Image Processing Reference
In-Depth Information
Therefore,
e t
11
11
0
e At
(t)M 1
¼ ML
¼
e 2t
1
2
0
1
2
2e t
e 2t
e t
e 2t
¼
2e t
2e 2t
e t
2e 2t
þ
þ
Since matrix A is nonsingular, we have
1
ð
t
01
2e t
e 2t
e t
e 2t
10
01
e At d
t¼A 1 (e At
I)
¼
2e t
2e 2t
e t
2e 2t
2
3
þ
þ
0
2e t
1
5
10
:
5
0
:
e 2t
1
e t
e 2t
¼
2e t
2e 2t
e t
2e 2t
þ
þ
1
2e t
5e 2t
e t
5e 2t
þ
0
:
þ
1
:
5
0
:
¼
2e t
e 2t
e t
e 2t
1
(b) In this case, matrix A is singular, and
2e t
2e t
1
þ
2
e At
¼
þ e t
e t
1
2
Therefore, we use direct integration:
2
4
3
5 ¼
Ð
t
t Ð
t
2e t )d
2e t )d
ð
t
(
1
þ
(2
t
2e t 2t þ
2e t
t
2
þ
2
e At d
0
0
t ¼
Ð
Ð
t
t
t
1
þe t
2t þ
1
e t
þe t )d
e t )d
(
1
t
(2
t
0
0
0
3.11.6 C OMPUTING e At U SING L APLACE T RANSFORM
Laplace transform can be used to compute e At . In this method, e At
is computed by
solving the DE describing e At using the Laplace transform. Let
w( t ) ¼ e At , then
dw( t )
d t ¼ Ae At
¼ A w( t )
(
3
:
195
)
) ¼ e A0
with
¼ I
Taking the Laplace transform from both sides of Equation 3.195, we have
w(
0
s F( s ) w(
) ¼ A F( s )
(
:
)
0
3
196
Since w( 0 ) ¼ I, then
( sI A )F( s ) ¼ I
(
3
:
197
)
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