168 research outputs found

    HAVOSS: A Maturity Model for Handling Vulnerabilities in Third Party OSS Components

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    Security has been recognized as a leading barrier for IoT adoption. The growing number of connected devices and reported software vulnerabilities increases the importance firmware updates. Maturity models for software security do include parts of this, but are lacking in several aspects. This paper presents and evaluates a maturity model (HAVOSS) for handling vulnerabilities in third party OSS and COTS components. The maturity model was designed by first reviewing industry interviews, current best practice guidelines and other maturity models. After that, the practices were refined through industry interviews, resulting in six capability areas covering in total 21 practices. These were then evaluated based on their importance according to industry experts. It is shown that the practices are seen as highly important, indicating that the model can be seen as a valuable tool when assessing strengths and weaknesses in an organization's ability to handle firmware updates

    Simple analytic solution of fireball hydrodynamics

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    A new family of simple analytic solutions of hydrodynamics is found for non-relativistic, rotationally symmetric fireballs assuming an ideal gas equation of state. The solution features linear flow profile and a non-trivial transverse temperature profile. The radial temperature gradient vanishes only in the collisionless gas limit. The Zimanyi-Bondorf-Garpman solution and the Buda-Lund parameterization of expanding hydrodynamical sources are recovered as special cases. The results are applied to predict new features of proton-proton correlations and spectra data at 1.93 AGeV Ni + Ni reactions.Comment: Latex, Revte

    Role of isospin dependent mean field in pion production in heavy ion reactions

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    The importance of a isospin dependent nuclear mean field (IDMF) in regard to the pion production mechanism is studied for the reaction Au+AuAu+Au at 1 GeV/nucleon using the Quantum Molecular Dynamics (QMD) model. In particular, the effect of the IDMF on pion spectra and the charged pion ratio are analyzed. It is found that the inclusion of a IDMF considerably suppresses the lowpt-p_t pions, thus, leading to a better agreement with the data on pion spectra. Moreover, the rapidity distribution of the charged pion ratio appears to be sensitive to the isospin dependence of the nuclear mean field.Comment: 16 pages, using RevTex, 6 PS-Figure

    Anomalous radial expansion in central heavy-ion reactions

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    The expansion velocity profile in central heavy-ion reactions in the Fermi energy domain is examined. The radial expansion is non-hubblean and in the surface region it scales proportional to a higher exponent (α>1\alpha > 1) of the radius. The anomalous expansion velocity profile is accompanied by a power law nucleon density profile in the surface region. Both these features of central heavy-ion reactions disappear at higher energies, and the system follows a uniform Hubble expansion (α1\alpha \simeq 1)

    Delta excitation in K^+-nucleus collisions

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    We present calculations for \Delta excitation in the (K^+,K^+) reaction in nuclei. The background from quasielastic K^+ scattering in the \Delta region is also evaluated and shown to be quite small in some kinematical regions, so as to allow for a clean identification of the \Delta excitation strength. Nuclear effects tied to the \Delta renormalization in the nucleus are considered and the reaction is shown to provide new elements to enrich our knowledge of the \Delta properties in a nuclear medium.Comment: 11 pages, 6 figures, LaTe

    Securing recruitment and obtaining informed consent in minority ethnic groups in the UK

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    Background: Previous health research has often explicitly excluded individuals from minority ethnic backgrounds due to perceived cultural and communication difficulties, including studies where there might be language/literacy problems in obtaining informed consent. This study addressed these difficulties by developing audio-recorded methods of obtaining informed consent and recording data. This report outlines 1) our experiences with securing recruitment to a qualitative study investigating alternative methods of data collection, and 2) the development of a standardised process for obtaining informed consent from individuals from minority ethnic backgrounds whose main language does not have an agreed written form. Methods: Two researchers from South Asian backgrounds recruited adults with Type 2 diabetes whose main language was spoken and not written, to attend a series of focus groups. A screening tool was used at recruitment in order to assess literacy skills in potential participants. Informed consent was obtained using audio-recordings of the patient information and recording patients' verbal consent. Participants' perceptions of this method of obtaining consent were recorded. Results: Recruitment rates were improved by using telephone compared to face-to-face methods. The screening tool was found to be acceptable by all potential participants. Audio-recorded methods of obtaining informed consent were easy to implement and accepted by all participants. Attrition rates differed according to ethnic group. Snowballing techniques only partly improved participation rates. Conclusion: Audio-recorded methods of obtaining informed consent are an acceptable alternative to written consent in study populations where literacy skills are variable. Further exploration of issues relating to attrition is required, and a range of methods may be necessary in order to maximise response and participation

    Quantum-Statistical Correlations and Single Particle Distributions for Slowly Expanding Systems with Temperature Profile

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    Competition among particle evaporation, temperature gradient and flow is investigated in a phenomenological manner, based on a simultaneous analysis of quantum statistical correlations and momentum distributions for a non-relativistic, spherically symmetric, three-dimensionally expanding, finite source. The parameters of the model emission function are constrained by fits to neutron and proton momentum distributions and correlation functions in intermediate energy heavy-ion collisions. The temperature gradient is related to the momentum dependence of the radius parameters of the two-particle correlation function, as well as to the momentum-dependent temperature parameter of the single particle spectrum, while a long duration of particle evaporation is found to be responsible for the low relative momentum behavior of the two-particle correlations.Comment: 20 pages + 5 ps figures, ReVTeX, uses psfig.sty, the description is extended to include final state interactions, phenomenological evaporation and to fit intermediate energy heavy ion proton and neutron spectrum and correlation dat

    Analysis of charged particle emission sources and coalescence in E/A = 61 MeV 36^{36}Ar + 27^{27}Al, 112^{112}Sn and 124^{124}Sn collisions

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    Single-particle kinetic energy spectra and two-particle small angle correlations of protons (pp), deuterons (dd) and tritons (tt) have been measured simultaneously in 61A MeV 36^{36}Ar + 27^{27}Al, 112^{112}Sn and 124^{124}Sn collisions. Characteristics of the emission sources have been derived from a ``source identification plot'' (βsource\beta_{source}--ECME_{CM} plot), constructed from the single-particle invariant spectra, and compared to the complementary results from two-particle correlation functions. Furthermore, the source identification plot has been used to determine the conditions when the coalescence mechanism can be applied for composite particles. In our data, this is the case only for the Ar + Al reaction, where pp, dd and tt are found to originate from a common source of emission (from the overlap region between target and projectile). In this case, the coalescence model parameter, p~0\tilde{p}_0 -- the radius of the complex particle emission source in momentum space, has been analyzed.Comment: 20 pages, 5 figures, submitted to Nuclear Physics
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