A hierarchical detection method in external communication for self-driving vehicles based on TDMA

Security is considered a major challenge for self-driving and semi self-driving vehicles. These vehicles depend heavily on communications to predict and sense their external environment used in their motion. They use a type of ad hoc network termed Vehicular ad hoc networks (VANETs). Unfortunately, VANETs are potentially exposed to many attacks on network and application level. This paper, proposes a new intrusion detection system to protect the communication system of self-driving cars; utilising a combination of hierarchical models based on clusters and log parameters. This security system is designed to detect Sybil and Wormhole attacks in highway usage scenarios. It is based on clusters, utilising Time Division Multiple Access (TDMA) to overcome some of the obstacles of VANETs such as high density, high mobility and bandwidth limitations in exchanging messages. This makes the security system more efficient, accurate and capable of real time detection and quick in identification of malicious behaviour in VANETs. In this scheme, each vehicle log calculates and stores different parameter values after receiving the cooperative awareness messages from nearby vehicles. The vehicles exchange their log data and determine the difference between the parameters, which is utilised to detect Sybil attacks and Wormhole attacks. In order to realize efficient and effective intrusion detection system, we use the well-known network simulator (ns-2) to verify the performance of the security system. Simulation results indicate that the security system can achieve high detection rates and effectively detect anomalies with low rate of false alarms

The Observation of Up-going Charged Particles Produced by High Energy Muons in Underground Detectors

An experimental study of the production of up-going charged particles in inelastic interactions of down-going underground muons is reported, using data obtained from the MACRO detector at the Gran Sasso Laboratory. In a sample of 12.2 10^6 single muons, corresponding to a detector livetime of 1.55 y, 243 events are observed having an up-going particle associated with a down-going muon. These events are analysed to determine the range and emission angle distributions of the up-going particle, corrected for detection and reconstruction efficiency. Measurements of the muon neutrino flux by underground detectors are often based on the observation of through-going and stopping muons produced in $\nu_\mu$ interactions in the rock below the detector. Up-going particles produced by an undetected down-going muon are a potential background source in these measurements. The implications of this background for neutrino studies using MACRO are discussed.Comment: 18 pages, 9 figures. Accepted by Astrop. Physic

Limits on dark matter WIMPs using upward-going muons in the MACRO detector

We perform an indirect search for Weakly Interacting Massive Particles (WIMPs) using the MACRO detector to look for neutrino-induced upward-going muons resulting from the annihilation of WIMPs trapped in the Sun and Earth. The search is conducted in various angular cones centered on the Sun and Earth to accommodate a range of WIMP masses. No significant excess over the background from atmospheric neutrinos is seen and limits are placed on the upward-going muon fluxes from Sun and Earth. These limits are used to constrain neutralino particle parameters from supersymmetric theory, including those suggested by recent results from DAMA/NaI.Comment: 14 pages, 7 figures, submitted to Phys. Rev.

Atmospheric neutrino induced muons in the MACRO detector

A measurement of the flux of neutrino-induced muons using the MACRO detector is presented. Different event topologies, corresponding to different neutrino parent energies can be detected. The upward throughgoing muon sample is the larger event sample. The observed upward-throughgoing muons are 26% fewer than expected and the zenith angle distribution does not fit with the expected one. Assuming neutrino oscillations, both measurements suggest maximum mixing and Dm2 of a few times 10-3 eV2. The other samples are due to the internally produced events and to upward-going stopping muons. These data show a regular deficit of observed events in each angular bin, as expected assuming neutrino oscillations with maximum mixing, in agreement with the analysis of the upward-throughgoing muon sample.Comment: 7 pages 6 figures to appear in the proceedings of XVIII International Conference on Neutrino Physics and Astrophysics (Neutrino'98), Takayama, Japan 4-9 June, 199

Measurement of the atmospheric neutrino-induced upgoing muon flux using MACRO

We present a measurement of the flux of neutrino-induced upgoing muons (~100 GeV) using the MACRO detector. The ratio of the number of observed to expected events integrated over all zenith angles is 0.74 +/- 0.036 (stat) +/- 0.046(systematic) +/- 0.13 (theoretical). The observed zenith distribution for -1.0 < cos(theta) < -0.1 does not fit well with the no oscillation expectation, giving a maximum probability for chi^2 of 0.1%. The acceptance of the detector has been extensively studied using downgoing muons, independent analyses and Monte-Carlo simulations. The other systematic uncertainties cannot be the source of the discrepancies between the data and expectations. We have investigated whether the observed number of events and the shape of the zenith distribution can be explained by a neutrino oscillation hypothesis. Fitting either the flux or zenith distribution independently yields mixing parameters of sin^2 (2theta)=1.0 and delta m^2 of a few times 10^-3 eV^2. However, the observed zenith distribution does not fit well with any expectations giving a maximum probability for chi^2 of 5% for the best oscillation hypothesis, and the combined probability for the shape and number of events is 17%. We conclude that these data favor a neutrino oscillation hypothesis, but with unexplained structure in the zenith distribution not easily explained by either the statistics or systematics of the experiment.Comment: 7 pages (two-column) with 4 figure

SEARCH FOR SLOWLY MOVING MAGNETIC MONOPOLES WITH THE MACRO DETECTOR

A search for slowly moving magnetic monopoles in the cosmic radiation was conducted from October 1989 to November 1991 using the large liquid scintillator detector subsystem of the first supermodule of the MACRO detector at the Gran Sasso underground laboratory. The absence of candidates established an upper limit on the monopole flux of 5.6 x 10(-15) cm-2 sr-1 s-1 at 90% confidence level in the velocity range of 10(-4) less than or similar to beta < 4 x 10(-3). This result places a new constraint on the abundance of monopoles trapped in our solar system