18,709 research outputs found
On the Capacity Region of the Cognitive Interference Channel with Unidirectional Destination Cooperation
The cognitive interference channel with unidirectional destination
cooperation (CIFC-UDC) is a variant of the cognitive interference channel
(CIFC) where the cognitive (secondary) destination not only decodes the
information sent from its sending dual but also helps enhance the communication
of the primary user. This channel is an extension of the original CIFC to
achieve a win-win solution under the coexistence condition. The CIFC-UDC
comprises a broadcast channel (BC), a relay channel (RC), as well as a
partially cooperative relay broadcast channel (PCRBC), and can be degraded to
any one of them. In this paper, we propose a new achievable rate region for the
dis-crete memoryless CIFC-UDC which improves the previous re-sults and includes
the largest known rate regions of the BC, the RC, the PCRBC and the CIFC. A new
outer bound is presented and proved to be tight for two classes of the
CIFC-UDCs, result-ing in the characterization of the capacity region.Comment: submitted to ISIT 201
SegFlow: Joint Learning for Video Object Segmentation and Optical Flow
This paper proposes an end-to-end trainable network, SegFlow, for
simultaneously predicting pixel-wise object segmentation and optical flow in
videos. The proposed SegFlow has two branches where useful information of
object segmentation and optical flow is propagated bidirectionally in a unified
framework. The segmentation branch is based on a fully convolutional network,
which has been proved effective in image segmentation task, and the optical
flow branch takes advantage of the FlowNet model. The unified framework is
trained iteratively offline to learn a generic notion, and fine-tuned online
for specific objects. Extensive experiments on both the video object
segmentation and optical flow datasets demonstrate that introducing optical
flow improves the performance of segmentation and vice versa, against the
state-of-the-art algorithms.Comment: Accepted in ICCV'17. Code is available at
https://sites.google.com/site/yihsuantsai/research/iccv17-segflo
Foliations by Stable Spheres with Constant Mean Curvature for Isolated Systems with General Asymptotics
We prove the existence and uniqueness of constant mean curvature foliations
for initial data sets which are asymptotically flat satisfying the
Regge-Teitelboim condition near infinity. It is known that the (Hamiltonian)
center of mass is well-defined for manifolds satisfying this condition. We also
show that the foliation is asymptotically concentric, and its geometric center
is the center of mass. The construction of the foliation generalizes the
results of Huisken-Yau, Ye, and Metzger, where strongly asymptotically flat
manifolds and their small perturbations were studied.Comment: 45 pages. Some revisions in exposition and typos corrected; to appear
in Comm. Math. Phys
Reconstruction of penetrable obstacles in the anisotropic acoustic scattering
We develop reconstruction schemes to determine penetrable obstacles in a
region of \mathbb{R}^{2} or \mathbb{R}^{3} and we consider anisotropic elliptic
equations. This algorithm uses oscillating-decaying solutions to the equation.
We apply the oscillating-decaying solutions and the Runge approximation
property to the inverse problem of identifying an inclusion in an anisotropic
elliptic differential equation.Comment: 18 page
There are no 76 equiangular lines in
Maximum size of equiangular lines in has been known in the
range between 72 to 76 since 1973. Acoording to the nonexistence of strongly
regular graph \cite{aza15}, Larmen-Rogers-Seidel Theorem
\cite{lar77} and Lemmen-Seidel bounds on equiangular lines with common angle
\cite{lem73}, we can prove that there are no 76 equiangular lines
in . As a corollary, there is no strongly regular graph
. Similar discussion can prove that there are no 96 equiangular
lines in
On the Achievable Rate Regions for a Class of Cognitive Radio Channels: Interference Channel with Degraded Message Sets with Unidirectional Destination Cooperation
This paper considers the capacity gains due to unidirectional destination
cooperation in cognitive radio channels. We propose a novel channel,
interference channel with degraded message sets with unidirectional destination
cooperation (IC-DMS-UDC), to allow the receiver of cognitive radio (secondary
user) to participate in relaying the information for primary system (legitimate
user). Our main result is the development of an achievable rate region which
combines Gel'fand-Pinkser coding with partial-decode-and-forward strategy
employed in the relay channel. A numerical evaluation of the region in the
Gaussian case is also provided to demonstrate the improvements
Weighted-SVD: Matrix Factorization with Weights on the Latent Factors
The Matrix Factorization models, sometimes called the latent factor models,
are a family of methods in the recommender system research area to (1) generate
the latent factors for the users and the items and (2) predict users' ratings
on items based on their latent factors. However, current Matrix Factorization
models presume that all the latent factors are equally weighted, which may not
always be a reasonable assumption in practice. In this paper, we propose a new
model, called Weighted-SVD, to integrate the linear regression model with the
SVD model such that each latent factor accompanies with a corresponding weight
parameter. This mechanism allows the latent factors have different weights to
influence the final ratings. The complexity of the Weighted-SVD model is
slightly larger than the SVD model but much smaller than the SVD++ model. We
compared the Weighted-SVD model with several latent factor models on five
public datasets based on the Root-Mean-Squared-Errors (RMSEs). The results show
that the Weighted-SVD model outperforms the baseline methods in all the
experimental datasets under almost all settings
Witten Deformation and Its Application toward Morse Inequalities
In this undergraduate thesis, we present an analytical proof of the Morse
inequalities for closed smooth -manifolds following Witten's approach. Using
techniques from PDE theory, the proof is reduced to study the eigenspaces and
eigenvalues of harmonic oscillators on
Monotonicity-based inversion of fractional semilinear elliptic equations with power type nonlinearities
We investigate the monotonicity method for fractional semilinear elliptic
equations with power type nonlinearities. We prove that if-and-only-if
monotonicity relations between coefficients and the derivative of the
Dirichlet-to-Neumann map hold. Based on the strong monotonicity relations, we
study a constructive global uniqueness for coefficients and inclusion detection
for the fractional Calder\'on type inverse problem. Meanwhile, we can also
derive the Lipschitz stability with finitely many measurements. The results
hold for any .Comment: 28 pages Some typos are corrected in V
Strong unique continuation for a residual stress system with Gevrey coefficients
We consider the problem of the strong unique continuation for an elasticity
system with general residual stress. Due to the known counterexamples, we
assume the coefficients of the elasticity system are in the Gevrey class of
appropriate indices. The main tools are Carleman estimates for product of two
second order elliptic operators
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