fst
Optimal Spatio-Temporal Decoupling for Bayesian Conformal Prediction
Online Conformal Prediction (CP) struggles to balance temporal adaptability and structural stability. Feedback-driven methods (e.g., Adaptive Conformal Inference (ACI)) suffer from systemic marginal under-coverage and high interval variance during abrupt shifts, while temporally discounted Bayesian CP suffers from severe structural lag and uncalibrated interval bloat. We propose State-Adaptive Bayesian Conformal Prediction (SA-BCP) to achieve optimal spatio-temporal decoupling. By gating long-term temporal inertia with spatial kernel-density evidence, SA-BCP proactively expands intervals for recognized historical regimes while maintaining tight efficiency during stable states. We rigorously prove this mechanism's optimality, identifying a minimax bias-variance tradeoff governed by an evidence threshold $K$. Extensive benchmarks on volatile financial datasets (2016--2026), including AMD, Gold, and GBP/USD, demonstrate that SA-BCP consistently minimizes the strictly proper Winkler score across diverse confidence levels. Specifically, SA-BCP resolves the systematic under-coverage inherent to ACI variants while simultaneously reducing the uncalibrated interval bloat of Bayesian CP by 10\% to 37\% under high-confidence requests. By elegantly navigating this tradeoff, SA-BCP achieves an optimal balance between conditional reliability and predictive efficiency.
LearningfromFuture: ANovelSelf-Training FrameworkforSemanticSegmentation-SupplementaryMaterial-YeDu1,2 YujunShen3 HaochenWang4 JingjingFei5 WeiLi5 LiweiWu5 RuiZhao5,6 ZehuaFu1,2 QingjieLiu1,2
C provide more ablation studies of our FST, including the ablation on SYNTHIA Cityscapes and evaluation of various segmentation decoders. PASCALVOC2012 [6] consists of21 classes with1,464, 1,449, and 1,456 images for the training, validation, and test set,respectively. Ablation on SYNTHIA.We also provide ablation results on SYNTHIA Cityscapes UDA benchmark andtheresults areshowninTab.S2. The MLP head fuses multi-levelfeatures and upsamples the feature map to predict the segmentation mask, which is designed for Transformer-based segmentation model[36]. We compare our FST with previous state-of-the-art semi-supervised semantic segmentation frameworks, including CCT [22], GCT [16]and CPS [3].
Training
To break through the predicament of seeking supervision only from the past states, we propose future-self-training(FST), which allows the model to learn from itsfuture self. Figure 1b illustrates the concept diagram of our FST. Compared to the conventional ST framework in Figure 1a, which employs thet-step teacher (i.e., updated with the student at moments1,2,...,t 1) to guide the t-step student, FST presents a new training manner by urging thet-step student to learn from the (t+1)-stepteacher.
Phase Transition for Stochastic Block Model with more than $\sqrt{n}$ Communities (II)
Carpentier, Alexandra, Giraud, Christophe, Verzelen, Nicolas
A fundamental theoretical question in network analysis is to determine under which conditions community recovery is possible in polynomial time in the Stochastic Block Model (SBM). When the number $K$ of communities remains smaller than $\sqrt{n}$ --where $n$ denotes the number of nodes--, non-trivial community recovery is possible in polynomial time above, and only above, the Kesten--Stigum (KS) threshold, originally postulated using arguments from statistical physics. When $K \geq \sqrt{n}$, Chin, Mossel, Sohn, and Wein recently proved that, in the \emph{sparse regime}, community recovery in polynomial time is achievable below the KS threshold by counting non-backtracking paths. This finding led them to postulate a new threshold for the many-communities regime $K \geq \sqrt{n}$. Subsequently, Carpentier, Giraud, and Verzelen established the failure of low-degree polynomials below this new threshold across all density regimes, and demonstrated successful recovery above the threshold in certain moderately sparse settings. While these results provide strong evidence that, in the many community setting, the computational barrier lies at the threshold proposed in~Chin et al., the question of achieving recovery above this threshold still remains open in most density regimes. The present work is a follow-up to~Carpentier et al., in which we prove Conjecture~1.4 stated therein by: \\ 1- Constructing a family of motifs satisfying specific structural properties; and\\ 2- Proving that community recovery is possible above the proposed threshold by counting such motifs.\\ Our results complete the picture of the computational barrier for community recovery in the SBM with $K \geq \sqrt{n}$ communities. They also indicate that, in moderately sparse regimes, the optimal algorithms appear to be fundamentally different from spectral methods.
On the Role of Calibration in Benchmarking Algorithmic Fairness for Skin Cancer Detection
Dominique, Brandon, Lam, Prudence, Kurtansky, Nicholas, Weber, Jochen, Kose, Kivanc, Rotemberg, Veronica, Dy, Jennifer
Artificial Intelligence (AI) models have demonstrated expert-level performance in melanoma detection, yet their clinical adoption is hindered by performance disparities across demographic subgroups such as gender, race, and age. Previous efforts to benchmark the performance of AI models have primarily focused on assessing model performance using group fairness metrics that rely on the Area Under the Receiver Operating Characteristic curve (AUROC), which does not provide insights into a model's ability to provide accurate estimates. In line with clinical assessments, this paper addresses this gap by incorporating calibration as a complementary benchmarking metric to AUROC-based fairness metrics. Calibration evaluates the alignment between predicted probabilities and observed event rates, offering deeper insights into subgroup biases. We assess the performance of the leading skin cancer detection algorithm of the ISIC 2020 Challenge on the ISIC 2020 Challenge dataset and the PROVE-AI dataset, and compare it with the second and third place models, focusing on subgroups defined by sex, race (Fitzpatrick Skin Tone), and age. Our findings reveal that while existing models enhance discriminative accuracy, they often over-diagnose risk and exhibit calibration issues when applied to new datasets. This study underscores the necessity for comprehensive model auditing strategies and extensive metadata collection to achieve equitable AI-driven healthcare solutions. All code is publicly available at https://github.com/bdominique/testing_strong_calibration.