I have been wondering what is the meaning of this sigma with delta negative or plus in there (if my read is correct).
$$ \sum_{i \in \Delta^{-}(j)} x_{i j k}-\sum_{i \in \Delta^{+}(j)} x_{j i k}=0 \quad \forall k \in K, j \in N $$
$\begingroup$
$\endgroup$
2
-
$\begingroup$ from the paper : ieeexplore.ieee.org/document/9648591 $\endgroup$– overboxedCommented Jul 20, 2022 at 13:43
-
$\begingroup$ or can refer to toth, and vigo, Vehicle Routing Problem with Time Windows $\endgroup$– overboxedCommented Jul 20, 2022 at 13:44
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
The set of equations are used to represent the conservation of flow at every node $j$ in a network. Here, $\Delta^{-}(j)$ represents the set of nodes coming into node $j$ and $\Delta^{+}(j)$ represents the set of nodes coming out of node $j$.
