Goto

Collaborating Authors

 Country


Advances in Diffusion-Based Generative Compression

arXiv.org Machine Learning

Popularized by their strong image generation performance, diffusion and related methods for generative modeling have found widespread success in visual media applications. In particular, diffusion methods have enabled new approaches to data compression, where realistic reconstructions can be generated at extremely low bit-rates. This article provides a unifying review of recent diffusion-based methods for generative lossy compression, with a focus on image compression. These methods generally encode the source into an embedding and employ a diffusion model to iteratively refine it in the decoding procedure, such that the final reconstruction approximately follows the ground truth data distribution. The embedding can take various forms and is typically transmitted via an auxiliary entropy model, and recent methods also explore the use of diffusion models themselves for information transmission via channel simulation. We review representative approaches through the lens of rate-distortion-perception theory, highlighting the role of common randomness and connections to inverse problems, and identify open challenges.


Implicit Q-Learning and SARSA: Liberating Policy Control from Step-Size Calibration

arXiv.org Machine Learning

Q-learning and SARSA are foundational reinforcement learning algorithms whose practical success depends critically on step-size calibration. Step-sizes that are too large can cause numerical instability, while step-sizes that are too small can lead to slow progress. We propose implicit variants of Q-learning and SARSA that reformulate their iterative updates as fixed-point equations. This yields an adaptive step-size adjustment that scales inversely with feature norms, providing automatic regularization without manual tuning. Our non-asymptotic analyses demonstrate that implicit methods maintain stability over significantly broader step-size ranges. Under favorable conditions, it permits arbitrarily large step-sizes while achieving comparable convergence rates. Empirical validation across benchmark environments spanning discrete and continuous state spaces shows that implicit Q-learning and SARSA exhibit substantially reduced sensitivity to step-size selection, achieving stable performance with step-sizes that would cause standard methods to fail.


Statistical Inference for Explainable Boosting Machines

arXiv.org Machine Learning

Explainable boosting machines (EBMs) are popular "glass-box" models that learn a set of univariate functions using boosting trees. These achieve explainability through visualizations of each feature's effect. However, unlike linear model coefficients, uncertainty quantification for the learned univariate functions requires computationally intensive bootstrapping, making it hard to know which features truly matter. We provide an alternative using recent advances in statistical inference for gradient boosting, deriving methods for statistical inference as well as end-to-end theoretical guarantees. Using a moving average instead of a sum of trees (Boulevard regularization) allows the boosting process to converge to a feature-wise kernel ridge regression. This produces asymptotically normal predictions that achieve the minimax-optimal mean squared error for fitting Lipschitz GAMs with $p$ features at rate $O(pn^{-2/3})$, successfully avoiding the curse of dimensionality. We then construct prediction intervals for the response and confidence intervals for each learned univariate function with a runtime independent of the number of datapoints, enabling further explainability within EBMs.


Time series forecasting with Hahn Kolmogorov-Arnold networks

arXiv.org Machine Learning

Recent Transformer- and MLP-based models have demonstrated strong performance in long-term time series forecasting, yet Transformers remain limited by their quadratic complexity and permutation-equivariant attention, while MLPs exhibit spectral bias. We propose HaKAN, a versatile model based on Kolmogorov-Arnold Networks (KANs), leveraging Hahn polynomial-based learnable activation functions and providing a lightweight and interpretable alternative for multivariate time series forecasting. Our model integrates channel independence, patching, a stack of Hahn-KAN blocks with residual connections, and a bottleneck structure comprised of two fully connected layers. The Hahn-KAN block consists of inter- and intra-patch KAN layers to effectively capture both global and local temporal patterns. Extensive experiments on various forecasting benchmarks demonstrate that our model consistently outperforms recent state-of-the-art methods, with ablation studies validating the effectiveness of its core components.


A Generalized Adaptive Joint Learning Framework for High-Dimensional Time-Varying Models

arXiv.org Machine Learning

In modern biomedical and econometric studies, longitudinal processes are often characterized by complex time-varying associations and abrupt regime shifts that are shared across correlated outcomes. Standard functional data analysis (FDA) methods, which prioritize smoothness, often fail to capture these dynamic structural features, particularly in high-dimensional settings. This article introduces Adaptive Joint Learning (AJL), a hierarchical regularization framework designed to integrate functional variable selection with structural changepoint detection in multivariate time-varying coefficient models. Unlike standard simultaneous estimation approaches, we propose a theoretically grounded two-stage screening-and-refinement procedure. This framework first synergizes adaptive group-wise penalization with sure screening principles to robustly identify active predictors, followed by a refined fused regularization step that effectively borrows strength across multiple outcomes to detect local regime shifts. We provide a rigorous theoretical analysis of the estimator in the ultra-high-dimensional regime (p >> n). Crucially, we establish the sure screening consistency of the first stage, which serves as the foundation for proving that the refined estimator achieves the oracle property-performing as well as if the true active set and changepoint locations were known a priori. A key theoretical contribution is the explicit handling of approximation bias via undersmoothing conditions to ensure valid asymptotic inference. The proposed method is validated through comprehensive simulations and an application to Sleep-EDF data, revealing novel dynamic patterns in physiological states.


