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In-Depth Information
2 Mathematical Model
⎧
⎫
∑∑∑
∈∈∈
Z
=
Min
Max
X
ijk
d
(1)
⎨
⎬
ij
⎩
⎭
i
S
j
S
k
V
Constraints:
∑∑
∈∈
q
X
≤
W
,
k
∈
V
(2)
i
ijk
k
i
H
j
S
∑
∈
X
=
Y
,
j
∈
S
,
k
∈
V
(3)
ijk
ik
i
S
∑
∈
X
=
Y
,
i
∈
S
,
k
∈
V
(4)
ijk
ik
j
S
{
}
∑∑
∈∈
x
≤
m
−
1
∀
m
⊆
2
...,
n
,
k
∈
V
(5)
ijk
i
S
j
S
{
}
is a series of aggregations of distribution centre in the
place
R
(this essay only has one);
In the formula:
G
r
r
=
1
,...,
R
{
}
H
i
i
=
R
+
1
,...
R
+
N
is a series of clients' aggregations
{}
{
}
in the place
N
;
S
G
H
is the combination of all distribution centres and clients.
U
{
}
V
k
k
=
1
,...
K
is travel vehicle
k
's aggregation;
q
is the demand amount of cli-
(
)
ent
i
i
∈
H
;
W
is travel vehicle
k
's loading capacity;
i
d
is the linear distance from
client
i
to client
j
.
3 Parameter Design for Tabu Search Algorithm
3.1 The Formation of Initial Solution
Given
h
as the total number of client nodes served by vehicle
k
, aggregation
}
to correspond the client nodes served by the number
k
vehicle,
i
Y
signified that vehicle
k
served in node
i
,
R
=
{
y
0
≤
i
≤
h
k
ik
k
Y
0
signified that the number
k
vehicle's
beginning point was distribution centre. The procedures as such:
k
Step1: Order vehicles' initial remaining load capacity:
w
1
=
w
,
k
=
0
,
h
=
0
,
k
k
R
;
Step2: The demand amount corresponding to the
i
client node in a route
=
Φ
q
, order
k
=
1
;
{
1
k
1
1
Step3: if
q
i
w
≤
, then order
w
=
Min
(
w
−
q
),
w
}
, if not turn to Step6;
k
k
i
k
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