2,377 research outputs found
Landscapes of the invisible: sounds, cosmologies and poetics of space
In this PhD by Publication I revisit and contextualize art works and essays I have collaboratively created under the name Flow Motion between 2004-13, in order to generate new insights on the contributions they have made to diverse and emerging fields of contemporary arts practice/research, including digital, virtual, sonic and interdisciplinary art.
The works discussed comprise the digital multimedia installation and sound art performance Astro Black Morphologies/Astro Dub Morphologies (2004-5), the sound
installation and performance Invisible (2006-7), the web art archive and performance presentation project promised lands (2008-10), and two related texts, Astro Black Morphologies: Music and Science Lovers (2004) and Music and Migration (2013).
I show how these works map new thematic constellations around questions of space and diaspora, music and cosmology, invisibility and spectrality, the body and perception. I also show how the works generate new connections between and across contemporary avant-garde, experimental and popular music, and visual art and cinema traditions.
I describe the methodological design, approaches and processes through which the works were produced, with an emphasis on transversality, deconstruction and contemporary black music forms as key tools in my collaborative artistic and textual practice. I discuss how, through the development of methods of data translation and transformation, and distinctive visual approaches for the re-elaboration of archival material, the works produced multiple readings of scientific narratives, digital X-ray data derived from astronomical research on black holes and dark energy, and musical, photographic and textual material related to historical and contemporary accounts of migration.
I also elaborate on the relation between difference and repetition, the concepts of multiplicity and translation, and the processes of collective creation which characterize my/Flow Motion’s work. The art works and essays I engage with in this commentary produce an idea of contemporary art as the result of a fluid, open and mutating assemblage of diverse and hybrid methods and mediums, and as an embodiment of a cross-cultural, transversal and transdisciplinary knowledge shaped by research, process, creative dialogues, collaborative practice and collective signature
Image Forgery Localization via Block-Grained Analysis of JPEG Artifacts
In this paper, we propose a forensic algorithm to discriminate between original and forged regions in JPEG images, under the hypothesis that the tampered image presents a double JPEG compression, either aligned (A-DJPG) or non-aligned (NA-DJPG). Unlike previous approaches, the proposed algorithm does not need to manually select a suspect region in order to test the presence or the absence of double compression artifacts. Based on an improved and unified statistical model characterizing the artifacts that appear in the presence of both A-DJPG or NA-DJPG, the proposed algorithm automatically computes a likelihood map indicating the probability for each discrete cosine transform block of being doubly compressed. The validity of the proposed approach has been assessed by evaluating the performance of a detector based on thresholding the likelihood map, considering different forensic scenarios. The effectiveness of the proposed method is also confirmed by tests carried on realistic tampered images. An interesting property of the proposed Bayesian approach is that it can be easily extended to work with traces left by other kinds of processin
Detection of Nonaligned Double JPEG Compression Based on Integer Periodicity Maps
In this paper, a simple yet reliable algorithm to detect the presence of nonaligned double JPEG compression (NA-JPEG) in compressed images is proposed. The method evaluates a single feature based on the integer periodicity of the blockwise discrete cosine transform (DCT) coefficients when the DCT is computed according to the grid of the previous JPEG compression. Even if the proposed feature is computed relying only on DC coefficient statistics, a simple threshold detector can classify NA-JPEG images with improved accuracy with respect to existing methods and on smaller image sizes, without resorting to a properly trained classifier. Moreover, the proposed scheme is able to accurately estimate the grid shift and the quantization step of the DC coefficient of the primary JPEG compression, allowing one to perform a more detailed analysis of possibly forged image
Scaling properties in the production range of shear dominated flows
Recent developments in turbulence are focused on the effect of large scale
anisotropy on the small scale statistics of velocity increments. According to
Kolmogorov, isotropy is recovered in the large Reynolds number limit as the
scale is reduced and, in the so-called inertial range, universal features
-namely the scaling exponents of structure functions - emerge clearly. However
this picture is violated in a number of cases, typically in the high shear
region of wall bounded flows. The common opinion ascribes this effect to the
contamination of the inertial range by the larger anisotropic scales, i.e. the
