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Diffeomorphic deformable image registration is one of the crucial tasks in medical image analysis, which aims to find a unique transformation while preserving the topology and invertibility of the transformation. Deep convolutional neural…

Image and Video Processing · Electrical Eng. & Systems 2022-02-09 Ameneh Sheikhjafari , Michelle Noga , Kumaradevan Punithakumar , Nilanjan Ray

The Normalizing Flow (NF) models a general probability density by estimating an invertible transformation applied on samples drawn from a known distribution. We introduce a new type of NF, called Deep Diffeomorphic Normalizing Flow (DDNF).…

Machine Learning · Statistics 2018-11-26 Hadi Salman , Payman Yadollahpour , Tom Fletcher , Kayhan Batmanghelich

Recently there has been an increase in the studies on time-series data mining specifically time-series clustering due to the vast existence of time-series in various domains. The large volume of data in the form of time-series makes it…

Machine Learning · Computer Science 2019-12-06 Hossein Kamalzadeh , Abbas Ahmadi , Saeed Mansour

Recent learning-based methods for event-based optical flow estimation utilize cost volumes for pixel matching but suffer from redundant computations and limited scalability to higher resolutions for flow refinement. In this work, we take…

Computer Vision and Pattern Recognition · Computer Science 2025-06-23 Daikun Liu , Lei Cheng , Teng Wang , changyin Sun

Non-stationarity is an intrinsic property of real-world time series and plays a crucial role in time series forecasting. Previous studies primarily adopt instance normalization to attenuate the non-stationarity of original series for better…

Machine Learning · Computer Science 2025-03-05 Tianyu Jia , Zongxia Xie , Yanru Sun , Dilfira Kudrat , Qinghua Hu

Time series analysis plays a vital role in fields such as finance, healthcare, industry, and meteorology, underpinning key tasks including classification, forecasting, and anomaly detection. Although deep learning models have achieved…

Machine Learning · Computer Science 2025-12-17 Da Zhang , Bingyu Li , Zhiyuan Zhao , Feiping Nie , Junyu Gao , Xuelong Li

An algorithm is presented to update the multi-fractal spectrum of a time series in constant time when new data arrives. The discrete wavelet transform (DWT) of the time series is first updated for the new data value. This is done optimally…

Chaotic Dynamics · Physics 2007-05-23 Nicolas Brodu

Dynamic time warping ($\texttt{DTW}$) is one of the most used distance functions to compare time series, e.$\,$g. in nearest neighbor classifiers. Yet, fast state of the art algorithms only compare 1-dimensional time series efficiently. One…

Data Structures and Algorithms · Computer Science 2018-11-28 Jörg P. Bachmann , Johann-Christoph Freytag

This paper addresses the problem of time series forecasting for non-stationary signals and multiple future steps prediction. To handle this challenging task, we introduce DILATE (DIstortion Loss including shApe and TimE), a new objective…

Machine Learning · Statistics 2019-11-12 Vincent Le Guen , Nicolas Thome

In multivariate time series systems, lead-lag relationships reveal dependencies between time series when they are shifted in time relative to each other. Uncovering such relationships is valuable in downstream tasks, such as control,…

Statistical Finance · Quantitative Finance 2023-09-19 Yichi Zhang , Mihai Cucuringu , Alexander Y. Shestopaloff , Stefan Zohren

The dynamic time warping (DTW) distance has been used as a misfit function for wave-equation inversion to mitigate the local minima issue. However, the original DTW distance is not smooth; therefore it can yield a strong discontinuity in…

Geophysics · Physics 2022-03-22 Fuqiang Chen , Daniel Peter , Matteo Ravasi

Producing probabilistic forecasts for large collections of similar and/or dependent time series is a practically relevant and challenging task. Classical time series models fail to capture complex patterns in the data, and multivariate…

Machine Learning · Statistics 2019-05-30 Yuyang Wang , Alex Smola , Danielle C. Maddix , Jan Gasthaus , Dean Foster , Tim Januschowski

Irregular sampling occurs in many time series modeling applications where it presents a significant challenge to standard deep learning models. This work is motivated by the analysis of physiological time series data in electronic health…

Machine Learning · Computer Science 2021-06-08 Satya Narayan Shukla , Benjamin M. Marlin

We introduce a new version of dynamic time warping for samples of observed event times that are modeled as time-warped intensity processes. Our approach is devel- oped within a framework where for each experimental unit or subject in a…

Methodology · Statistics 2012-11-07 Ana Arribas-Gil , Hans-Georg Müller

In many real-world application, e.g., speech recognition or sleep stage classification, data are captured over the course of time, constituting a Time-Series. Time-Series often contain temporal dependencies that cause two otherwise…

Machine Learning · Computer Science 2017-01-10 John Cristian Borges Gamboa

Time series analysis faces significant challenges in handling variable-length data and achieving robust generalization. While Transformer-based models have advanced time series tasks, they often struggle with feature redundancy and limited…

Machine Learning · Computer Science 2025-09-23 Kai Zhang , Siming Sun , Zhengyu Fan , Qinmin Yang , Xuejun Jiang

While most time series are non-stationary, it is inevitable for models to face the distribution shift issue in time series forecasting. Existing solutions manipulate statistical measures (usually mean and std.) to adjust time series…

Machine Learning · Computer Science 2024-07-02 Wei Fan , Kun Yi , Hangting Ye , Zhiyuan Ning , Qi Zhang , Ning An

Deep learning models lack shift invariance, making them sensitive to input shifts that cause changes in output. While recent techniques seek to address this for images, our findings show that these approaches fail to provide…

Machine Learning · Computer Science 2025-02-28 Berken Utku Demirel , Christian Holz

We propose a new class of univariate nonstationary time series models, using the framework of modulated time series, which is appropriate for the analysis of rapidly-evolving time series as well as time series observations with missing…

The numerical analysis of time fractional evolution equations with the second-order elliptic operator including general time-space dependent variable coefficients is challenging, especially when the classical weak initial singularities are…

Numerical Analysis · Mathematics 2021-03-02 Pin Lyu , Seakweng Vong