Title
Post Hoc Explainability for Time Series Classification: Toward a signal processing perspective
Abstract
Time series data correspond to observations of phenomena that are recorded over time <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> . Such data are encountered regularly in a wide range of applications, such as speech and music recognition, monitoring health and medical diagnosis, financial analysis, motion tracking, and shape identification, to name a few. With such a diversity of applications and the large variations in their characteristics, time series classification is a complex and challenging task. One of the fundamental steps in the design of time series classifiers is that of defining or constructing the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">discriminant features</i> that help differentiate between classes. This is typically achieved by designing novel <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">representation techniques</i> <xref ref-type="bibr" rid="ref2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[2]</xref> that transform the raw time series data to a new data domain, where subsequently a classifier is trained on the transformed data, such as one-nearest neighbors <xref ref-type="bibr" rid="ref3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[3]</xref> or random forests <xref ref-type="bibr" rid="ref4" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[4]</xref> . In recent time series classification approaches, deep neural network models have been employed that are able to jointly learn a representation of time series and perform classification <xref ref-type="bibr" rid="ref5" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[5]</xref> . In many of these sophisticated approaches, the discriminant features tend to be complicated to analyze and interpret, given the high degree of nonlinearity.
Year
DOI
Venue
2022
10.1109/MSP.2022.3155955
IEEE Signal Processing Magazine
Keywords
DocType
Volume
post hoc explainability,signal processing perspective,music recognition,medical diagnosis,time series classifiers,discriminant features,raw time series data,data domain,transformed data,recent time series classification approaches
Journal
39
Issue
ISSN
Citations 
4
1053-5888
0
PageRank 
References 
Authors
0.34
16
5
Name
Order
Citations
PageRank
Rami Mochaourab100.34
Arun Venkitaraman200.34
Isak Samsten300.34
Panagiotis Papapetrou445243.51
Cristian R. Rojas525243.97