360 research outputs found
Toward Robust Sensing for Autonomous Vehicles: An Adversarial Perspective
Autonomous Vehicles rely on accurate and robust sensor observations for
safety critical decision-making in a variety of conditions. Fundamental
building blocks of such systems are sensors and classifiers that process
ultrasound, RADAR, GPS, LiDAR and camera signals~\cite{Khan2018}. It is of
primary importance that the resulting decisions are robust to perturbations,
which can take the form of different types of nuisances and data
transformations, and can even be adversarial perturbations (APs). Adversarial
perturbations are purposefully crafted alterations of the environment or of the
sensory measurements, with the objective of attacking and defeating the
autonomous systems. A careful evaluation of the vulnerabilities of their
sensing system(s) is necessary in order to build and deploy safer systems in
the fast-evolving domain of AVs. To this end, we survey the emerging field of
sensing in adversarial settings: after reviewing adversarial attacks on sensing
modalities for autonomous systems, we discuss countermeasures and present
future research directions
Obtaining and Structural Characterization of M-type Hexaferrites Doped with Two Cations in the Fe3+ Sites
A study of the microstructural and structural properties of M-type barium hexaferrites (BaM) samples doped with two dopants in the Fe3+ sites: (Co3+, Al3+), (Co2+, Ti4+) and (Co2+, Sn4+) is reported. The samples were obtained using the conventional ceramic method. The structure was investigated by using of X-ray diffraction (XRD) to determine the dopant distribution in the Fe3+ sites
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SimArray: a user-friendly and user-configurable microarray design tool.
BACKGROUND: Microarrays were first developed to assess gene expression but are now also used to map protein-binding sites and to assess allelic variation between individuals. Regardless of the intended application, efficient production and appropriate array design are key determinants of experimental success. Inefficient production can make larger-scale studies prohibitively expensive, whereas poor array design makes normalisation and data analysis problematic. RESULTS: We have developed a user-friendly tool, SimArray, which generates a randomised spot layout, computes a maximum meta-grid area, and estimates the print time, in response to user-specified design decisions. Selected parameters include: the number of probes to be printed; the microtitre plate format; the printing pin configuration, and the achievable spot density. SimArray is compatible with all current robotic spotters that employ 96-, 384- or 1536-well microtitre plates, and can be configured to reflect most production environments. Print time and maximum meta-grid area estimates facilitate evaluation of each array design for its suitability. Randomisation of the spot layout facilitates correction of systematic biases by normalisation. CONCLUSION: SimArray is intended to help both established researchers and those new to the microarray field to develop microarray designs with randomised spot layouts that are compatible with their specific production environment. SimArray is an open-source program and is available from http://www.flychip.org.uk/SimArray/.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Conception and strategic management of publics in the energy companies in Spain
The notion of publics as specifics and segmented groups has been a paradigm shift in public relations and corporate
communication. This change in the way of understanding the receiver in the communication process allows communicate
function to manage the relationship between the organization and those groups more effectively. For this reason,
organizations should implement processes of identifying and prioritizing publics to communicate and be engaged with these
groups in a strategic and effective way. The aim of this paper is to know what conception of “publics” prevails in the
communication departments of natural gas and electricity companies in Spain, and on the other hand to assess the level of
coherence /correlation between the identification and prioritization of strategic publics and the design of
communicative actions to strategically manage the relationship between the organizations and these groups. The methodology of the quantitative study was aimed at Spanish energy companies and implemented through a questionnaire in an
online platform. The results indicate that there is a dichotomy in the idea of publics in energy companies: on the one hand,
they are conceived as specific groups, and on the other hand, they are considered as a massive collective. Nevertheless, it is
observed that there is a methodological consistency between the importance assigned to the publics and the implementation of
communication actions towards them
Intracluster Red Giant Stars in the Virgo Cluster
We have used the WFPC2 camera of the Hubble Space Telescope to obtain deep
F814W images of a blank field in the Virgo Cluster located 41 arcmin northwest
of M87. We perform star counts in that field, and in another Virgo field
observed by Ferguson, Tanvir & von Hippel (1998), and show that, when compared
to the Hubble Deep Field North and South, the Virgo Cluster contains an excess
of objects with magnitudes I > 27. We attribute this excess to a population of
intracluster red-giant branch (IC-RGB) stars. By modeling the luminosity
function of these stars, we show that the tip of the Virgo RGB is at I = 27.31
+0.27/-0.17 and that the cluster contains a small, but significant, excess of
stars that are up to ~1 mag brighter than this tip. If this luminous component
is due entirely to stars on the asymptotic giant branch (AGB), it implies an
age for the population of > 2 Gyr; if foreground RGB stars contribute to the
luminous tail, then the derived age for the stars is older still. The
luminosity function also suggests that most of the intracluster stars are
moderately metal-rich (-0.8 < [Fe/H] <-0.2), a result consistent with that
expected from stars that have been tidally stripped from intermediate
luminosity galaxies. Additionally, a comparison with the planetary nebulae in
our field also supports this view, although the existence of a more metal-poor
population (from stripped dwarfs) cannot be ruled out. Our derived average
surface brightness, mu_I = 27.9 +0.3/-0.5 mag/arcsec^2 for Virgo's diffuse
component suggests that intracluster stars contribute 10% to 20% of the
cluster's total I-band luminosity.Comment: 21 pages, 8 figures included, accepted for publication in the
Astrophysical Journa
What fraction of stars formed in infrared galaxies at high redshift?
