A tight lower-bounding measure for dynamic time warping (DTW) distances for univariate time series was introduced in [Keogh 2002] and a proof for its lower-bounding property was presented. Here we extend these findings to allow lower-bounding of DTW distances for multivariate time series.

Dynamic time warping (DTW), which finds the minimum path by providing non-linear alignments between two time series, has been widely used as a distance measure for time series classification and clustering. However, DTW does not account for the relative importance regarding the phase difference between a reference point and a testing point. Thismay lead tomisclassification especially in applica...

Groundwater levels represent the aggregation of different hydrological processes acting at multiple spatial and temporal scales within aquifer systems. Analyzing trends in groundwater is therefore essential to quantify available resources for beneficial use, devise plans/policies better manage these resources. In this work, three trend analysis methods are employed detect long-term (1971–2021) ...

Data mining has been flourishing in the information-based world. In data mining, the DTW-kNN framework is widely applied for classification in miscellaneous application domains. Most of the studies in the DTW-kNN framework focus on accuracy and speedup. However, with increasingly emphasis on applications of mobile and embedded systems, energy efficiency becomes an urgent consideration in data m...

BACKGROUND Gait ability and cognitive function are interrelated during both normal walking (NW) and dual-task walking (DTW), and gait ability is thus adversely affected by cognitive impairment in both situations. However, this association is insufficiently understood in people with mild cognitive impairment (MCI). Here, we conducted a study with MCI participants, to examine whether the associat...

Annotation of phrases in birdsongs can be helpful to behavioral and population studies. To reduce the need for manual annotation, an automated birdsong phrase classification algorithm for limited data is developed. Limited data occur because of limited recordings or the existence of rare phrases. In this paper, classification of up to 81 phrase classes of Cassin's Vireo is performed using one t...

A DTW-based biometric user authentication system needs a DTW template to set up a warping function for a query biometric. In addition, a matching template is required to examine similarity. In this paper, we present a hardened template to protect the DTW template. For the matching template, it is protected by cryptographic framework. We compare our scheme with a transformation approach and an u...

There are two common methodologies to verify signatures: the functional approach and the parametric approach. In this paper, we propose a new warping technique for the functional approach in signature verification. The commonly used warping technique is dynamic time warping (DTW). It was originally used in speech recognition and has been applied in the field of signature verification with some ...

We propose to learn multiple local Mahalanobis distance metrics to perform knearest neighbor (kNN) classification of temporal sequences. Temporal sequences are first aligned by dynamic time warping (DTW); given the alignment path, similarity between two sequences is measured by the DTW distance, which is computed as the accumulated distance between matched temporal point pairs along the alignme...

The chapter commences with an overview of automatic speech recognition (ASR), which covers not only the de facto standard approach of hidden Markov models (HMMs), but also the tried-andproven techniques of dynamic time warping and artificial neural networks (ANNs). The coverage then switches to Gluck’s (2004) draw-talk-write (DTW) process, developed over the past two decades to assist non-text ...