Let\u27s Observe!

Teaching the non-science major how to teach science is a challenge! No matter what science course is being taught, professors must model good teaching strategies that promote an inquiry approach that incorporates prior knowledge, connections, a social environment, relevance, and time to actively construct new understandings of scientific concepts

LOTS of LTA applications

Current problems facing the logistical planner in utilizing the new ships of the modern, intermodal sea transportation systems in a logistics-over-the-shore (undeveloped) environment are described. Then the employment of two potential LTA vehicle systems are described and discussed as significant parts of possible solutions to this range of logistical problems. Vulnerability aspects of these LTA vehicles are also briefly addressed because of their possible employment near combat areas

Semigroups, rings, and Markov chains

We analyze random walks on a class of semigroups called ``left-regular bands''. These walks include the hyperplane chamber walks of Bidigare, Hanlon, and Rockmore. Using methods of ring theory, we show that the transition matrices are diagonalizable and we calculate the eigenvalues and multiplicities. The methods lead to explicit formulas for the projections onto the eigenspaces. As examples of these semigroup walks, we construct a random walk on the maximal chains of any distributive lattice, as well as two random walks associated with any matroid. The examples include a q-analogue of the Tsetlin library. The multiplicities of the eigenvalues in the matroid walks are ``generalized derangement numbers'', which may be of independent interest.Comment: To appear in J. Theoret. Proba

The Effects of Airline Behavior on Aircraft Accidents

The purpose of this paper is to study the effects of specific airline business decisions on aircraft accident propensity. Airline safety affects everyone and has large regulatory and policy implications. Existing research has focused largely on three areas: airline financial health, safety and the resulting effects of accidents. I use both Poisson and Negative Binomial models to study two different airline features: low-cost carriers and flight length, and how they relate to the probability of an aircraft accident. Based on results using a Generalized Negative Binomial model, I find statistically significant evidence at the 99% confidence level that a 1-unit increase in the flight length leads to a 0.11% decrease in the number of accidents. I also find statistically significant evidence at the 99% confidence level that when an airline is classified as a low-cost carrier, the number of accidents decreases by 79.16%. These results indicate that a homogenous safety regulation framework is not appropriate for the airline industry with regard to flight length and cost structure