5,865 research outputs found
Proving the correctness of the flight director program EADIFD, volume 1
EADIFD is written in symbolic assembly language for execution on the C4000 airborne computer. It is a subprogram of an aircraft navigation and guidance program and is used to generate pitch and roll command signals for use in terminal airspace. The proof of EADIFD was carried out by an inductive assertion method consisting of two parts, a verification condition generator and a source language independent proof checker. With the specifications provided by NASA, EADIFD was proved correct. The termination of the program is guaranteed and the program contains no instructions that can modify it under any conditions
Technical Note: The impact of spatial scale in bias correction of climate model output for hydrologic impact studies
Statistical downscaling is a commonly used technique for translating
large-scale climate model output to a scale appropriate for assessing
impacts. To ensure downscaled meteorology can be used in climate impact
studies, downscaling must correct biases in the large-scale signal. A simple
and generally effective method for accommodating systematic biases in
large-scale model output is quantile mapping, which has been applied to many
variables and shown to reduce biases on average, even in the presence of
non-stationarity. Quantile-mapping bias correction has been applied at
spatial scales ranging from hundreds of kilometers to individual
points, such as weather station locations. Since water resources and other
models used to simulate climate impacts are sensitive to biases in input
meteorology, there is a motivation to apply bias correction at a scale fine
enough that the downscaled data closely resemble historically observed
data, though past work has identified undesirable consequences to applying
quantile mapping at too fine a scale. This study explores the role of the
spatial scale at which the quantile-mapping bias correction is applied, in
the context of estimating high and low daily streamflows across the western
United States. We vary the spatial scale at which quantile-mapping bias
correction is performed from 2° ( ∼  200 km) to
1∕8° ( ∼  12 km) within a statistical downscaling
procedure, and use the downscaled daily precipitation and temperature to
drive a hydrology model. We find that little additional benefit is obtained,
and some skill is degraded, when using quantile mapping at scales finer than
approximately 0.5° ( ∼  50 km). This can provide
guidance to those applying the quantile-mapping bias correction method for
hydrologic impacts analysis
Blogging about Service-Learning Experiences
Presentation given at the SoTL Commons: A Conference for the Scholarship of Teaching and Learning. This project examines a year-long Honors First Year Experience course in Animal-Assisted Therapy, a course introducing students to the effects of therapy animals on various populations with various conditions in multiple settings. From Fall 2012 to Spring 2013, students were required to participate in service-learning activities with either the local chapter of Therapy Dogs International or the local therapeutic horseback riding program and to blog about their experiences. For their blogs, students had to describe their experiences, their reactions to the experiences, how the experiences related to the course, and any questions or concerns that arose. Qualitative analyses of students’ blogs were conducted, using a Grounded Theory approach. Results revealed that students could identify the key role therapy animals can play in enhancing rehabilitation and development. Additionally, service-learning augmented the students’ knowledge of, awareness of, and interest in animal-assisted therapy and showed how animals themselves appear to act as crucial learning instruments in certain settings. Session objectives include introducing attendees to service-learning and exploring the lurking implication that animals can enhance learning environments. Attendees will learn how service-learning has the potential to add to all disciplines and will be challenged to think of ways to implement animals into student learning
The Claims Culture: A Taxonomy of Industry Attitudes
This paper presents an analysis of a familiar aspect of construction industry culture that we have dubbed 'the claims culture'. This is a culture of contract administration that lays a strong emphasis on the planning and management of claims. The principal elements of the analysis are two sets of distinctions. The first comprises economic and occupational orders, referring to two kinds of control that are exercised over the construction process; predicated respectively on economic ownership and occupational competence. The second refers to contrasting attitudes towards relationships and problem solving within these orders: respectively 'distributive' and 'integrative'. The concepts of economic and occupational order entail further sub-categories. The various attitudes associated with these categories and sub-categories are described. They are assessed as to their consequences for change initiatives in the industry
Specific heat of the Kelvin modes in low temperature superfluid turbulence
It is pointed out that the specific heat of helical vortex line excitations,
in low temperature superfluid turbulence experiments carried out in helium II,
can be of the same order as the specific heat of the phononic quasiparticles.
The ratio of Kelvin mode and phonon specific heats scales with L_0 T^{-5/2},
where L_0 represents the smoothed line length per volume within the vortex
tangle, such that the contribution of the vortex mode specific heat should be
observable for L_0 = 10^6-10^8 cm^{-2}, and at temperatures which are of order
1-10 mK.Comment: 3 pages, 1 figur
Polarization of superfluid turbulence
We show that normal fluid eddies in turbulent helium II polarize the tangle
of quantized vortex lines present in the flow, thus inducing superfluid
vorticity patterns similar to the driving normal fluid eddies. We also show
that the polarization is effective over the entire inertial range. The results
help explain the surprising analogies between classical and superfluid
turbulence which have been observed recently.Comment: 3 figure
Flow Phase Diagram for the Helium Superfluids
The flow phase diagram for He II and He-B is established and discussed
based on available experimental data and the theory of Volovik [JETP Letters
{\bf{78}} (2003) 553]. The effective temperature - dependent but scale -
independent Reynolds number , where
and are the mutual friction parameters and the superfluid Reynolds
number characterizing the circulation of the superfluid component in units of
the circulation quantum are used as the dynamic parameters. In particular, the
flow diagram allows identification of experimentally observed turbulent states
I and II in counterflowing He II with the turbulent regimes suggested by
Volovik.Comment: 2 figure
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