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Two Scalable Approaches for Burned-Area Mapping Using U-Net and Landsat Imagery

arXiv.org Artificial Intelligence

Monitoring wildfires is an essential step in minimizing their impact on the planet, understanding the many negative environmental, economic, and social consequences. Recent advances in remote sensing technology combined with the increasing application of artificial intelligence methods have improved real-time, high-resolution fire monitoring. This study explores two proposed approaches based on the U-Net model for automating and optimizing the burned-area mapping process. Denoted 128 and AllSizes (AS), they are trained on datasets with a different class balance by cropping input images to different sizes. They are then applied to Landsat imagery and time-series data from two fire-prone regions in Chile. The results obtained after enhancement of model performance by hyperparameter optimization demonstrate the effectiveness of both approaches. Tests based on 195 representative images of the study area show that increasing dataset balance using the AS model yields better performance. More specifically, AS exhibited a Dice Coefficient (DC) of 0.93, an Omission Error (OE) of 0.086, and a Commission Error (CE) of 0.045, while the 128 model achieved a DC of 0.86, an OE of 0.12, and a CE of 0.12. These findings should provide a basis for further development of scalable automatic burned-area mapping tools.


B-LSTM-MIONet: Bayesian LSTM-based Neural Operators for Learning the Response of Complex Dynamical Systems to Length-Variant Multiple Input Functions

arXiv.org Artificial Intelligence

Rapid surrogate models derived from observational data now substantially reduce the computational cost to solve practical problems like solid mechanics [1], structural health monitoring [2, 3, 4], field problem solutions [5], fault diagnosis [6, 7], medical imaging [8, 9], autonomous driving [10], and power grid simulation [11] A significant challenge in current neural network surrogate models lies in their generalization capability. Addressing this, the foundational work [12] introduced Operator Learning, a novel method aimed at learning the mapping between different function spaces. Building on this, [13] developed the Deep Operator Neural Network (DeepONet), capable of being trained with limited datasets while minimizing generalization errors. This influential research has been applied in various domains, including the prediction of linear instability waves in high-speed boundary layers [14], forecasting power grid's post-fault trajectories [15], learning nonlinear operators in oscillatory function spaces for seismic wave responses [4], and analyzing nanoscale heat transport [16]. Additionally, several advancements of DeepONet have been proposed, such as Bayesian DeepONet [17, 18], DeepONet with proper orthogonal decomposition [19], multiscale DeepONet [4], a neural operator with coupled attention [20], physics-informed DeepONet [21, 22], and the multiple-input deep neural operators (MIONet) [23].


PyDCM: Custom Data Center Models with Reinforcement Learning for Sustainability

arXiv.org Artificial Intelligence

The increasing global emphasis on sustainability and reducing carbon emissions is pushing governments and corporations to rethink their approach to data center design and operation. Given their high energy consumption and exponentially large computational workloads, data centers are prime candidates for optimizing power consumption, especially in areas such as cooling and IT energy usage. A significant challenge in this pursuit is the lack of a configurable and scalable thermal data center model that offers an end-to-end pipeline. Data centers consist of multiple IT components whose geometric configuration and heat dissipation make thermal modeling difficult. This paper presents PyDCM, a customizable Data Center Model implemented in Python, that allows users to create unique configurations of IT equipment with custom server specifications and geometric arrangements of IT cabinets. The use of vectorized thermal calculations makes PyDCM orders of magnitude faster (30 times) than current Energy Plus modeling implementations and scales sublinearly with the number of CPUs. Also, PyDCM enables the use of Deep Reinforcement Learning via the Gymnasium wrapper to optimize data center cooling and offers a user-friendly platform for testing various data center design prototypes.


