time slice
- Asia > Middle East > Jordan (0.04)
- North America > United States (0.04)
- North America > Canada > Quebec > Montreal (0.04)
- Leisure & Entertainment (0.94)
- Media > Film (0.47)
- Asia > Middle East > Jordan (0.04)
- North America > United States (0.04)
- North America > Canada > Quebec > Montreal (0.04)
- Leisure & Entertainment (1.00)
- Media > Film (0.69)
Auto-Adaptive PINNs with Applications to Phase Transitions
We propose an adaptive sampling method for the training of Physics Informed Neural Networks (PINNs) which allows for sampling based on an arbitrary problem-specific heuristic which may depend on the network and its gradients. In particular we focus our analysis on the Allen-Cahn equations, attempting to accurately resolve the characteristic interfacial regions using a PINN without any post-hoc resampling. In experiments, we show the effectiveness of these methods over residual-adaptive frameworks.
- North America > United States > Indiana (0.04)
- Europe > Switzerland (0.04)
deFOREST: Fusing Optical and Radar satellite data for Enhanced Sensing of Tree-loss
Castrillon-Candas, Julio Enrique, Gu, Hanfeng, Meredith, Caleb, Li, Yulin, Tang, Xiaojing, Olofsson, Pontus, Kon, Mark
In this paper we develop a deforestation detection pipeline that incorporates optical and Synthetic Aperture Radar (SAR) data. A crucial component of the pipeline is the construction of anomaly maps of the optical data, which is done using the residual space of a discrete Karhunen-Loève (KL) expansion. Anomalies are quantified using a concentration bound on the distribution of the residual components for the nominal state of the forest. This bound does not require prior knowledge on the distribution of the data. This is in contrast to statistical parametric methods that assume knowledge of the data distribution, an impractical assumption that is especially infeasible for high dimensional data such as ours. Once the optical anomaly maps are computed they are combined with SAR data, and the state of the forest is classified by using a Hidden Markov Model (HMM). We test our approach with Sentinel-1 (SAR) and Sentinel-2 (Optical) data on a $92.19\,km \times 91.80\,km$ region in the Amazon forest. The results show that both the hybrid optical-radar and optical only methods achieve high accuracy that is superior to the recent state-of-the-art hybrid method. Moreover, the hybrid method is significantly more robust in the case of sparse optical data that are common in highly cloudy regions.
- Asia > Southeast Asia (0.04)
- South America > Brazil (0.04)
- North America > United States > Massachusetts > Middlesex County > Natick (0.04)
- (8 more...)
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy (0.71)
- Health & Medicine (0.68)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Information Fusion (0.93)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Undirected Networks > Markov Models (0.89)
Multilinear Dynamical Systems for Tensor Time Series
Many scientific data occur as sequences of multidimensional arrays called tensors. How can hidden, evolving trends in such data be extracted while preserving the tensor structure? The model that is traditionally used is the linear dynamical system (LDS), which treats the observation at each time slice as a vector. In this paper, we propose the multilinear dynamical system (MLDS) for modeling tensor time series and an expectation-maximization (EM) algorithm to estimate the parameters. Compared to the LDS with an equal number of parameters, the MLDS achieves higher prediction accuracy and marginal likelihood for both simulated and real datasets.
TacticExpert: Spatial-Temporal Graph Language Model for Basketball Tactics
Lingrui, Xu, Mandi, Liu, Lei, Zhang
The core challenge in basketball tactic modeling lies in efficiently extracting complex spatial-temporal dependencies from historical data and accurately predicting various in-game events. Existing state-of-the-art (SOTA) models, primarily based on graph neural networks (GNNs), encounter difficulties in capturing long-term, long-distance, and fine-grained interactions among heterogeneous player nodes, as well as in recognizing interaction patterns. Additionally, they exhibit limited generalization to untrained downstream tasks and zero-shot scenarios. In this work, we propose a Spatial-Temporal Propagation Symmetry-Aware Graph Transformer for fine-grained game modeling. This architecture explicitly captures delay effects in the spatial space to enhance player node representations across discrete-time slices, employing symmetry-invariant priors to guide the attention mechanism. We also introduce an efficient contrastive learning strategy to train a Mixture of Tactics Experts module, facilitating differentiated modeling of offensive tactics. By integrating dense training with sparse inference, we achieve a 2.4x improvement in model efficiency. Moreover, the incorporation of Lightweight Graph Grounding for Large Language Models enables robust performance in open-ended downstream tasks and zero-shot scenarios, including novel teams or players. The proposed model, TacticExpert, delineates a vertically integrated large model framework for basketball, unifying pretraining across multiple datasets and downstream prediction tasks. Fine-grained modeling modules significantly enhance spatial-temporal representations, and visualization analyzes confirm the strong interpretability of the model.
