2,960 research outputs found
Analytical solutions for quasi-geostrophic inertial modes and onset of thermal convection in rapidly rotating spheroids
The poster session as fusing theory and practice in art and design education: exhibiting an occluded genre
While the academic poster has been used extensively in the sciences, its particular pertinence in art and design education remains unrecognised. Posters (outputs) and the poster sessions which accompany them (processes) form an ‘occluded genre’ in design education. The secondary literature about academic posters is typically ‘how-to’ rather than pedagogical analysis. We identify the benefits of using posters in design education, whether as formats for ‘regenring’ the conventional contextual studies essay, or as iterations towards essay work which draw on the skills students are developing in their design briefs and thereby bridging theory and practice, and accommodating diversity. Based on our pedagogical research in the UK and the Netherlands, this article reflects on how students respond to the benefits of the poster, and the poster session, and provides teachers with a clear rationale for their increased use in design education
Two-time-scale MPC for economically optimal real-time operation of balance responsible parties
Impact of reionization on CMB polarization tests of slow-roll inflation
Estimates of inflationary parameters from the CMB B-mode polarization
spectrum on the largest scales depend on knowledge of the reionization history,
especially at low tensor-to-scalar ratio. Assuming an incorrect reionization
history in the analysis of such polarization data can strongly bias the
inflationary parameters. One consequence is that the single-field slow-roll
consistency relation between the tensor-to-scalar ratio and tensor tilt might
be excluded with high significance even if this relation holds in reality. We
explain the origin of the bias and present case studies with various tensor
amplitudes and noise characteristics. A more model-independent approach can
account for uncertainties about reionization, and we show that parametrizing
the reionization history by a set of its principal components with respect to
E-mode polarization removes the bias in inflationary parameter measurement with
little degradation in precision.Comment: 9 pages, 6 figures; submitted to Phys. Rev.
A novel educational model based on "knowing how to do" paradigm implemented in an academic makerspace
The design discipline is faced with radical changes related to new technologies and to an increasingly globalized world with more and more competitive markets. These factors are profoundly influencing methods and processes of design, and the knowledge and skills related to the designer's role. Consequently, the design educational models are radically changing. Today, one of the most impacting evolutions is related to rapid prototyping techniques, which are bringing design practice closer to the auto-production. This emerging trend cannot be anymore supported with traditional didactic approaches, but it is necessary to create spaces for allowing students to learn, design and experiment in a shared way. This paper presents the Polifactory Lab at Politecnico di Milano, an innovative makerspace established with the aim of creating a new research and teaching space. In this paper, the authors present the Polifactory Lab, its theoretical purposes, and some examples of didactic activities carried out in the lab
Surveying the Borders ‘Authenticity’ in Mexican-American Food Packaging, Imagery and Architecture
Norman Bel Geddes: The Rise and Fall of Subjective Vision
The following text investigates the
rhetoric and designs of the pioneering industrial
designer, Norman Bel Geddes, and the way in
which they exemplified a subjective approach to
design practice, focusing on the firm’s work for
the radio manufacturer the Philadelphia Storage
Battery Company (Philco) in the 1930s. The
research investigates how the public image of the
visionary designer was strategically produced and
enthusiastically, as well as critically, received. This
article shows that the Bel Geddes’s firm engaged
in objective design research, which was further
guided by subjective design choices. This tension
between the objective and subjective lay at the
heart of Bel Geddes’s design practice and helped
his company to make products that appeared
simultaneously modern and fantastic, practical and
visionary. This approach had wide appeal in the
1930s, but later lost its attraction
Spherical orbit closures in simple projective spaces and their normalizations
Let G be a simply connected semisimple algebraic group over an algebraically
closed field k of characteristic 0 and let V be a rational simple G-module of
finite dimension. If G/H \subset P(V) is a spherical orbit and if X is its
closure, then we describe the orbits of X and those of its normalization. If
moreover the wonderful completion of G/H is strict, then we give necessary and
sufficient combinatorial conditions so that the normalization morphism is a
homeomorphism. Such conditions are trivially fulfilled if G is simply laced or
if H is a symmetric subgroup.Comment: 24 pages, LaTeX. v4: Final version, to appear in Transformation
Groups. Simplified some proofs and corrected minor mistakes, added
references. v3: major changes due to a mistake in previous version
Simulations for single-dish intensity mapping experiments
HI intensity mapping is an emerging tool to probe dark energy. Observations
of the redshifted HI signal will be contaminated by instrumental noise,
atmospheric and Galactic foregrounds. The latter is expected to be four orders
of magnitude brighter than the HI emission we wish to detect. We present a
simulation of single-dish observations including an instrumental noise model
with 1/f and white noise, and sky emission with a diffuse Galactic foreground
and HI emission. We consider two foreground cleaning methods: spectral
parametric fitting and principal component analysis. For a smooth frequency
spectrum of the foreground and instrumental effects, we find that the
parametric fitting method provides residuals that are still contaminated by
foreground and 1/f noise, but the principal component analysis can remove this
contamination down to the thermal noise level. This method is robust for a
range of different models of foreground and noise, and so constitutes a
promising way to recover the HI signal from the data. However, it induces a
leakage of the cosmological signal into the subtracted foreground of around 5%.
The efficiency of the component separation methods depends heavily on the
smoothness of the frequency spectrum of the foreground and the 1/f noise. We
find that as, long as the spectral variations over the band are slow compared
to the channel width, the foreground cleaning method still works.Comment: 14 pages, 12 figures. Submitted to MNRA
Detection of Zak phases and topological invariants in a chiral quantum walk of twisted photons
Topological insulators are fascinating states of matter exhibiting protected
edge states and robust quantized features in their bulk. Here, we propose and
validate experimentally a method to detect topological properties in the bulk
of one-dimensional chiral systems. We first introduce the mean chiral
displacement, and we show that it rapidly approaches a multiple of the Zak
phase in the long time limit. Then we measure the Zak phase in a photonic
quantum walk, by direct observation of the mean chiral displacement in its
bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe,
and combine the two windings to characterize the full phase diagram of this
Floquet system. Finally, we prove the robustness of the measure by introducing
dynamical disorder in the system. This detection method is extremely general,
as it can be applied to all one-dimensional platforms simulating static or
Floquet chiral systems.Comment: 10 pages, 7 color figures (incl. appendices) Close to the published
versio
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