695 research outputs found

    Combined automotive safety and security pattern engineering approach

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    Automotive systems will exhibit increased levels of automation as well as ever tighter integration with other vehicles, traffic infrastructure, and cloud services. From safety perspective, this can be perceived as boon or bane - it greatly increases complexity and uncertainty, but at the same time opens up new opportunities for realizing innovative safety functions. Moreover, cybersecurity becomes important as additional concern because attacks are now much more likely and severe. However, there is a lack of experience with security concerns in context of safety engineering in general and in automotive safety departments in particular. To address this problem, we propose a systematic pattern-based approach that interlinks safety and security patterns and provides guidance with respect to selection and combination of both types of patterns in context of system engineering. A combined safety and security pattern engineering workflow is proposed to provide systematic guidance to support non-expert engineers based on best practices. The application of the approach is shown and demonstrated by an automotive case study and different use case scenarios.EC/H2020/692474/EU/Architecture-driven, Multi-concern and Seamless Assurance and Certification of Cyber-Physical Systems/AMASSEC/H2020/737422/EU/Secure COnnected Trustable Things/SCOTTEC/H2020/732242/EU/Dependability Engineering Innovation for CPS - DEIS/DEISBMBF, 01IS16043, Collaborative Embedded Systems (CrESt

    Testing of quantum phase in matter wave optics

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    Various phase concepts may be treated as special cases of the maximum likelihood estimation. For example the discrete Fourier estimation that actually coincides with the operational phase of Noh, Fouge`res and Mandel is obtained for continuous Gaussian signals with phase modulated mean.Since signals in quantum theory are discrete, a prediction different from that given by the Gaussian hypothesis should be obtained as the best fit assuming a discrete Poissonian statistics of the signal. Although the Gaussian estimation gives a satisfactory approximation for fitting the phase distribution of almost any state the optimal phase estimation offers in certain cases a measurable better performance. This has been demonstrated in neutron--optical experiment.Comment: 8 pages, 4 figure

    Synthesis and characterization of polyimide-silica hybrids : effect of matrix polarity on the mechanical and thermal properties

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    Polyimide-silica hybrid materials have been prepared through the sol-gel process by mixing various proportions oftetraethoxysilane (TEOS) with polyamic acids (PAAs). Two types of PPAs were employed. The first was obtained by reacting an equimolar mixture of oxydianiline (ODA) andpyromellitic dianhydride (PMDA) in dimethylactamide (DMAc) as solvent. The second was prepared using a mixture of ODA and 2,2-Bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6F-OHDA) in molar ratio 9:1, respectively and reacting with a stoichiometric amount of PMDA in DMAc. Polyamic acids were converted to polyimides and a sol-gel reaction proceeded simultaneously by heating the hybrid films to 300°C. The hydroxyl groups from 6F-OHDA allows the secondary bonding between the polyimide and growing silica phase and thus retard the gross phase separation. Only the 10mol% addition of 6F-OHDA in the polyimide chain resulted in a drastically different microstructure for the resulting hybrids. SEM, stress-strain analysis, temperature variation of storage and loss modulus, and thermal stability were used to characterize the hybrid materials. Properties of both types of hybrids have been compared and related to the two different types of structures of polyimides used in the preparation of the hybrids

    Comparative study of TERT promoter mutation status within spatially, temporally and morphologically distinct components of urothelial carcinoma

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141213/1/his13318.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141213/2/his13318_am.pd

    Magnetic Lattice Dynamics of the Oxygen-Free FeAs Pnictides: How Sensitive are Phonons to Magnetic Ordering?

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    To shed light on the role of magnetism on the superconducting mechanism of the oxygen-free FeAs pnictides, we investigate the effect of magnetic ordering on phonon dynamics in the low-temperature orthorhombic parent compounds, which present a spin-density wave. The study covers both the 122 (AFe2As2; A=Ca, Sr, Ba) and 1111 (AFeAsF; A=Ca, Sr) phases. We extend our recent work on the Ca (122 and 1111) and Ba (122) cases by treating computationally and experimentally the 122 and 1111 Sr compounds. The effect of magnetic ordering is investigated through detailed non-magnetic and magnetic lattice dynamical calculations. The comparison of the experimental and calculated phonon spectra shows that the magnetic interactions/ordering have to be included in order to reproduce well the measured density of states. This highlights a spin-correlated phonon behavior which is more pronounced than the apparently weak electron-phonon coupling estimated in these materials. Furthermore, there is no noticeable difference between phonon spectra of the 122 Ba and Sr, whereas there are substantial differences when comparing these to CaFe2As2 originating from different aspects of structure and bonding
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