Europe
Tempered Guided Diffusion
Makris, Andreas, Fearnhead, Paul, Nemeth, Chris
Training-free conditional diffusion provides a flexible alternative to task-specific conditional model training, but existing samplers often allocate computation inefficiently: independent guided trajectories can vary widely in quality, and additional function evaluations along a single trajectory may not recover from poor early decisions. We propose Tempered Guided Diffusion (TGD), an annealed sequential Monte Carlo framework for training-free conditional sampling with diffusion priors. TGD targets tempered posterior distributions over the clean signal, using noisy diffusion states only as auxiliary variables for proposing reconstructions and propagating particles. Particles are reweighted by incremental likelihood ratios, resampled, and propagated across noise levels, concentrating computation on trajectories plausible under both the prior and observation. Under idealized exact-reconstruction assumptions, full TGD yields a consistent particle approximation to the posterior as the number of particles grows. For expensive reconstruction tasks, Accelerated TGD (A-TGD) retains early particle exploration but prunes to a single high-likelihood trajectory partway through sampling. Experiments on a controlled two-dimensional inverse problem and image inverse problems show improved posterior approximation and favorable wall-clock speed-quality tradeoffs over independent multi-trajectory baselines.
Vanishing L2 regularization for the softmax Multi Armed Bandit
Anita, Stefana-Lucia, Turinici, Gabriel
Multi Armed Bandit (MAB) algorithms are a cornerstone of reinforcement learning and have been studied both theoretically and numerically. One of the most commonly used implementation uses a softmax mapping to prescribe the optimal policy and served as the foundation for downstream algorithms, including REINFORCE. Distinct from vanilla approaches, we consider here the L2 regularized softmax policy gradient where a quadratic term is subtracted from the mean reward. Previous studies exploiting convexity failed to identify a suitable theoretical framework to analyze its convergence when the regularization parameter vanishes. We prove here theoretical convergence results and confirm empirically that this regime makes the L2 regularization numerically advantageous on standard benchmarks.
TabSurv: Adapting Modern Tabular Neural Networks to Survival Analysis
Kirpichenko, Stanislav, Konstantinov, Andrei, Utkin, Lev
Survival analysis on tabular data is a well-studied problem. However, existing deep learning methods are often highly task-specific, which can limit the transfer of new approaches from other domains and introduce constraints that may affect performance. We propose TabSurv, an approach that adapts modern tabular architectures to survival analysis using either the Weibull distribution or non-parametric survival prediction. TabSurv optimizes SurvHL, a novel histogram loss function supporting censored data. In addition to a baseline feed-forward network, we implement deep ensembles of MLPs for survival analysis within TabSurv. In contrast to prior work, the ensemble components are trained in parallel, optimizing survival distribution parameters before averaging, which promotes diversity across ensemble component predictions. We perform a comprehensive empirical evaluation of different proposed architectures on 10 diverse real-world survival datasets. Our results show that TabSurv consistently outperforms on average established classical and deep learning baselines, such as RSF, DeepSurv, DeepHit, SurvTRACE. Notably, deep ensembles with Weibull parametrization instead of non-parametric models achieve the highest average rank by C-index. Overall, our study clarifies how modern tabular neural networks can be adapted and trained to tackle survival analysis problems, offering a strong and reliable approach. The TabSurv implementation is publicly available.
Conditional Diffusion Sampling
Castro-Macรญas, Francisco M., Morales-รlvarez, Pablo, Syed, Saifuddin, Hernรกndez-Lobato, Daniel, Molina, Rafael, Hernรกndez-Lobato, Josรฉ Miguel
Sampling from unnormalized multimodal distributions with limited density evaluations remains a fundamental challenge in machine learning and natural sciences. Successful approaches construct a bridge between a tractable reference and the target distribution. Parallel Tempering (PT) serves as the gold standard, while recent diffusion-based approaches offer a continuous alternative at the cost of neural training. In this work, we introduce Conditional Diffusion Sampling (CDS), a framework that combines these two paradigms. To this end, we derive Conditional Interpolants, a class of stochastic processes whose transport dynamics are governed by an exact, closed-form stochastic differential equation (SDE), requiring no neural approximation. Although these dynamics require sampling from a non-trivial initialization distribution, we show both theoretically and empirically that the cost of this initialization diminishes for sufficiently short diffusion times. CDS leverages this by a two-stage procedure: (1) PT is used to efficiently sample the initial distribution, and then (2) samples are transported via the transport SDE. This combination couples the robust global exploration of PT with efficient local transport. Experiments suggest that CDS has the potential to achieve a superior trade-off between sample quality and density evaluation cost compared to state-of-the-art samplers.
