Model Evaluation Data Processing Model Training Results
Data
Unfolding
Segmentation
&
Labeling
Load data as
Numpy
Random
Forest
Classifier
Dataset
Confusion
Matrix
Classification
Report
Accuracy
Figure 1: Experiments pipeline.
The rest of the paper is organized as follows. Sec-
tion 1 as introduction. The related work is presented
in Section 2. Then, we explain our proposed method-
ology in Section 3, which we explain in it the experi-
ments pipeline shown in Figure 1. After that, we show
our experiments in Section 4. Our results and discus-
sion are presented in Section 5. Finally, Section 6 is
the conclusion of our work and the future plans.
2 RELATED WORK
(Kunze et al., 2005) managed to derive the location
of the acceleration sensor on the user’s body using
the sensor’s signals only. Their algorithm in detecting
the location of the sensor is not affected by the sen-
sor’s orientation. Using this algorithm, they managed
to identify the time periods where the user is walking
and then by using the unique characteristics of walk-
ing they could identify the location of the sensor on
the user’s body. The fact that the location of the sensor
is an interesting context was what motivated them to
do this work. In addition to that, They denoted that the
locations of the sensors was chosen according to reg-
ularly used devices and sensors. They used four clas-
sifiers: C 4.5, Naive Bayes, Naive Bayes simple and
Nearest Neighbor. The experiments were on 6 sub-
jects. They conducted 3 runs each run was between
12 and 15 minutes with 8 activities performed. The
senors were placed on 6 different body parts: wrist,
right side of the head, left trouser’s pocket and left
breast pocket. The C 4.5 classifier got the highest ac-
curacy among the four used classifiers by accuracy
89.81%.
On the other hand, (Vahdatpour et al., 2011) used
accelerometers to capture the motion data of subjects’
actions. This data allowed them to detect the loca-
tion of the sensor on the subject’s body by using a
mixed supervised and unsupervised time series analy-
sis model. They used Support Vector Machine (SVM)
algorithm to identify the sensors’ locations. Further-
more, they used their own dataset which consisted
of 25 subjects with sensors mounted on 10 different
places on the body. Those 10 places were classi-
fied into 6 regions: forearm, upper arm, head, thigh,
shin and waist. In their first conducted experiment,
they trained and tested the SVM on each subject sep-
arately with training and testing ratio 2:8. The results
were 88%, 98% and 100% for the minimum, mean
and maximum precision, respectively. In the second
conducted experiment, they trained the model on ran-
domly chosen segment from different subjects and the
average accuracy for this experiment was 89%.
In (Sztyler and Stuckenschmidt, 2016), the au-
thors presented a dataset with 17 subjects with 8 per-
formed activities, each subject wore 7 sensors on the
head, chest, upper arm, waist, forearm, thigh and shin.
They used acceleration sensor’s data like the previ-
ous two works to identify the sensor’s location by us-
ing a Random Forest Classifier. They introduced their
method for the location identification by treating the
position as a multi class classification problem that
made the sensors’ locations the targeted classes. They
conducted their experiments on each subject individu-
ally, as they reasoned, due to the difference in individ-
ual behaviour and ages. After they had conducted the
experiments, they achieved an average performance
accuracy of 89% across all positions and subjects.
The authors in (Weenk et al., 2013) introduced an
automatic identification method for inertial sensors
on different body parts during walking. This intro-
duced method allows the user to place inertial sen-
sors in a full body or lower body plus trunk configu-
rations. The number of sensors that implemented by
the user ranges from 17 to 8 inertial sensor in the men-
tioned places respectively. Based on the acceleration
and angular velocity data extracted from the user’s
walking for a few seconds, the identification process
is automatically done. Their dataset is composed of
11 healthy subjects performed 35 walking trials, and
then tested on 7 patients after a reconstruction surgery
in their knee. The authors extracted RMS, variance,
correlation and inter-axis correlation co-efficients fea-
tures from magnitudes and the 3D components of the
acceleration, angular acceleration and angular veloc-
ity. In their experiments, the authors used J4.8 deci-
sion tree algorithm as their classifier. J4.8 is an im-
plementation for C 4.5 algorithm which is the same
classifier used in (Kunze et al., 2005). Their process
gets 100% for lower body sensors plus trunk configu-
rations and 97% for full body sensors.
In this work, however, we conduct our experi-
ments on four publicly available datasets with vary-
ing number of subjects and activities using a Random
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