11,578 research outputs found
A Framework for Evaluating Security in the Presence of Signal Injection Attacks
Sensors are embedded in security-critical applications from medical devices
to nuclear power plants, but their outputs can be spoofed through
electromagnetic and other types of signals transmitted by attackers at a
distance. To address the lack of a unifying framework for evaluating the
effects of such transmissions, we introduce a system and threat model for
signal injection attacks. We further define the concepts of existential,
selective, and universal security, which address attacker goals from mere
disruptions of the sensor readings to precise waveform injections. Moreover, we
introduce an algorithm which allows circuit designers to concretely calculate
the security level of real systems. Finally, we apply our definitions and
algorithm in practice using measurements of injections against a smartphone
microphone, and analyze the demodulation characteristics of commercial
Analog-to-Digital Converters (ADCs). Overall, our work highlights the
importance of evaluating the susceptibility of systems against signal injection
attacks, and introduces both the terminology and the methodology to do so.Comment: This article is the extended technical report version of the paper
presented at ESORICS 2019, 24th European Symposium on Research in Computer
Security (ESORICS), Luxembourg, Luxembourg, September 201
Global neonatal and perinatal mortality: a review and case study for the Loreto Province of Peru
Jamie B Warren,1 William E Lambert,2 Rongwei Fu,2 JoDee M Anderson,1 Alison B Edelman31Department of Pediatrics, 2Department of Public Health and Preventive Medicine, 3Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, OR, USABackground: Millennium Development Goal 4 calls for the reduction of the under-five mortality rate by two-thirds between 1990 and 2015. To reach this goal, neonatal mortality must be decreased. The lack of information on global neonatal and perinatal mortality impedes appropriate implementation of interventions, as vital registration systems are not available for the majority of the world's neonatal deaths. Verbal autopsy (VA) is a tool that has been used to determine cause of death. Recent studies have attempted to standardize and validate the use of this tool in resource-limited areas. The World Health Organization (WHO) International Standard VA Questionnaire was used to conduct a needs assessment in nine rural Peruvian villages. The goal was to determine the neonatal mortality rate (NMR), perinatal mortality rate (PMR), and causes of, and risk factors for, death in these villages.Methods: Eligible women were interviewed using the WHO International Standard VA Questionnaire or a set of questions based on the WHO VA Questionnaire. NMR and PMR were calculated using a generalized estimating equation model. Three neonatologists independently reviewed VA records to provide cause of death determination. Reviewer agreement was assessed using percent agreement. Fisher's exact test was used to determine risk factors associated with death.Results: The NMR was 31.4 per 1000 live births and the PMR was 49.7 per 1000 pregnancies. The main contributor to neonatal death was infection (43%). Percent agreement among reviewers was 90.5% and 38.9% for cause of neonatal death and stillbirth, respectively. Risk factors for death were pregnancy with twins (P = 0.001), preterm delivery (P = 0.003), and cesarean section delivery (P = 0.049).Conclusion: The WHO VA proved useful for NMR and PMR calculation, cause of death determination, and risk factor identification. Information gathered in this needs assessment will allow for the design and implementation of tailored interventions.Keywords: neonatal mortality, perinatal mortality, verbal autopsy, needs assessmen
Pre-B cells and other possible precursor lymphoid cell lines derived from patients with X-linked agammaglobulinemia
