Happy Holidays O.R. Style

The previous owners of our house were kind enough to leave their piano behind. It’s a beautiful old-school player piano. It uses paper rolls to encode the songs like punch cards (we inherited a number of rolls as well). I’ve never taken piano classes, but every now and then I enjoy poking around the keys until I manage to play something simple. Here’s a picture:

After managing to play “We Wish You a Merry Christmas”, I decided to create a happy-holidays video card as a thank you to all my readers (yes, all nine of you). However, having a tendency to think about alternative lyrics to well-known songs, I could not help doing it again. The result is an O.R.-ish version of the song, which I hope you’ll enjoy.

YouTube Videos on Solving LPs with Excel

This had been in the back burner for a long while. Each time I taught my O.R. class (either undergrad or MBA), I kept thinking that the students would like to be able to see the Excel setup of an LP model over and over again. Many of them are not proficient in Excel, and my class is their first contact with things like absolute cell references and SUMPRODUCT. I watched a number of YouTube videos on the topic, but I wasn’t happy with any of them. Besides, I wanted the video to be about the same example that I use in the classroom. So I decided to bite the bullet and go for it. I think the outcome was decent: not great, but not terrible either. My wife said I sound a little stilted. I agree. I was only willing to do it once, no second takes, which means I was a little nervous :-)

Before I give you the link to the videos, I need to bring your attention to two disclaimers:

Disclaimer 1: I used the demo version of iShowU to record my screen action. That means you’ll see a green watermark on top of the video. I know it’s ugly, but I didn’t want to pay $29.95 for it. At least not until I get some feedback to convince me that I’ll be doing more of these videos.

Disclaimer 2: I shamelessly use the same example that they (used to?) use at the Tepper School in my classes: the “famous” farmer problem (sorry Javier :-). I was the head TA for that class a number of times and I literally sat through it at least 3 or 4 times.

Here they are:

Linear Programming: The Farmer Problem, Part I (9:07 min)

Linear Programming: The Farmer Problem, Part II (8:57 min)

I hope these videos turn out to be useful to my students and to anyone who wants to learn about linear programming and Excel Solver. I’m thinking about doing more videos on the diet problem, transportation, sensitivity analysis, etc. Let’s see how things go.