Multi-Technology Cooperative Driving: An Analysis Based on PLEXE

Cooperative Driving requires ultra-reliable communications, and it is now clear that no single technology will ever be able to satisfy such stringent requirements, if only because active jamming can kill (almost) any wireless technology. Cooperative driving with multiple communication technologies which complement each other opens new spaces for research and development, but also poses several challenges. The work we present tackles the fallback and recovery mechanisms that the longitudinal controlling system of a platoon of vehicles can implement as a distributed system with multiple communication interfaces. We present a protocol and procedure to correctly compute the safe transition between different controlling algorithms, down to autonomous (or manual) driving when no communication is possible. To empower the study, we also develop a new version of PLEXE, which is an integral part of this contribution as the only Open Source, free simulation tool that enables the study of such systems with a modular approach, and that we deem offers the community the possibility of boosting research in this field. The results we present demonstrate the feasibility of safe fallback, but also highlight that such complex systems require careful design choices, as naive approaches can lead to instabilities or even collisions, and that such design can only be done with appropriate in-silico experiments

Investigating the feasibility of visible light communication for platooning applications

Platooning ist eine vielversprechende Anwendung von Fahrzeugnetzen, die dienegativen Effekte des Verkehrs zu reduzieren verspricht, indem Sicherheit, sowie Energieffizienz erhöht, und Straßen besser ausgelastet werden. Damit Platooning zuverlässig funktioniert, muss jedoch verlässliche Kommunikation selbst bei hohen Nachrichtenaufkommen gewährleistet sein. Dies ist mit aktueller Funktechnologie insbesondere bei hohen Verkehrsdichten schwierig, da in solchen Fällen die Zuverlässigkeit des Netzwerks durch Überlastung stark reduziert wird. Eine mögliche Lösung ist, zusätzlich zum Funk, oder anstatt dessen, Kommunikation im sichtbaren Spektrum einzusetzen. Um diese Möglichkeit zu evaluieren, entwerfe ich verschieden Kommunikationsansätze, die Funk und sichtbares Licht nutzen, und analysiere ihr Verhalten durch Simulationen. Die Ergebnisse dieser Simulationen zeigen, dass durch Verwendung von sichtbarem Licht deutliche Verbesserung sowohl der Sicherheit, als auch der Funkkanallast möglich sind. Die Ergebnisse der realistischen Simulationen weisen darauf hin, dass heterogene Kommunikation mit Funk und sichtbarem Licht für Platooning von Vorteil ist, und dass damit ein weiterer Schritt zur Verwendung in der Praxis.Platooning is a promising Intelligent Transport System (ITS) application which is set to reduce the negative aspects of road traffic, by improving safety, fuel efficiency,and road efficiency. In order to operate safely, however, platooning requires reliable communication at high rates. Achieving this with current Radio Frequency (RF) technology is challenging with high vehicle densities, because the high network load reduces its reliability. In order to alleviate this, the use of Visible Light Communication (VLC) instead of, or in addition to RF, has been proposed. To investigate VLCs feasibility I design different communication approaches which use RF and VLC and analyze their performance in an extensive simulation campaign. These simulations show that significant improvements in terms of safety and RF channel utilization can be achieved by beaconing with VLC. Based on realistic simulations, my results indicate that heterogeneous communication with RF and VLC is beneficial, and can bring platooning one step closer to real-world deployment.vorgelegt von Max Schettler angefertigt in der Fachgruppe Distributed Embedded Systems (CCS Labs), Heinz Nixdorf Institut, Universität Paderborn ; Betreuer: Agon Memedi, Gutachter: Falko Dressler, Tibor JagerTag der Abgabe: 17.09.2018Universität Paderborn, Masterarbeit, 201

Search for pair-produced vector-like B quarks in proton-proton collisions at s\sqrt{s} = 8 TeV

A search for the production of a heavy B quark, having electric charge -1/3 and vector couplings to W, Z, and H bosons, is carried out using proton-proton collision data recorded at the CERN LHC by the CMS experiment, corresponding to an integrated luminosity of 19.7 inverse femtobarns. The B quark is assumed to be pair-produced and to decay in one of three ways: to tW, bZ, or bH. The search is carried out in final states with one, two, and more than two charged leptons, as well as in fully hadronic final states. Each of the channels in the exclusive final-state topologies is designed to be sensitive to specific combinations of the B quark-antiquark pair decays. The observed event yields are found to be consistent with the standard model expectations in all the final states studied. A statistical combination of these results is performed and upper limits are set on the cross section of the strongly produced B quark-antiquark pairs as a function of the B quark mass. Lower limits on the B quark mass between 740 and 900 GeV are set at a 95% confidence level, depending on the values of the branching fractions of the B quark to tW, bZ, and bH. Overall, these limits are the most stringent to date

Search for supersymmetry with photons in pp collisions at s\sqrt s = 8 TeV

Two searches for physics beyond the standard model in events containing photons are presented. The data sample used corresponds to an integrated luminosity of 19.7 inverse femtobarns of proton-proton collisions at $\sqrt{s}$ = 8 TeV, collected with the CMS experiment at the CERN LHC. The analyses pursue different inclusive search strategies. One analysis requires at least one photon, at least two jets, and a large amount of transverse momentum imbalance, while the other selects events with at least two photons and at least one jet, and uses the razor variables to search for signal events. The background expected from standard model processes is evaluated mainly from data. The results are interpreted in the context of general gauge-mediated supersymmetry, with the next-to-lightest supersymmetric particle either a bino- or wino-like neutralino, and within simplified model scenarios. Upper limits at 95% confidence level are obtained for cross sections as functions of the masses of the intermediate supersymmetric particles