Fine Tuning a Simulation-Driven Estimator

arXiv.org Machine Learning

Many industries now deploy high-fidelity simulators (digital twins) to represent physical systems, yet their parameters must be calibrated to match the true system. This motivated the construction of simulation-driven parameter estimators, built by generating synthetic observations for sampled parameter values and learning a supervised mapping from observations to parameters. However, when the true parameters lie outside the sampled range, predictions suffer from an out-of-distribution (OOD) error. This paper introduces a fine-tuning approach for the Two-Stage estimator that mitigates OOD effects and improves accuracy. The effectiveness of the proposed method is verified through numerical simulations.


Mark Zuckerberg was initially opposed to parental controls for AI chatbots, according to legal filing

Engadget

Apple could unveil Gemini-powered Siri in Feb. Despite not wanting minors to have explicit conversations, Meta's CEO allegedly rejected this particular safety measure. Meta has faced some serious questions about how it allows its underage users to interact with AI-powered chatbots. Most recently, internal communications obtained by the New Mexico Attorney General's Office revealed that although Meta CEO Mark Zuckerberg was opposed to the chatbots having explicit conversations with minors, he also rejected the idea of placing parental controls on the feature. In its statement to the publication, Meta accused the New Mexico Attorney General of cherry picking documents to paint a flawed and inaccurate picture.


After Minneapolis shootings, California moves forward bill allowing lawsuits against federal agents

Los Angeles Times

Things to Do in L.A. Tap to enable a layout that focuses on the article. Residents confront ICE agents on Atlantic Blvd. in the city of Bell in June. This is read by an automated voice. Please report any issues or inconsistencies here . SACRAMENTO -- Amid a national uproar over the recent killing of a Minnesota man by immigration agents, the California Senate on Tuesday approved proposed legislation that would make it easier to sue law enforcement officials suspected of violating an individual's constitutional rights.


Meta allowed minors access to sex-talking chatbots despite staff concerns, lawsuit alleges

The Guardian

Filing by New Mexico's attorney general includes Meta staff emails objecting to AI companion policy Mark Zuckerberg, Meta's chief executive, approved allowing minors to access artificial intelligence chatbot companions that safety staffers warned were capable of sexual interactions, according to internal Meta documents filed in a New Mexico state court case and made public on Monday. The lawsuit - brought by the state's attorney general, Raul Torrez, and scheduled for trial next month - alleges Meta "failed to stem the tide of damaging sexual material and sexual propositions delivered to children" on Facebook and Instagram. The filing on Monday included internal Meta employee emails and messages obtained by the New Mexico attorney general's office through legal discovery. The state alleges they show that "Meta, driven by Zuckerberg, rejected the recommendations of its integrity staff and declined to impose reasonable guardrails to prevent children from being subject to sexually exploitative conversations with its AI chatbots", the attorney general said in the filing. Meta announced last week that it had removed teen access to AI companions entirely, pending creation of a new version of the chatbots.


NASA jet erupts in flames as it skids down runway at Houston airport

Daily Mail - Science & tech

America's fastest-growing state is selling the perfect lifestyle... and everyone's falling for it I was using my vape 160 times a day, it was costing me a fortune and its toll on my face was truly shocking. Then I discovered a miracle one-day cure... and stopped overnight: MARY KILLEN Lost tomb of the mysterious'cloud people' unearthed after 1,400 years in'discovery of the decade' Devastating truth about Blind Side actor Quinton Aaron: More to this'than everyone is letting on', friends reveal... as co-star Sandra Bullock'monitors' situation Harper Beckham, 14, puts on a stylish display in a fluffy coat and vintage Chanel bag as she heads out in Paris with her family... after Nicola's Peltz's heartbreaking comments about sister-in-law America's earthquake hotspot is more dangerous than feared as scientists make surprising discovery Terrifying animation shows pilot's-eye view of DC mid-air collision between airliner and helicopter that killed 67 Explosive twist in'diva' inmate Bryan Kohberger's life in prison revealed in the FREE The Crime Desk newsletter Marco Rubio'cocoons like a mummy' in bizarre strategy to hide naps from Trump Lawyer, 44, who died on flight to London after falling asleep on her mother's shoulder had undiagnosed cardiac condition, inquest hears Sydney Sweeney shows off her bombshell curves in racy lingerie to promote her new SYRN line - as it's revealed Hollywood Sign bra stunt could leave her facing trespassing and vandalism charges Truth about America's favorite pasture-raised egg brand after tests revealed what its chickens are eating and sparked huge boycotts A NASA jet skidded across a Houston runway Tuesday after a mechanical failure prevented its landing gear from deploying. Footage from Ellington Airport shows the research aircraft touching down before its belly scraped along the runway, sending sparks and flames trailing behind it. Emergency crews rushed in moments later, helping the pilot exit the aircraft as responders secured the scene, KHOU 11 News reported. NASA confirmed that all crew members are safe.