Geoscience Reference
In-Depth Information
dt
¼
X
N
n
i
d
a
ijk
n
j
ð
t
Þn
k
ð
t
Þþ
b
ij
n
j
ð
t
Þ
ð
2
:
35
Þ
k
;
j¼1
Putting the initial conditions as
n
i
ðÞ
i ¼ 1
ð
; ...;
N
Þ
ð
2
:
36
Þ
the reconstruction task of
ʾ
i
(t) for the arbitrary time t
∈
[0,T] comes down to the
simple task of determining unknown coef
cients based on the criterion:
(
)
E ¼
X
X
M
N
i¼1
n
i
ð
t
s
Þn
i
ð
t
s
Þ
2
½
=
N
=
M
ð
2
:
37
Þ
s¼1
where 0
t
1
t
M
T.
Coef
cients {a
ijk
,b
ij
) can be evaluated as solution of the following optimization
task:
E
0
¼
min
a
ijk
;
b
ij
;n
i
ð
0
Þ
E
ð
2
:
38
Þ
f
g
There are many methods to solve this task. One of them is based on the
Bellman
s dynamic programming method (Bellman and Roth 1966; Krapivin and
Kondratyev 2002; Krapivin 1969; Ram 2010). In this case search of minimal value
of function E comes to the dynamic programming task. Let us supposed that
coef
'
cients {a
ijk
,b
ij
) are functions of time:
n
1
ð
t
Þ
.
n
N
ð
t
Þ
a
111
ð
t
Þ
.
a
NNN
ð
t
Þ
b
11
ð
t
Þ
.
b
NN
ð
t
Þ
Y
ð
t
Þ
¼
ð
2
:
39
Þ
We can consider that a
ijk
=a
ikj
. Then addicting the system (
2.35
) Cauchy
problem (
2.35
), (
2.36
) comes to the following task:
dY
=
dt ¼ G
ðÞ
ð
2
:
40
Þ
Search WWH ::
Custom Search