2,332 research outputs found
Legal Requirements for Admission to Public Schools
Advanced driver assistance systems for heavy duty vehicles, such as lookahead cruise and gearshift controllers, rely on high quality map data. Current digital maps do not offer the required level of road grade information. This contribution presents an algorithm for on-board road grade estimation based on fusion of GPS and vehicle sensor data with measurements from previous runs over the same road segment. An incremental update scheme is utilized to ensure that data storage requirements are independent of the number of measurement runs. Results of the implemented system based on six traversals of a known road with three different vehicles are presented.QC 20120216</p
Pure Gravities via Color-Kinematics Duality for Fundamental Matter
We give a prescription for the computation of loop-level scattering
amplitudes in pure Einstein gravity, and four-dimensional pure supergravities,
using the color-kinematics duality. Amplitudes are constructed using double
copies of pure (super-)Yang-Mills parts and additional contributions from
double copies of fundamental matter, which are treated as ghosts. The
opposite-statistics states cancel the unwanted dilaton and axion in the bosonic
theory, as well as the extra matter supermultiplets in supergravities. As a
spinoff, we obtain a prescription for obtaining amplitudes in supergravities
with arbitrary non-self-interacting matter. As a prerequisite, we extend the
color-kinematics duality from the adjoint to the fundamental representation of
the gauge group. We explain the numerator relations that the fundamental
kinematic Lie algebra should satisfy. We give nontrivial evidence supporting
our construction using explicit tree and loop amplitudes, as well as more
general arguments.Comment: 48 pages + refs, 15 figures, 3 tables; v2 minor corrections, journal
versio
Color-Kinematics Duality for QCD Amplitudes
We show that color-kinematics duality is present in tree-level amplitudes of
quantum chromodynamics with massive flavored quarks. Starting with the color
structure of QCD, we work out a new color decomposition for n-point tree
amplitudes in a reduced basis of primitive amplitudes. These primitives, with k
quark-antiquark pairs and (n-2k) gluons, are taken in the (n-2)!/k! Melia
basis, and are independent under the color-algebra Kleiss-Kuijf relations. This
generalizes the color decomposition of Del Duca, Dixon, and Maltoni to an
arbitrary number of quarks. The color coefficients in the new decomposition are
given by compact expressions valid for arbitrary gauge group and
representation. Considering the kinematic structure, we show through explicit
calculations that color-kinematics duality holds for amplitudes with general
configurations of gluons and massive quarks. The new (massive) amplitude
relations that follow from the duality can be mapped to a well-defined subset
of the familiar BCJ relations for gluons. They restrict the amplitude basis
further down to (n-3)!(2k-2)/k! primitives, for two or more quark lines. We
give a decomposition of the full amplitude in that basis. The presented results
provide strong evidence that QCD obeys the color-kinematics duality, at least
at tree level. The results are also applicable to supersymmetric and
D-dimensional extensions of QCD.Comment: 33 pages + refs, 7 figures, 4 tables; v3 minor corrections, journal
versio
Model reduction of networked passive systems through clustering
In this paper, a model reduction procedure for a network of interconnected
identical passive subsystems is presented. Here, rather than performing model
reduction on the subsystems, adjacent subsystems are clustered, leading to a
reduced-order networked system that allows for a convenient physical
interpretation. The identification of the subsystems to be clustered is
performed through controllability and observability analysis of an associated
edge system and it is shown that the property of synchronization (i.e., the
convergence of trajectories of the subsystems to each other) is preserved
during reduction. The results are illustrated by means of an example.Comment: 7 pages, 2 figures; minor changes in the final version, as accepted
for publication at the 13th European Control Conference, Strasbourg, Franc
On the Exact Solution to a Smart Grid Cyber-Security Analysis Problem
This paper considers a smart grid cyber-security problem analyzing the
vulnerabilities of electric power networks to false data attacks. The analysis
problem is related to a constrained cardinality minimization problem. The main
result shows that an relaxation technique provides an exact optimal
solution to this cardinality minimization problem. The proposed result is based
on a polyhedral combinatorics argument. It is different from well-known results
based on mutual coherence and restricted isometry property. The results are
illustrated on benchmarks including the IEEE 118-bus and 300-bus systems
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