observation data
Simulation-based Bayesian inference with ameliorative learned summary statistics -- Part I
This paper, which is Part 1 of a two-part paper series, considers a simulation-based inference with learned summary statistics, in which such a learned summary statistic serves as an empirical-likelihood with ameliorative effects in the Bayesian setting, when the exact likelihood function associated with the observation data and the simulation model is difficult to obtain in a closed form or computationally intractable. In particular, a transformation technique which leverages the Cressie-Read discrepancy criterion under moment restrictions is used for summarizing the learned statistics between the observation data and the simulation outputs, while preserving the statistical power of the inference. Here, such a transformation of data-to-learned summary statistics also allows the simulation outputs to be conditioned on the observation data, so that the inference task can be performed over certain sample sets of the observation data that are considered as an empirical relevance or believed to be particular importance. Moreover, the simulation-based inference framework discussed in this paper can be extended further, and thus handling weakly dependent observation data. Finally, we remark that such an inference framework is suitable for implementation in distributed computing, i.e., computational tasks involving both the data-to-learned summary statistics and the Bayesian inferencing problem can be posed as a unified distributed inference problem that will exploit distributed optimization and MCMC algorithms for supporting large datasets associated with complex simulation models.
- North America > United States (0.14)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- Information Technology > Modeling & Simulation (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Uncertainty > Bayesian Inference (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (0.46)
- Information Technology > Artificial Intelligence > Representation & Reasoning (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Undirected Networks > Markov Models (0.72)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning (0.68)
TAMO: Fine-Grained Root Cause Analysis via Tool-Assisted LLM Agent with Multi-Modality Observation Data in Cloud-Native Systems
Zhang, Xiao, Wang, Qi, Li, Mingyi, Yuan, Yuan, Xiao, Mengbai, Zhuang, Fuzhen, Yu, Dongxiao
Implementing large language models (LLMs)-driven root cause analysis (RCA) in cloud-native systems has become a key topic of modern software operations and maintenance. However, existing LLM-based approaches face three key challenges: multi-modality input constraint, context window limitation, and dynamic dependence graph. To address these issues, we propose a tool-assisted LLM agent with multi-modality observation data for fine-grained RCA, namely TAMO, including multimodality alignment tool, root cause localization tool, and fault types classification tool. In detail, TAMO unifies multi-modal observation data into time-aligned representations for cross-modal feature consistency. Based on the unified representations, TAMO then invokes its specialized root cause localization tool and fault types classification tool for further identifying root cause and fault type underlying system context. This approach overcomes the limitations of LLMs in processing real-time raw observational data and dynamic service dependencies, guiding the model to generate repair strategies that align with system context through structured prompt design. Experiments on two benchmark datasets demonstrate that TAMO outperforms state-of-the-art (SOTA) approaches with comparable performance.
- Asia > China > Beijing > Beijing (0.04)
- Asia > China > Shandong Province > Qingdao (0.04)
- North America > United States > Ohio (0.04)
- Asia > China > Hong Kong (0.04)
- Research Report (0.64)
- Workflow (0.46)
MODS: Multi-source Observations Conditional Diffusion Model for Meteorological State Downscaling
Tu, Siwei, Xu, Jingyi, Yang, Weidong, Bai, Lei, Fei, Ben
Accurate acquisition of high-resolution surface meteorological conditions is critical for forecasting and simulating meteorological variables. Directly applying spatial interpolation methods to derive meteorological values at specific locations from low-resolution grid fields often yields results that deviate significantly from the actual conditions. Existing downscaling methods primarily rely on the coupling relationship between geostationary satellites and ERA5 variables as a condition. However, using brightness temperature data from geostationary satellites alone fails to comprehensively capture all the changes in meteorological variables in ERA5 maps. To address this limitation, we can use a wider range of satellite data to make more full use of its inversion effects on various meteorological variables, thus producing more realistic results across different meteorological variables. To further improve the accuracy of downscaling meteorological variables at any location, we propose the Multi-source Observation Down-Scaling Model (MODS). It is a conditional diffusion model that fuses data from multiple geostationary satellites GridSat, polar-orbiting satellites (AMSU-A, HIRS, and MHS), and topographic data (GEBCO), as conditions, and is pre-trained on the ERA5 reanalysis dataset. During training, latent features from diverse conditional inputs are extracted separately and fused into ERA5 maps via a multi-source cross-attention module. By exploiting the inversion relationships between reanalysis data and multi-source atmospheric variables, MODS generates atmospheric states that align more closely with real-world conditions. During sampling, MODS enhances downscaling consistency by incorporating low-resolution ERA5 maps and station-level meteorological data as guidance. Experimental results demonstrate that MODS achieves higher fidelity when downscaling ERA5 maps to a 6.25 km resolution.