residual anisotropy is assumed as a weak perturbation of an otherwise isotropic
dynamics. In this case, given the rotational invariance of the Navier-Stokes
equations, the isotropic component of the structure functions keeps the same
exponents of isotropic turbulence. This kind of reasoning fails when the
anisotropic effects are strong as in the production range of shear dominated
flows. This regime is analyzed here by means of both numerical and experimental
data for a homogeneous shear flow. A well defined scaling behavior is found to
exist, with exponents which differ substantially from those of classical
isotropic turbulence. Contrary to what predicted by the perturbation approach,
such a deep alteration concerns the isotropic sector itself. The general
validity of these results is discussed in the context of turbulence near solid
walls, where more appropriate closure models for the coarse grained
Navier-Stokes equations would be advisable.Comment: 4 pages, 4 figure
Linear Chains of Styrene and Methyl-Styrene Molecules and their Heterojunctions on Silicon: Theory and Experiment
We report on the synthesis, STM imaging and theoretical studies of the
structure, electronic structure and transport properties of linear chains of
styrene and methyl-styrene molecules and their heterojunctions on
hydrogen-terminated dimerized silicon (001) surfaces. The theory presented here
accounts for the essential features of the experimental STM data including the
nature of the corrugation observed along the molecular chains and the
pronounced changes in the contrast between the styrene and methyl-styrene parts
of the molecular chains that are observed as the applied bias is varied. The
observed evolution with applied bias of the STM profiles near the ends of the
molecular chains is also explained. Calculations are also presented of electron
transport along styrene linear chains adsorbed on the silicon surface at
energies in the vicinity of the molecular HOMO and LUMO levels. For short
styrene chains this lateral transport is found to be due primarily to direct
electron transmission from molecule to molecule rather than through the silicon
substrate, especially in the molecular LUMO band. Differences between the
calculated position-dependences of the STM current around a junction of styrene
and methyl-styrene molecular chains under positive and negative tip bias are
related to the nature of lateral electron transmission along the molecular
chains and to the formation in the LUMO band of an electronic state localized
around the heterojunction.Comment: 17 pages plus 11 figures. To appear in Physical Review
Missing women in STEM occupations: The impact of university education on the gender gap in graduates' transition to work
This paper contributes to the literature on the drivers of the gender gap in STEM by focusing on a critical career juncture: the bridge between university study in STEM fields and work. We investigate the effect of selected characteristics of recent STEM graduates' university education on the difference between women and men in their likelihood of obtaining STEM occupations shortly after graduation. Using unique data on a large sample of graduates in male-dominated STEM fields, we show that a diversified university curriculum increases the likelihood of women graduates getting STEM occupations shortly after graduation, while it does not affect men. In contrast, doing internships during university studies and participating in study abroad programs reduce the likelihood of men graduates entering STEM occupations, but does not affect women. Additionally, students' graduation grades increase the probability of both women and men securing STEM occupations
Characterization and development of different methods to extend shelf life of fresh cut fruit. Case study: novel controlled release system by layer-by-layer assembly
The research project aimed at the investigation of different methods for the storage of fresh-cut fruit. This case study relates to the proposal of an innovative controlled release system to improve the shelf life of ready-to-eat fruit. The methods applied during three research years included the application of active molecules from natural substances, some widely used in commerce and other tested for the first time; first analyzed in vitro and then applied in vivo. The under consideration methods concerned dipping, coating and the layer-by-layer assembly. The analysis carried out on the fruit have monitored pomological traits performances (soluble solids content, titratable acidity, pH, color, flesh firmness), the chemical profile (polyphenoloxidase, carotenoids) and microbial growth
Preliminary studies on the effect of Oidium tuckeri on the phenolic composition of grapes and wines
Research NoteA study of the influence of Oidium tuckeri on anthocyanins and the hydroxycinnamic tartaric esters of grapes and red wines was carried out during the 1993 harvest. After infection the level of anthocyanins in the skins of berries and in wines was lower than in healthy grapes and their wines. It is of particular interest that two bisubstituted anthocyanins reacted less sensitive to the pathogen. Wines from infected grapes contained more hydroxycinnamic tartaric esters
- …