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Related papers: (Quasi)Periodicity Quantification in Video Data, U…

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We present a new method of analysis of measure-preserving dynamical systems, based on frequency analysis and ergodic theory, which extends our earlier work [1]. Our method employs the novel concept of harmonic time average [2], and is…

Chaotic Dynamics · Physics 2014-07-29 Zoran Levnajić , Igor Mezić

We introduce a very general approach to the analysis of signals from their noisy measurements from the perspective of Topological Data Analysis (TDA). While TDA has emerged as a powerful analytical tool for data with pronounced topological…

Signal Processing · Electrical Eng. & Systems 2025-07-29 Juan Manuel Miramont , Kin Aun Tan , Soumendu Sundar Mukherjee , Rémi Bardenet , Subhroshekhar Ghosh

Topological phases of matter have sparked an immense amount of activity in recent decades. Topological materials are classified by topological invariants that act as a non-local order parameter for any symmetry and condition. As a result,…

Materials Science · Physics 2020-12-08 Oded Zilberberg

In artificial-intelligence-aided signal processing, existing deep learning models often exhibit a black-box structure, and their validity and comprehensibility remain elusive. The integration of topological methods, despite its relatively…

Machine Learning · Computer Science 2023-11-28 Pingyao Feng , Siheng Yi , Qingrui Qu , Zhiwang Yu , Yifei Zhu

A function is called quasiperiodic if its fundamental frequencies are linearly independent over the rationals. With appropriate parameters, the sliding window point clouds of such functions can be shown to be dense in tori with dimension…

Algebraic Topology · Mathematics 2023-08-04 Hitesh Gakhar , Jose A. Perea

Generic motion understanding from video involves not only tracking objects, but also perceiving how their surfaces deform and move. This information is useful to make inferences about 3D shape, physical properties and object interactions.…

Computer Vision and Pattern Recognition · Computer Science 2023-04-03 Carl Doersch , Ankush Gupta , Larisa Markeeva , Adrià Recasens , Lucas Smaira , Yusuf Aytar , João Carreira , Andrew Zisserman , Yi Yang

Persistent homology, the study of holes that appear in data as one thickens balls centered around its points over time, has theoretically guaranteed stability. That is, small data perturbations guarantee small changes in the lifetimes of…

Algebraic Topology · Mathematics 2026-04-21 Bala Krishnamoorthy , Elizabeth P. Thompson

Action repetition counting is to estimate the occurrence times of the repetitive motion in one action, which is a relatively new, important but challenging measurement problem. To solve this problem, we propose a new method superior to the…

Computer Vision and Pattern Recognition · Computer Science 2020-03-17 Jianqin Yin , Yanchun Wu , Huaping Liu , Yonghao Dang , Zhiyi Liu , Jun Liu

Periodic point sets model all solid crystalline materials (crystals) whose atoms can be considered zero-sized points with or without atomic types. This paper addresses the fundamental problem of checking whether claimed crystals are novel,…

Computational Geometry · Computer Science 2025-10-03 Daniel E Widdowson , Vitaliy A Kurlin

We present a new test-time optimization method for estimating dense and long-range motion from a video sequence. Prior optical flow or particle video tracking algorithms typically operate within limited temporal windows, struggling to track…

Computer Vision and Pattern Recognition · Computer Science 2023-09-13 Qianqian Wang , Yen-Yu Chang , Ruojin Cai , Zhengqi Li , Bharath Hariharan , Aleksander Holynski , Noah Snavely

Despite the recent success of neural networks in image feature learning, a major problem in the video domain is the lack of sufficient labeled data for learning to model temporal information. In this paper, we propose an unsupervised…

Computer Vision and Pattern Recognition · Computer Science 2016-11-29 Linchao Zhu , Zhongwen Xu , Yi Yang

Generating geometrically consistent videos remains an open challenge: text-to-video diffusion models trained on web-scale data treat geometry only implicitly, leading to object deformation, texture drift, and non-rigid backgrounds under…

Computer Vision and Pattern Recognition · Computer Science 2026-05-19 Jan Ackermann , Shengqu Cai , Boyang Deng , Zhengfei Kuang , Songyou Peng , Gordon Wetzstein

Quantifying patterns in visual or tactile textures provides important information about the process or phenomena that generated these patterns. In manufacturing, these patterns can be intentionally introduced as a design feature, or they…

Computational Geometry · Computer Science 2023-06-13 Max M. Chumley , Melih C. Yesilli , Jisheng Chen , Firas A. Khasawneh , Yang Guo

We investigate a family of quasiperiodic continuous elastic beams, the topological properties of their vibrational spectra, and their relation to the existence of localized modes. We specifically consider beams featuring arrays of ground…

Mesoscale and Nanoscale Physics · Physics 2019-06-04 Raj Kumar Pal , Matheus I. N. Rosa , Massimo Ruzzene

Topological boundary and interface modes are generated in an acoustic waveguide by simple quasi-periodic patternings of the walls. The procedure opens many topological gaps in the resonant spectrum and qualitative as well as quantitative…

Mesoscale and Nanoscale Physics · Physics 2019-03-13 David J. Apigo , Wenting Cheng , Kyle F. Dobiszewski , Emil Prodan , Camelia Prodan

We consider a signal composed of several periods of a periodic function, of which we observe a noisy reparametrisation. The phase estimation problem consists of finding that reparametrisation, and, in particular, the number of observed…

Computational Geometry · Computer Science 2022-05-31 Thomas Bonis , Frédéric Chazal , Bertrand Michel , Wojciech Reise

Quasiperiodicity, a partially synchronous state that precedes the onset of forced synchronization in hydrodynamic systems, exhibits distinct geometrical patterns based on the specific route to lock-in. In this study, we explore these…

We propose a topological framework for the detection of Hopf bifurcations directly from time series, based on persistent homology applied to phase space reconstructions via Takens embedding within the framework of Topological Data Analysis.…

Dynamical Systems · Mathematics 2026-03-31 Jhonathan Barrios , Yásser Echávez , Carlos F. Álvarez

This monograph introduces key concepts and problems in the new research area of Periodic Geometry and Topology for materials applications.Periodic structures such as solid crystalline materials or textiles were previously classified in…

Computational Geometry · Computer Science 2021-06-10 Olga Anosova , Vitaliy Kurlin

We study the persistent homology of both functional data on compact topological spaces and structural data presented as compact metric measure spaces. One of our goals is to define persistent homology so as to capture primarily properties…

Algebraic Topology · Mathematics 2018-11-27 Haibin Hang , Facundo Mémoli , Washington Mio