404 research outputs found
Measuring what matters: the positioning of students in feedback processes within national student satisfaction surveys
The increasing prominence of neoliberal agendas in international higher education has led to greater weight being ascribed to student satisfaction, and the national surveys through which students evaluate courses of study. In this article, we focus on the evaluation of feedback processes. Rather than the transmission of information from teacher to student, greater recognition of the fundamental role of the learner in seeking, generating, and using feedback information is evident in recent international literature. Through an analysis of the framing of survey items from 10 national student satisfaction surveys, we seek to question what conceptions or models of feedback are conveyed through survey items, and how such framing might shape perceptions and practice. Primarily, the surveys promote an outdated view of feedback as information transmitted from teacher to student in a timely and specific manner, largely ignoring the role of the student in learning through feedback processes. Widespread and meaningful change in the ways in which feedback is represented in research, policy, and practice requires a critical review of the positioning of students in artefacts such as evaluation surveys. We conclude with recommendations for practice by proposing amended survey items that are more consistent with contemporary theoretical conceptions of feedback
Personal Pedagogical Systems: Core Beliefs, Foundational Knowledge, and Informal Theories of Teaching
This case study describes a personal pedagogical system that acts a guide for adult educators in their practice. The system reflects core beliefs (assumptions about truth or propriety), foundational knowledge (essential knowledge for effective teaching of adults) and an informal theory of teaching (a theory of what works and what doesn\u27t work), all of which interact dialectically. Implications for further research and practice are discussed
Critical Reflection and Imaginative Engagement: Towards an Integrated Theory of Transformative Learning
Based on a review of the literature, we propose an integrated approach to transformative learning that recognizes the importance of both the rational and affective, as well as the personal and the social dimensions in fostering self-understanding
Planetary Radio Interferometry and Doppler Experiment (PRIDE) Technique: a Test Case of the Mars Express Phobos Fly-by. 2. Doppler tracking: Formulation of observed and computed values, and noise budget
Context. Closed-loop Doppler data obtained by deep space tracking networks
(e.g., NASA's DSN and ESA's Estrack) are routinely used for navigation and
science applications. By "shadow tracking" the spacecraft signal, Earth-based
radio telescopes involved in Planetary Radio Interferometry and Doppler
Experiment (PRIDE) can provide open-loop Doppler tracking data when the
dedicated deep space tracking facilities are operating in closed-loop mode
only. Aims. We explain in detail the data processing pipeline, discuss the
capabilities of the technique and its potential applications in planetary
science. Methods. We provide the formulation of the observed and computed
values of the Doppler data in PRIDE tracking of spacecraft, and demonstrate the
quality of the results using as a test case an experiment with ESA's Mars
Express spacecraft. Results. We find that the Doppler residuals and the
corresponding noise budget of the open-loop Doppler detections obtained with
the PRIDE stations are comparable to the closed-loop Doppler detections
obtained with the dedicated deep space tracking facilities
Tidally Heated Exomoons around Eridani b: Observability and prospects for characterization
Exomoons are expected to orbit gas giant exoplanets just as moons orbit solar
system planets. Tidal heating is present in solar system satellites and it can
heat up their interior depending on their orbital and interior properties. We
aim to identify a Tidally Heated Exomoon's (THEM) orbital parameter space that
would make it observable in infrared wavelengths with MIRI/JWST around
Eridani b. We study the possible constraints on orbital eccentricity
and interior properties that a successful THEM detection in infrared
wavelengths can bring. We also investigate what exomoon properties need to be
independently known in order to place these constraints. We use a coupled
thermal-tidal model to find stable equilibrium points between the tidally
produced heat and heat transported within a moon. For the latter, we consider a
spherical and radially symmetric satellite with heat being transported via
magma advection in a sub-layer of melt (asthenosphere) and convection in the
lower mantle. We incorporate uncertainties in the interior and tidal model
parameters to assess the fraction of simulated moons that would be observable
with MIRI. We find that a THEM orbiting Eridani b with an
eccentricity of 0.02, would need to have a semi-major axis of 4 planetary
Roche-radii for 100% of the simulations to produce an observable moon. These
values are comparable with the orbital properties of gas giant solar system
satellites. We place similar constraints for eccentricities up to 0.1. We
conclude that if the semi-major axis and radius of the moon are known (eg. with
exomoon transits), tidal dissipation can constrain the orbital eccentricity and
interior properties of the satellite, such as the presence of melt and the
thickness of the melt containing sub-layer
Combining astrometry and JUICE-Europa Clipper radio science to improve the ephemerides of the Galilean moons
