Four units in mythology for use in English classes in grades eight and nine

Thesis (Ed.M.)--Boston University, 1948. This item was digitized by the Internet Archive

Factors Leading to Effectiveness and Satisfaction in Civil Engineer Information Systems

The Air Force Civil Engineer Support Agency (AFCESA) has developed information systems in support of civil engineer operations. Over the last decade, the number of systems has grown to support the breadth of civil engineer functions. At this time, numerous (900+) decentralized systems support civil engineer functions around the world. Due to budget constraints, AFCESA is transforming civil engineer business processes to leverage the workforce in an optimized fashion. In support of this transition, AFCESA is posturing to acquire new information systems in support of civil engineer business processes. To help AFCESA improve upon its suite of information systems development efforts it is important to evaluate the effectiveness of its current systems. This thesis develops a model based on cumulative research to assess information system effectiveness. The thesis evaluates 10 systems developed for the civil engineer community. Predictors of information system effectiveness are System Quality, Information Quality, and Service Quality. The study indicates that one system, GeoBase, is significantly better in all areas of information system effectiveness. It is recommended that future system development be fashioned after GeoBase

Supporting ethnographic studies of ubiquitous computing in the wild

Ethnography has become a staple feature of IT research over the last twenty years, shaping our understanding of the social character of computing systems and informing their design in a wide variety of settings. The emergence of ubiquitous computing raises new challenges for ethnography however, distributing interaction across a burgeoning array of small, mobile devices and online environments which exploit invisible sensing systems. Understanding interaction requires ethnographers to reconcile interactions that are, for example, distributed across devices on the street with online interactions in order to assemble coherent understandings of the social character and purchase of ubiquitous computing systems. We draw upon four recent studies to show how ethnographers are replaying system recordings of interaction alongside existing resources such as video recordings to do this and identify key challenges that need to be met to support ethnographic study of ubiquitous computing in the wild

Plasticity in current-driven vortex lattices

We present a theoretical analysis of recent experiments on current-driven vortex dynamics in the Corbino disk geometry. This geometry introduces controlled spatial gradients in the driving force and allows the study of the onset of plasticity and tearing in clean vortex lattices. We describe plastic slip in terms of the stress-driven unbinding of dislocation pairs, which in turn contribute to the relaxation of the shear, yielding a nonlinear response. The steady state density of free dislocations induced by the applied stress is calculated as a function of the applied current and temperature. A criterion for the onset of plasticity at a radial location $r$ in the disk yields a temperature-dependent critical current that is in qualitative agreement with experiments.Comment: 11 pages, 4 figure

Power systems research at MSFC

Power systems research reviews at Marshall Space Flight Cente

Weak turbulence theory of the non-linear evolution of the ion ring distribution

The nonlinear evolution of an ion ring instability in a low-beta magnetospheric plasma is considered. The evolution of the two-dimensional ring distribution is essentially quasilinear. Ignoring nonlinear processes the time-scale for the quasilinear evolution is the same as for the linear instability 1/t_ql gamma_l. However, when nonlinear processes become important, a new time scale becomes relevant to the wave saturation mechanism. Induced nonlinear scattering of the lower-hybrid waves by plasma electrons is the dominant nonlinearity relevant for plasmas in the inner magnetosphere and typically occurs on the timescale 1/t_ql w(M/m)W/nT, where W is the wave energy density, nT is the thermal energy density of the background plasma, and M/m is the ion to electron mass ratio, which has the consequence that the wave amplitude saturates at a low level, and the timescale for quasilinear relaxation is extended by orders of magnitude