Student Activities from Lecture 25
November 29, 2006
Overview
This lecture was designed to give indepth coverage of a single network
flow reduction: reducing the Open Pit mining problem to MinCut. This
lecture had been given last year as a student submission lecture, and
the plan was to give the lecture with only minor changes. The two
changes I decided on were to make the first example a little trickier,
and to drop the final student submission activity.
Activity 1: Construct an Open Pit Mine
Notes: This activity was to find the optimal min in a
moderately large graph. The activity had been introduced by a pair of
slides - so it was clear what the problem was. This activity was
adjusted from last year to make it more challenging - last year, the
"obvious" solution turned out to be the right one - this year the
solution was a fairly small set of nodes.
I was surprised that few students seemed to be bothered by the
anti-environmental slant to the problem!
This example worked well, and was an improvement over last year.
Student submission examples
Activity: Find a Finite Cut
Notes:
This activity was to draw an finite cut in a graph. This required
students to understand that the infinite cost edges could go from T to
S, but not from S to T. The activity was highly technical - but I
believe effective in having students think more deeply about the
points than if they were just presented.
Student submission examples
Activity: Enumerate the Finite Cuts
Notes:
The final activity was to identify cuts on a graph, and give the cut
values. Again, this seemed to be an effective activity for a
technical point, and provided an example that could be discussed in
more detail.
Student submission examples
Activity: Derive the cut value
Notes: This had been a submission activity last year -
however, I had not left enough time for it, and it was too hard, so I
did not expect to use it as an activity. As it turned out, I got a
verbal answer which provided the basis for this discussion. I did the
derivation at the end of lecture very quickly (relying on the
instructor note!)