A group of unique Epstein-Barr virus-containing cell lines was derived from the bone marrow of three patients with X-linked agammaglobulinemia. Efforts to obtain cell lines from the peripheral blood of these patients were uniformly unsuccessful. Immunofluorescence analyses as well as biosynthetic studies with [(35)S]methionine indicated unusual patterns of Ig synthesis in many of these bone marrow derived lines. Seven of the lines were of particular interest in that two produced no Ig of any type; two others showed no Ig by fluorescence but small amounts by [(35)S]methionine labeling; one expressed only cytoplasmic μ chains without any evidence of light chain synthesis, and two produced primarily μ chains with only slight amounts of light chains. One of the lines without membrane or cytoplasmic Ig studied in detail grew like a typical lymphoid line and was carried in intermittent culture over a period of 2 yr without Ig expression. One line grew quite differently and resembled the round cell type described previously, which has been obtained from a variety of sources. The cell line with cytoplasmic μ chains and no light-chain expression had the characteristic properties of pre-B cells. Three normal type Ig-producing cell lines also were obtained from the patients. The accumulated evidence obtained in the present study indicates that these unusual cell lines represent normal precursor cells of the B-cell lineage; these grew out in these cases because of the virtual absence of mature B cells that ordinarily overgrow the culture system. However, the possibility that in certain instances they reflect abnormal Ig synthesis characteristic of the disease has not been ruled out
Prevalence of Microalbuminuria among Diabetic Patients in Usmanu Danfodiyo University Teaching Hospital, Sokoto
Diabetic nephropathy is a common phenomenon in patients with diabetes. Its prevalence risk factors have not been fully described in black African patients. This study determined the prevalence of microalbuminuria (mal) among diabetic patients in Usmanu Danfodiyo University Teaching Hospital (UDUTH) Sokoto. It involved 100 diabetics and 50 healthy controls. Mal was estimated by BCG-dye binding method, while fasting blood glucose (FBG) by glucose oxidation method. The prevalence of mal varied between males (24.3%) and females (16.6%). The duration of the disease ranged from < 5 years (42.0%) with 8(14.5%) having abnormal mal, (58%) >5 years with (31%) having abnormal mal, (30%) < 30 years having (17.1%) having abnormal mal and (70%) >30 years having (24%) with abnormal mal. The prevalence of mal was 22% (17% males and 5% females). FBG differed significantly (p<0.05) between patients (11.01±1.03mmol/l) and control subjects (4.38±0.07 mmol/l). Urinary albumin excretion was significantly higher in diabetics than in control (57.65±18.92 versus 24.16±1.48mg/24hrs respectively). Mal significantly (p<0.05) increased with duration of diagnosis of diabetes (108.6±14 versus 214.6±9.1 mg/24hrs in <5 years and >5years group respectively). Poor glycaemic control was the only modifiable predictor for the development of mal. Other non-modifiable risk factors related to progression of mal are sex and duration of disease. Early diagnosis of mal and aggressive glycaemic control is hereby recommended.Keywords: Microalbuminuria, Diabetic nephropathy, Fasting blood glucos
From lightcone actions to maximally supersymmetric amplitudes
In this article actions for N=4 SYM and N=8 supergravity are formulated in
terms of a chiral superfield, which contains only the physical degrees of
freedom of either theory. In these new actions, which originate from the
lightcone superspace, the supergravity cubic vertex is the square of the gauge
theory one (omitting the color structures). Amplitude calculations using the
corresponding Feynman supergraph rules are tedious, but can be simplified by
choosing a preferred superframe. Recursive calculations of all MHV amplitudes
in N=4 SYM and the four-point N=8 supergravity amplitude are shown to agree
with the known results and connections to the BCFW recursion relations are
pointed out. Finally, the new path integrals are discussed in the context of
the double-copy property relating N=4 SYM theory to N=8 supergravity.Comment: 29 pages, 2 figures, v2: title modified, published versio
Evaluation of Retinal Image Quality Assessment Networks in Different Color-spaces
Retinal image quality assessment (RIQA) is essential for controlling the
quality of retinal imaging and guaranteeing the reliability of diagnoses by
ophthalmologists or automated analysis systems. Existing RIQA methods focus on
the RGB color-space and are developed based on small datasets with binary
quality labels (i.e., `Accept' and `Reject'). In this paper, we first
re-annotate an Eye-Quality (EyeQ) dataset with 28,792 retinal images from the
EyePACS dataset, based on a three-level quality grading system (i.e., `Good',
`Usable' and `Reject') for evaluating RIQA methods. Our RIQA dataset is
characterized by its large-scale size, multi-level grading, and multi-modality.
