508 research outputs found
Selective Jamming of LoRaWAN using Commodity Hardware
Long range, low power networks are rapidly gaining acceptance in the Internet
of Things (IoT) due to their ability to economically support long-range sensing
and control applications while providing multi-year battery life. LoRa is a key
example of this new class of network and is being deployed at large scale in
several countries worldwide. As these networks move out of the lab and into the
real world, they expose a large cyber-physical attack surface. Securing these
networks is therefore both critical and urgent. This paper highlights security
issues in LoRa and LoRaWAN that arise due to the choice of a robust but slow
modulation type in the protocol. We exploit these issues to develop a suite of
practical attacks based around selective jamming. These attacks are conducted
and evaluated using commodity hardware. The paper concludes by suggesting a
range of countermeasures that can be used to mitigate the attacks.Comment: Mobiquitous 2017, November 7-10, 2017, Melbourne, VIC, Australi
Uncertainty in Building Energy Performance Characterization: Impact of Gas Consumption Decomposition on Estimated Heat Loss Coefficient
Characterization of building energy performance indicators such as the Heat Loss Coefficient (HLC) based on in-situ measurement data calls for thorough building physical insight, a well- designed measurement set-up to collect sufficient, qualitative data and adequate data analysis methods. On-board monitoring may be an alternative for dedicated experiments to perform the data collection task. This paper analyses the sensitivity of the end-result of the characterization, the HLC estimate, to flaws in the monitoring data set. More specifically, the impact of not installing submeters to disentangle the gas consumption for space heating and the production of domestic hot water is evaluated. Hereto, multiple gas decomposition methods are applied on a case study monitoring data set, after which the HLC is assessed. The results show deviations up to 33% for the mean estimate. Nevertheless, the 95% confidence intervals largely overlap
Commit* to change? A call to end the publication of the phrase ‘commit* suicide’
Background: Countering stigma is a fundamental facet of suicide prevention efforts. Integral to this is the promotion of accurate and sensitive language. The phrase ‘commit* suicide’ has prompted marked opposition primarily due to the connotations of immorality and illegality.
Methods: The study investigated the frequency of the use of the wordstem ‘commit’, in relation to self-harm and suicidal behaviours, in the three leading suicide-specific academic journals between 2000 and 2015.
Results: One third (34%) of articles published since the year 2000 used the word ‘commit*’ when describing an act of self-harm or suicide. Over half of these articles (57%) used the phrase on more than one occasion, with 6% using it more than 10 times in the same manuscript. The percentage of papers utilising the word ‘commit*’ has fluctuated over time, but there is a promising downward trend in the use of this phrase from 33% in 2000 to 13% in 2015 (p < 0.001).
Discussion: We advocate for the implementation of publication requirements regarding the language used when discussing suicide. Whilst we call for collective responsibility amongst academics and clinicians, editors hold a unique position in ensuring that outdated, inaccurate and stigma-laden terms are expunged from the scientific literature
Bulk Mediated Surface Diffusion: Non Markovian Desorption with Finite First Moment
Here we address a fundamental issue in surface physics: the dynamics of
adsorbed molecules. We study this problem when the particle's desorption is
characterized by a non Markovian process, while the particle's adsorption and
its motion in the bulk are governed by a Markovian dynamics. We study the
diffusion of particles in a semi-infinite cubic lattice, and focus on the
effective diffusion process at the interface . We calculate analytically
the conditional probability to find the particle on the plane as well as
the surface dispersion as functions of time. The comparison of these results
with Monte Carlo simulations show an excellent agreement.Comment: 16 pages, 7 figs. European Physical Journal B (in press
Prospects for the Improvement of Energy Performance in Agroindustry Using Phase Change Materials
This work was partially supported by the Fundação para a Ciência e Tecnologia, UIDB/00066/2020 (CTS – Center of Technology and Systems).The use of Phase Change Materials (PCMs), able to store latent heat, represents an opportunity to improve energy efficiency in the agroindustry by means of thermal energy storage. PCMs provide higher energy density then sensible heat storage mediums, thus paving the way to multiple applications, like supporting the integration of renewables or allowing for new storage architectures, decentralized and directly installed in the chain production equipment, creating e.g. the opportunity to recover and value low-grade operational heat sub-products. Such new and decentralized architecture, not currently applied in agroindustry, is proposed in this work. A chocolate tempering machine using an organic PCM is conceived and analyzed using ANSYS Fluent software for computational fluid dynamics simulations, comparing the main aspects in the storage capacity and discharging process with a conventional sensitive heat storage solution that uses water. PCMs allows improving the stored energy, keeping the chocolate in the working temperature after being tempered for more than four times longer than using only hot water. If the PCMs are charged by renewables, the self-consumption ratio can be improved while providing energy flexibility to the user.authorsversionpublishe
The utility of metabolic parameters on baseline F-18 FDG PET/CT in predicting treatment response and survival in paediatric and adolescent Hodgkin lymphoma
Lymphoma is the third most common paediatric cancer. Early detection of high-risk patients
is necessary to anticipate those who require intensive therapy and follow-up. Current literature
shows that residual tumor avidity on PET (Positron Emission Tomography) following chemotherapy
corresponds with decreased survival. However, the value of metabolic parameters has not been
adequately investigated. In this retrospective study, we aimed to evaluate the prognostic value of
metabolic and other parameters in paediatric and adolescent Hodgkin lymphoma. We recorded
tMTV (total Metabolic Tumor Volume), TLG (Total Lesion Glycolysis), and SUVmax (maximum
Standard Uptake Value) on baseline PET, as well the presence of bone marrow or visceral involvement.
HIV (human immunodeficiency virus) status and baseline biochemistry from clinical records
were noted. All patients received stage-specific standard of care therapy. Response assessment on
end-of-treatment PET was evaluated according to the Deauville criteria. We found that bone marrow
involvement (p = 0.028), effusion (p < 0.001), and treatment response (p < 0.001) on baseline PET, as
well as HIV status (p = 0.036) and baseline haemoglobin (p = 0.039), were significantly related to
progression-free survival (PFS), whereas only effusion (p = 0.017) and treatment response (p = 0.050)
were predictive of overall survival (OS). Only baseline tMTV predicted treatment response (p = 0.017).
This confirms the value of F-18 FDG PET/CT (Fluoro-deoxy-glucose Positron Emission Tomography/
Computed Tomography) in prognostication in paediatric and adolescent Hodgkin lymphoma;
however, further studies are required to define the significance of metabolic parameters.https://www.mdpi.com/journal/jcmam2022Medical OncologyNuclear MedicineStatistic
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