MAFAT Challenge - WiFi Sensing: Non Invasive Human Presence Detection - Track 2 Forum

Go back to competition Back to thread list Post in this thread

> Evaluation - Definition of occupancy and number of people in non-homogenous windows in the test set

The data in the public and private test sets is partitioned into 3-minute "windows", every window contains 360 entries, one entry every 0.5 seconds, and contains RSSI values from one device only. Participants’ models are required to predict a single prediction of occupancy or people counting (depending on the given track) per every 3-minute window.

Participants have asked us:
How exactly do you define occupancy / people counting in the cases where those windows are not homogenous, i.e. the "ground truth" of occupancy / number of people in the room has different values for different entries inside the same window.

Answer:
Occupancy definition: a window is defined as occupied if there are at least 20 consecutive entries (10 seconds) with one person or more, labeled in the data (ground truth). Otherwise, it’s defined as empty.
Number of people definition: a window is defined as having 3/2/1/0 people in the room if the maximal labeled number of people that appear in at least 20 consecutive entries (10 seconds) is 3/2/1/0 correspondently.

Please note that in the provided baseline model, we assumed homogenous windows (occupied by the same number of people or empty in all window entries) - which is a simplistic and naïve assumption. We recommend the participants implement a more accurate model to support heterogeneous windows as well.

Posted by: MAFAT_Challenge @ May 16, 2022, 12:20 p.m.

"Number of people definition: a window is defined as having 3/2/1/0 people in the room if the maximal labeled number of people that appear in at least 20 consecutive entries (10 seconds) is 3/2/1/0 correspondently."

Confirming that if there are ten entries of 3, ten entries of 2, and the remainder as 0, this would be classified as 0, not 2.

Posted by: TrueFit @ May 17, 2022, 7:46 a.m.

Yes, that's correct.
Notice that this is a (very not probable) edge-case.

MAFAT Challenge Team

Posted by: MAFAT_Challenge @ May 17, 2022, 9 a.m.

I am still confused by the definition,

In the above example, if there were 20 entries of 1, 20 entries of 2, and 20 entries of 3 (instead of 10 entries), and the rest as 0, will the target for this example be 3 ?

Posted by: devnikhilmishra @ May 21, 2022, 9:31 a.m.

Yes indeed.
MAFAT Challenge Team

Posted by: MAFAT_Challenge @ May 22, 2022, 6:29 a.m.

After some questions were raised by participants, we would like to help by providing an example that will further demonstrate the definition of the label for a window.
To make it easier for the reader, we concatenated lists’ labels (0/1/2/3) sequences so that the length will be 360.
Small scale example: np.array(([0] * 5) + ([1] * 3) is [0,0,0,0,0,1,1,1]Now, suppose there are five windows, and these are their Num_People:
Num_People_win1 = np.array(([0] * 100) + ([1] * 19) + ([2] * 2) + ([0] * 239))
Num_People_win2 = np.array(([0] * 200) + ([1] * 19) + ([0] * 5) + ([1] * 20) + ([0] * 116))
Num_People_win3 = np.array(([1] * 100) + ([2] * 21) + ([0] * 220)+([3]*19))
Num_People_win4 = np.array(([2] * 90) + ([1] * 90) + ([3] * 90) + ([0] * 90))
Num_People_win5 = np.array(([0] * 50) + ([1] * 19) + ([0] * 100) + ([3] * 15) +([2]*3)+ ([0]*173))

In track1 the labels for that windows:
1
1
1
1
0

In track2 the labels for that windows:
0
1
2
3
0
MAFAT Challenge Team

Posted by: MAFAT_Challenge @ June 16, 2022, 8:07 a.m.
Post in this thread