spatial scale
- North America > United States > Minnesota > Hennepin County > Minneapolis (0.14)
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.04)
- North America > United States > Maryland > Prince George's County > College Park (0.04)
- (3 more...)
Transformation
Particularly important is the ability to incorporate domain knowledge of invariances, e.g., translational invariance ofimages. Kernels based onthemaximumsimilarity overagroup of transformations are not generally positive definite. Perhaps it is for this reason that they have not been studied theoretically. We address this lacuna and show thatpositivedefiniteness indeed holdswith high probabilityforkernels based on the maximum similarity in the small training sample set regime of interest, and that they do yield the best results in that regime.
Transformation
Particularly important is the ability to incorporate domain knowledge of invariances, e.g., translational invariance ofimages. Kernels based onthemaximumsimilarity overagroup of transformations are not generally positive definite. Perhaps it is for this reason that they have not been studied theoretically. We address this lacuna and show thatpositivedefiniteness indeed holdswith high probabilityforkernels based on the maximum similarity in the small training sample set regime of interest, and that they do yield the best results in that regime.
- Asia > Japan > Honshū > Kantō > Tokyo Metropolis Prefecture > Tokyo (0.05)
- Oceania > Australia (0.05)
- North America > United States > Maryland (0.05)
- (6 more...)
- Energy > Renewable > Solar (0.73)
- Government (0.70)
Search at Scale: Improving Numerical Conditioning of Ergodic Coverage Optimization for Multi-Scale Domains
Lahrach, Yanis, Hughes, Christian, Abraham, Ian
Recent methods in ergodic coverage planning have shown promise as tools that can adapt to a wide range of geometric coverage problems with general constraints, but are highly sensitive to the numerical scaling of the problem space. The underlying challenge is that the optimization formulation becomes brittle and numerically unstable with changing scales, especially under potentially nonlinear constraints that impose dynamic restrictions, due to the kernel-based formulation. This paper proposes to address this problem via the development of a scale-agnostic and adaptive ergodic coverage optimization method based on the maximum mean discrepancy metric (MMD). Our approach allows the optimizer to solve for the scale of differential constraints while annealing the hyperparameters to best suit the problem domain and ensure physical consistency. We also derive a variation of the ergodic metric in the log space, providing additional numerical conditioning without loss of performance. We compare our approach with existing coverage planning methods and demonstrate the utility of our approach on a wide range of coverage problems.
- North America > United States > Connecticut > New Haven County > New Haven (0.04)
- Europe > Belgium > Wallonia > Walloon Brabant > Louvain-la-Neuve (0.04)
- Atlantic Ocean (0.04)
- Asia > Philippines (0.04)
Geo-Aware Models for Stream Temperature Prediction across Different Spatial Regions and Scales
Luo, Shiyuan, Yu, Runlong, Chen, Shengyu, Fan, Yingda, Xie, Yiqun, Li, Yanhua, Jia, Xiaowei
Understanding environmental ecosystems is vital for the sustainable management of our planet. However,existing physics-based and data-driven models often fail to generalize to varying spatial regions and scales due to the inherent data heterogeneity presented in real environmental ecosystems. This generalization issue is further exacerbated by the limited observation samples available for model training. To address these issues, we propose Geo-STARS, a geo-aware spatio-temporal modeling framework for predicting stream water temperature across different watersheds and spatial scales. The major innovation of Geo-STARS is the introduction of geo-aware embedding, which leverages geographic information to explicitly capture shared principles and patterns across spatial regions and scales. We further integrate the geo-aware embedding into a gated spatio-temporal graph neural network. This design enables the model to learn complex spatial and temporal patterns guided by geographic and hydrological context, even with sparse or no observational data. We evaluate Geo-STARS's efficacy in predicting stream water temperature, which is a master factor for water quality. Using real-world datasets spanning 37 years across multiple watersheds along the eastern coast of the United States, Geo-STARS demonstrates its superior generalization performance across both regions and scales, outperforming state-of-the-art baselines. These results highlight the promise of Geo-STARS for scalable, data-efficient environmental monitoring and decision-making.