A Comprehensive Survey on Distributed Training of Graph Neural Networks

arXiv.org Artificial Intelligence

Graph neural networks (GNNs) have been demonstrated to be a powerful algorithmic model in broad application fields for their effectiveness in learning over graphs. To scale GNN training up for large-scale and ever-growing graphs, the most promising solution is distributed training which distributes the workload of training across multiple computing nodes. At present, the volume of related research on distributed GNN training is exceptionally vast, accompanied by an extraordinarily rapid pace of publication. Moreover, the approaches reported in these studies exhibit significant divergence. This situation poses a considerable challenge for newcomers, hindering their ability to grasp a comprehensive understanding of the workflows, computational patterns, communication strategies, and optimization techniques employed in distributed GNN training. As a result, there is a pressing need for a survey to provide correct recognition, analysis, and comparisons in this field. In this paper, we provide a comprehensive survey of distributed GNN training by investigating various optimization techniques used in distributed GNN training. First, distributed GNN training is classified into several categories according to their workflows. In addition, their computational patterns and communication patterns, as well as the optimization techniques proposed by recent work are introduced. Second, the software frameworks and hardware platforms of distributed GNN training are also introduced for a deeper understanding. Third, distributed GNN training is compared with distributed training of deep neural networks, emphasizing the uniqueness of distributed GNN training. Finally, interesting issues and opportunities in this field are discussed.


Building Open Knowledge Graph for Metal-Organic Frameworks (MOF-KG): Challenges and Case Studies

arXiv.org Artificial Intelligence

Metal-Organic Frameworks (MOFs) are a class of modular, porous crystalline materials that have great potential to revolutionize applications such as gas storage, molecular separations, chemical sensing, catalysis, and drug delivery. The Cambridge Structural Database (CSD) reports 10,636 synthesized MOF crystals which in addition contains ca. 114,373 MOF-like structures. The sheer number of synthesized (plus potentially synthesizable) MOF structures requires researchers pursue computational techniques to screen and isolate MOF candidates. In this demo paper, we describe our effort on leveraging knowledge graph methods to facilitate MOF prediction, discovery, and synthesis. We present challenges and case studies about (1) construction of a MOF knowledge graph (MOF-KG) from structured and unstructured sources and (2) leveraging the MOF-KG for discovery of new or missing knowledge.


CD-GAN: a robust fusion-based generative adversarial network for unsupervised remote sensing change detection with heterogeneous sensors

arXiv.org Artificial Intelligence

In the context of Earth observation, change detection boils down to comparing images acquired at different times by sensors of possibly different spatial and/or spectral resolutions or different modalities (e.g., optical or radar). Even when considering only optical images, this task has proven to be challenging as soon as the sensors differ by their spatial and/or spectral resolutions. This paper proposes a novel unsupervised change detection method dedicated to images acquired by such so-called heterogeneous optical sensors. It capitalizes on recent advances which formulate the change detection task into a robust fusion framework. Adopting this formulation, the work reported in this paper shows that any off-the-shelf network trained beforehand to fuse optical images of different spatial and/or spectral resolutions can be easily complemented with a network of the same architecture and embedded into an adversarial framework to perform change detection. A comparison with state-of-the-art change detection methods demonstrates the versatility and the effectiveness of the proposed approach.


