*3.2. Database*

For this study, two datasets were obtained from UCI Machine Learning Repository [18]. The datasets consist of dataset 1 and dataset 2, containing 5447 data samples and 10,299 data samples, respectively. Dataset 1 was collected from a smartphone worn around the waist of 31 participants within the age group of 22–79 years. Each activity was performed for 60 s. For dataset 2, a group of 30 volunteers with ages ranging 19–48 years were selected. Each person was instructed to follow

a protocol of activities while wearing a waist mounted smartphone. For both datasets, the data collections were performed using Samsung Galaxy S2 smartphones which comprise an accelerometer and gyroscope to acquire tri-axial linear acceleration and angular velocity signals at a sampling rate of 50 Hz. Although the tasks were carried out in laboratory conditions, volunteers were asked to perform freely the sequence of activities aiming to simulate a more naturalistic dataset. Table 1 shows the activities that were carried out for both the datasets.


**Table 1.** List of daily living activities.