Star formation happens in two types of environment: ultraviolet-bright
starbursts (like 30 Doradus and HII galaxies at low redshift and Lyman-break
galaxies at high redshift) and infrared-bright dust-enshrouded regions (which
may be moderately star-forming like Orion in the Galaxy or extreme like the
core of Arp 220). In this work I will estimate how many of the stars in the
local Universe formed in each type of environment, using observations of
star-forming galaxies at all redshifts at different wavelengths and of the
evolution of the field galaxy population.Comment: 7 pages, 0 figs, to appear in proceedings of "Starbursts - From 30
Doradus to Lyman break galaxies", edited by Richard de Grijs and Rosa M.
Gonzalez Delgado, published by Kluwe
Learning to Detect and Track Visible and Occluded Body Joints in a Virtual World
Multi-People Tracking in an open-world setting requires a special effort in precise detection. Moreover, temporal continuity in the detection phase gains more importance when scene cluttering introduces the challenging problems of occluded targets. For the purpose, we propose a deep network architecture that jointly extracts people body parts and associates them across short temporal spans. Our model explicitly deals with occluded body parts, by hallucinating plausible solutions of not visible joints. We propose a new end-to-end architecture composed by four branches (visible heatmaps, occluded heatmaps, part affinity fields and temporal affinity fields) fed by a time linker feature extractor. To overcome the lack of surveillance data with tracking, body part and occlusion annotations we created the vastest Computer Graphics dataset for people tracking in urban scenarios by exploiting a photorealistic videogame. It is up to now the vastest dataset (about 500.000 frames, almost 10 million body poses) of human body parts for people tracking in urban scenarios. Our architecture trained on virtual data exhibits good generalization capabilities also on public real tracking benchmarks, when image resolution and sharpness are high enough, producing reliable tracklets useful for further batch data association or re-id modules
Cpd-1 Null Mice Display a Subtle Neurological Phenotype
CPD1 (also known as ANP32-E) belongs to a family of evolutionarily conserved acidic proteins with leucine rich repeats implicated in a variety of cellular processes regulating gene expression, vesicular trafficking, intracellular signaling and apoptosis. Because of its spatiotemporal expression pattern, CPD1 has been proposed to play an important role in brain morphogenesis and synaptic development.We have generated CPD1 knock-out mice that we have subsequently characterized. These mice are viable and fertile. However, they display a subtle neurological clasping phenotype and mild motor deficits.CPD1 is not essential for normal development; however, it appears to play a role in the regulation of fine motor functions. The minimal phenotype suggests compensatory biological mechanisms
10 ÎĽ m-thick four-quadrant transmissive silicon photodiodes for beam position monitor application: Electrical characterization and gamma irradiation effects
Silicon photodiodes are very useful devices as X-ray beam monitors in synchrotron radiation beamlines. Owing to Si absorption, devices thinner than 10 ÎĽ m are needed to achieve transmission over 90% for energies above 10 keV . In this work, new segmented four-quadrant diodes for beam alignment purposes are fabricated on both ultrathin (10 ÎĽ m-thick) and bulk silicon substrates. Four-quadrant diodes implementing different design parameters as well as auxiliary test structures (single diodes and MOS capacitors) are studied. An extensive electrical characterization, including current-voltage (I-V) and capacitance-voltage (C-V) techniques, is carried out on non-irradiated and gamma-irradiated devices up to 100 Mrad doses. Special attention is devoted to the study of radiation-induced charge build-up in diode interquadrant isolation dielectric, as well as its impact on device interquadrant resistance. Finally, the devices have been characterized with an 8 keV laboratory X-ray source at 108 ph/s and in BL13-XALOC ALBA Synchroton beamline with 1011 ph/s and energies from 6 to 16 keV . Sensitivity, spatial resolution and uniformity of the devices have been evaluated.Peer reviewe
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