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Time series anomaly detection is important in modern large-scale systems and is applied in a variety of domains to analyze and monitor the operation of diverse systems. Unsupervised approaches have received widespread interest, as they do…

Machine Learning · Computer Science 2025-10-23 Buang Zhang , Tung Kieu , Xiangfei Qiu , Chenjuan Guo , Jilin Hu , Aoying Zhou , Christian S. Jensen , Bin Yang

We consider a new type of defect in the scope of linear elasticity theory, using geometrical methods. This defect is produced by a spherically symmetric dislocation, or ball dislocation. We derive the induced metric as well as the affine…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Alcides F. Andrade , Guilherme de Berredo-Peixoto

Spatiotemporal graph neural networks have shown to be effective in time series forecasting applications, achieving better performance than standard univariate predictors in several settings. These architectures take advantage of a graph…

Machine Learning · Computer Science 2023-11-13 Andrea Cini , Ivan Marisca , Daniele Zambon , Cesare Alippi

Deep forecasting models often suffer from attenuated periodic perception and entangled trend-noise representations as network depth increases. Moreover, the widely adopted channel-independent paradigm, while improving training stability,…

Machine Learning · Computer Science 2026-05-19 Hua Wang , Xianhao Jiao , Fan Zhang

Given a set of synchronous time series, each associated with a sensor-point in space and characterized by inter-series relationships, the problem of spatiotemporal forecasting consists of predicting future observations for each point.…

Machine Learning · Computer Science 2024-06-11 Ivan Marisca , Cesare Alippi , Filippo Maria Bianchi

We propose criteria that define a trend for time series with inherent multi-scale features. We call this trend the {\it tendency} of a time series. The tendency is defined empirically by a set of criteria and captures the large-scale…

Data Analysis, Statistics and Probability · Physics 2015-06-19 Juan M. Restrepo , Shankar C. Venkataramani , Darin Comeau , Hermann Flaschka

In modelling time series data coming from different sources, frequencies can easily vary since some variable can be measured at higher frequencies, others, at lower frequencies. Given data measured over spatial units and at varying…

Methodology · Statistics 2025-03-05 Vladimir A. Malabanan , Joseph Ryan G. Lansangan , Erniel B. Barrios

Many econometric analyses involve spatio--temporal data. A considerable amount of literature has addressed spatio--temporal models, with Spatial Dynamic Panel Data (SDPD) being widely investigated and applied. In real data applications,…

Methodology · Statistics 2016-07-18 Maria Lucia Parrella

Many real-world complex systems, such as epidemic spreading networks and ecosystems, can be modeled as networked dynamical systems that produce multivariate time series. Learning the intrinsic dynamics from observational data is pivotal for…

Machine Learning · Computer Science 2024-12-30 Yanna Ding , Zijie Huang , Malik Magdon-Ismail , Jianxi Gao

Encoder-decoder recurrent neural network models (RNN Seq2Seq) have achieved great success in ubiquitous areas of computation and applications. It was shown to be successful in modeling data with both temporal and spatial dependencies for…

Machine Learning · Computer Science 2020-02-03 Kun Su , Eli Shlizerman

Spherical regression, in which both covariates and responses lie on the sphere, arises in many scientific applications and has attracted considerable methodological attention in recent years. Despite this progress, constructing flexible and…

Methodology · Statistics 2026-05-19 Tin Lok James Ng , Kwok-Kun Kwong , Jiakun Liu , Andrew Zammit-Mangion

We introduce persistence spheres, a novel functional representation of persistence diagrams. Unlike existing embeddings (such as persistence images, landscapes, or kernel methods), persistence spheres provide a bi-continuous mapping: they…

Machine Learning · Computer Science 2025-10-01 Matteo Pegoraro

Many astrophysical phenomena are time-varying, in the sense that their brightness change over time. In the case of periodic stars, previous approaches assumed that changes in period, amplitude, and phase are well described by either…

Methodology · Statistics 2022-02-02 Giovanni Motta , Darlin Soto , Márcio Catelan

We study a classical reparametrization-invariant system, in which ``time'' is not a priori defined. It consists of a nonrelativistic particle moving in five dimensions, two of which are compactified to form a torus. There, assuming a…

General Relativity and Quantum Cosmology · Physics 2009-11-07 H. -Th. Elze , O. Schipper

A notorious problem in mathematics and physics is to create a solvable model for random sequential adsorption of non-overlapping congruent spheres in the $d$-dimensional Euclidean space with $d\geq 2$. Spheres arrive sequentially at…

Probability · Mathematics 2019-01-25 Souvik Dhara , Johan S. H. van Leeuwaarden , Debankur Mukherjee

Spatiotemporal forecasting is critical for real-world applications like traffic management, yet capturing reliable interactions remains challenging under noisy and non-stationary conditions. Existing methods primarily rely on historical…

Machine Learning · Computer Science 2026-05-20 Yinghao Ai , Yukai Zhou , Ruoxi Jiang , Junyi An , Chao Qu , Zhijian Zhou , Shiyu Wang , Fenglei Cao , Zenglin Xu , Furao Shen , Yuan Qi

I propose a novel framework that integrates stochastic differential equations (SDEs) with deep generative models to improve uncertainty quantification in machine learning applications involving structured and temporal data. This approach,…

Machine Learning · Statistics 2026-01-09 James Rice

Predicting high-dimensional dynamical systems with irregular time steps presents significant challenges for current data-driven algorithms. These irregularities arise from missing data, sparse observations, or adaptive computational…

Machine Learning · Computer Science 2026-03-27 Kewei Zhu , Yanze Xin , Jinwei Hu , Xiaoyuan Cheng , Yiming Yang , Sibo Cheng

There exists a correlation between geospatial activity temporal patterns and type of land use. A novel self-supervised approach is proposed to stratify landscape based on mobility activity time series. First, the time series signal is…

Artificial Intelligence · Computer Science 2023-04-27 Yi Cao , Swetava Ganguli , Vipul Pandey

Linear autoregressive models serve as basic representations of discrete time stochastic processes. Different attempts have been made to provide non-linear versions of the basic autoregressive process, including different versions based on…

Machine Learning · Statistics 2016-03-17 Edgar A. Valencia , Mauricio A. Álvarez