Energy
'It Was Nuts': The Extreme Tests that Show Why Hail Is a Multibillion-Dollar Problem
'It Was Nuts': The Extreme Tests that Show Why Hail Is a Multibillion-Dollar Problem The costs of a hail damage have ballooned over the past two decades, prompting researchers to resort to extreme measures to understand how these storms destroy buildings. The scars left on houses look like shotgun blasts, sometimes. In the aftermath of major storms, Andrew Shick, owner and chief executive of Illinois-based firm Roofing USA, has driven through suburbs blasted by hail and been left stunned by the damage. Earlier this year, he visited a farm complex in western Illinois where roofs, even sturdy metal ones, were left pockmarked and perforated after 3-inch balls of ice fell from the sky. "It was nuts," he recalls.
How one controversial startup hopes to cool the planet
And why many scientists are freaked out about the first serious for-profit company moving into the solar geoengineering field. Stardust Solutions believes that it can solve climate change--for a price. The Israel-based geoengineering startup has said it expects nations will soon pay it more than a billion dollars a year to launch specially equipped aircraft into the stratosphere. Once they've reached the necessary altitude, those planes will disperse particles engineered to reflect away enough sunlight to cool down the planet, purportedly without causing environmental side effects. The proprietary (and still secret) particles could counteract all the greenhouse gases the world has emitted over the last 150 years, the company stated in a 2023 pitch deck it presented to venture capital firms. In fact, it's the "only technologically feasible solution" to climate change, the company said. The company disclosed it raised $60 million in funding in October, marking by far the largest known funding round to date for a startup working on solar geoengineering.
Fourier-Enhanced Recurrent Neural Networks for Electrical Load Time Series Downscaling
Abstract--We present a Fourier-enhanced recurrent neural network (RNN) for downscaling electrical loads. The model combines (i) a recurrent backbone driven by low-resolution inputs, (ii) explicit Fourier seasonal embeddings fused in latent space, and (iii) a self-attention layer that captures dependencies among high-resolution components within each period. Energy policy and infrastructure investment decisions require an integrated system-wide perspective that captures the interdependencies of supply, conversion, and end-use sectors, as well as feedback from macroeconomic, technology-cost, and policy drivers. Many such energy modeling systems exist [1], of which the National Energy Modeling System (NEMS), developed by the U.S. Energy Information Administration (EIA) [2], is widely used by policymakers and stakeholders for this very reason. However, as noted in the study of energy plant pollution studies provided by NEMS [3], using temporally and spatially averaged data may significantly miss essential features and pricing signals.
Non Normalized Shared-Constraint Dynamic Games for Human-Robot Collaboration with Asymmetric Responsibility
Pustilnik, Mark, Borrelli, Francesco
Dynamic games is emerging as a prominent and very natural tool that can overcome the shortages of other techniques. If the players are two humans weighted equally, the solution will have different characteristics relative to a human-robot interaction where the robot abilities and effort could be very different. In many scenarios, humans move naturally with minimal attention to constraints, while robots must take on most of the responsibility for enforcing safety boundaries such as collision avoidance or required proximity limits. Classical control approaches typically enforce constraints centrally or assume symmetric responsibility, which does not reflect the inherent asymmetry of human-robot interaction (HRI). In this paper, we propose a dynamic game formulation in which a human and a robot jointly satisfy safety constraints while pursuing a common task.
LiDAS: Lighting-driven Dynamic Active Sensing for Nighttime Perception
de Moreau, Simon, Bursuc, Andrei, El-Idrissi, Hafid, Moutarde, Fabien
Nighttime environments pose significant challenges for camera-based perception, as existing methods passively rely on the scene lighting. We introduce Lighting-driven Dynamic Active Sensing (LiDAS), a closed-loop active illumination system that combines off-the-shelf visual perception models with high-definition headlights. Rather than uniformly brightening the scene, LiDAS dynamically predicts an optimal illumination field that maximizes downstream perception performance, i.e., decreasing light on empty areas to reallocate it on object regions. LiDAS enables zero-shot nighttime generalization of daytime-trained models through adaptive illumination control. Trained on synthetic data and deployed zero-shot in real-world closed-loop driving scenarios, LiDAS enables +18.7% mAP50 and +5.0% mIoU over standard low-beam at equal power. It maintains performances while reducing energy use by 40%. LiDAS complements domain-generalization methods, further strengthening robustness without retraining. By turning readily available headlights into active vision actuators, LiDAS offers a cost-effective solution to robust nighttime perception.