- North America > United States > Minnesota > Hennepin County > Minneapolis (0.16)
- Asia > Middle East > Jordan (0.04)
- North America > United States > New York > New York County > New York City (0.04)
- (2 more...)
- Asia > Japan > Honshū > Kantō > Tokyo Metropolis Prefecture > Tokyo (0.05)
- Oceania > Australia (0.05)
- North America > United States > Maryland (0.05)
- (6 more...)
- North America > United States > Minnesota > Hennepin County > Minneapolis (0.14)
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.04)
- North America > United States > Maryland > Prince George's County > College Park (0.04)
- (3 more...)
ST-Hyper: Learning High-Order Dependencies Across Multiple Spatial-Temporal Scales for Multivariate Time Series Forecasting
Wu, Binqing, Huang, Jianlong, Shang, Zongjiang, Chen, Ling
In multivariate time series (MTS) forecasting, many deep learning based methods have been proposed for modeling dependencies at multiple spatial (inter-variate) or temporal (intra-variate) scales. However, existing methods may fail to model dependencies across multiple spatial-temporal scales (ST-scales, i.e., scales that jointly consider spatial and temporal scopes). In this work, we propose ST-Hyper to model the high-order dependencies across multiple ST-scales through adaptive hypergraph modeling. Specifically, we introduce a Spatial-Temporal Pyramid Modeling (STPM) module to extract features at multiple ST-scales. Furthermore, we introduce an Adaptive Hypergraph Modeling (AHM) module that learns a sparse hypergraph to capture robust high-order dependencies among features. In addition, we interact with these features through tri-phase hypergraph propagation, which can comprehensively capture multi-scale spatial-temporal dynamics. Experimental results on six real-world MTS datasets demonstrate that ST-Hyper achieves the state-of-the-art performance, outperforming the best baselines with an average MAE reduction of 3.8\% and 6.8\% for long-term and short-term forecasting, respectively.
- Asia > China > Zhejiang Province > Ningbo (0.04)
- Asia > China > Zhejiang Province > Hangzhou (0.04)
- North America > United States > New York > New York County > New York City (0.04)
- Asia > Japan > Honshū > Tōhoku > Fukushima Prefecture > Fukushima (0.04)
Multi-scale species richness estimation with deep learning
Boussange, Victor, Wuyts, Bert, Brun, Philipp, Malle, Johanna T., Midolo, Gabriele, Portier, Jeanne, Sanchez, Théophile, Zimmermann, Niklaus E., Axmanová, Irena, Bruelheide, Helge, Chytrý, Milan, Kambach, Stephan, Lososová, Zdeňka, Večeřa, Martin, Biurrun, Idoia, Ecker, Klaus T., Lenoir, Jonathan, Svenning, Jens-Christian, Karger, Dirk Nikolaus
Biodiversity assessments are critically affected by the spatial scale at which species richness is measured. How species richness accumulates with sampling area depends on natural and anthropogenic processes whose effects can change depending on the spatial scale considered. These accumulation dynamics, described by the species-area relationship (SAR), are challenging to assess because most biodiversity surveys are restricted to sampling areas much smaller than the scales at which these processes operate. Here, we combine sampling theory and deep learning to predict local species richness within arbitrarily large sampling areas, enabling for the first time to estimate spatial differences in SARs. We demonstrate our approach by predicting vascular plant species richness across Europe and evaluate predictions against an independent dataset of plant community inventories. The resulting model, named deep SAR, delivers multi-scale species richness maps, improving coarse grain richness estimates by 32% compared to conventional methods, while delivering finer grain estimates. Additional to its predictive capabilities, we show how our deep SAR model can provide fundamental insights on the multi-scale effects of key biodiversity processes. The capacity of our approach to deliver comprehensive species richness estimates across the full spectrum of ecologically relevant scales is essential for robust biodiversity assessments and forecasts under global change.
- Europe > Switzerland > Zürich > Zürich (0.14)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- Europe > Germany > Saxony > Leipzig (0.04)
- (8 more...)