20,517 research outputs found
Efficient Data Gathering in Wireless Sensor Networks Based on Matrix Completion and Compressive Sensing
Gathering data in an energy efficient manner in wireless sensor networks is
an important design challenge. In wireless sensor networks, the readings of
sensors always exhibit intra-temporal and inter-spatial correlations.
Therefore, in this letter, we use low rank matrix completion theory to explore
the inter-spatial correlation and use compressive sensing theory to take
advantage of intra-temporal correlation. Our method, dubbed MCCS, can
significantly reduce the amount of data that each sensor must send through
network and to the sink, thus prolong the lifetime of the whole networks.
Experiments using real datasets demonstrate the feasibility and efficacy of our
MCCS method
Exploiting Image Local And Nonlocal Consistency For Mixed Gaussian-Impulse Noise Removal
Most existing image denoising algorithms can only deal with a single type of
noise, which violates the fact that the noisy observed images in practice are
often suffered from more than one type of noise during the process of
acquisition and transmission. In this paper, we propose a new variational
algorithm for mixed Gaussian-impulse noise removal by exploiting image local
consistency and nonlocal consistency simultaneously. Specifically, the local
consistency is measured by a hyper-Laplace prior, enforcing the local
smoothness of images, while the nonlocal consistency is measured by
three-dimensional sparsity of similar blocks, enforcing the nonlocal
self-similarity of natural images. Moreover, a Split-Bregman based technique is
developed to solve the above optimization problem efficiently. Extensive
experiments for mixed Gaussian plus impulse noise show that significant
performance improvements over the current state-of-the-art schemes have been
achieved, which substantiates the effectiveness of the proposed algorithm.Comment: 6 pages, 4 figures, 3 tables, to be published at IEEE Int. Conf. on
Multimedia & Expo (ICME) 201
Image Super-Resolution via Dual-Dictionary Learning And Sparse Representation
Learning-based image super-resolution aims to reconstruct high-frequency (HF)
details from the prior model trained by a set of high- and low-resolution image
patches. In this paper, HF to be estimated is considered as a combination of
two components: main high-frequency (MHF) and residual high-frequency (RHF),
and we propose a novel image super-resolution method via dual-dictionary
learning and sparse representation, which consists of the main dictionary
learning and the residual dictionary learning, to recover MHF and RHF
respectively. Extensive experimental results on test images validate that by
employing the proposed two-layer progressive scheme, more image details can be
recovered and much better results can be achieved than the state-of-the-art
algorithms in terms of both PSNR and visual perception.Comment: 4 pages, 4 figures, 1 table, to be published at IEEE Int. Symposium
of Circuits and Systems (ISCAS) 201
Enhancement of coherent energy transfer by disorder and temperature in light harvesting processes
We investigate the influence of static disorder and thermal excitations on
excitonic energy transport in the light-harvesting apparatus of photosynthetic
systems by solving the Schr\"{o}dinger equation and taking into account the
coherent hoppings of excitons, the rates of exciton creation and annihilation
in antennas and reaction centers, and the coupling to thermally excited
phonons. The antennas and reaction centers are modeled, respectively, as the
sources and drains which provide the channels for creation and annihilation of
excitons. Phonon modes below a maximum frequency are coupled to the excitons
that are continuously created in the antennas and depleted in the reaction
centers, and the phonon population in these modes obeys the Bose-Einstein
distribution at a given temperature. It is found that the energy transport is
not only robust against the static disorder and the thermal noise, but it can
also be enhanced by increasing the randomness and temperature in most parameter
regimes. Relevance of our work to the highly efficient energy transport in
photosynthetic systems is discussed.Comment: 21 pages, 6 figure
One-Loop Matching for Parton Distributions: Non-Singlet Case
We derive one-loop matching condition for non-singlet quark distributions in
transverse-momentum cut-off scheme, including unpolarized, helicity and
transversity distributions. The matching is between the quasi-distribution
defined by static correlation at finite nucleon momentum and the light-cone
distribution measurable in experiments. The result is useful for extracting the
latter from the former in a lattice QCD calculation.Comment: 10 pages, 1 figur
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