time segment
- Research Report > Experimental Study (0.93)
- Research Report > New Finding (0.67)
- North America > United States > Washington > King County > Seattle (0.04)
- North America > United States > Louisiana > Orleans Parish > New Orleans (0.04)
- North America > United States > California > Los Angeles County > Los Angeles (0.04)
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- Research Report > New Finding (1.00)
- Research Report > Experimental Study (1.00)
- Health & Medicine > Epidemiology (1.00)
- Health & Medicine > Consumer Health (1.00)
- Education (0.94)
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- Information Technology > Data Science > Data Quality (1.00)
- Information Technology > Data Science > Data Mining (1.00)
- Information Technology > Communications > Mobile (1.00)
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- Research Report > Experimental Study (0.93)
- Research Report > New Finding (0.67)
- North America > United States > New York > New York County > New York City (0.04)
- North America > United States > Washington > King County > Seattle (0.04)
- North America > United States > Louisiana > Orleans Parish > New Orleans (0.04)
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- Research Report > New Finding (1.00)
- Research Report > Experimental Study (1.00)
- Health & Medicine > Epidemiology (1.00)
- Health & Medicine > Consumer Health (1.00)
- Education (0.68)
- (5 more...)
- Information Technology > Data Science > Data Quality (1.00)
- Information Technology > Data Science > Data Mining (1.00)
- Information Technology > Communications > Mobile (1.00)
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Interpretable Time Series Autoregression for Periodicity Quantification
Chen, Xinyu, Digalakis, Vassilis Jr, Ding, Lijun, Zhuang, Dingyi, Zhao, Jinhua
Time series autoregression (AR) is a classical tool for modeling auto-correlations and periodic structures in real-world systems. We revisit this model from an interpretable machine learning perspective by introducing sparse autoregression (SAR), where $\ell_0$-norm constraints are used to isolate dominant periodicities. We formulate exact mixed-integer optimization (MIO) approaches for both stationary and non-stationary settings and introduce two scalable extensions: a decision variable pruning (DVP) strategy for temporally-varying SAR (TV-SAR), and a two-stage optimization scheme for spatially- and temporally-varying SAR (STV-SAR). These models enable scalable inference on real-world spatiotemporal datasets. We validate our framework on large-scale mobility and climate time series. On NYC ridesharing data, TV-SAR reveals interpretable daily and weekly cycles as well as long-term shifts due to COVID-19. On climate datasets, STV-SAR uncovers the evolving spatial structure of temperature and precipitation seasonality across four decades in North America and detects global sea surface temperature dynamics, including El Niño. Together, our results demonstrate the interpretability, flexibility, and scalability of sparse autoregression for periodicity quantification in complex time series.
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.14)
- North America > Canada > Quebec > Montreal (0.14)
- North America > United States > Illinois > Cook County > Chicago (0.04)
- (14 more...)
Decoding the Stressed Brain with Geometric Machine Learning
Koszut, Sonia, Nallaperuma-Herzberg, Sam, Lio, Pietro
Stress significantly contributes to both mental and physical disorders, yet traditional self-reported questionnaires are inherently subjective. In this study, we introduce a novel framework that employs geometric machine learning to detect stress from raw EEG recordings. Our approach constructs graphs by integrating structural connectivity (derived from electrode spatial arrangement) with functional connectivity from pairwise signal correlations. A spatio-temporal graph convolu-tional network (ST-GCN) processes these graphs to capture spatial and temporal dynamics. Experiments on the SAM-40 dataset show that the ST-GCN outperforms standard machine learning models on all key classification metrics and enhances interpretability, explored through ablation analyses of key channels and brain regions. These results pave the way for more objective and accurate stress detection methods.
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.14)
- North America > United States > New York (0.04)
3D Characterization of Smoke Plume Dispersion Using Multi-View Drone Swarm
Krishnakumar, Nikil, Sharma, Shashank, Pal, Srijan Kumar, Hong, Jiarong
This study presents an advanced multi-view drone swarm imaging system for the three-dimensional characterization of smoke plume dispersion dynamics. The system comprises a manager drone and four worker drones, each equipped with high-resolution cameras and precise GPS modules. The manager drone uses image feedback to autonomously detect and position itself above the plume, then commands the worker drones to orbit the area in a synchronized circular flight pattern, capturing multi-angle images. The camera poses of these images are first estimated, then the images are grouped in batches and processed using Neural Radiance Fields (NeRF) to generate high-resolution 3D reconstructions of plume dynamics over time. Field tests demonstrated the ability of the system to capture critical plume characteristics including volume dynamics, wind-driven directional shifts, and lofting behavior at a temporal resolution of about 1 s. The 3D reconstructions generated by this system provide unique field data for enhancing the predictive models of smoke plume dispersion and fire spread. Broadly, the drone swarm system offers a versatile platform for high resolution measurements of pollutant emissions and transport in wildfires, volcanic eruptions, prescribed burns, and industrial processes, ultimately supporting more effective fire control decisions and mitigating wildfire risks.