Lightweight Trustworthy Distributed Clustering
Li, Hongyang, Wu, Caesar, Chadli, Mohammed, Mammar, Said, Bouvry, Pascal
Ensuring data trustworthiness within individual edge node s while facilitating collaborative data processing poses a critical challenge in edge computing system s (ECS), particularly in resource-constrained scenarios such as autonomous systems sensor networks, indu strial IoT, and smart cities. This paper presents a lightweight, fully distributed k -means clustering algorithm specifically adapted for edge e nvi-ronments, leveraging a distributed averaging approach wit h additive secret sharing, a secure multiparty computation technique, during the cluster center update ph ase to ensure the accuracy and trustworthiness of data across nodes. Edge computing, a paradigm emerging from distributed compu ting, emphasizes processing data at or near its source to minimize latency and reduce band width consumption [1]-[3]. The rapid advancements in edge computing technologies, includ ing algorithms for decentralized and efficient data processing, have significantly accelerated t he deployment of distributed sensor networks. Two key properties of ECS are crucial in large-scale deploym ents.
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- North America > United States (0.04)
- Information Technology > Security & Privacy (1.00)
- Information Technology > Communications > Networks > Sensor Networks (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning > Clustering (0.57)
BI-EqNO: Generalized Approximate Bayesian Inference with an Equivariant Neural Operator Framework
Zhou, Xu-Hui, Liu, Zhuo-Ran, Xiao, Heng
Bayesian inference offers a robust framework for updating prior beliefs based on new data using Bayes' theorem, but exact inference is often computationally infeasible, necessitating approximate methods. Though widely used, these methods struggle to estimate marginal likelihoods accurately, particularly due to the rigid functional structures of deterministic models like Gaussian processes and the limitations of small sample sizes in stochastic models like the ensemble Kalman method. In this work, we introduce BI-EqNO, an equivariant neural operator framework for generalized approximate Bayesian inference, designed to enhance both deterministic and stochastic approaches. BI-EqNO transforms priors into posteriors conditioned on observation data through data-driven training. The framework is flexible, supporting diverse prior and posterior representations with arbitrary discretizations and varying numbers of observations. Crucially, BI-EqNO's architecture ensures (1) permutation equivariance between prior and posterior representations, and (2) permutation invariance with respect to observational data. We demonstrate BI-EqNO's utility through two examples: (1) as a generalized Gaussian process (gGP) for regression, and (2) as an ensemble neural filter (EnNF) for sequential data assimilation. Results show that gGP outperforms traditional Gaussian processes by offering a more flexible representation of covariance functions. Additionally, EnNF not only outperforms the ensemble Kalman filter in small-ensemble settings but also has the potential to function as a "super" ensemble filter, capable of representing and integrating multiple ensemble filters for enhanced assimilation performance. This study highlights BI-EqNO's versatility and effectiveness, improving Bayesian inference through data-driven training while reducing computational costs across various applications.
