Thursday, December 28, 2006

Two OR applications in Florida Trip

The first one is queueing theory.
When I was in Magic Kingdom, I found an interesting application of queueing theor - Fast Pass. The procedure is the following. 1) When you see a waiting line is quite long at one attraction say Space Mountain, you can insert your ticket in one machine to get a fast pass which indicates you return during the specific time usually one or two hours laters. 2) Then when you return after playing other stuffs, you can go through the fast pass line.
There are several key points. 1) Once you get your fast pass for one attraction, you cannot get fast pass for another attraction until your current fast pass expire. For example, if I get fast pass for Space Mountain from 1pm to 2pm. I can only get fast pass for Splash Mountain after 2pm. 2) The number of fast pass in one attraction must be limited. Since the available time for the fast pass is different at different attraction, the hotter the attraction is, the longer time difference between available time of fast pass and current will be. In the last attraction-Jungle Cruise we go at 5pm, its fast pass is unavailable. We need to wait 40mins to play.
The decision to make for the visitor. 1) What is the sequence of attraction I should follow. 2) Which attraction should I get the fast pass.
The decision to make for the Theme Park. 1) How much fast passes to available at each attraction and each time periods.
Game theory might not be suitable in this case. Probably, something like priority queue plus abandon and other customer behavior can be used to formulate the problem.

My experience of fast pass in Unversal Studio at CA is different. We got the fast pass after we experienced a half hour technique difficulty at Jurassic Park. Then we can get into fast pass line for every attraction. But actually, you need to spend 30$ to get one fast pass. So the decision for the theme park is how much fast pass to offer and how much to charge.

The second one is network flow. It is very wise decision to buy a GPS just before this trip. We don't need to print every map. And we can avoid the traffic jam in the high way by going through the local. It was very crucial when we tried to catch up our flight back. And the calculation of route is very fast, it is much faster than O(A) I learned last semester. But actually it can only calculate the route from two points. If I want to go several points a day, I need to manually choose the sequence of points I need to goal. If GPS can provide the function of solve small TSP problem such as 5 points, it will be wonderful. Since real map satisfy triangle inequality, there is heuristic to get solution within 1.5 time of optimal solution. So the calculation time won't increase a lot.

3 comments:

Anonymous said...

Nice trip :)

By the way, how much is your GPS and what is the brand? I am thinking buying one. Any suggestions?

Ying said...

Mine is Garmin C320 with $270 from Walmart. I think it is enough. Fast calculation and accurate voice command. And if the two consecutive turn is quite close. It will give tell tell before the first turn such as turn right and turn left. There are two drawbacks. One is you cannot find a route based on toll free requirement. The second is that it cannot tell you street name by voice. But they are minor. For the first one, you just bring AAA map. For the second, it is easy to get to used. I don't think the GPS over $300 is worth buying.

Also Mio is quite good low-price brand considering its utility/price ratio. I was told that it can be hacked to be a PDA so that you don't need to put another MP3 player in your car.

Anonymous said...

Thanks! I will buy one for my graduation road trip.