These 123 Last-Chance Cyber Monday Deals Are Still Going Strong Right Now

WIRED

CYBER MONDAY IS officially over, but many of our favorite deals are still available. If you took an extended holiday from screens or celebrated Buy Nothing Weekend, fear not--some deals remain. We've sifted through all our Cyber Monday deals guides and picked out the best ones remaining. Who knows how long they'll last, many may even expire before the day's end, but have a look if you're still hunting for holiday bargains and we'll keep it updated crossing out deals as they vanish. We test products year-round and handpicked these deals. The discount amounts we show are based on actual street prices at retailers in the past few months. Products that are sold out or no longer discounted as of publishing will be crossed out. If you buy something using links in our stories, we may earn a commission. This helps support our journalism. Just like upgrading the bed you sleep on, a few things will improve your life like a good chair. Some of our favorites are on sale right now. See our Best Office Chairs guide and our Work-From-Home Gear guide for more picks. This is our favorite office chair. It's easy to assemble and there are tons of little tweaks you can make to dial it the fit. You can push the armrest back and forward, up and down; the seat can extend out or be pushed all the way in; you can lock the recline. Fair warning though: Pet hair tends to cling to the upholstery, and I've noticed the fabric on the front end of the seat tends to pill quite quickly, but this is a great deal on an excellent chair. Take everything about the Branch Ergonomic Chair and upgrade it a notch--that's the Branch Verve. It looks more elegant (especially in the lovely Coral color), it keeps my back straighter, it's quite comfy, and it can make nearly the same adjustments with a higher level of polish. Branch's Ergonomic Chair is excellent for most people, but the Verve is the more refined seat if your budget can stretch. If you need a wide seat and your room tends to run hot, then get this X-Chair. The all-mesh design allows for excellent airflow, whisking your body heat away so that you don't end up sweaty.


PlaNet-ClothPick: Effective Fabric Flattening Based on Latent Dynamic Planning

arXiv.org Artificial Intelligence

Why do Recurrent State Space Models such as PlaNet fail at cloth manipulation tasks? Recent work has attributed this to the blurry prediction of the observation, which makes it difficult to plan directly in the latent space. This paper explores the reasons behind this by applying PlaNet in the pick-and-place fabric-flattening domain. We find that the sharp discontinuity of the transition function on the contour of the fabric makes it difficult to learn an accurate latent dynamic model, causing the MPC planner to produce pick actions slightly outside of the article. By limiting picking space on the cloth mask and training on specially engineered trajectories, our mesh-free PlaNet-ClothPick surpasses visual planning and policy learning methods on principal metrics in simulation, achieving similar performance as state-of-the-art mesh-based planning approaches. Notably, our model exhibits a faster action inference and requires fewer transitional model parameters than the state-of-the-art robotic systems in this domain. Other supplementary materials are available at: https://sites.google.com/view/planet-clothpick.


Robust Ocean Subgrid-Scale Parameterizations Using Fourier Neural Operators

arXiv.org Artificial Intelligence

In climate simulations, small-scale processes shape ocean dynamics but remain computationally expensive to resolve directly. For this reason, their contributions are commonly approximated using empirical parameterizations, which lead to significant errors in long-term projections. In this work, we develop parameterizations based on Fourier Neural Operators, showcasing their accuracy and generalizability in comparison to other approaches. Finally, we discuss the potential and limitations of neural networks operating in the frequency domain, paving the way for future investigation.


Neural General Circulation Models

arXiv.org Artificial Intelligence

General circulation models (GCMs) are the foundation of weather and climate prediction. GCMs are physics-based simulators which combine a numerical solver for large-scale dynamics with tuned representations for small-scale processes such as cloud formation. Recently, machine learning (ML) models trained on reanalysis data achieved comparable or better skill than GCMs for deterministic weather forecasting. However, these models have not demonstrated improved ensemble forecasts, or shown sufficient stability for long-term weather and climate simulations. Here we present the first GCM that combines a differentiable solver for atmospheric dynamics with ML components, and show that it can generate forecasts of deterministic weather, ensemble weather and climate on par with the best ML and physics-based methods. NeuralGCM is competitive with ML models for 1-10 day forecasts, and with the European Centre for Medium-Range Weather Forecasts ensemble prediction for 1-15 day forecasts. With prescribed sea surface temperature, NeuralGCM can accurately track climate metrics such as global mean temperature for multiple decades, and climate forecasts with 140 km resolution exhibit emergent phenomena such as realistic frequency and trajectories of tropical cyclones. For both weather and climate, our approach offers orders of magnitude computational savings over conventional GCMs. Our results show that end-to-end deep learning is compatible with tasks performed by conventional GCMs, and can enhance the large-scale physical simulations that are essential for understanding and predicting the Earth system.