Energy
Robust Sampling for Active Statistical Inference
Li, Puheng, Zrnic, Tijana, Candès, Emmanuel
Collecting high-quality labeled data remains a challenge in data-driven research, especially when each label is costly and time-consuming to obtain. In response, many fields have embraced machine learning as a practical solution for predicting unobserved labels, such as annotating satellite imagery in remote sensing [46] and predicting protein structures in proteomics [24]. Prediction-powered inference [1] is a methodological framework showing how to perform valid statistical inference despite the inherent biases in such predicted labels. Active statistical inference [51] was recently introduced to further enhance inference by actively selecting which data points to label. The basic idea is to compute the model's uncertainty scores for all data points and prioritize collecting those labels for which the predictive model is most uncertain. When the uncertainty scores appropriately reflect the model's errors, Zrnic and Cand` es [51] show that active inference can significantly outperform prediction-powered inference (which can essentially be thought of as active inference with naive uniform sampling), meaning it results in more accurate estimates and narrower confidence intervals. However, when uncertainty scores are of poor quality, active inference can result in overly noisy estimates and large confidence intervals.
A star unleashed a planet-destroying flare
It's the first coronal mass ejection seen outside our sun. Breakthroughs, discoveries, and DIY tips sent every weekday. Skygazers can once again thank the sun for the latest round of Northern Lights that recently danced above much of the United States. Also known as the aurora borealis in the north, (or aurora australis in the Southern Hemisphere) these night sky events get their start on the sun's surface after coronal mass ejections (CMEs) spew ionized clouds of high energy particles towards Earth. The radiation then interacts with the planet's magnetosphere and generates the vivid colors in Earth's atmosphere-as well as the occasional electrical grid and satellite array headache .
Climate-sceptic IPA refuses to reveal funders in fiery Senate inquiry
Gina Rinehart is an honorary life member of the IPA and'a generous contributor to many causes,' IPA executive director, Scott Hargreaves, says. Gina Rinehart is an honorary life member of the IPA and'a generous contributor to many causes,' IPA executive director, Scott Hargreaves, says. Australia's richest person, Gina Rinehart has previously donated to Institute of Public Affairs but thinktank won't say if she remains a donor A thinktank known for its rejection of the climate crisis and a conservation group that has opposed renewable energy projects refused to identify their funders during a fiery Senate inquiry into climate and energy misinformation on Wednesday. Chair of the committee, Greens senator Peter Whish-Wilson, asked Rainforest Reserves Australia's vice-president, Steven Nowakowski, who had funded nine full-page newspaper advertisements promoting an open letter attacking a shift to renewable energy and promoting nuclear. Nowakowski said they were paid for by donations, some coming from the signatories of the letter, but would not name them.
FlowTIE: Flow-based Transport of Intensity Equation for Phase Gradient Estimation from 4D-STEM Data
Bangun, Arya, Töllner, Maximilian, Zhao, Xuan, Kübel, Christian, Scharr, Hanno
We introduce FlowTIE, a neural-network-based framework for phase reconstruction from 4D-Scanning Transmission Electron Microscopy (STEM) data, which integrates the Transport of Intensity Equation (TIE) with a flow-based representation of the phase gradient. This formulation allows the model to bridge data-driven learning with physics-based priors, improving robustness under dynamical scattering conditions for thick specimen. The validation on simulated datasets of crystalline materials, benchmarking to classical TIE and gradient-based optimization methods are presented. The results demonstrate that FlowTIE improves phase reconstruction accuracy, fast, and can be integrated with a thick specimen model, namely multislice method.
Accelerating Visual-Policy Learning through Parallel Differentiable Simulation
You, Haoxiang, Liu, Yilang, Abraham, Ian
In this work, we propose a computationally efficient algorithm for visual policy learning that leverages differentiable simulation and first-order analytical policy gradients. Our approach decouple the rendering process from the computation graph, enabling seamless integration with existing differentiable simulation ecosystems without the need for specialized differentiable rendering software. This decoupling not only reduces computational and memory overhead but also effectively attenuates the policy gradient norm, leading to more stable and smoother optimization. We evaluate our method on standard visual control benchmarks using modern GPU-accelerated simulation. Experiments show that our approach significantly reduces wall-clock training time and consistently outperforms all baseline methods in terms of final returns. Notably, on complex tasks such as humanoid locomotion, our method achieves a $4\times$ improvement in final return, and successfully learns a humanoid running policy within 4 hours on a single GPU.
Towards High Resolution Probabilistic Coastal Inundation Forecasting from Sparse Observations
Islam, Kazi Ashik, Mehrab, Zakaria, Halappanavar, Mahantesh, Mortveit, Henning, Katragadda, Sridhar, Loftis, Jon Derek, Hoops, Stefan, Marathe, Madhav
Coastal flooding poses increasing threats to communities worldwide, necessitating accurate and hyper-local inundation forecasting for effective emergency response. However, real-world deployment of forecasting systems is often constrained by sparse sensor networks, where only a limited subset of locations may have sensors due to budget constraints. To approach this challenge, we present DIFF -SPARSE, a masked conditional diffusion model designed for probabilistic coastal inundation forecasting from sparse sensor observations. DIFF -SPARSE primarily utilizes the inundation history of a location and its neighboring locations from a context time window as spatiotemporal context. The fundamental challenge of spatiotemporal prediction based on sparse observations in the context window is addressed by introducing a novel masking strategy during training. Digital elevation data and temporal co-variates are utilized as additional spatial and temporal contexts, respectively. A convolutional neural network and a conditional UNet architecture with cross-attention mechanism are employed to capture the spatiotemporal dynamics in the data. We trained and tested DIFF -SPARSE on coastal inundation data from the Eastern Shore of Virginia and systematically assessed the performance of DIFF -SPARSE across different sparsity levels 0%, 50%, 95% missing observations. Our experiment results show that DIFF -SPARSE achieves upto 62% improvement in terms of two forecasting performance metrics compared to existing methods, at 95% sparsity level. Moreover, our ablation studies reveal that digital elevation data becomes more useful at high sparsity levels compared to temporal co-variates.