- Europe > Germany > Baden-Württemberg > Stuttgart Region > Stuttgart (0.04)
- North America > United States > Virginia (0.04)
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- Health & Medicine (0.67)
- Government (0.46)
- Information Technology > Modeling & Simulation (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Uncertainty > Bayesian Inference (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (1.00)
Latent-EnSF: A Latent Ensemble Score Filter for High-Dimensional Data Assimilation with Sparse Observation Data
Accurate modeling and prediction of complex physical systems often rely on data assimilation techniques to correct errors inherent in model simulations. Traditional methods like the Ensemble Kalman Filter (EnKF) and its variants as well as the recently developed Ensemble Score Filters (EnSF) face significant challenges when dealing with high-dimensional and nonlinear Bayesian filtering problems with sparse observations, which are ubiquitous in real-world applications. In this paper, we propose a novel data assimilation method, Latent-EnSF, which leverages EnSF with efficient and consistent latent representations of the full states and sparse observations to address the joint challenges of high dimensionlity in states and high sparsity in observations for nonlinear Bayesian filtering. We introduce a coupled Variational Autoencoder (VAE) with two encoders to encode the full states and sparse observations in a consistent way guaranteed by a latent distribution matching and regularization as well as a consistent state reconstruction. With comparison to several methods, we demonstrate the higher accuracy, faster convergence, and higher efficiency of Latent-EnSF for two challenging applications with complex models in shallow water wave propagation and medium-range weather forecasting, for highly sparse observations in both space and time. Many complex physical systems are traditionally modeled by partial differential equations (PDEs).
- North America > United States > Pennsylvania > Philadelphia County > Philadelphia (0.04)
- North America > United States > Georgia > Fulton County > Atlanta (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- (2 more...)
OXYGENERATOR: Reconstructing Global Ocean Deoxygenation Over a Century with Deep Learning
Lu, Bin, Zhao, Ze, Han, Luyu, Gan, Xiaoying, Zhou, Yuntao, Zhou, Lei, Fu, Luoyi, Wang, Xinbing, Zhou, Chenghu, Zhang, Jing
Accurately reconstructing the global ocean deoxygenation over a century is crucial for assessing and protecting marine ecosystem. Existing expert-dominated numerical simulations fail to catch up with the dynamic variation caused by global warming and human activities. Besides, due to the high-cost data collection, the historical observations are severely sparse, leading to big challenge for precise reconstruction. In this work, we propose OxyGenerator, the first deep learning based model, to reconstruct the global ocean deoxygenation from 1920 to 2023. Specifically, to address the heterogeneity across large temporal and spatial scales, we propose zoning-varying graph message-passing to capture the complex oceanographic correlations between missing values and sparse observations. Additionally, to further calibrate the uncertainty, we incorporate inductive bias from dissolved oxygen (DO) variations and chemical effects. Compared with in-situ DO observations, OxyGenerator significantly outperforms CMIP6 numerical simulations, reducing MAPE by 38.77%, demonstrating a promising potential to understand the "breathless ocean" in data-driven manner.
- North America > United States > District of Columbia > Washington (0.14)
- Europe > Austria > Vienna (0.14)
- Atlantic Ocean > Black Sea (0.05)
- (26 more...)
- Government (0.46)
- Energy (0.46)
ORBIT: Oak Ridge Base Foundation Model for Earth System Predictability
Wang, Xiao, Tsaris, Aristeidis, Liu, Siyan, Choi, Jong-Youl, Fan, Ming, Zhang, Wei, Yin, Junqi, Ashfaq, Moetasim, Lu, Dan, Balaprakash, Prasanna
Earth system predictability is challenged by the complexity of environmental dynamics and the multitude of variables involved. Current AI foundation models, although advanced by leveraging large and heterogeneous data, are often constrained by their size and data integration, limiting their effectiveness in addressing the full range of Earth system prediction challenges. To overcome these limitations, we introduce the Oak Ridge Base Foundation Model for Earth System Predictability (ORBIT), an advanced vision-transformer model that scales up to 113 billion parameters using a novel hybrid tensor-data orthogonal parallelism technique. As the largest model of its kind, ORBIT surpasses the current climate AI foundation model size by a thousandfold. Performance scaling tests conducted on the Frontier supercomputer have demonstrated that ORBIT achieves 230 to 707 PFLOPS, with scaling efficiency maintained at 78% to 96% across 24,576 AMD GPUs. These breakthroughs establish new advances in AI-driven climate modeling and demonstrate promise to significantly improve the Earth system predictability.
- Europe > Italy > Calabria > Catanzaro Province > Catanzaro (0.04)
- North America > United States > New York > New York County > New York City (0.04)