Deep learning based classification of sheep behaviour from accelerometer data with imbalance

Classification of sheep behaviour from a sequence of tri-axial accelerometer data has the potential to enhance sheep management. Sheep behaviour is inherently imbalanced (e.g., more ruminating than walking) resulting in underperforming classification for the minority activities which hold importance...

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Main Authors: Kirk E. Turner, Andrew Thompson, Ian Harris, Mark Ferguson, Ferdous Sohel
Format: Article
Language:English
Published: Elsevier 2023-09-01
Series:Information Processing in Agriculture
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2214317322000415
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author Kirk E. Turner
Andrew Thompson
Ian Harris
Mark Ferguson
Ferdous Sohel
author_facet Kirk E. Turner
Andrew Thompson
Ian Harris
Mark Ferguson
Ferdous Sohel
author_sort Kirk E. Turner
collection DOAJ
description Classification of sheep behaviour from a sequence of tri-axial accelerometer data has the potential to enhance sheep management. Sheep behaviour is inherently imbalanced (e.g., more ruminating than walking) resulting in underperforming classification for the minority activities which hold importance. Existing works have not addressed class imbalance and use traditional machine learning techniques, e.g., Random Forest (RF). We investigated Deep Learning (DL) models, namely, Long Short Term Memory (LSTM) and Bidirectional LSTM (BLSTM), appropriate for sequential data, from imbalanced data. Two data sets were collected in normal grazing conditions using jaw-mounted and ear-mounted sensors. Novel to this study, alongside typical single classes, e.g., walking, depending on the behaviours, data samples were labelled with compound classes, e.g., walking_grazing. The number of steps a sheep performed in the observed 10 s time window was also recorded and incorporated in the models. We designed several multi-class classification studies with imbalance being addressed using synthetic data. DL models achieved superior performance to traditional ML models, especially with augmented data (e.g., 4-Class + Steps: LSTM 88.0%, RF 82.5%). DL methods showed superior generalisability on unseen sheep (i.e., F1-score: BLSTM 0.84, LSTM 0.83, RF 0.65). LSTM, BLSTM and RF achieved sub-millisecond average inference time, making them suitable for real-time applications. The results demonstrate the effectiveness of DL models for sheep behaviour classification in grazing conditions. The results also demonstrate the DL techniques can generalise across different sheep. The study presents a strong foundation of the development of such models for real-time animal monitoring.
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spelling doaj.art-435f6ee3b9b2413ea49006f3555181032023-09-22T04:38:47ZengElsevierInformation Processing in Agriculture2214-31732023-09-01103377390Deep learning based classification of sheep behaviour from accelerometer data with imbalanceKirk E. Turner0Andrew Thompson1Ian Harris2Mark Ferguson3Ferdous Sohel4Discipline of Information Technology, Murdoch University, Murdoch, WA 6150, Australia; Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA 6150, AustraliaCollege of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA 6150, AustralianeXtgen Agri, Saint Martins, Christchurch 8022, New ZealandneXtgen Agri, Saint Martins, Christchurch 8022, New ZealandDiscipline of Information Technology, Murdoch University, Murdoch, WA 6150, Australia; Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia; Corresponding author at: Discipline of Information Technology, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.Classification of sheep behaviour from a sequence of tri-axial accelerometer data has the potential to enhance sheep management. Sheep behaviour is inherently imbalanced (e.g., more ruminating than walking) resulting in underperforming classification for the minority activities which hold importance. Existing works have not addressed class imbalance and use traditional machine learning techniques, e.g., Random Forest (RF). We investigated Deep Learning (DL) models, namely, Long Short Term Memory (LSTM) and Bidirectional LSTM (BLSTM), appropriate for sequential data, from imbalanced data. Two data sets were collected in normal grazing conditions using jaw-mounted and ear-mounted sensors. Novel to this study, alongside typical single classes, e.g., walking, depending on the behaviours, data samples were labelled with compound classes, e.g., walking_grazing. The number of steps a sheep performed in the observed 10 s time window was also recorded and incorporated in the models. We designed several multi-class classification studies with imbalance being addressed using synthetic data. DL models achieved superior performance to traditional ML models, especially with augmented data (e.g., 4-Class + Steps: LSTM 88.0%, RF 82.5%). DL methods showed superior generalisability on unseen sheep (i.e., F1-score: BLSTM 0.84, LSTM 0.83, RF 0.65). LSTM, BLSTM and RF achieved sub-millisecond average inference time, making them suitable for real-time applications. The results demonstrate the effectiveness of DL models for sheep behaviour classification in grazing conditions. The results also demonstrate the DL techniques can generalise across different sheep. The study presents a strong foundation of the development of such models for real-time animal monitoring.http://www.sciencedirect.com/science/article/pii/S2214317322000415Sheep behaviour classificationData synthesisClass imbalanceGrazing sheep
spellingShingle Kirk E. Turner
Andrew Thompson
Ian Harris
Mark Ferguson
Ferdous Sohel
Deep learning based classification of sheep behaviour from accelerometer data with imbalance
Information Processing in Agriculture
Sheep behaviour classification
Data synthesis
Class imbalance
Grazing sheep
title Deep learning based classification of sheep behaviour from accelerometer data with imbalance
title_full Deep learning based classification of sheep behaviour from accelerometer data with imbalance
title_fullStr Deep learning based classification of sheep behaviour from accelerometer data with imbalance
title_full_unstemmed Deep learning based classification of sheep behaviour from accelerometer data with imbalance
title_short Deep learning based classification of sheep behaviour from accelerometer data with imbalance
title_sort deep learning based classification of sheep behaviour from accelerometer data with imbalance
topic Sheep behaviour classification
Data synthesis
Class imbalance
Grazing sheep
url http://www.sciencedirect.com/science/article/pii/S2214317322000415
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AT ianharris deeplearningbasedclassificationofsheepbehaviourfromaccelerometerdatawithimbalance
AT markferguson deeplearningbasedclassificationofsheepbehaviourfromaccelerometerdatawithimbalance
AT ferdoussohel deeplearningbasedclassificationofsheepbehaviourfromaccelerometerdatawithimbalance