Revealing the Hidden Third Dimension of Point Defects in Two-Dimensional MXenes
Guinan, Grace, Smeaton, Michelle A., Wyatt, Brian C., Goldy, Steven, Egan, Hilary, Glaws, Andrew, Tucker, Garritt J., Anasori, Babak, Spurgeon, Steven R.
Point defects govern many important functional properties of two - dimensional ( 2D) materials. However, resolving the three - dimensional (3D) arrangement of these defects in multi - layer 2D materials remains a fundamental challenge, hindering rational defect engineering . Our approach reconstructs the 3D coordinates of vacancies across hundreds of thousands of lattice sites, generating robust statistical insight into their dist ribution that can be correlated with specinullic synthesis pathways. This large - scale data enables us to classify a hierarchy of defect structures -- from isolated vacancies to nanopores -- revealing their preferred formation and interaction mechanisms, as corroborated by molecular dynamics simulations . This work provides a generalizable framework for understanding and ultimately controlling point defects across large volumes, paving the way for the rational design of defect - engineered functional 2D materials. Keywords: 2D materials, point defects, autonomous materials science, electron microscopy, machine learning 2 Two - dimensional (2D) materials have become a major nullield of modern research in materials science after the discovery of graphene in 2004 . The challenge of characterizing point defects is signinullicantly amplinullied in few - layered 2D materials. For instance, MXenes -- a class of 2D transition metal carbides, carbonitrides, and nitrides -- consist of nanosheets containing two to nullive layers of metal ato ms, which complicates defect analysis compared to single - layer materials .
Learning Omnidirectional Locomotion for a Salamander-Like Quadruped Robot
Liu, Zhiang, Liu, Yang, Fang, Yongchun, Guo, Xian
Salamander-like quadruped robots are designed inspired by the skeletal structure of their biological counterparts. However, existing controllers cannot fully exploit these morphological features and largely rely on predefined gait patterns or joint trajectories, which prevents the generation of diverse and flexible locomotion and limits their applicability in real-world scenarios. In this paper, we propose a learning framework that enables the robot to acquire a diverse repertoire of omnidirectional gaits without reference motions. Each body part is controlled by a phase variable capable of forward and backward evolution, with a phase coverage reward to promote the exploration of the leg phase space. Additionally, morphological symmetry of the robot is incorporated via data augmentation, improving sample efficiency and enforcing both motion-level and task-level symmetry in learned behaviors. Extensive experiments show that the robot successfully acquires 22 omnidirectional gaits exhibiting both dynamic and symmetric movements, demonstrating the effectiveness of the proposed learning framework.
Multi-Agent GraphRAG: A Text-to-Cypher Framework for Labeled Property Graphs
Gusarov, Anton, Volkova, Anastasia, Khrulkov, Valentin, Kuznetsov, Andrey, Maslov, Evgenii, Oseledets, Ivan
While Retrieval-Augmented Generation (RAG) methods commonly draw information from unstructured documents, the emerging paradigm of GraphRAG aims to leverage structured data such as knowledge graphs. Most existing GraphRAG efforts focus on Resource Description Framework (RDF) knowledge graphs, relying on triple representations and SP ARQL queries. However, the potential of Cypher and Labeled Property Graph (LPG) databases to serve as scalable and effective reasoning engines within GraphRAG pipelines remains underexplored in current research literature. To fill this gap, we propose Multi-Agent GraphRAG, a modular LLM agentic system for text-to-Cypher query generation serving as a natural language interface to LPG-based graph data. Our proof-of-concept system features an LLMbased workflow for automated Cypher queries generation and execution, using Memgraph as the graph database backend. Iterative content-aware correction and normalization, reinforced by an aggregated feedback loop, ensures both semantic and syntactic refinement of generated queries. We evaluate our system on the CypherBench graph dataset covering several general domains with diverse types of queries. In addition, we demonstrate performance of the proposed workflow on a property graph derived from the IFC (Industry Foundation Classes) data, representing a digital twin of a building. This highlights how such an approach can bridge AI with real-world applications at scale, enabling industrial digital automation use cases.
ParliaBench: An Evaluation and Benchmarking Framework for LLM-Generated Parliamentary Speech
Koniaris, Marios, Tsipi, Argyro, Tsanakas, Panayiotis
Parliamentary speech generation presents specific challenges for large language models beyond standard text generation tasks. Unlike general text generation, parliamentary speeches require not only linguistic quality but also political authenticity and ideological consistency. Current language models lack specialized training for parliamentary contexts, and existing evaluation methods focus on standard NLP metrics rather than political authenticity. To address this, we present ParliaBench, a benchmark for parliamentary speech generation. We constructed a dataset of speeches from UK Parliament to enable systematic model training. We introduce an evaluation framework combining computational metrics with LLM-as-a-judge assessments for measuring generation quality across three dimensions: linguistic quality, semantic coherence, and political authenticity. We propose two novel embedding-based metrics, Political Spectrum Alignment and Party Alignment, to quantify ideological positioning. We fine-tuned five large language models (LLMs), generated 28k speeches, and evaluated them using our framework, comparing baseline and fine-tuned models. Results show that fine-tuning produces statistically significant improvements across the majority of metrics and our novel metrics demonstrate strong discriminative power for political dimensions.