bonferroni correction
Efficient and scalable clustering of survival curves
Villanueva, Nora M., Sestelo, Marta, Meira-Machado, Luis
Survival analysis encompasses a broad range of methods for analyzing time-to-event data, with one key objective being the comparison of survival curves across groups. Traditional approaches for identifying clusters of survival curves often rely on computationally intensive bootstrap techniques to approximate the null hypothesis distribution. While effective, these methods impose significant computational burdens. In this work, we propose a novel approach that leverages the k-means and log-rank test to efficiently identify and cluster survival curves. Our method eliminates the need for computationally expensive resampling, significantly reducing processing time while maintaining statistical reliability. By systematically evaluating survival curves and determining optimal clusters, the proposed method ensures a practical and scalable alternative for large-scale survival data analysis. Through simulation studies, we demonstrate that our approach achieves results comparable to existing bootstrap-based clustering methods while dramatically improving computational efficiency. These findings suggest that the log-rank-based clustering procedure offers a viable and time-efficient solution for researchers working with multiple survival curves in medical and epidemiological studies.
- Europe > Netherlands > South Holland > Rotterdam (0.05)
- South America > Chile > Santiago Metropolitan Region > Santiago Province > Santiago (0.04)
- Europe > Spain > Galicia > A Coruña Province > Santiago de Compostela (0.04)
- (2 more...)
Reward Engineering for Spatial Epidemic Simulations: A Reinforcement Learning Platform for Individual Behavioral Learning
Rakhshandehroo, Radman, Coombs, Daniel
We present ContagionRL, a Gymnasium-compatible reinforcement learning platform specifically designed for systematic reward engineering in spatial epidemic simulations. Unlike traditional agent-based models that rely on fixed behavioral rules, our platform enables rigorous evaluation of how reward function design affects learned survival strategies across diverse epidemic scenarios. ContagionRL integrates a spatial SIRS+D epidemiological model with configurable environmental parameters, allowing researchers to stress-test reward functions under varying conditions including limited observability, different movement patterns, and heterogeneous population dynamics. We evaluate five distinct reward designs, ranging from sparse survival bonuses to a novel potential field approach, across multiple RL algorithms (PPO, SAC, A2C). Through systematic ablation studies, we identify that directional guidance and explicit adherence incentives are critical components for robust policy learning. Our comprehensive evaluation across varying infection rates, grid sizes, visibility constraints, and movement patterns reveals that reward function choice dramatically impacts agent behavior and survival outcomes. Agents trained with our potential field reward consistently achieve superior performance, learning maximal adherence to non-pharmaceutical interventions while developing sophisticated spatial avoidance strategies. The platform's modular design enables systematic exploration of reward-behavior relationships, addressing a knowledge gap in models of this type where reward engineering has received limited attention. ContagionRL is an effective platform for studying adaptive behavioral responses in epidemic contexts and highlight the importance of reward design, information structure, and environmental predictability in learning.
- North America > United States > New York > New York County > New York City (0.14)
- North America > Canada > British Columbia (0.04)
- South America > Chile > Santiago Metropolitan Region > Santiago Province > Santiago (0.04)
- (8 more...)
- Research Report > New Finding (1.00)
- Research Report > Experimental Study (1.00)
- Health & Medicine > Therapeutic Area > Infections and Infectious Diseases (1.00)
- Health & Medicine > Public Health (1.00)
- Health & Medicine > Epidemiology (1.00)
- Health & Medicine > Therapeutic Area > Immunology (0.69)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Agents (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Reinforcement Learning (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Undirected Networks > Markov Models (0.46)
Appendix Table of Contents
The naive aggregation of these public datasets results in a database with partial and incomplete labels, e.g., LiTS only had labels for the liver and its tumors, and KiTS only had labels for the kidneys and its tumors. Conversely, our AbdomenAtlas 1.0 is fully-annotated, offering detailed per-voxel labels Figure 3: Anatomical boundaries and structures can be indistinct due to disease, as seen in the JHH dataset. We display CT volumes with patients depicted under unhealthy conditions that are challenging for most AI algorithms to identify. The CT volumes are from patients in unhealthy conditions. The encoder performs down-sampling operations, and it is designed to capture high-level semantics and context information.
- Asia > China > Hong Kong (0.04)
- Asia > China > Shanghai > Shanghai (0.04)
- North America > United States > New York > Suffolk County > Stony Brook (0.04)
- (13 more...)
- Health & Medicine > Diagnostic Medicine > Imaging (0.48)
- Health & Medicine > Therapeutic Area > Oncology (0.46)
- Information Technology > Sensing and Signal Processing > Image Processing (1.00)
- Information Technology > Artificial Intelligence > Vision (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Neural Networks > Deep Learning (0.68)
- Information Technology > Artificial Intelligence > Natural Language (0.67)
- North America > United States > Michigan > Washtenaw County > Ann Arbor (0.04)
- North America > Canada (0.04)
Appendix Table of Contents
The naive aggregation of these public datasets results in a database with partial and incomplete labels, e.g., LiTS only had labels for the liver and its tumors, and KiTS only had labels for the kidneys and its tumors. Conversely, our AbdomenAtlas 1.0 is fully-annotated, offering detailed per-voxel labels Figure 3: Anatomical boundaries and structures can be indistinct due to disease, as seen in the JHH dataset. We display CT volumes with patients depicted under unhealthy conditions that are challenging for most AI algorithms to identify. The CT volumes are from patients in unhealthy conditions. The encoder performs down-sampling operations, and it is designed to capture high-level semantics and context information.
