modeling
drorzel | August 12, 2011I am an inveterate driver of "back ways" to places. My preferred route to campus involves driving through a whole bunch of residential streets, rather than taking the "main" road leading from our neighborhood to campus. I do this because there are four traffic lights on the main-road route, and they're not well timed, so it's a rare day when I don't get stuck at one or more of them. My preferred route has a lot of stop signs, but very little traffic, so they're quick stops, and I spend more time in motion, which makes me feel like I'm getting there faster.
That's the psychological reason, but…
lborkowski | February 17, 2011Cross-posted from the American Geophysical Union's GeoSpace blog.
Even though the deadly cholera epidemic in Haiti is now spreading more slowly, health officials are still working to prevent as many new cases as possible. Detailed models of the disease's spread help those in charge of making public health decisions understand the effectiveness of control measures, from vaccines to investments in clean water supply and education.
A new study by Enrico Bertuzzo and colleagues just accepted for publication in Geophysical Research Letters looks at how the Haitian cholera outbreak is likely to…
rallain | July 8, 2010In my last zombie post, I looked at a human moving in a circle to avoid a zombie (if they are stuck in a room). What if I build a zombie evading robot that always moves perpendicular to the path of the zombie? Would this work?
This shouldn't be too difficult to model. I can use my existing model for the zombie (where there is a force towards the human and a drag force). For the right-turning-robot, I will also have a drag force and a "driving" force. How do I find the direction of the driving force for the robot? Here is a diagram.
This Fdrive force will really be the frictional force…
gregladen | February 19, 2009Diatoms are algae with hard parts. They make up a major part of the plankton found in fresh and salt water environments. Usually, diatoms exist as single celled free floating organisms, but they can also be colonies of several single cells. Their tiny little 'shells' are made up of silica (these shells are called "fustules").
The fustules have a characteristic shape that goes with each species, and since these are hard (essentially, made of glass) they are often well preserved in sediments. Thus, diatoms actually provide an excellent, even if very tiny, fossil record. In addition, since…