Energy
fabSAM: A Farmland Boundary Delineation Method Based on the Segment Anything Model
Xie, Yufeng, Wu, Hanzhi, Tong, Hongxiang, Xiao, Lei, Zhou, Wenwen, Li, Ling, Wanger, Thomas Cherico
Delineating farmland boundaries is essential for agricultural management such as crop monitoring and agricultural census. Traditional methods using remote sensing imagery have been efficient but limited in generalisation. The Segment Anything Model (SAM), known for its impressive zero shot performance, has been adapted for remote sensing tasks through prompt learning and fine tuning. Here, we propose a SAM based farmland boundary delineation framework 'fabSAM' that combines a Deeplabv3+ based Prompter and SAM. Also, a fine tuning strategy was introduced to enable SAMs decoder to improve the use of prompt information. Experimental results on the AI4Boundaries and AI4SmallFarms datasets have shown that fabSAM has a significant improvement in farmland region identification and boundary delineation. Compared to zero shot SAM, fabSAM surpassed it by 23.5% and 15.1% in mIOU on the AI4Boundaries and AI4SmallFarms datasets, respectively. For Deeplabv3+, fabSAM outperformed it by 4.9% and 12.5% in mIOU, respectively. These results highlight the effectiveness of fabSAM, which also means that we can more easily obtain the global farmland region and boundary maps from open source satellite image datasets like Sentinel2.
SafePowerGraph-HIL: Real-Time HIL Validation of Heterogeneous GNNs for Bridging Sim-to-Real Gap in Power Grids
Ma, Aoxiang, Ghamizi, Salah, Cao, Jun, Rodriguez, Pedro
As machine learning (ML) techniques gain prominence in power system research, validating these methods' effectiveness under real-world conditions requires real-time hardware-in-the-loop (HIL) simulations. HIL simulation platforms enable the integration of computational models with physical devices, allowing rigorous testing across diverse scenarios critical to system resilience and reliability. In this study, we develop a SafePowerGraph-HIL framework that utilizes HIL simulations on the IEEE 9-bus system, modeled in Hypersim, to generate high-fidelity data, which is then transmitted in real-time via SCADA to an AWS cloud database before being input into a Heterogeneous Graph Neural Network (HGNN) model designed for power system state estimation and dynamic analysis. By leveraging Hypersim's capabilities, we simulate complex grid interactions, providing a robust dataset that captures critical parameters for HGNN training. The trained HGNN is subsequently validated using newly generated data under varied system conditions, demonstrating accuracy and robustness in predicting power system states. The results underscore the potential of integrating HIL with advanced neural network architectures to enhance the real-time operational capabilities of power systems. This approach represents a significant advancement toward the development of intelligent, adaptive control strategies that support the robustness and resilience of evolving power grids.
Controlling Ensemble Variance in Diffusion Models: An Application for Reanalyses Downscaling
Merizzi, Fabio, Evangelista, Davide, Loukos, Harilaos
In recent years, diffusion models have emerged as powerful tools for generating ensemble members in meteorology. In this work, we demonstrate that a Denoising Diffusion Implicit Model (DDIM) can effectively control ensemble variance by varying the number of diffusion steps. Introducing a theoretical framework, we relate diffusion steps to the variance expressed by the reverse diffusion process. Focusing on reanalysis downscaling, we propose an ensemble diffusion model for the full ERA5-to-CERRA domain, generating variance-calibrated ensemble members for wind speed at full spatial and temporal resolution. Our method aligns global mean variance with a reference ensemble dataset and ensures spatial variance is distributed in accordance with observed meteorological variability. Additionally, we address the lack of ensemble information in the CARRA dataset, showcasing the utility of our approach for efficient, high-resolution ensemble generation.
Advancing Earth Observation: A Survey on AI-Powered Image Processing in Satellites
Duggan, Aidan, Andrade, Bruno, Afli, Haithem
Advancements in technology and reduction in it's cost have led to a substantial growth in the quality & quantity of imagery captured by Earth Observation (EO) satellites. This has presented a challenge to the efficacy of the traditional workflow of transmitting this imagery to Earth for processing. An approach to addressing this issue is to use pre-trained artificial intelligence models to process images on-board the satellite, but this is difficult given the constraints within a satellite's environment. This paper provides an up-to-date and thorough review of research related to image processing on-board Earth observation satellites. The significant constraints are detailed along with the latest strategies to mitigate them.
On the practical applicability of modern DFT functionals for chemical computations. Case study of DM21 applicability for geometry optimization
Kulaev, Kirill, Ryabov, Alexander, Medvedev, Michael, Burnaev, Evgeny, Vanovskiy, Vladimir
Density functional theory (DFT) is probably the most promising approach for quantum chemistry calculations considering its good balance between calculations precision and speed. In recent years, several neural network-based functionals have been developed for exchange-correlation energy approximation in DFT, DM21 developed by Google Deepmind being the most notable between them. This study focuses on evaluating the efficiency of DM21 functional in predicting molecular geometries, with a focus on the influence of oscillatory behavior in neural network exchange-correlation functionals. We implemented geometry optimization in PySCF for the DM21 functional in geometry optimization problem, compared its performance with traditional functionals, and tested it on various benchmarks. Our findings reveal both the potential and the current challenges of using neural network functionals for geometry optimization in DFT. We propose a solution extending the practical applicability of such functionals and allowing to model new substances with their help.