- Asia > China > Hong Kong (0.04)
- Asia > China > Shanghai > Shanghai (0.04)
- North America > United States > New York > Suffolk County > Stony Brook (0.04)
- (13 more...)
- Health & Medicine > Diagnostic Medicine > Imaging (0.48)
- Health & Medicine > Therapeutic Area > Oncology (0.46)
- Information Technology > Sensing and Signal Processing > Image Processing (1.00)
- Information Technology > Artificial Intelligence > Vision (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Neural Networks > Deep Learning (0.68)
- Information Technology > Artificial Intelligence > Natural Language (0.67)
- North America > United States > Michigan > Washtenaw County > Ann Arbor (0.04)
- North America > Canada > British Columbia > Metro Vancouver Regional District > Vancouver (0.04)
Surface Fairness, Deep Bias: A Comparative Study of Bias in Language Models
Sorokovikova, Aleksandra, Chizhov, Pavel, Eremenko, Iuliia, Yamshchikov, Ivan P.
Modern language models are trained on large amounts of data. These data inevitably include controversial and stereotypical content, which contains all sorts of biases related to gender, origin, age, etc. As a result, the models express biased points of view or produce different results based on the assigned personality or the personality of the user. In this paper, we investigate various proxy measures of bias in large language models (LLMs). We find that evaluating models with pre-prompted personae on a multi-subject benchmark (MMLU) leads to negligible and mostly random differences in scores. However, if we reformulate the task and ask a model to grade the user's answer, this shows more significant signs of bias. Finally, if we ask the model for salary negotiation advice, we see pronounced bias in the answers. With the recent trend for LLM assistant memory and personalization, these problems open up from a different angle: modern LLM users do not need to pre-prompt the description of their persona since the model already knows their socio-demographics.
- Africa > Middle East > Egypt > Cairo Governorate > Cairo (0.04)
- North America > United States > Florida > Miami-Dade County > Miami (0.04)
- North America > United States > Colorado > Denver County > Denver (0.04)
- (8 more...)
- Education > Curriculum > Subject-Specific Education (0.68)
- Government (0.68)
Examining the legibility of humanoid robot arm movements in a pointing task
Lúčny, Andrej, Antonj, Matilde, Mazzola, Carlo, Hornáčková, Hana, Farić, Ana, Malinovská, Kristína, Vavrecka, Michal, Farkaš, Igor
Human--robot interaction requires robots whose actions are legible, allowing humans to interpret, predict, and feel safe around them. This study investigates the legibility of humanoid robot arm movements in a pointing task, aiming to understand how humans predict robot intentions from truncated movements and bodily cues. We designed an experiment using the NICO humanoid robot, where participants observed its arm movements towards targets on a touchscreen. Robot cues varied across conditions: gaze, pointing, and pointing with congruent or incongruent gaze. Arm trajectories were stopped at 60\% or 80\% of their full length, and participants predicted the final target. We tested the multimodal superiority and ocular primacy hypotheses, both of which were supported by the experiment.
- Europe > Italy > Liguria > Genoa (0.05)
- Europe > Spain > Catalonia > Barcelona Province > Barcelona (0.04)
- Europe > Slovenia > Central Slovenia > Municipality of Ljubljana > Ljubljana (0.04)
- Europe > Slovakia > Bratislava > Bratislava (0.04)
Bridging the Theoretical Gap in Randomized Smoothing
Delattre, Blaise, Caillon, Paul, Barthélemy, Quentin, Fagnou, Erwan, Allauzen, Alexandre
Randomized smoothing has become a leading approach for certifying adversarial robustness in machine learning models. However, a persistent gap remains between theoretical certified robustness and empirical robustness accuracy. This paper introduces a new framework that bridges this gap by leveraging Lipschitz continuity for certification and proposing a novel, less conservative method for computing confidence intervals in randomized smoothing. Our approach tightens the bounds of certified robustness, offering a more accurate reflection of model robustness in practice. Through rigorous experimentation we show that our method improves the robust accuracy, compressing the gap between empirical findings and previous theoretical results. We argue that investigating local Lipschitz constants and designing ad-hoc confidence intervals can further enhance the performance of randomized smoothing. These results pave the way for a deeper understanding of the relationship between Lipschitz continuity and certified robustness.
- Europe > France > Île-de-France > Paris > Paris (0.04)
- Europe > United Kingdom > England > Oxfordshire > Oxford (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- Asia > Thailand (0.04)