5,340 research outputs found
ScaRR: Scalable Runtime Remote Attestation for Complex Systems
The introduction of remote attestation (RA) schemes has allowed academia and
industry to enhance the security of their systems. The commercial products
currently available enable only the validation of static properties, such as
applications fingerprint, and do not handle runtime properties, such as
control-flow correctness. This limitation pushed researchers towards the
identification of new approaches, called runtime RA. However, those mainly work
on embedded devices, which share very few common features with complex systems,
such as virtual machines in a cloud. A naive deployment of runtime RA schemes
for embedded devices on complex systems faces scalability problems, such as the
representation of complex control-flows or slow verification phase.
In this work, we present ScaRR: the first Scalable Runtime Remote attestation
schema for complex systems. Thanks to its novel control-flow model, ScaRR
enables the deployment of runtime RA on any application regardless of its
complexity, by also achieving good performance. We implemented ScaRR and tested
it on the benchmark suite SPEC CPU 2017. We show that ScaRR can validate on
average 2M control-flow events per second, definitely outperforming existing
solutions.Comment: 14 page
Statin-associated muscle symptoms (SAMS) in primary prevention for cardiovascular disease in older adults:A protocol for a systematic review and meta-analysis of randomised controlled trials
IntroductionAlthough statins are commonly used for prevention of cardiovascular disease, there is limited evidence about statin-related adverse effects in older people. Statin-related adverse events (AEs), especially the statin-associated muscle symptoms (SAMS), are the most common reasons for their discontinuation. Therefore, it is important to determine the risk of SAMS in the older population. We will undertake a systematic review and meta-analysis primarily focusing on the risk of SAMS and secondarily targeting myopathy, rhabdomyolysis, AEs and serious AEs, dropouts due to SAMS in run-in period, related permanent discontinuation rate of statins and creatine kinase level, among older people who received statins for primary prevention.Methods and analysisThis study has been developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement. We will include randomised controlled trials in which statin was compared with placebo with at least 1âyear follow-up among older adults aged â„65. This review is an update of a Cochrane systematic review that included the articles published before 2012. Cochrane Central Register of Controlled Trials, Medline OvidSP and Embase electronic database searches will be performed to identify relevant articles, limiting the publication date from 1 January 2012 to 13 February 2017. There will be no language limitation. Two independent reviewers will screen titles and abstracts and full text in duplicate. Risk of bias and evidence quality will be assessed using the Cochrane Collaborationâs tool and the Grading of Recommendations Assessment, Development and Evaluation approach, respectively. A meta-analysis using pooled data will be undertaken, if appropriate. We will also perform metaregression and subgroup analyses to identify sources of heterogeneity.Ethics and disseminationThis study is exempt from ethics approval due to the anonymous and aggregated data used. The outcomes will be disseminated by conference presentations and published in a peer-reviewed journal.Trial registration numberCRD42017058436.</jats:sec
Theoretical evidence for efficient p-type doping of GaN using beryllium
Ab initio calculations predict that Be is a shallow acceptor in GaN. Its
thermal ionization energy is 0.06 eV in wurtzite GaN; the level is valence
resonant in the zincblende phase. Be incorporation is severely limited by the
formation of Be_3N_2. We show however that co-incorporation with reactive
species can enhance the solubility. H-assisted incorporation should lead to
high doping levels in MOCVD growth after post-growth annealing at about 850 K.
Be-O co-incorporation produces high Be and O concentrations at MBE growth
temperatures.Comment: revised Feb 24 199
A Global Database of Domestic and International Tourist Numbers at National and Subnational Level
We present a new, global data base on tourist destinations. The data base differs from other data bases in that it includes both domestic and international tourists; and it contains data, for the most important destinations, data at national level as well as at lower administrative levels. Missing observations are interpolated using statistical models. The data are freely accessible on the internet.Tourism, Data
Inhomogeneous critical current in nanowire superconducting single-photon detectors
A superconducting thin film with uniform properties is the key to realize
nanowire superconducting single-photon detectors (SSPDs) with high performance
and high yield. To investigate the uniformity of NbN films, we introduce and
characterize simple detectors consisting of short nanowires with length ranging
from 100nm to 15{\mu}m. Our nanowires, contrary to meander SSPDs, allow probing
the homogeneity of NbN at the nanoscale. Experimental results, endorsed by a
microscopic model, show the strongly inhomogeneous nature of NbN films on the
sub-100nm scale.Comment: 10 pages, 4 figure
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