Forecasting Fails: Unveiling Evasion Attacks in Weather Prediction Models
Arif, Huzaifa, Chen, Pin-Yu, Gittens, Alex, Diffenderfer, James, Kailkhura, Bhavya
With the increasing reliance on AI models for weather forecasting, it is imperative to evaluate their vulnerability to adversarial perturbations. This work introduces Weather Adaptive Adversarial Perturbation Optimization (W AAPO), a novel framework for generating targeted adversarial perturbations that are both effective in manipulating forecasts and stealthy to avoid detection. W AAPO achieves this by incorporating constraints for channel sparsity, spatial localization, and smoothness, ensuring that perturbations remain physically realistic and imperceptible. Using the ERA5 dataset and FourCastNet (Pathak et al. 2022), we demonstrate W AAPO's ability to generate adversarial trajectories that align closely with predefined targets, even under constrained conditions. Our experiments highlight critical vulnerabilities in AI-driven forecasting models, where small perturbations to initial conditions can result in significant deviations in predicted weather patterns. These findings underscore the need for robust safeguards to protect against adversarial exploitation in operational forecasting systems. The code for W AAPO is available at: https://github.com/Huzaifa-Arif/W
Gradient-Informed Monte Carlo Fine-Tuning of Diffusion Models for Low-Thrust Trajectory Design
Graebner, Jannik, Beeson, Ryne
Preliminary mission design of low-thrust spacecraft trajectories in the Circular Restricted Three-Body Problem is a global search characterized by a complex objective landscape and numerous local minima. Formulating the problem as sampling from an unnormalized distribution supported on neighborhoods of locally optimal solutions, provides the opportunity to deploy Markov chain Monte Carlo methods and generative machine learning. In this work, we extend our previous self-supervised diffusion model fine-tuning framework to employ gradient-informed Markov chain Monte Carlo. We compare two algorithms - the Metropolis-Adjusted Langevin Algorithm and Hamiltonian Monte Carlo - both initialized from a distribution learned by a diffusion model. Derivatives of an objective function that balances fuel consumption, time of flight and constraint violations are computed analytically using state transition matrices. We show that incorporating the gradient drift term accelerates mixing and improves convergence of the Markov chain for a multi-revolution transfer in the Saturn-Titan system. Among the evaluated methods, MALA provides the best trade-off between performance and computational cost. Starting from samples generated by a baseline diffusion model trained on a related transfer, MALA explicitly targets Pareto-optimal solutions. Compared to a random walk Metropolis algorithm, it increases the feasibility rate from 17.34% to 63.01% and produces a denser, more diverse coverage of the Pareto front. By fine-tuning a diffusion model on the generated samples and associated reward values with reward-weighted likelihood maximization, we learn the global solution structure of the problem and eliminate the need for a tedious separate data generation phase.
Sim2Swim: Zero-Shot Velocity Control for Agile AUV Maneuvering in 3 Minutes
Fosso, Lauritz Rismark, Amundsen, Herman Biørn, Xanthidis, Marios, Ohrem, Sveinung Johan
Holonomic autonomous underwater vehicles (AUVs) have the hardware ability for agile maneuvering in both translational and rotational degrees of freedom (DOFs). However, due to challenges inherent to underwater vehicles, such as complex hydrostatics and hydrodynamics, parametric uncertainties, and frequent changes in dynamics due to payload changes, control is challenging. Performance typically relies on carefully tuned controllers targeting unique platform configurations, and a need for re-tuning for deployment under varying payloads and hydrodynamic conditions. As a consequence, agile maneuvering with simultaneous tracking of time-varying references in both translational and rotational DOFs is rarely utilized in practice. To the best of our knowledge, this paper presents the first general zero-shot sim2real deep reinforcement learning-based (DRL) velocity controller enabling path following and agile 6DOF maneuvering with a training duration of just 3 minutes. Sim2Swim, the proposed approach, inspired by state-of-the-art DRL-based position control, leverages domain randomization and massively parallelized training to converge to field-deployable control policies for AUVs of variable characteristics without post-processing or tuning. Sim2Swim is extensively validated in pool trials for a variety of configurations, showcasing robust control for highly agile motions.
Magneton: Optimizing Energy Efficiency of ML Systems via Differential Energy Debugging
Pan, Yi, Qian, Wenbo, Xie, Dedong, Hu, Ruiyan, Hu, Yigong, Kasikci, Baris
The training and deployment of machine learning (ML) models have become extremely energy-intensive. While existing optimization efforts focus primarily on hardware energy efficiency, a significant but overlooked source of inefficiency is software energy waste caused by poor software design. This often includes redundant or poorly designed operations that consume more energy without improving performance. These inefficiencies arise in widely used ML frameworks and applications, yet developers often lack the visibility and tools to detect and diagnose them. We propose differential energy debugging, a novel approach that leverages the observation that competing ML systems often implement similar functionality with vastly different energy consumption. Building on this insight, we design and implement Magneton, an energy profiler that compares energy consumption between similar ML systems at the operator level and automatically pinpoints code regions and configuration choices responsible for excessive energy use. Applied to 9 popular ML systems spanning LLM inference, general ML frameworks, and image generation, Magneton detects and diagnoses 16 known cases of software energy inefficiency and further discovers 8 previously unknown cases, 7 of which have been confirmed by developers.
Geometry-Aware Sparse Depth Sampling for High-Fidelity RGB-D Depth Completion in Robotic Systems
Salloom, Tony, Zhou, Dandi, Sun, Xinhai
Accurate three-dimensional perception is essential for modern industrial robotic systems that perform manipulation, inspection, and navigation tasks. RGB-D and stereo vision sensors are widely used for this purpose, but the depth maps they produce are often noisy, incomplete, or biased due to sensor limitations and environmental conditions. Depth completion methods aim to generate dense, reliable depth maps from RGB images and sparse depth input. However, a key limitation in current depth completion pipelines is the unrealistic generation of sparse depth: sparse pixels are typically selected uniformly at random from dense ground-truth depth, ignoring the fact that real sensors exhibit geometry-dependent and spatially nonuniform reliability. In this work, we propose a normal-guided sparse depth sampling strategy that leverages PCA-based surface normal estimation on the RGB-D point cloud to compute a per-pixel depth reliability measure. The sparse depth samples are then drawn according to this reliability distribution. We integrate this sampling method with the Marigold-DC diffusion-based depth completion model and evaluate it on NYU Depth v2 using the standard metrics. Experiments show that our geometry-aware sparse depth improves accuracy, reduces artifacts near edges and discontinuities, and produces more realistic training conditions that better reflect real sensor behavior.