Then, we analyze the influences on RIQA of different color-spaces, and propose
a simple yet efficient deep network, named Multiple Color-space Fusion Network
(MCF-Net), which integrates the different color-space representations at both a
feature-level and prediction-level to predict image quality grades. Experiments
on our EyeQ dataset show that our MCF-Net obtains a state-of-the-art
performance, outperforming the other deep learning methods. Furthermore, we
also evaluate diabetic retinopathy (DR) detection methods on images of
different quality, and demonstrate that the performances of automated
diagnostic systems are highly dependent on image quality.Comment: Accepted by MICCAI 2019. Corrected two typos in Table 1 as: (1) in
training set, the number of "Usable + All" should be '1,876'; (2) In testing
set, the number of "Total + DR-0" should be '11,362'. Project page:
https://github.com/hzfu/Eye
New families of interpolating type IIB backgrounds
We construct new families of interpolating two-parameter solutions of type
IIB supergravity. These correspond to D3-D5 systems on non-compact
six-dimensional manifolds which are T^2 fibrations over Eguchi-Hanson and
multi-center Taub-NUT spaces, respectively. One end of the interpolation
corresponds to a solution with only D5 branes and vanishing NS three-form flux.
A topology changing transition occurs at the other end, where the internal
space becomes a direct product of the four-dimensional surface and the
two-torus and the complexified NS-RR three-form flux becomes imaginary
self-dual. Depending on the choice of the connections on the torus fibre, the
interpolating family has either N=2 or N=1 supersymmetry. In the N=2 case it
can be shown that the solutions are regular.Comment: 20 page
The Subleading Term of the Strong Coupling Expansion of the Heavy-Quark Potential in a Super Yang-Mills Plasma
Applying the AdS/CFT correspondence, the expansion of the heavy-quark
potential of the supersymmetric Yang-Mills theory at large is
carried out to the sub-leading term in the large 't Hooft coupling at nonzero
temperatures. The strong coupling corresponds to the semi-classical expansion
of the string-sigma model, the gravity dual of the Wilson loop operator, with
the sub-leading term expressed in terms of functional determinants of
fluctuations. The contributions of these determinants are evaluated
numerically.Comment: 17 pages in JHEP3, typos fixed, updated version to be published in
JHE
Time-like constant slope surfaces and space-like Bertrand curves in Minkowski 3-space
Defining Lorentzian Sabban frame of the unit speed time-like curves on de
Sitter 2-space and introducing space-like height function
on the unit speed time-like curves on , the invariants of
the unit speed time-like curves on and geometric
properties of de Sitter evolutes of the unit speed time-like curves on
are studied. A relation between space-like Bertrand curves
and helices is obtained. De Sitter Darboux images of space-like Bertrand curves
are equal to de Sitter evolutes. The relations between time-like constant slope
surfaces lying in the space-like cone and space-like Bertrand curves in
Minkowski 3-space are obtained.Comment: 15 Pages, 2 Figures. Accepted for publication in the Proceedings of
the National Academy of Sciences, India Section A: Physical Science
Low-order discrete dynamical system for H2-air finite-rate chemistry in 3D
Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.A low-order discrete dynamical system (DDS) model for
finite-rate chemistry of H2-air combustion is derived in 3D. Simulation
is performed in the context of a new subgrid-scale (SGS)
method. Regime maps are used to determine useful ranges of
values for bifurcation parameters. Specifically, a nine-step mechanism
of H2-air reactions with N2-dilution is studied. As input to
the DDS model, one fixed position within the flow chosen from
Meier et al., is used (Combustion Science and Technology, 1996).
The results in terms of time series of velocities, species mass
fractions and the sum of mass fractions are analyzed. Moreover,
the results are compared with experimental data at the selected
position in the flame field. Discrepancies between computed and
experimental results are discussed, and possible causes for discrepancies
are analyzed. The potential of applying the current
DDS in large-eddy simulation is addressed.dc201
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