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Position Paper: Towards a Hybrid Approach to Protect Against Memory Safety Vulnerabilities
No full textMemory corruption bugs continue to plague lowlevel systems software, generally written in unsafe programming languages. In order to detect and protect against such exploits, many pre- and post-deployment techniques exist. In this position paper, we propose and motivate the need for a hybrid approach for the protection against memory safety vulnerabilities, combining techniques that can identify the presence (and absence) of vulnerabilities pre-deployment with those that can detect and mitigate such vulnerabilities post-deployment. Our proposed hybrid approach involves three layers: hardware runtime protection provided by capability hardware, software runtime protection provided by compiler instrumentation, and static analysis provided by bounded model checking and symbolic execution. The key aspect of the proposed hybrid approach is that the protection offered is greater than the sum of its parts – the expense of postdeployment runtime checks is potentially reduced via information obtained during pre-deployment analysis. During pre-deployment analysis, static checking can be guided by runtime information
A Benchmark for Multi-Class Object Counting and Size Estimation Using Deep Convolutional Neural Networks
No full textAutomatic object counting and object size estimation in digital images can be very useful in many real-world applications such as surveillance, smart farming, intelligent traffic systems, etc. However, most existing research mainly focus on scenarios where only one type of object is considered due to the lack of proper datasets. Furthermore, they use the traditional detection algorithms for size estimation and can only do segmenting tasks but cannot identify different types of objects and return corresponding individual size information. To fill these gaps, we create a synthetic dataset and propose a benchmark for multi-class object counting and size estimation (MOCSE) within a unified framework. We create the dataset MOCSE13 by using Unity to generate synthetic images for 13 different objects (fruits and vegetables). Besides, we propose a deep architecture approach for multi-class object counting and object size estimation. Our proposed models with different backbones are evaluated on the synthetic dataset. The experimental results provide a benchmark for multi-class object counting and size estimation and the synthetic dataset can be served as a proper testbed for future studies
Picturing Displaced Persons (DPs), Exhibiting French Prestige? Photographs of humanitarian aid for European DPs in French-occupied Germany, c. 1945-1952
No full textThis article explores how photography documenting humanitarian aid for European DPs in French-occupied Germany was mobilised to enhance France’s image in Allied occupied Germany, against the backdrop of increasing anxieties about its international standing. It draws on a selection of images found in the archives of the United Nations Relief and Rehabilitation Administration [UNRRA] and the French occupation zone at La Courneuve, which sat between the ‘official’ and the ‘private’. In doing so, this article calls for a recognition of the role of amateur and relief workers photographers in sustaining post-war visual discourses of internationalism and national-self fashioning. Although largely overlooked today, these images play a role in wider debates about what it meant to be ‘French’ in the aftermath of the Nazi occupation. In particular, relief workers and amateur photographers built on and reproduced aspects of the widely disseminated narrative about the universalism of resistance that was being circulated in metropolitan France and Britain at the same time to disrupt conventional images of the French zone as a refuge for French wartime collaborators. Ultimately, this article argues that this hitherto neglected aspect of humanitarian imagery offers fresh insights into the contribution of relief workers and amateur photographers to French post-war diplomatic and occupation strategies
Stitches and patches: The Franciscan habit in an engraving by Lucas Vorsterman
No full textAn early seventeenth century engraving by Lucas Vorsterman held by the National Gallery of Victoria and catalogued as the ‘Death of Saint Francis’ depicts the saint in a habit which shows clear wear and repair: there are frayed edges at the ends of the sleeves and several patches have been added. Focusing on Vorsterman’s engraving, this article explores the importance ascribed to the making and mending of the Franciscan habit - and the ways in which this could be indicated in prints from the late sixteenth to mid seventeenth century - with particular reference to the value placed on stitching
A Molecular Simulation Study into the Stability of Hydrated Graphene Nanochannels used in Nanofluidics Devices
No full textGraphene-based nanochannels are a popular choice in emerging nanofluidics applications because of their tunable and nanometer-scale channels. In this work, molecular dynamics (MD) simulations were employed both to i) assess the stability of dry and hydrated graphene nanochannels and ii) elucidate the properties of water confined in these channels, using replica-scale models with 0.66 – 2.38 nm channel heights. The use of flexible nanochannel walls allows the nanochannel height to relax in response to the solvation forces arising from the confined fluid and the forces between the confining surfaces, without the need for application of arbitrarily high external pressures. Dry nanochannels were found to completely collapse if the initial nanochannel height was less than 2 nm, due to attractive van der Waals interactions between the confining graphene surfaces. However, the presence of water was found to prevent total nanochannel collapse, due to repulsive hydration