46,058 research outputs found
Improved Chebyshev series ephemeris generation capability of GTDS
An improved implementation of the Chebyshev ephemeris generation capability in the operational version of the Goddard Trajectory Determination System (GTDS) is described. Preliminary results of an evaluation of this orbit propagation method for three satellites of widely different orbit eccentricities are also discussed in terms of accuracy and computing efficiency with respect to the Cowell integration method. An empirical formula is deduced for determining an optimal fitting span which would give reasonable accuracy in the ephemeris with a reasonable consumption of computing resources
Shock tube instrumentation techniques for study of hypervelocity entry problems
Shock tube instrumentation methods for convective heat transfer study and radiative properties of high temperature gas at conditions simulating hypervelocity entr
Material Flow Analysis: Outcome Focus (MFA:OF) for Elucidating the Role of Infrastructure in the Development of a Liveable City
Engineered infrastructures (i.e., utilities, transport & digital) underpin modern society. Delivering services via these
is especially challenging in cities where differing infrastructures form a web of interdependencies. There must be a
step change in how infrastructures deliver services to cities, if those cities are to be liveable in the future (i.e., provide
for citizen wellbeing, produce less CO2 & ensure the security of the resources they use). Material Flow Analysis
(MFA) is a useful methodology for understanding how infrastructures transfer resources to, within and from cities
and contribute to the city’s metabolism. Liveable Cities, a five-year research programme was established to identify
& test radical engineering interventions leading to liveable cities of the future. In this paper, the authors propose an
outcome-focussed variation on the MFA methodology (MFA: OF), evidenced through work on the resource flows of
Birmingham, UK. These flows include water, energy, food & carbon-intensive materials (e.g., steel, paper, glass), as
well as their associated waste. The contribution MFA: OF makes to elucidating the interactions & interdependencies
between the flows is highlighted and suggestions are made for how it can contribute to the (radical) rethinking of the
engineered infrastructure associated with such flow
Gauge fixing and equivariant cohomology
The supersymmetric model developed by Witten to study the equivariant
cohomology of a manifold with an isometric circle action is derived from the
BRST quantization of a simple classical model. The gauge-fixing process is
carefully analysed, and demonstrates that different choices of gauge-fixing
fermion can lead to different quantum theories.Comment: 18 pages LaTe
Telehealth for expanding the reach of early autism training to parents.
Although there is consensus that parents should be involved in interventions designed for young children with autism spectrum disorder (ASD), parent participation alone does not ensure consistent, generalized gains in children's development. Barriers such as costly intervention, time-intensive sessions, and family life may prevent parents from using the intervention at home. Telehealth integrates communication technologies to provide health-related services at a distance. A 12 one-hour per week parent intervention program was tested using telehealth delivery with nine families with ASD. The goal was to examine its feasibility and acceptance for promoting child learning throughout families' daily play and caretaking interactions at home. Parents became skilled at using teachable moments to promote children's spontaneous language and imitation skills and were pleased with the support and ease of telehealth learning. Preliminary results suggest the potential of technology for helping parents understand and use early intervention practices more often in their daily interactions with children
Breaking the habit: measuring and predicting departures from routine in individual human mobility
Researchers studying daily life mobility patterns have recently shown that humans are typically highly predictable in their movements. However, no existing work has examined the boundaries of this predictability, where human behaviour transitions temporarily from routine patterns to highly unpredictable states. To address this shortcoming, we tackle two interrelated challenges. First, we develop a novel information-theoretic metric, called instantaneous entropy, to analyse an individual’s mobility patterns and identify temporary departures from routine. Second, to predict such departures in the future, we propose the first Bayesian framework that explicitly models breaks from routine, showing that it outperforms current state-of-the-art predictor
Spatial electron density and electric field strength measurements in microwave cavity experiments
Measurements of electron density and electric field strength have been made in an argon plasma contained in a resonant microwave cavity at 2.45 GHz. Spatial measurements of electron density, n sub e, are correlated with fluorescence observations of the discharge. Measurements of n sub e were made with Stark broadening and compared with n sub 3 calculated from measured plasma conductivity. Additional measurements of n sub 3 as a function of pressure and in mixtures of argon and oxygen are presented for pressures from 10 Torr to 1 atm. Measurements in flowing gases and in static systems are presented. In addition, limitations of these measurements are identified
Old and New Fields on Super Riemann Surfaces
The ``new fields" or ``superconformal functions" on super Riemann
surfaces introduced recently by Rogers and Langer are shown to coincide with
the Abelian differentials (plus constants), viewed as a subset of the functions
on the associated super Riemann surface. We confirm that, as originally
defined, they do not form a super vector space.Comment: 9 pages, LaTex. Published version: minor changes for clarity, two new
reference
INS3D: An incompressible Navier-Stokes code in generalized three-dimensional coordinates
The operation of the INS3D code, which computes steady-state solutions to the incompressible Navier-Stokes equations, is described. The flow solver utilizes a pseudocompressibility approach combined with an approximate factorization scheme. This manual describes key operating features to orient new users. This includes the organization of the code, description of the input parameters, description of each subroutine, and sample problems. Details for more extended operations, including possible code modifications, are given in the appendix
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