1,831 research outputs found

    NASA control research overview

    Get PDF
    An overview of NASA research activities related to the control of aeronautical vehicles is presented. A groundwork is laid by showing the organization at NASA Headquarters for supporting programs and providing funding. Then a synopsis of many of the ongoing activities is presented, some of which will be presented in greater detail elsewhere. A major goal of the workshop is to provide a showcase of ongoing NASA sponsored research. Then, through the panel sessions and conversations with workshop participants, it is hoped to glean a focus for future directions in aircraft controls research

    Avionics and controls research and technology

    Get PDF
    The workshop provided a forum for industry and universities to discuss the state-of-the-art, identify the technology needs and opportunities, and describe the role of NASA in avionics and controls research

    The Influence of Administrators’ Allocations of the Local Control Funding Formula on African American Students’ Academic Achievement

    Get PDF
    This qualitative phenomenological research explored how administrators perceive Local Control Funding Formula (LCFF) resources and their influence on African American student achievement. The central phenomenon was the role of district office administrators in determining LCFF resource allocations. A nonrandom recruitment selection of 10 public-school transitional kindergarten through Grade 12 district employees in a southern California county from seven districts with African American student populations of 8% or higher participated in the study. The district administrators who participated in semistructured interviews were superintendents, assistant superintendents, and directors. Seven themes emerged from the collected and analyzed data: (a) African American students indirectly addressed by LCFF, (b) African American achievement indirectly impacted by LCFF, (c) LCFF statutory regulations: intentional policy and practice, (d) LCFF metrics to determine effective versus ineffective expenditures, (e) LCFF resource allocation methodology, (f) LCFF voice: advocacy and stakeholder engagement, and (g) culturally responsive school leadership. Districts have flexibility with LCFF to allocate resources to meet local needs and address disparities and inequities that impact historically underperforming student groups. In order to understand how to eradicate the persistent underperformance by African American students, this study looks at the perspective of those who have the LCFF decision-making power to allocate resources in districts

    Teaching forest stand dynamics or what happens when you thin your Marigold plantation

    Get PDF
    Teaching forestry students about forest stand dynamics can be an abstract activity. Very quickly concepts are reduced to mathematical formulae, graphs and diagrams, all with relatively complicated explanations. Alternatively, computer simulation and individual tree models can be used to demonstrate important concepts such as the \u273/2 Power law\u27 of self thinning. Students can also be taken to visit plantations to talk about practical issues of density management and perhaps produce a thinning prescription. However, no single teaching strategy enables students to have \u27hands on\u27 practice at manipulating a real plant population while being able to wait and see the results of their work

    Upland forestry field course, Scotland

    Get PDF

    Direct optical probe of magnon topology in two-dimensional quantum magnets

    Get PDF
    Controlling edge states of topological magnon insulators is a promising route to stable spintronics devices. However, to experimentally ascertain the topology of magnon bands is a challenging task. Here we derive a fundamental relation between the light-matter coupling and the quantum geometry of magnon states. This allows to establish the two-magnon Raman circular dichroism as an optical probe of magnon topology in honeycomb magnets, in particular of the Chern number and the topological gap. Our results pave the way for interfacing light and topological magnons in functional quantum devices

    All-optical generation of antiferromagnetic magnon currents via the magnon circular photogalvanic effect

    Get PDF
    We introduce the magnon circular photogalvanic effect enabled by two-magnon Raman scattering. This provides an all-optical pathway to the generation of directed magnon currents with circularly polarized light in honeycomb antiferromagnetic insulators. The effect is the leading order contribution to magnon photocurrent generation via optical fields. Control of the magnon current by the polarization and angle of incidence of the laser is demonstrated. Experimental detection by sizable inverse spin Hall voltages in platinum contacts is proposed

    Perfect Information Stochastic Priority Games

    Get PDF
    International audienceWe introduce stochastic priority games - a new class of perfect information stochastic games. These games can take two different, but equivalent, forms. In stopping priority games a play can be stopped by the environment after a finite number of stages, however, infinite plays are also possible. In discounted priority games only infinite plays are possible and the payoff is a linear combination of the classical discount payoff and of a limit payoff evaluating the performance at infinity. Shapley games and parity games are special extreme cases of priority games

    Bolus ingestion of whey protein immediately post-exercise does not influence rehydration compared to energy-matched carbohydrate ingestion

    Get PDF
    Whey protein is a commonly ingested nutritional supplement amongst athletes and regular exercisers; however, its role in post-exercise rehydration remains unclear. Eight healthy male and female participants completed two experimental trials involving the ingestion of 35 g of whey protein (WP) or maltodextrin (MD) at the onset of a rehydration period, followed by ingestion of water to a volume equivalent to 150% of the amount of body mass lost during exercise in the heat. The gastric emptying rates of the solutions were measured using 13C breath tests. Recovery was monitored for a further 3 h by the collection of blood and urine samples. The time taken to empty half of the initial solution (T1/2) was different between the trials (WP = 65.5 ± 11.4 min; MD = 56.7 ± 6.3 min; p = 0.05); however, there was no difference in cumulative urine volume throughout the recovery period (WP = 1306 ± 306 mL; MD = 1428 ± 443 mL; p = 0.314). Participants returned to net negative fluid balance 2 h after the recovery period with MD and 3 h with WP. The results of this study suggest that whey protein empties from the stomach at a slower rate than MD; however, this does not seem to exert any positive or negative effects on the maintenance of fluid balance in the post-exercise period
    • …
    corecore