Operations Research 08A: Directed & Undirected Networks

Operations Research 08A: Directed & Undirected Networks


In this video, I’ll talk about directed and
undirected networks. A network is also called a graph. It is defined by two sets of symbols: nodes
and arcs. Nodes are also called vertices. Arcs are also called edges. An arc consists of an ordered pair of nodes
and represents a possible direction of flow. If flow through an arc is allowed in only
one direction, the arc is a directed arc. Otherwise, it is an undirected arc. For the arc (i, j), i is the initial node,
j is the terminal node. Let’s see some examples. This is a network. It has 6 nodes: A, B, C, D, E, F. It has 9
directed arcs: (A,B), (B,C), (C,D), (C,E), (C,F), (A,F), (F,B), (F,E), and (E,D). This is another network. It also has 6 nodes: A through F. It has 9
undirected arcs: (A,B), (B,C), (C,D), (C,E), (C,F), (A,F), (F,B), (F,E), and (E,D). A network that has only directed arcs is called
a directed network. If all its arcs are undirected, the network
is said to be an undirected network. The left one is a directed network. The right one is an undirected network. Okay, these are the concepts of directed and
undirected networks. Thanks for watching.

2 Comments

  • zainabhashimi says:

    OMG this is what I was looking for! I can't express just how much your videos have helped me. Thank you so much!

  • Yong Wang says:

    Hi Guys, please comment and let me know what you think about this Operations Research Open Course. Your feedback is really appreciated. If you enjoy the video, please subscribe and share. All my replies here are only related to the content in my own videos. I am afraid I won't be able to answer other questions. Thanks for your understanding.

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