13,311 research outputs found
Fault-Tolerance by Graceful Degradation for Car Platoons
The key advantage of autonomous car platoons are their short inter-vehicle distances that increase traffic flow and reduce fuel consumption. However, this is challenging for operational and functional safety. If a failure occurs, the affected vehicles cannot suddenly stop driving but instead should continue their operation with reduced performance until a safe state can be reached or, in the case of temporal failures, full functionality can be guaranteed again. To achieve this degradation, platoon members have to be able to compensate sensor and communication failures and have to adjust their inter-vehicle distances to ensure safety. In this work, we describe a systematic design of degradation cascades for sensor and communication failures in autonomous car platoons using the example of an autonomous model car. We describe our systematic design method, the resulting degradation modes, and formulate contracts for each degradation level. We model and test our resulting degradation controller in Simulink/Stateflow
Electroweak Phase Transition and LHC Signatures in the Singlet Majoron Model
We reconsider the strength of the electroweak phase transition in the singlet
Majoron extension of the Standard Model, with a low (~TeV) scale of the singlet
VEV. A strongly first order phase transition, of interest for electroweak
baryogenesis, is found in sizeable regions of the parameter space, especially
when the cross-coupling lambda_{hs}|S|^2|H|^2 between the singlet and the
doublet Higgs is significant. Large Majorana Yukawa couplings of the singlet
neutrinos, y_i S nu_i^c nu_i, are also important for strengthening the
transition. We incorporate the LEP and Tevatron constraints on the Higgs
masses, and electroweak precision constraints, in our search for allowed
parameters; successful examples include singlet masses ranging from 5 GeV to
several TeV. Models with a strong phase transition typically predict a
nonstandard Higgs with mass in the range 113 GeV < m_H < 200 GeV and production
cross sections reduced by mixing with the singlet, with cos^2(theta)
significantly less than 1. We also find examples where the singlet is light and
the decay H -> SS can modify the Higgs branching ratios relative to Standard
Model expectations.Comment: 36 pages, 18 figure
Genetics of autistic disorders : review and clinical implications
Twin and family studies in autistic disorders (AD) have elucidated a high heritability of AD. In this literature review, we will present an overview on molecular genetic studies in AD and highlight the most recent findings of an increased rate of copy number variations in AD. An extensive literature search in the PubMed database was performed to obtain English published articles on genetic findings in autism. Results of linkage, (genome wide) association and cytogenetic studies are presented, and putative aetiopathological pathways are discussed. Implications of the different genetic findings for genetic counselling and genetic testing at present will be described. The article ends with a prospectus on future directions. Keywords: Autistic disorder , Linkage , Whole genome association , Copy number variation , Mutatio
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