New moth species named for Pope Leo
'Pyralis papaleonei' reflects his strong stance on environmental conservation. More information Adding us as a Preferred Source in Google by using this link indicates that you would like to see more of our content in Google News results. The moth appears to be endemic to the island of Crete. Breakthroughs, discoveries, and DIY tips sent six days a week. Pope Leo XIV receives gifts from visitors from all over the world every year, but a newly identified insect may be the first papal tribute of its kind.
US to safety test new AI models from Google, Microsoft, xAI
New artificial intelligence (AI) tools and capabilities from Google, Microsoft and xAI will now be tested by the US Department of Commerce before they are released to the public. The tech firms have agreed to voluntarily submit their models for testing through Commerce's Center for AI Standards and Innovation (CAISI). The new pacts are an expansion on agreements by AI companies like OpenAI and Anthropic that were reached during the Biden Administration, and will see AI models from all of the companies evaluated for their capabilities and security. These expanded industry collaborations help us scale our work in the public interest at a critical moment, CAISI's director Chris Fall said. Overall, the evaluations of the AI tools will cover testing, collaborative research and best practice development related to commercial AI systems.
Ukraine, Russia exchange drone strikes ahead of V-Day 'ceasefire'
Ukraine strikes multiple sites in Moscow, following Russia's strikes on a Ukrainian gas production facility that killed at least 5 people. This escalation comes after each side announced a ceasefire - but for different days. West Bengal Chief refuses to resign after'dirty' election Hegseth says US'hasn't capitulated on anything' regarding Iran Smotrich says he promised his son'more destruction' in Lebanon Hegseth says US blockade on Iran'gift to the world'
Backlash builds over NHS plan to hide source code from AI hacking risk
NHS England is pulling its open-source software from the internet because of fears around computer-hacking AI models like Mythos. A decision by NHS England to withdraw open-source code created with UK taxpayer funds because of the risk posed by computer-hacking AI models is attracting growing backlash. Last month, Mythos, an AI created by technology firm Anthropic, was widely reported to be capable of discovering flaws in virtually any software, potentially allowing hackers to break into systems running it. NHS England has now told staff that existing and future software must be pulled from public view and kept behind closed doors by 11 May because of this risk. The decision goes against the NHS service standard, which requires that staff make any software they produce open-source so that tools can be built upon, improved and used without the need for duplicated effort.
The Italian Dubbing of 'The Devil Wears Prada 2' Has Stirred Up a Surprising Controversy
The voice actors from the original film have returned for the sequel--and not everyone is happy about it. One thing is certain about: The ambitious undertaking of making a sequel of a cult status film after 20 years has succeeded, at least as far as box office figures are concerned. The numbers speak for themselves, with $77 million generated in US theaters and another $157 million in the rest of the world since its April 29 release. In the face of such a box office smash, this installment has inspired heated debates for days about its quality and comparisons to the original. In Italy, those arguments even extend to the dubbing of the film. The controversy stems from the choice of voice actors in the Italian version of, who are themselves a nod to continuity; it's the same cast as the original.
Robotically assembled building blocks could make construction more efficient and sustainable
Robotically assembled building blocks could be a more environmentally friendly method for erecting large-scale structures than some existing construction techniques, according to a new study by MIT researchers. The team conducted a feasibility study to evaluate the efficiency of constructing a simple building using "voxels," which are modular 3D subunits that assemble into complex, durable structures. After studying the performance of multiple voxels, the researchers developed three new designs intended to streamline building construction. They also produced a robotic assembler and a user-friendly interface for generating voxel-based building layouts and feeding instructions to the robots. Their results indicate this voxel-based robotic assembly system could reduce embodied carbon -- all of the carbon emitted during the lifecycle of building materials -- by as much as 82 percent, compared with popular techniques like 3D concrete printing, precast modular concrete, and steel framing.