERT is pre-trained on a large corpus of biomedical text, it is better suited to capturing the unique language patterns, complex terminology, and the relationships between entities in the biomedical domain.
Spatially Resolved Gene Expression Prediction from H&E Histology Images via Bi-modal Contrastive Learning Supplemental Material Ronald Xie 1,2,3,4 Kuan Pang 1,2,4 Sai W. Chung
However, ViT-Base and ViT-Large demonstrate reduced expression prediction accuracy, with fewer genes scoring above 0.3 correlation compared to the original expression profiles. A plausible explanation for this discrepancy is that the utilization of larger models, when combined with a relatively small training dataset (n = 9269), may encourage the memorization of information within the network weights rather than effective encoding in the projections. Consequently, the learned joint embedding becomes less effective for downstream imputation in our specific use case. Supplementary Table 1: The choice of image encoder versus the number of genes with predicted expression correlation 0.3 to original. These two genes ranked highly among the top most well predicted genes across all three methods.
Spatially Resolved Gene Expression Prediction from H&E Histology Images via Bi-modal Contrastive Learning Ronald Xie 1,2,3,4 Kuan Pang 1,2,4 Sai W. Chung 1,5
Histology imaging is an important tool in medical diagnosis and research, enabling the examination of tissue structure and composition at the microscopic level. Understanding the underlying molecular mechanisms of tissue architecture is critical in uncovering disease mechanisms and developing effective treatments. Gene expression profiling provides insight into the molecular processes underlying tissue architecture, but the process can be time-consuming and expensive. We present BLEEP (Bi-modaL Embedding for Expression Prediction), a bi-modal embedding framework capable of generating spatially resolved gene expression profiles of whole-slide Hematoxylin and eosin (H&E) stained histology images. BLEEP uses contrastive learning to construct a low-dimensional joint embedding space from a reference dataset using paired image and expression profiles at micrometer resolution. With this approach, the gene expression of any query image patch can be imputed using the expression profiles from the reference dataset. We demonstrate BLEEP's effectiveness in gene expression prediction by benchmarking its performance on a human liver tissue dataset captured using the 10x Visium platform, where it achieves significant improvements over existing methods. Our results demonstrate the potential of BLEEP to provide insights into the molecular mechanisms underlying tissue architecture, with important implications in diagnosis and research of various diseases. The proposed approach can significantly reduce the time and cost associated with gene expression profiling, opening up new avenues for high-throughput analysis of histology images for both research and clinical applications.
Learning Dense Flow Field for Highly-accurate Cross-view Camera Localization Zhenbo Song 1
This paper addresses the problem of estimating the 3-DoF camera pose for a ground-level image with respect to a satellite image that encompasses the local surroundings. We propose a novel end-to-end approach that leverages the learning of dense pixel-wise flow fields in pairs of ground and satellite images to calculate the camera pose. Our approach differs from existing methods by constructing the feature metric at the pixel level, enabling full-image supervision for learning distinctive geometric configurations and visual appearances across views. Specifically, our method employs two distinct convolution networks for ground and satellite feature extraction. Then, we project the ground feature map to the bird's eye view (BEV) using a fixed camera height assumption to achieve preliminary geometric alignment.
Operator Learning with Neural Fields: Tackling PDEs on General Geometries Louis Serrano 1
Machine learning approaches for solving partial differential equations require learning mappings between function spaces. While convolutional or graph neural networks are constrained to discretized functions, neural operators present a promising milestone toward mapping functions directly. Despite impressive results they still face challenges with respect to the domain geometry and typically rely on some form of discretization. In order to alleviate such limitations, we present CORAL, a new method that leverages coordinate-based networks for solving PDEs on general geometries. CORAL is designed to remove constraints on the input mesh, making it applicable to any spatial sampling and geometry. Its ability extends to diverse problem domains, including PDE solving, spatio-temporal forecasting, and geometry-aware inference. CORAL demonstrates robust performance across multiple resolutions and performs well in both convex and non-convex domains, surpassing or performing on par with state-of-the-art models.