180,262 research outputs found
PeerHunter: Detecting Peer-to-Peer Botnets through Community Behavior Analysis
Peer-to-peer (P2P) botnets have become one of the major threats in network
security for serving as the infrastructure that responsible for various of
cyber-crimes. Though a few existing work claimed to detect traditional botnets
effectively, the problem of detecting P2P botnets involves more challenges. In
this paper, we present PeerHunter, a community behavior analysis based method,
which is capable of detecting botnets that communicate via a P2P structure.
PeerHunter starts from a P2P hosts detection component. Then, it uses mutual
contacts as the main feature to cluster bots into communities. Finally, it uses
community behavior analysis to detect potential botnet communities and further
identify bot candidates. Through extensive experiments with real and simulated
network traces, PeerHunter can achieve very high detection rate and low false
positives.Comment: 8 pages, 2 figures, 11 tables, 2017 IEEE Conference on Dependable and
Secure Computin
Systolic VLSI for Kalman filters
A novel two-dimensional parallel computing method for real-time Kalman filtering is presented. The mathematical formulation of a Kalman filter algorithm is rearranged to be the type of Faddeev algorithm for generalizing signal processing. The data flow mapping from the Faddeev algorithm to a two-dimensional concurrent computing structure is developed. The architecture of the resulting processor cells is regular, simple, expandable, and therefore naturally suitable for VLSI chip implementation. The computing methodology and the two-dimensional systolic arrays are useful for Kalman filter applications as well as other matrix/vector based algebraic computations
Articulated elastic-loop roving vehicles
Prototype vehicle features exceptional obstacle-negotiating and slope-climbing capabilities plus high propulsive efficiency. Concept should interest designers of polar or ocean-bottom research vehicles. Also, its large footprint and low ground pressure will minimize ecological damage on terrain with low bearing strength, as in off-the-road application
Pulse Profiles, Spectra and Polarization Characteristics of Non-Thermal Emissions from the Crab-Like Pulsars
We discuss non-thermal emission mechanism of the Crab-like pulsars with both
a two-dimensional electrodynamical study and a three-dimensional model. We
investigate the emission process in the outer gap accelerator. In the
two-dimensional electrodynamical study, we solve the Poisson equation of the
accelerating electric field in the outer gap and the equation of motion of the
primary particles with the synchrotron and the curvature radiation process and
the pair-creation process. We show a solved gap structure which produces a
consistent gamma-ray spectrum with EGRET observation. Based on the
two-dimensional model, we conduct a three-dimensional emission model to
calculate the synchrotron and the inverse-Compton processes of the secondary
pairs produced outside the outer gap. We calculate the pulse profiles, the
phase-resolved spectra and the polarization characteristics in optical to
-ray bands to compare the observation of the Crab pulsar and PSR
B0540-69. For the Crab pulsar, we find that the outer gap geometry extending
from near the stellar surface to near the light cylinder produces a complex
morphology change of the pulse profiles as a function of the photon energy.
This predicted morphology change is quite similar with that of the
observations. The calculated phase-resolved spectra are consistent with the
data through optical to the -ray bands. We demonstrate that the
1020 % of the polarization degree in the optical emissions from the Crab
pulsar and the Vela pulsar are explained by the synchrotron emissions with the
particle gyration motion.Comment: 39 pages, 11 figures, Accepted for publication in Ap
- …