- North America > United States > Minnesota > Hennepin County > Minneapolis (0.28)
- Oceania > Vanuatu (0.04)
- North America > United States > Ohio (0.04)
- (2 more...)
- Transportation (0.47)
- Information Technology (0.47)
- Materials > Chemicals (0.46)
- Energy (0.46)
Energy Dissipation Preserving Physics Informed Neural Network for Allen-Cahn Equations
Kütük, Mustafa, Yücel, Hamdullah
This paper investigates a numerical solution of Allen-Cahn equation with constant and degenerate mobility, with polynomial and logarithmic energy functionals, with deterministic and random initial functions, and with advective term in one, two, and three spatial dimensions, based on the physics-informed neural network (PINN). To improve the learning capacity of the PINN, we incorporate the energy dissipation property of the Allen-Cahn equation as a penalty term into the loss function of the network. To facilitate the learning process of random initials, we employ a continuous analogue of the initial random condition by utilizing the Fourier series expansion. Adaptive methods from traditional numerical analysis are also integrated to enhance the effectiveness of the proposed PINN. Numerical results indicate a consistent decrease in the discrete energy, while also revealing phenomena such as phase separation and metastability.
- Asia > Middle East > Republic of Türkiye (0.14)
- Asia > Singapore (0.14)
- North America > United States > New York (0.14)
Nested Deep Learning Model Towards A Foundation Model for Brain Signal Data
Wei, Fangyi, Mo, Jiajie, Zhang, Kai, Shen, Haipeng, Nagarajan, Srikantan, Jiang, Fei
Epilepsy affects over 50 million people globally, with EEG/MEG-based spike detection playing a crucial role in diagnosis and treatment. Manual spike identification is time-consuming and requires specialized training, limiting the number of professionals available to analyze EEG/MEG data. To address this, various algorithmic approaches have been developed. However, current methods face challenges in handling varying channel configurations and in identifying the specific channels where spikes originate. This paper introduces a novel Nested Deep Learning (NDL) framework designed to overcome these limitations. NDL applies a weighted combination of signals across all channels, ensuring adaptability to different channel setups, and allows clinicians to identify key channels more accurately. Through theoretical analysis and empirical validation on real EEG/MEG datasets, NDL demonstrates superior accuracy in spike detection and channel localization compared to traditional methods. The results show that NDL improves prediction accuracy, supports cross-modality data integration, and can be fine-tuned for various neurophysiological applications.
- North America > United States > California > San Francisco County > San Francisco (0.14)
- Asia > China > Beijing > Beijing (0.04)
- Asia > China > Hong Kong (0.04)
Machine Learning for Complex Systems with Abnormal Pattern by Exception Maximization Outlier Detection Method
Zhang, Zhikun, Duan, Yiting, Wang, Xiangjun, Zhang, Mingyuan
This paper proposes a novel fast online methodology for outlier detection called the exception maximization outlier detection method(EMODM), which employs probabilistic models and statistical algorithms to detect abnormal patterns from the outputs of complex systems. The EMODM is based on a two-state Gaussian mixture model and demonstrates strong performance in probability anomaly detection working on real-time raw data rather than using special prior distribution information. We confirm this using the synthetic data from two numerical cases. For the real-world data, we have detected the short circuit pattern of the circuit system using EMODM by the current and voltage output of a three-phase inverter. The EMODM also found an abnormal period due to COVID-19 in the insured unemployment data of 53 regions in the United States from 2000 to 2024. The application of EMODM to these two real-life datasets demonstrated the effectiveness and accuracy of our algorithm.
- North America > United States > New York (0.04)
- North America > United States > California (0.04)
- Asia > China > Hubei Province > Wuhan (0.04)
- (2 more...)
- Banking & Finance > Economy (1.00)
- Health & Medicine > Therapeutic Area > Infections and Infectious Diseases (0.35)
- Health & Medicine > Therapeutic Area > Immunology (0.35)