13,796 research outputs found
Mono3D++: Monocular 3D Vehicle Detection with Two-Scale 3D Hypotheses and Task Priors
We present a method to infer 3D pose and shape of vehicles from a single
image. To tackle this ill-posed problem, we optimize two-scale projection
consistency between the generated 3D hypotheses and their 2D
pseudo-measurements. Specifically, we use a morphable wireframe model to
generate a fine-scaled representation of vehicle shape and pose. To reduce its
sensitivity to 2D landmarks, we jointly model the 3D bounding box as a coarse
representation which improves robustness. We also integrate three task priors,
including unsupervised monocular depth, a ground plane constraint as well as
vehicle shape priors, with forward projection errors into an overall energy
function.Comment: Proc. of the AAAI, September 201
Neutrino Masses and Heavy Triplet Leptons at the LHC: Testability of Type III Seesaw
We study LHC signatures of Type III seesaw in which SU(2)_L triplet leptons
are introduced to supply the heavy seesaw masses. To detect the signals of
these heavy triplet leptons, one needs to understand their decays to standard
model particles which depend on how light and heavy leptons mix with each
other. We concentrate on the usual solutions with small light and heavy lepton
mixing of order the square root of the ratio of light and heavy masses,
(m_\nu/M_{\nu_R})^{1/2}. This class of solutions can lead to a visible
displaced vertex detectable at the LHC which can be used to distinguish small
mixing and large mixing between light and heavy leptons. We show that, in this
case, the couplings of light and heavy triplet leptons to gauge and Higgs
bosons, which determine the decay widths and branching ratios, can be expressed
in terms of light neutrino masses and their mixing. Using these relations, we
study heavy triplet lepton decay patterns and production cross section at the
LHC. If these heavy triplet leptons are below a TeV or so, they can be easily
produced at the LHC due to their gauge interactions from being non-trivial
representations of SU(2)_L. We consider two ideal production channels, 1)
E^+E^- \to \ell^+\ell^+ \ell^-\ell^- jj (\ell=e,\mu,\tau) and 2) E^\pm N \to
\ell^\pm \ell^\pm jjjj in detail. For case 1), we find that with one or two of
the light leptons being \tau it can also be effectively studied. With judicious
cuts at the LHC, the discovery of the heavy triplet leptons as high as a TeV
can be achieved with 100 fb^{-1} integrated luminosity.Comment: 39 pages, 36 figures, accepted version by PR
Anonymous Networking amidst Eavesdroppers
The problem of security against timing based traffic analysis in wireless
networks is considered in this work. An analytical measure of anonymity in
eavesdropped networks is proposed using the information theoretic concept of
equivocation. For a physical layer with orthogonal transmitter directed
signaling, scheduling and relaying techniques are designed to maximize
achievable network performance for any given level of anonymity. The network
performance is measured by the achievable relay rates from the sources to
destinations under latency and medium access constraints. In particular,
analytical results are presented for two scenarios:
For a two-hop network with maximum anonymity, achievable rate regions for a
general m x 1 relay are characterized when nodes generate independent Poisson
transmission schedules. The rate regions are presented for both strict and
average delay constraints on traffic flow through the relay.
For a multihop network with an arbitrary anonymity requirement, the problem
of maximizing the sum-rate of flows (network throughput) is considered. A
selective independent scheduling strategy is designed for this purpose, and
using the analytical results for the two-hop network, the achievable throughput
is characterized as a function of the anonymity level. The throughput-anonymity
relation for the proposed strategy is shown to be equivalent to an information
theoretic rate-distortion function
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