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

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

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

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

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