forces opposing the attractive van der Waals force. For nanochannel heights less than ~1.7 nm, the confining surfaces must be relaxed to obtain accurate hydration pressures and water diffusion coefficients, by ensuring commensurability between the number of confined water layers and the channel height. For very small (~0.7 nm), hydrated channels a pressure of 231 MPa due to the van der Waals forces was obtained. In the same system, the confined water forms a mobile, liquid monolayer with a diffusion coefficient of 4.0 × 10–5 cm2 s–1, much higher than bulk liquid water. Although this finding conflicts with most classical MD simulations, which predict in-plane order and arrested dynamics, it is supported by experiments and recently published first-principles MD simulations. Classical simulations can therefore be used to predict the properties of water confined in sub-nanometre graphene channels, providing sufficiently realistic molecular models and accurate intermolecular potentials are employed
A discontinuous model of duopoly with isoelastic demand and innovation costs
No full textThe paper studies the dynamic properties of a duopoly game in which firms strategically compete in quality-enhancing innovation investments and quantities. Market demands are assumed to be isolastic (reciprocal to the price) functions. The non-linearity of the demand functions, as already highlighted by T. Puu in [11], suggests the existence of complicated dynamics (cyclical or chaotic) in a standard dynamic Cournot duopoly. In addition to this, competition in innovation introduces the presence of discontinuities in the best response functions, expanding the set of possible equilibria (including asymmetric and multiple ones) of the standard Cournot duopoly and further enriching the dynamic features of the model.<br/
Amygdala responses to negative faces are not associated with depressive symptoms: cross-sectional data from 28 638 individuals in the UK Biobank cohort
No full textThe Magnetic Field in the Milky Way Filamentary Bone G47
No full textStar formation primarily occurs in laments where magnetic fields are expected to be dynamicallyimportant. The largest and densest laments trace spiral structure within galaxies. Over a dozen ofthese dense (∼10 4 cm-3) and long (>10 pc) laments have been found within the Milky Way, and they are often referred to as 'bones." Until now, none of these bones have had their magnetic field resolved and mapped in their entirety. We introduce the SOFIA legacy project FIELDMAPS which has begun mapping ∼10 of these Milky Way bones using the HAWC+ instrument at 214 μm and 18:002 resolution. Here we present a first result from this survey on the ∼60 pc long bone G47. Contrary to some studies of dense laments in the Galactic plane, we find that the magnetic field is often not perpendicular to the spine (i.e., the center-line of the bone). Fields tend to be perpendicular in the densest areas of active star formation and more parallel or random in other areas. The average field is neither parallel or perpendicular to the Galactic plane nor the bone. The magnetic field strengths along the spine typically vary from ∼20 to ∼100 μG. Magnetic fields tend to be strong enough to suppress collapse along much of the bone, but for areas that are most active in star formation, the fields are notably less able to resist gravitational collapse.<br/
Investigating Characteristics of Idiopathic Inflammatory Myopathy Flares Using Daily Symptom Data Collected Via a Smartphone App
No full textObjectivesTo use daily data collected via a smartphone app for characterisation of patient-reported and “symptom-based” (using an a priori definition) flares in an adult idiopathic inflammatory myopathy (IIM) cohort.MethodsUK adults with an IIM answered patient-reported outcome measurements (PROMs) daily via a smartphone app during a 91 day study. Daily symptom PROMs addressed global activity, overall pain, myalgia, fatigue, and weakness (0-100 visual analogue scale). Patient-reported flares were recorded via a weekly app question. “Symptom-based” flares were defined via an a priori definition based on increase of daily symptom data from the previous four day mean.ResultsTwenty participants (65% female) participated. Patient-reported flares occurred on a median of five weeks (IQR 3, 7) per participant, out of a possible 13. The mean of each symptom score was significantly higher in flare weeks, compared to non-flare weeks (e.g. mean flare week myalgia score 34/100, vs 21/100 during non-flare week, t-test p-value <0.01).Fatigue accounted for the most symptom-based flares (incidence-rate 23/100 person-days [95% CI 19, 27]), and myalgia the fewest (incidence rate 13/100 person-days [95% CI 11, 16]). Symptom-based flares typically resolved after three days, although fatigue-predominant flares lasted two days. The majority (69%) of patient-reported flare weeks coincided with at least one symptom-based flare.ConclusionsIIM flares are frequent and associated with increased symptom scores. This study has demonstrated the ability to identify and characterise patient-reported and symptom-based flares (based on an a priori definition), using daily app-collected data
Bounds for the chi-square approximation of Friedman’s statistic by Stein’s method
No full textFriedman’s chi-square test is a non-parametric statistical test for r treatments across n trials to assess the null hypothesis that there is no treatment effect. We use Stein’s method with an exchangeable pair coupling to derive a bound on the distance between the distribution of Friedman’s statistic and its limiting chi-square distribution, measured using smooth test functions. Our bound is of the optimal order n−1, and also has an optimal dependence on the parameter r, in that the bound tends to zero if and only if r/n→0. From this bound, we deduce a Kolmogorov distance bound that decays to zero under the weaker condition r1/2/n→0