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Measurement of the velocity field in thermal-hydraulic experiments is of great importance for phenomena interpretation and code validation. Direct measurement employing Particle Image Velocimetry (PIV) is challenging in some multiphase…

Fluid Dynamics · Physics 2025-09-03 Xicheng Wang , YiMeng Chan , KinWing Wong , Dmitry Grishchenko , Pavel Kudinov

Inhomogeneous refractive index fields lead to errors in optical flow velocity measurements. Former respective studies are mostly in quasi two-dimensional flows, and attribute the measurement errors to spatial gradients in the refractive…

Fluid Dynamics · Physics 2025-02-04 Huixin Li , Andreas Fischer , Marc Avila , Duo Xu

While flow matching is elegant, its reliance on single-sample conditional velocities leads to high-variance training targets that destabilize optimization and slow convergence. By explicitly characterizing this variance, we identify 1) a…

Computer Vision and Pattern Recognition · Computer Science 2026-02-06 Donglin Yang , Yongxing Zhang , Xin Yu , Liang Hou , Xin Tao , Pengfei Wan , Xiaojuan Qi , Renjie Liao

In the real world, trajectory data is often sparse and incomplete due to low collection frequencies or limited device coverage. Trajectory recovery aims to recover these missing trajectory points, making the trajectories denser and more…

Artificial Intelligence · Computer Science 2025-03-25 Qingyue Long , Can Rong , Huandong Wang , Shaw Rajib , Yong Li

We experimentally assess the capabilities of an active, open-loop technique for drag reduction in turbulent wall flows recently introduced by Quadrio et al. [J. Fluid Mech., v.627, 161, (2009)]. The technique consists in generating…

Fluid Dynamics · Physics 2015-05-19 Franco Auteri , Arturo Baron , Marco Belan , Gabriele Campanardi , Maurizio Quadrio

Predicting the near-term behavior of a reactive agent is crucial in many robotic scenarios, yet remains challenging when observations of that agent are sparse or intermittent. Vision-Language Models (VLMs) offer a promising avenue by…

Reference frame optimization is a generic framework to calculate a spatially-varying observer field that views an unsteady fluid flow in a reference frame that is as-steady-as-possible. In this paper, we show that the optimized vector field…

Fluid Dynamics · Physics 2021-11-03 Holger Theisel , Markus Hadwiger , Peter Rautek , Thomas Theußl , Tobias Günther

Ideally, robots should move in ways that maximize the knowledge gained about the state of both their internal system and the external operating environment. Trajectory design is a challenging problem that has been investigated from a…

Robotics · Computer Science 2022-01-07 Christopher Grebe , Emmett Wise , Jonathan Kelly

Understanding human mobility is an important aspect of traffic analysis and urban planning. Trajectories provide detailed views on specific routes, but typically do not capture all traffic. Loop detectors capture all traffic flow at…

Computational Geometry · Computer Science 2020-12-10 Bram Custers , Wouter Meulemans , Bettina Speckmann , Kevin Verbeek

Event cameras hold significant promise for high-temporal-resolution (HTR) motion estimation. However, estimating event-based HTR optical flow faces two key challenges: the absence of HTR ground-truth data and the intrinsic sparsity of event…

Computer Vision and Pattern Recognition · Computer Science 2025-08-20 Qianang Zhou , Zhiyu Zhu , Junhui Hou , Yongjian Deng , Youfu Li , Junlin Xiong

Constructing valid and informative conformal prediction regions for multi-dimensional outputs remains a fundamental challenge. While conformal prediction provides finite-sample, distribution-free coverage guarantees, its practical…

Machine Learning · Statistics 2026-05-11 Zhenhan Fang , Aixin Tan , Jian Huang

This paper concerns applications of a recently-developed output-tracking technique to trajectory control of autonomous vehicles. The technique is based on three principles: Newton-Raphson flow for solving algebraic equations,output…

Systems and Control · Computer Science 2019-03-07 Shashwat Shivam , Ian Buckley , Yorai Wardi , Carla Seatzu , Magnus Egerstedt

Trajectory segmentation refers to dividing a trajectory into meaningful consecutive sub-trajectories. This paper focuses on trajectory segmentation for 3D rigid-body motions. Most segmentation approaches in the literature represent the…

Robotics · Computer Science 2024-10-28 Arno Verduyn , Maxim Vochten , Joris De Schutter

We introduce OpenVO, a novel framework for Open-world Visual Odometry (VO) with temporal awareness under limited input conditions. OpenVO effectively estimates real-world-scale ego-motion from monocular dashcam footage with varying…

Computer Vision and Pattern Recognition · Computer Science 2026-04-28 Phuc D. A. Nguyen , Anh N. Nhu , Ming C. Lin

We use importance sampling in a redefined way to highlight and investigate rare events in the form of trajectories trapped inside a target coherent set. We take a transfer operator approach to finding these sets on a reconstructed…

Chaotic Dynamics · Physics 2020-10-16 Meagan Carney , Holger Kantz

3D Multi-Object Tracking (MOT) is an important part of the unmanned vehicle perception module. Most methods optimize object detection and data association independently. These methods make the network structure complicated and limit the…

Computer Vision and Pattern Recognition · Computer Science 2022-03-07 Yueling Shen , Guangming Wang , Hesheng Wang

Trajectories that capture object movement have numerous applications, in which similarity computation between trajectories often plays a key role. Traditionally, the similarity between two trajectories is quantified by means of heuristic…

Databases · Computer Science 2024-06-13 Yanchuan Chang , Egemen Tanin , Gao Cong , Christian S. Jensen , Jianzhong Qi

Trajectory analysis is essential in many applications. In this paper, we address the problem of representing motion trajectories in a highly informative way, and consequently utilize it for analyzing trajectories. Our approach first…

Computer Vision and Pattern Recognition · Computer Science 2017-04-27 Weiyao Lin , Yang Zhou , Hongteng Xu , Junchi Yan , Mingliang Xu , Jianxin Wu , Zicheng Liu

The rotational dynamics of anisotropic particles advected in a turbulent fluid flow are important in many industrial and natural setting. Particle rotations are controlled by small scale properties of turbulence that are nearly universal,…

Fluid Dynamics · Physics 2013-04-19 Shima Parsa , Enrico Calzavarini , Federico Toschi , Greg A. Voth

We present simultaneous experimental measurements of the dynamics of anisotropic particles transported by a turbulent flow and the velocity gradient tensor of the flow surrounding them. We track both rod-shaped particles and small spherical…

Fluid Dynamics · Physics 2015-06-23 Rui Ni , Stefan Kramel , Nicholas T. Ouellette , Greg A. Voth