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Table 18.3: Post-ictal: Results of the ADF unit root tests for each channel during
the segments 2 s immediately
after each seizure
for three consecutive seizures. (The
significance level is set at 2.5%)
Seizure #
Stationary
Integrated
Seizure 1
1,3,5,6,7,8,9,10,12,14,15
2,4,13,16
Seizure 2
2,3,5,7,8,10,11,12,13,14,15,16
1,4,6,9
Seizure 3
1,2,4,5,7,8,11,12,13,15,16
3,6,9,10,14
Akaike information criteria (AIC) was used. This led us to choose several lag length
for each segment and each seizure. Finally, Johansen cointegration rank procedure
was applied to determine the values of cointegration rank
r
for each case. The results
are summarized in Tables 18.4, 18.5, and 18.6.
Table 18.4: Pre-ictal cointegration rank: Results of the Johansen procedure for the
multiple series during 2 s immediately before seizure for three consecutive seizures.
Significance level is 1%. Full rank is denoted by
†
Seizure #
Short lag
Long lag
pr
pr
Seizure 1
p
=
2
,
r
=
13
p
=
22
,
r
=
12
p
=
,
r
=
p
=
,
r
=
Seizure 2
2
16
†
21
14
p
=
,
r
=
p
=
,
r
=
Seizure 3
2
9
24
13
Table 18.5: Ictal cointegration rank: Results of the Johansen procedure for the mul-
tiple series during a seizure. Significance level is 1%. Full rank
is denoted by
†
Seizure #
Short lag
Long lag
pr
pr
Seizure 1
p
=
2
,
r
=
16
†
p
=
23
,
r
=
11,
p
=
20
,
r
=
13
Seizure 2
p
=
3
,
r
=
16
†
p
=
26
,
r
=
12,
p
=
20
,
r
=
9
Seizure 3
p
=
2
,
r
=
16
†
p
=
26
,
r
=
16
†
,
p
=
20
,
r
=
16
†
Notice that during the seizure the system becomes stable, especially when mod-
eled using a short estimate of the lag parameter. Since the durations of the seizure 1
and seizure 2 are rather short, and only include 440-500 sample points, the models
