14,481 research outputs found
ToolNet: Holistically-Nested Real-Time Segmentation of Robotic Surgical Tools
Real-time tool segmentation from endoscopic videos is an essential part of
many computer-assisted robotic surgical systems and of critical importance in
robotic surgical data science. We propose two novel deep learning architectures
for automatic segmentation of non-rigid surgical instruments. Both methods take
advantage of automated deep-learning-based multi-scale feature extraction while
trying to maintain an accurate segmentation quality at all resolutions. The two
proposed methods encode the multi-scale constraint inside the network
architecture. The first proposed architecture enforces it by cascaded
aggregation of predictions and the second proposed network does it by means of
a holistically-nested architecture where the loss at each scale is taken into
account for the optimization process. As the proposed methods are for real-time
semantic labeling, both present a reduced number of parameters. We propose the
use of parametric rectified linear units for semantic labeling in these small
architectures to increase the regularization ability of the design and maintain
the segmentation accuracy without overfitting the training sets. We compare the
proposed architectures against state-of-the-art fully convolutional networks.
We validate our methods using existing benchmark datasets, including ex vivo
cases with phantom tissue and different robotic surgical instruments present in
the scene. Our results show a statistically significant improved Dice
Similarity Coefficient over previous instrument segmentation methods. We
analyze our design choices and discuss the key drivers for improving accuracy.Comment: Paper accepted at IROS 201
The CP-violating pMSSM at the Intensity Frontier
In this Snowmass whitepaper, we describe the impact of ongoing and proposed
intensity frontier experiments on the parameter space of the Minimally
Supersymmetric Standard Model (MSSM). We extend a set of phenomenological MSSM
(pMSSM) models to include non-zero CP-violating phases and study the
sensitivity of various flavor observables in these scenarios Future electric
dipole moment and rare meson decay experiments can have a strong impact on the
viability of these models that is relatively independent of the detailed
superpartner spectrum. In particular, we find that these experiments have the
potential to probe models that are expected to escape searches at the
high-luminosity LHC.Comment: 10 pages, 2 figures. Contributed to the Community Summer Study 2013,
Minneapolis, MN July 29 - August 6, 201
Sharper bounds and structural results for minimally nonlinear 0-1 matrices
The extremal function is the maximum possible number of ones in
any 0-1 matrix with rows and columns that avoids . A 0-1 matrix
is called minimally non-linear if but
for every that is contained in but not equal to .
Bounds on the maximum number of ones and the maximum number of columns in a
minimally non-linear 0-1 matrix with rows were found in (CrowdMath, 2018).
In this paper, we improve the bound on the maximum number of ones in a
minimally non-linear 0-1 matrix with rows from to . As a
corollary, this improves the upper bound on the number of columns in a
minimally non-linear 0-1 matrix with rows from to .
We also prove that there are not more than four ones in the top and bottom
rows of a minimally non-linear matrix and that there are not more than six ones
in any other row of a minimally non-linear matrix. Furthermore, we prove that
if a minimally non-linear 0-1 matrix has ones in the same row with exactly
columns between them, then within these columns there are at most rows
above and rows below with ones
Analytical, Optimal, and Sparse Optimal Control of Traveling Wave Solutions to Reaction-Diffusion Systems
This work deals with the position control of selected patterns in
reaction-diffusion systems. Exemplarily, the Schl\"{o}gl and FitzHugh-Nagumo
model are discussed using three different approaches. First, an analytical
solution is proposed. Second, the standard optimal control procedure is
applied. The third approach extends standard optimal control to so-called
sparse optimal control that results in very localized control signals and
allows the analysis of second order optimality conditions.Comment: 22 pages, 3 figures, 2 table
Quantum repeaters and quantum key distribution: analysis of secret key rates
We analyze various prominent quantum repeater protocols in the context of
long-distance quantum key distribution. These protocols are the original
quantum repeater proposal by Briegel, D\"ur, Cirac and Zoller, the so-called
hybrid quantum repeater using optical coherent states dispersively interacting
with atomic spin qubits, and the Duan-Lukin-Cirac-Zoller-type repeater using
atomic ensembles together with linear optics and, in its most recent extension,
heralded qubit amplifiers. For our analysis, we investigate the most important
experimental parameters of every repeater component and find their minimally
required values for obtaining a nonzero secret key. Additionally, we examine in
detail the impact of device imperfections on the final secret key rate and on
the optimal number of rounds of distillation when the entangled states are
purified right after their initial distribution.Comment: Published versio
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