Abstract
The use of Convolutional Neural Networks (CNNs) as a feature learning method for Human Activity Recognition (HAR) is becoming more and more common. Unlike conventional machine learning methods, which require domain-specic expertise, CNNs can extract features automatically. On the other hand, CNNs require a training phase, making them prone to the cold-start problem. In this work, a case study is presented where the use of a pre-trained CNN feature extractor is evaluated under realistic conditions. The case study consists of two main steps: (i) different topologies and parameters are assessed to identify the best candidate
models for HAR, thus obtaining a pre-trained CNN model. The pre-trained model (ii) is then employed as feature extractor evaluating its use with a large scale real-world dataset. Two CNN applications were considered: Inertial Measurement Unit (IMU) and audio based HAR. For the IMU data balanced accuracy was 91.98% on the UCI-HAR dataset and 67.51% on the real-world Extrasensory dataset. For the audio data, the balanced accuracy was 92.30% on the DCASE 2017 dataset, and 35.24% on the Extrasensory dataset.
models for HAR, thus obtaining a pre-trained CNN model. The pre-trained model (ii) is then employed as feature extractor evaluating its use with a large scale real-world dataset. Two CNN applications were considered: Inertial Measurement Unit (IMU) and audio based HAR. For the IMU data balanced accuracy was 91.98% on the UCI-HAR dataset and 67.51% on the real-world Extrasensory dataset. For the audio data, the balanced accuracy was 92.30% on the DCASE 2017 dataset, and 35.24% on the Extrasensory dataset.
Original language | English |
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Pages (from-to) | 18-32 |
Number of pages | 15 |
Journal | CCF Transactions on Pervasive Computing and Interaction |
Volume | 2 |
Early online date | 24 Jan 2020 |
DOIs | |
Publication status | Published - 31 Mar 2020 |
Keywords
- Convolutional Neural Networks
- Deep learning
- Human Activity Recognition
- Free-living