- Leisure & Entertainment > Sports > Basketball (0.93)
- Leisure & Entertainment > Games (0.88)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Spatial Reasoning (1.00)
- Information Technology > Artificial Intelligence > Natural Language > Large Language Model (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Neural Networks > Deep Learning (1.00)
Bridging Traffic State and Trajectory for Dynamic Road Network and Trajectory Representation Learning
Han, Chengkai, Wang, Jingyuan, Wang, Yongyao, Yu, Xie, Lin, Hao, Li, Chao, Wu, Junjie
Effective urban traffic management is vital for sustainable city development, relying on intelligent systems with machine learning tasks such as traffic flow prediction and travel time estimation. Traditional approaches usually focus on static road network and trajectory representation learning, and overlook the dynamic nature of traffic states and trajectories, which is crucial for downstream tasks. To address this gap, we propose TRACK, a novel framework to bridge traffic state and trajectory data for dynamic road network and trajectory representation learning. TRACK leverages graph attention networks (GAT) to encode static and spatial road segment features, and introduces a transformer-based model for trajectory representation learning. By incorporating transition probabilities from trajectory data into GAT attention weights, TRACK captures dynamic spatial features of road segments. Meanwhile, TRACK designs a traffic transformer encoder to capture the spatial-temporal dynamics of road segments from traffic state data. To further enhance dynamic representations, TRACK proposes a co-attentional transformer encoder and a trajectory-traffic state matching task. Extensive experiments on real-life urban traffic datasets demonstrate the superiority of TRACK over state-of-the-art baselines. Case studies confirm TRACK's ability to capture spatial-temporal dynamics effectively.
- Transportation > Infrastructure & Services (1.00)
- Transportation > Ground > Road (1.00)
Trajectories of Change: Approaches for Tracking Knowledge Evolution
Schlattmann, Raphael, Vogl, Malte
We explore local vs. global evolution of knowledge systems through the framework of socio-epistemic networks (SEN), applying two complementary methods to a corpus of scientific texts. The framework comprises three interconnected layers-social, semiotic (material), and semantic-proposing a multilayered approach to understanding structural developments of knowledge. To analyse diachronic changes on the semantic layer, we first use information-theoretic measures based on relative entropy to detect semantic shifts, assess their significance, and identify key driving features. Second, variations in document embedding densities reveal changes in semantic neighbourhoods, tracking how concentration of similar documents increase, remain stable, or disperse. This enables us to trace document trajectories based on content (topics) or metadata (authorship, institution). Case studies of Joseph Silk and Hans-J\"urgen Treder illustrate how individual scholar's work aligns with broader disciplinary shifts in general relativity and gravitation research, demonstrating the applications, limitations, and further potential of this approach.
- North America > United States > Minnesota > Hennepin County > Minneapolis (0.14)
- Europe > United Kingdom > England > Oxfordshire > Oxford (0.14)
- North America > United States > Illinois > Cook County > Chicago (0.04)
- (17 more...)
Hypergraph-Based Dynamic Graph Node Classification
Ma, Xiaoxu, Zhao, Chen, Shao, Minglai, Lin, Yujie
--Node classification on static graphs has achieved significant success, but achieving accurate node classification on dynamic graphs where node topology, attributes, and labels change over time has not been well addressed. Existing methods based on RNNs and self-attention only aggregate features of the same node across different time slices, which cannot adequately address and capture the diverse dynamic changes in dynamic graphs. Therefore, we propose a novel model named Hypergraph-Based Multi-granularity Dynamic Graph Node Classification (HYDG). More accurate representations are obtained through weighted information propagation and aggregation by the hypergraph neural network. Extensive experiments on five real dynamic graph datasets using two GNN backbones demonstrate the superiority of our proposed framework.
- Asia > China > Tianjin Province > Tianjin (0.04)
- North America > United States (0.04)
Parallel simulation for sampling under isoperimetry and score-based diffusion models
Zhou, Huanjian, Sugiyama, Masashi
In recent years, there has been a surge of interest in proving discretization bounds for sampling under isoperimetry and for diffusion models. As data size grows, reducing the iteration cost becomes an important goal. Inspired by the great success of the parallel simulation of the initial value problem in scientific computation, we propose parallel Picard methods for sampling tasks. Rigorous theoretical analysis reveals that our algorithm achieves better dependence on dimension $d$ than prior works in iteration complexity (i.e., reduced from $\widetilde{O}(\log^2 d)$ to $\widetilde{O}(\log d)$), which is even optimal for sampling under isoperimetry with specific iteration complexity. Our work highlights the potential advantages of simulation methods in scientific computation for dynamics-based sampling and diffusion models.
- Asia > Japan > Honshū > Kantō > Tokyo Metropolis Prefecture > Tokyo (0.14)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- North America > United States > Louisiana > Orleans Parish > New Orleans (0.04)
- Europe > France > Occitanie > Haute-Garonne > Toulouse (0.04)