A Fast, Scalable, and Robust Deep Learning-based Iterative Reconstruction Framework for Accelerated Industrial Cone-beam X-ray Computed Tomography
Pramanik, Aniket, Rahman, Obaidullah, Venkatakrishnan, Singanallur V., Ziabari, Amirkoushyar
Cone-beam X-ray Computed Tomography (XCT) with large detectors and corresponding large-scale 3D reconstruction plays a pivotal role in micron-scale characterization of materials and parts across various industries. In this work, we present a novel deep neural network-based iterative algorithm that integrates an artifact reduction-trained CNN as a prior model with automated regularization parameter selection, tailored for large-scale industrial cone-beam XCT data. Our method achieves high-quality 3D reconstructions even for extremely dense thick metal parts - which traditionally pose challenges to industrial CT images - in just a few iterations. Furthermore, we show the generalizability of our approach to out-of-distribution scans obtained under diverse scanning conditions. Our method effectively handles significant noise and streak artifacts, surpassing state-of-the-art supervised learning methods trained on the same data.
Topology of Out-of-Distribution Examples in Deep Neural Networks
Datta, Esha, Hennig, Johanna, Domschot, Eva, Mattes, Connor, Smith, Michael R.
As deep neural networks (DNNs) become increasingly common, concerns about their robustness do as well. A longstanding problem for deployed DNNs is their behavior in the face of unfamiliar inputs; specifically, these models tend to be overconfident and incorrect when encountering out-of-distribution (OOD) examples. In this work, we present a topological approach to characterizing OOD examples using latent layer embeddings from DNNs. Our goal is to identify topological features, referred to as landmarks, that indicate OOD examples. We conduct extensive experiments on benchmark datasets and a realistic DNN model, revealing a key insight for OOD detection. Well-trained DNNs have been shown to induce a topological simplification on training data for simple models and datasets; we show that this property holds for realistic, large-scale test and training data, but does not hold for OOD examples. More specifically, we find that the average lifetime (or persistence) of OOD examples is statistically longer than that of training or test examples. This indicates that DNNs struggle to induce topological simplification on unfamiliar inputs. Our empirical results provide novel evidence of topological simplification in realistic DNNs and lay the groundwork for topologically-informed OOD detection strategies.
Adaptive Data Exploitation in Deep Reinforcement Learning
Yuan, Mingqi, Li, Bo, Jin, Xin, Zeng, Wenjun
We introduce ADEPT: Adaptive Data ExPloiTation, a simple yet powerful framework to enhance the **data efficiency** and **generalization** in deep reinforcement learning (RL). Specifically, ADEPT adaptively manages the use of sampled data across different learning stages via multi-armed bandit (MAB) algorithms, optimizing data utilization while mitigating overfitting. Moreover, ADEPT can significantly reduce the computational overhead and accelerate a wide range of RL algorithms. We test ADEPT on benchmarks including Procgen, MiniGrid, and PyBullet. Extensive simulation demonstrates that ADEPT can achieve superior performance with remarkable computational efficiency, offering a practical solution to data-efficient RL. Our code is available at https://github.com/yuanmingqi/ADEPT.
Heterogeneous Federated Learning Systems for Time-Series Power Consumption Prediction with Multi-Head Embedding Mechanism
Syu, Jia-Hao, Lin, Jerry Chun-Wei, Srivastava, Gautam, Yun, Unil
Time-series prediction is increasingly popular in a variety of applications, such as smart factories and smart transportation. Researchers have used various techniques to predict power consumption, but existing models lack discussion of collaborative learning and privacy issues among multiple clients. To address these issues, we propose Multi-Head Heterogeneous Federated Learning (MHHFL) systems that consist of multiple head networks, which independently act as carriers for federated learning. In the federated period, each head network is embedded into 2-dimensional vectors and shared with the centralized source pool. MHHFL then selects appropriate source networks and blends the head networks as knowledge transfer in federated learning. The experimental results show that the proposed MHHFL systems significantly outperform the benchmark and state-of-the-art systems and reduce the prediction error by 24.9% to 94.1%. The ablation studies demonstrate the effectiveness of the proposed mechanisms in the MHHFL (head network embedding and selection mechanisms), which significantly outperforms traditional federated average and random transfer.
The Process of Categorical Clipping at the Core of the Genesis of Concepts in Synthetic Neural Cognition
Pichat, Michael, Pogrund, William, Gasparian, Armanush, Pichat, Paloma, Demarchi, Samuel, Veillet-Guillem, Michael, Corbet, Martin, Dasilva, Théo
The result of this categorical segmentation is reflected in the creation, by each neuron, of a synthetic category of thought, a concept, or, to put it differently, a categorical dimension carried by this neuron [101, 102]. This synthetic conceptual category is, among other things, defined by its extension, that is, the set of tokens for which the neuron associated with this category is (sufficiently) activated. In a previous work [105], we investigated the mathematical-cognitive factors of categorical segmentation performed by the synthetic neurons of language models. In this preliminary exploratory study, we examined, both quantitatively and qualitatively, the genetic elements influencing this categorical segmentation. Based on the aggregation function 1 Σ(w i,jx i,j) + b, which partly governs this cognitive process, we identified three key causal elements of a mathematical and cognitive nature involved in this conceptual partitioning process. First, the "x effect" or synthetic categorical priming, which refers to the fact that the activation of the categories carried by precursor neurons in layer n affects the activation of the categories specific to their associated target neurons in layer n + 1, thereby directly impacting their categorical extension. In other words, the more a token belongs to the extension of a precursor category in layer n (i.e., the more this token is activated in the involved neuron), the greater its potential to belong to the extension of its superordinate category (i.e., its potential activation in the neuron of layer n +1). This phenomenon of categorical priming thus partly governs the categorical segmentation performed in layer n + 1, that is, the determination of the subset of tokens constituting the categorical extension of the concepts carried by the neurons in layer n + 1. Second, the "w effect" or synthetic categorical attention, which relates to the fact that the weights of the connections between a target neuron (layer n + 1) and its precursor neurons (layer n) govern the degree of relevance attributed to the precursor categories in constructing the categorical segment of their corresponding target neurons.