Context. The upcoming JUICE and Europa Clipper missions targeting Jupiter s Galilean satellites will provide radio science tracking measurements of both spacecraft. Such data are expected to significantly help estimating the moons ephemerides and related dynamical parameters (e.g. tidal dissipation parameters). However, the two missions will yield an imbalanced dataset, with no flybys planned at Io, condensed over less than six years. Current ephemerides solutions for the Galilean moons, on the other hand, rely on ground-based astrometry collected over more than a century which, while being less accurate, bring very valuable constraints on the long-term dynamics of the system. Aims. An improved solution for the Galilean satellites complex dynamics could however be achieved by exploiting the existing synergies between these different observation sets. Methods. To quantify this, we merged simulated radio science data from both JUICE and Europa Clipper spacecraft with existing ground-based astrometric and radar observations, and performed the inversion in different configurations: either adding all available ground observations or individually assessing the contribution of different data subsets. Our discussion specifically focusses on the resulting formal uncertainties in the moons states, as well as Io s and Jupiter s tidal dissipation parameters. Results. Adding astrometry stabilises the moons state solution, especially beyond the missions timelines. It furthermore reduces the uncertainties in 1/Q (inverse of the tidal quality factor) by a factor two to four for Jupiter, and about 30- 35% for Io. Among all data types, classical astrometry data prior to 1960 proved particularly beneficial. Overall, we also show that ground observations of Io add the most to the solution, confirming that ground observations can fill the lack of radio science data for this specific moon. Conclusions. We obtained a noticeable solution improvement when making use of the complementarity between all different observation sets. The promising results obtained with simulations thus motivate future efforts to achieve a global solution from actual JUICE and Clipper radio science measurements
Combining astrometry and JUICE -- Europa Clipper radio science to improve the ephemerides of the Galilean moons
The upcoming JUICE and Europa Clipper missions to Jupiter's Galilean
satellites will provide radio science tracking measurements of both spacecraft.
Such data are expected to significantly help estimating the moons' ephemerides
and related dynamical parameters. However, the two missions will yield an
imbalanced dataset, with no flybys planned at Io, condensed over less than six
years. Current ephemerides' solutions for the Galilean moons, on the other
hand, rely on ground-based astrometry collected over more than a century which,
while being less accurate, bring very valuable constraints on the long-term
dynamics of the system. An improved solution for the Galilean satellites'
complex dynamics could however be achieved by exploiting the existing synergies
between these different observation sets. To quantify this, we merged simulated
JUICE and Clipper radio science data with existing ground-based astrometric and
radar observations, and performed the inversion. Our study specifically
focusses on the resulting formal uncertainties in the moons' states, as well as
Io's and Jupiter's tidal dissipation parameters. Adding astrometry stabilises
the moons' state solution, especially beyond the missions' timelines. It
furthermore reduces the uncertainties in (inverse of the tidal quality
factor) by a factor two to four for Jupiter, and about 30-35\% for Io. Among
all data types, classical astrometry data prior to 1960 proved particularly
beneficial. We also show that ground observations of Io add the most to the
solution, confirming that ground observations can fill the lack of radio
science data for this specific moon. We obtained a noticeable solution
improvement when exploiting the complementarity between all different
observation sets. These promising simulation results thus motivate future
efforts to achieve a global solution from actual JUICE and Clipper radio
science data
Spacecraft VLBI tracking to enhance stellar occultations astrometry of planetary satellites
Stellar occultations currently provide the most accurate ground-based
measurements of the positions of natural satellites (down to a few kilometres
for the Galilean moons). However, when using these observations in the
calculation of satellite ephemerides, the uncertainty in the planetary
ephemerides dominates the error budget of the occultation. We quantify the
local refinement in the central planet's position achievable by performing Very
Long Baseline Interferometry (VLBI) tracking of an in-system spacecraft
temporally close to an occultation. We demonstrate the potential of using VLBI
to enhance the science return of stellar occultations for satellite
ephemerides. We identified the most promising observation and tracking
opportunities offered by the Juno spacecraft around Jupiter as perfect test
cases, for which we ran simulations of our VLBI experiment. VLBI tracking at
Juno's perijove close to a stellar occultation locally (in time) reduces the
uncertainty in Jupiter's angular position in the sky to 250-400 m. This
represents up to an order of magnitude improvement with respect to current
solutions and is lower than the stellar occultation error, thus allowing the
moon ephemeris solution to fully benefit from the observation. Our simulations
showed that the proposed tracking and observation experiment can efficiently
use synergies between ground- and space-based observations to enhance the
science return on both ends. The reduced error budget for stellar occultations
indeed helps to improve the moons' ephemerides, which in turn benefit planetary
missions and their science products, such as the recently launched JUICE and
upcoming Europa Clipper missions
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