Corporate Response to a New Environment

The problem of minimizing a quadratic criterion for a linear system with control constraint is considered. It is shown how the solution can be generated numerically. A DC motor and a double integrator are used as examples. The importance of scaling the system variables is stressed

Changing Roles and Identities in a Teacher Driven Professional Development Community

In a climate where teachers feel deprofessionalized at the hands of regulations, testing, and politics, it is vital that teachers become empowered both in their own teaching and as agents of change. This physics education research study investigates the Streamline to Mastery professional development program, in which the teachers design professional development opportunities for themselves and for fellow teachers. The research reported here describes the process of teacher professional growth through changes in roles and identities. Videos, emails, and interviews were analyzed to glean insight into practice and participation shifts as these physical science teachers formed a community and engaged in their own classroom research. Implications for the role of PER in teacher professional development and teacher preparation will be discussed.Comment: 4 pages, 3 figures, Physics Education Research Conference 2011 Proceedings, Finalist in the PERC 2011 proceedings paper awar

IN SITU CONSERVATION OF CROP GENETIC RESOURCES IN A CENTER OF DIVERSITY

The purpose of this paper is to model farmer behavior with respect to in situ conservation, extending the existing literature beyond competition within the principal crop to encompass a broader definition of on-farm diversity and testing the hypothesis that factors affecting the principal crop explain overall crop diversity on the farm . Primary survey data is used from a rural area of Puebla state, Mexico. A Poisson regression is run on the total number of species in the milpa system as explained by cultural, agricultural and economic variables. A set of Poisson regressions, one for each crop group, is run in order test whether factors affect different crops in different ways. Policy implication of the findings are discussed for an in situ conservation program.Resource /Energy Economics and Policy,