44,583 research outputs found
Deep Learning Based Vehicle Make-Model Classification
This paper studies the problems of vehicle make & model classification. Some
of the main challenges are reaching high classification accuracy and reducing
the annotation time of the images. To address these problems, we have created a
fine-grained database using online vehicle marketplaces of Turkey. A pipeline
is proposed to combine an SSD (Single Shot Multibox Detector) model with a CNN
(Convolutional Neural Network) model to train on the database. In the pipeline,
we first detect the vehicles by following an algorithm which reduces the time
for annotation. Then, we feed them into the CNN model. It is reached
approximately 4% better classification accuracy result than using a
conventional CNN model. Next, we propose to use the detected vehicles as ground
truth bounding box (GTBB) of the images and feed them into an SSD model in
another pipeline. At this stage, it is reached reasonable classification
accuracy result without using perfectly shaped GTBB. Lastly, an application is
implemented in a use case by using our proposed pipelines. It detects the
unauthorized vehicles by comparing their license plate numbers and make &
models. It is assumed that license plates are readable.Comment: 10 pages, ICANN 2018: Artificial Neural Networks and Machine Learnin
Recent results in Euclidean dynamical triangulations
We study a formulation of lattice gravity defined via Euclidean dynamical
triangulations (EDT). After fine-tuning a non-trivial local measure term we
find evidence that four-dimensional, semi-classical geometries are recovered at
long distance scales in the continuum limit. Furthermore, we find that the
spectral dimension at short distance scales is consistent with 3/2, a value
that is also observed in the causal dynamical triangulation (CDT) approach to
quantum gravity.Comment: 7 pages, 3 figures. Proceedings for the 3rd conference of the Polish
society on relativit
Lattice Quantum Gravity and Asymptotic Safety
We study the nonperturbative formulation of quantum gravity defined via
Euclidean dynamical triangulations (EDT) in an attempt to make contact with
Weinberg's asymptotic safety scenario. We find that a fine-tuning is necessary
in order to recover semiclassical behavior. Such a fine-tuning is generally
associated with the breaking of a target symmetry by the lattice regulator; in
this case we argue that the target symmetry is the general coordinate
invariance of the theory. After introducing and fine-tuning a nontrivial local
measure term, we find no barrier to taking a continuum limit, and we find
evidence that four-dimensional, semiclassical geometries are recovered at long
distance scales in the continuum limit. We also find that the spectral
dimension at short distance scales is consistent with 3/2, a value that could
resolve the tension between asymptotic safety and the holographic entropy
scaling of black holes. We argue that the number of relevant couplings in the
continuum theory is one, once symmetry breaking by the lattice regulator is
accounted for. Such a theory is maximally predictive, with no adjustable
parameters. The cosmological constant in Planck units is the only relevant
parameter, which serves to set the lattice scale. The cosmological constant in
Planck units is of order 1 in the ultraviolet and undergoes renormalization
group running to small values in the infrared. If these findings hold up under
further scrutiny, the lattice may provide a nonperturbative definition of a
renormalizable quantum field theory of general relativity with no adjustable
parameters and a cosmological constant that is naturally small in the infrared.Comment: 69 pages, 25 figures. Revised discussion of target symmetry
throughout paper. Numerical results unchanged and main conclusions largely
unchanged. Added references and corrected typos. Conforms with version
published in Phys. Rev.
On the Approximability and Hardness of the Minimum Connected Dominating Set with Routing Cost Constraint
In the problem of minimum connected dominating set with routing cost
constraint, we are given a graph , and the goal is to find the
smallest connected dominating set of such that, for any two
non-adjacent vertices and in , the number of internal nodes on the
shortest path between and in the subgraph of induced by is at most times that in . For general graphs, the only
known previous approximability result is an -approximation algorithm
() for by Ding et al. For any constant , we
give an -approximation
algorithm. When , we give an -approximation
algorithm. Finally, we prove that, when , unless , for any constant , the problem admits no
polynomial-time -approximation algorithm, improving
upon the bound by Du et al. (albeit under a stronger hardness
assumption)
- …