A Rapid Prototyping Environment for Wireless Communication Embedded Systems

This paper introduces a rapid prototyping methodology which overcomes important barriers in the design and implementation of digital signal processing (DSP) algorithms and systems on embedded hardware platforms, such as cellular phones. This paper describes rapid prototyping in terms of a simulation/prototype bridge and in terms of appropriate language design. The simulation/prototype bridge combines the strengths of simulation and of prototyping, allowing the designer to develop and evaluate next-generation communications systems, partly in simulation on a host computer and partly as a prototype on embedded hardware. Appropriate language design allows designers to express a communications system as a block diagram, in which each block represents an algorithm specified by a set of equations. Software tools developed for this paper implement both concepts, and have been successfully used in the development of a next-generation code division multiple access (CDMA) cellular wireless communications system.NokiaTexas InstrumentsThe Texas Advanced Technology ProgramNational Science Foundatio

Small for Gestational Age Babies After 37 Weeks: An Impact Study of a Risk Stratification Protocol.

OBJECTIVES: Although no clear evidence exists, many international guidelines advocate early term delivery of small for gestational age (SGA) fetuses. The aim of this study was to determine whether a protocol that included monitoring SGA fetuses beyond 37 weeks affected perinatal and maternal outcomes. METHODS: The impact of the introduction in 2014 of a protocol for management of SGA, which included risk stratification with surveillance and expectant management after 37 weeks for lower risk babies (Group 2), was compared with the previous strategy, which recommended delivery at around 37 weeks (Group 1). Data from all referred SGA babies over a 39 month period were analyzed. RESULTS: In group 1 there were 138 SGA babies; in group 2 there were 143. The mean gestation at delivery was 37 + 4 and 38 + 2 weeks respectively (p = 0.04). The incidence of neonatal composite adverse outcomes was lower in Group 2 (9% v 22% v; p < 0.01) as was neonatal NNU admission (13% v 42%; p < 0.01). Induction of labour and caesarean section rates were lower, and vaginal delivery (83% v 60%; p < 0.01) was higher in group 2. Most of the differences were due to delayed delivery of SGA babies that were stratified as low risk. CONCLUSIONS: This study suggests that protocol-based management of SGA babies may improve outcomes and that identification of moderate SGA should not alone prompt delivery. Larger numbers are required to assess any impact on perinatal mortality

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

Exploiting vulnerabilities of deep neural networks for privacy protection

Adversarial perturbations can be added to images to protect their content from unwanted inferences. These perturbations may, however, be ineffective against classifiers that were not seen during the generation of the perturbation, or against defenses based on re-quantization, median filtering or JPEG compression. To address these limitations, we present an adversarial attack that is specifically designed to protect visual content against unseen classifiers and known defenses. We craft perturbations using an iterative process that is based on the Fast Gradient Signed Method and that randomly selects a classifier and a defense, in each iteration. This randomization prevents an undesirable overfitting to a specific classifier or defense. We validate the proposed attack in both targeted and untargeted settings on the private classes of the Places365-Standard dataset. Using ResNet18, ResNet50, AlexNet and DenseNet161 as classifiers, the performance of the proposed attack exceeds that of eleven state-of-the-art attacks

Mn valence instability in La2/3Ca1/3MnO3 thin films

A Mn valence instability on La2/3Ca1/3MnO3 thin films, grown on LaAlO3 (001)substrates is observed by x-ray absorption spectroscopy at the Mn L-edge and O K-edge. As-grown samples, in situ annealed at 800 C in oxygen, exhibit a Curie temperature well below that of the bulk material. Upon air exposure a reduction of the saturation magnetization, MS, of the films is detected. Simultaneously a Mn2+ spectral signature develops, in addition to the expected Mn3+ and Mn4+ contributions, which increases with time. The similarity of the spectral results obtained by total electron yield and fluorescence yield spectroscopy indicates that the location of the Mn valence anomalies is not confined to a narrow surface region of the film, but can extend throughout the whole thickness of the sample. High temperature annealing at 1000 C in air, immediately after growth, improves the magnetic and transport properties of such films towards the bulk values and the Mn2+ signature in the spectra does not appear. The Mn valence is then stable even to prolonged air exposure. We propose a mechanism for the Mn2+ ions formation and discuss the importance of these observations with respect to previous findings and production of thin films devices.Comment: Double space, 21 pages, 6 figure

New ATCA, ALMA and VISIR observations of the candidate LBV SK-67266 (S61): the nebular mass from modelling 3D density distributions

We present new observations of the nebula around the Magellanic candidate Luminous Blue Variable S61. These comprise high-resolution data acquired with the Australia Telescope Compact Array (ATCA), the Atacama Large Millimetre/Submillimetre Array (ALMA), and VISIR at the Very Large Telescope (VLT). The nebula was detected only in the radio, up to 17 GHz. The 17 GHz ATCA map, with 0.8 arcsec resolution, allowed a morphological comparison with the H$\alpha$ Hubble Space Telescope image. The radio nebula resembles a spherical shell, as in the optical. The spectral index map indicates that the radio emission is due to free-free transitions in the ionised, optically thin gas, but there are hints of inhomogeneities. We present our new public code RHOCUBE to model 3D density distributions, and determine via Bayesian inference the nebula's geometric parameters. We applied the code to model the electron density distribution in the S61 nebula. We found that different distributions fit the data, but all of them converge to the same ionised mass, ~0.1 $\rm M\odot$, which is an order of magnitude smaller than previous estimates. We show how the nebula models can be used to derive the mass-loss history with high-temporal resolution. The nebula was probably formed through stellar winds, rather than eruptions. From the ALMA and VISIR non-detections, plus the derived extinction map, we deduce that the infrared emission observed by space telescopes must arise from extended, diffuse dust within the ionised region.Comment: 17 pages, 9 figures. Authors list corrected. In press in MNRAS. RHOCUBE code available online ( https://github.com/rnikutta/rhocube

Microscopic cluster model for the description of (18O,16O) two-neutron transfer reactions

Excitation energy spectra and absolute cross-section angular distributions were measured for the 13C(18O,16O)15C two-neutron transfer reaction at 84 MeV incident energy. Exact finite-range coupled reaction channel calculations are used to analyse the data considering both the direct two-neutron transfer and the two-step sequential mechanism. For the direct calculations, two approaches are discussed: The extreme cluster and the newly introduced microscopic cluster. The latter makes use of spectroscopic amplitudes in the centre-of-mass reference frame, derived from shell-model calculations. The results describe well the experimental cross sections