Phase modulator Patent

Phase modulator with tuned variable length electrical lines including coupling and varactor diode circuit

Methods of determining loads and fiber orientations in anisotropic non-crystalline materials using energy flux deviation

An ultrasonic wave is applied to an anisotropic sample material in an initial direction and an angle of flux deviation of the ultrasonic wave front is measured from this initial direction. This flux deviation angle is induced by the unknown applied load. The flux shift is determined between this flux deviation angle and a previously determined angle of flux deviation of an ultrasonic wave applied to a similar anisotropic reference material under an initial known load condition. This determined flux shift is then compared to a plurality of flux shifts of a similarly tested, similar anisotropic reference material under a plurality of respective, known load conditions, whereby the load applied to the particular anisotropic sample material is determined. A related method is disclosed for determining the fiber orientation from known loads and a determined flux shift

Fixpoint semantics for logic programming a survey

AbstractThe variety of semantical approaches that have been invented for logic programs is quite broad, drawing on classical and many-valued logic, lattice theory, game theory, and topology. One source of this richness is the inherent non-monotonicity of its negation, something that does not have close parallels with the machinery of other programming paradigms. Nonetheless, much of the work on logic programming semantics seems to exist side by side with similar work done for imperative and functional programming, with relatively minimal contact between communities. In this paper we summarize one variety of approaches to the semantics of logic programs: that based on fixpoint theory. We do not attempt to cover much beyond this single area, which is already remarkably fruitful. We hope readers will see parallels with, and the divergences from the better known fixpoint treatments developed for other programming methodologies

An Analysis of Changes in Seasonal Dynamics and Generational Differences in the Maine Lobster Fishery

The American lobster (Homarus americanus) supports the most valuable single species fishery in the US. Lobster landings have been increasing steadily for the last three decades, but before that landings were more variable. The high value of the lobster fishery combined with the decline of other commercially important species in this region has created increasing dependence on the resource, and previous research questions the resilience of the fishery in the face of social and environmental changes. Important lobster life history processes, including migration patterns, growth rates, and reproduction, are driven by ocean bottom temperature, which creates a strong seasonal cycle in the fishery; however, warming waters are causing changes to lobster habitat which impact lobster phenology and is causing a shift in the seasonal dynamics of the fishery. Our research aimed to determine if seasonality in the lobster fishery in Maine is changing, specifically how it is changing along the coast. We use modeling to evaluate the changing seasonal dynamics of the fishery at the county level using historical monthly lobster landings. Our results show that the seasonal timing of landings is changing significantly, and changes are not uniform across counties. Previous research has shown that the Maine lobster fishery is experiencing graying of the fleet and that differences in fishing experience between generations of harvesters can influence perceptions and strategies for dealing with change important to social resilience. Our goal was to evaluate social resilience of lobster harvesters through an analysis of generational differences. Through analysis of a mail survey, we examined how perceptions about management, well-being, and the future and strategies for investment and operation differed between generations. We found that across generations, while views on management regulations were similar, there were different strategies for investment and operation, as well as different perceptions about the future and personal well-being. This thesis contributes information needed to create a better understanding of both the lobster stock and the social dimensions of the system in the face of threats to the fishery. The Gulf of Maine is changing rapidly, and it is critical to understand how these changes will impact the Maine lobster fishery in order to better prepare for and adapt to future changes