2,806 research outputs found
Multi-View Video Packet Scheduling
In multiview applications, multiple cameras acquire the same scene from
different viewpoints and generally produce correlated video streams. This
results in large amounts of highly redundant data. In order to save resources,
it is critical to handle properly this correlation during encoding and
transmission of the multiview data. In this work, we propose a
correlation-aware packet scheduling algorithm for multi-camera networks, where
information from all cameras are transmitted over a bottleneck channel to
clients that reconstruct the multiview images. The scheduling algorithm relies
on a new rate-distortion model that captures the importance of each view in the
scene reconstruction. We propose a problem formulation for the optimization of
the packet scheduling policies, which adapt to variations in the scene content.
Then, we design a low complexity scheduling algorithm based on a trellis search
that selects the subset of candidate packets to be transmitted towards
effective multiview reconstruction at clients. Extensive simulation results
confirm the gain of our scheduling algorithm when inter-source correlation
information is used in the scheduler, compared to scheduling policies with no
information about the correlation or non-adaptive scheduling policies. We
finally show that increasing the optimization horizon in the packet scheduling
algorithm improves the transmission performance, especially in scenarios where
the level of correlation rapidly varies with time
Constructions of Optimal and Almost Optimal Locally Repairable Codes
Constructions of optimal locally repairable codes (LRCs) in the case of
and over small finite fields were stated as open problems for
LRCs in [I. Tamo \emph{et al.}, "Optimal locally repairable codes and
connections to matroid theory", \emph{2013 IEEE ISIT}]. In this paper, these
problems are studied by constructing almost optimal linear LRCs, which are
proven to be optimal for certain parameters, including cases for which . More precisely, linear codes for given length, dimension, and
all-symbol locality are constructed with almost optimal minimum distance.
`Almost optimal' refers to the fact that their minimum distance differs by at
most one from the optimal value given by a known bound for LRCs. In addition to
these linear LRCs, optimal LRCs which do not require a large field are
constructed for certain classes of parameters.Comment: 5 pages, conferenc
On the Combinatorics of Locally Repairable Codes via Matroid Theory
This paper provides a link between matroid theory and locally repairable
codes (LRCs) that are either linear or more generally almost affine. Using this
link, new results on both LRCs and matroid theory are derived. The parameters
of LRCs are generalized to matroids, and the matroid
analogue of the generalized Singleton bound in [P. Gopalan et al., "On the
locality of codeword symbols," IEEE Trans. Inf. Theory] for linear LRCs is
given for matroids. It is shown that the given bound is not tight for certain
classes of parameters, implying a nonexistence result for the corresponding
locally repairable almost affine codes, that are coined perfect in this paper.
Constructions of classes of matroids with a large span of the parameters
and the corresponding local repair sets are given. Using
these matroid constructions, new LRCs are constructed with prescribed
parameters. The existence results on linear LRCs and the nonexistence results
on almost affine LRCs given in this paper strengthen the nonexistence and
existence results on perfect linear LRCs given in [W. Song et al., "Optimal
locally repairable codes," IEEE J. Sel. Areas Comm.].Comment: 48 pages. Submitted for publication. In this version: The text has
been edited to improve the readability. Parameter d for matroids is now
defined by the use of the rank function instead of the dual matroid. Typos
are corrected. Section III is divided into two parts, and some numberings of
theorems etc. have been change
Integrative Review on the Initiation of a Systematic Oral Care Education Program
Hospital-acquired infections, such as non-ventilated hospital-acquired pneumonia (NVHAP), are significant patient safety concerns. The lack of oral care in the non-ventilated acute care patient population is a significant contributor to NVHAP. The nursing staff is on the front line in providing oral care to hospitalized patients but often lacks knowledge and understanding regarding the relationship between oral care and NVHAP. Searching MEDLINE, PubMed, CINAHL, and EBSCO databases for current, peer-reviewed, scholarly articles for English language articles between 2010-2020 led to supporting findings. These findings revealed missed oral care as the most common modifiable risk factor contributing to increased hospital-acquired pneumonia incidences. Other findings revealed the impact an evidence-based educational program would have on oral care and outcomes. The influence of the learner\u27s engagement with education and training has proven to have substantial benefits
Optimized Packet Scheduling in Multiview Video Navigation Systems
In multiview video systems, multiple cameras generally acquire the same scene
from different perspectives, such that users have the possibility to select
their preferred viewpoint. This results in large amounts of highly redundant
data, which needs to be properly handled during encoding and transmission over
resource-constrained channels. In this work, we study coding and transmission
strategies in multicamera systems, where correlated sources send data through a
bottleneck channel to a central server, which eventually transmits views to
different interactive users. We propose a dynamic correlation-aware packet
scheduling optimization under delay, bandwidth, and interactivity constraints.
The optimization relies both on a novel rate-distortion model, which captures
the importance of each view in the 3D scene reconstruction, and on an objective
function that optimizes resources based on a client navigation model. The
latter takes into account the distortion experienced by interactive clients as
well as the distortion variations that might be observed by clients during
multiview navigation. We solve the scheduling problem with a novel
trellis-based solution, which permits to formally decompose the multivariate
optimization problem thereby significantly reducing the computation complexity.
Simulation results show the gain of the proposed algorithm compared to baseline
scheduling policies. More in details, we show the gain offered by our dynamic
scheduling policy compared to static camera allocation strategies and to
schemes with constant coding strategies. Finally, we show that the best
scheduling policy consistently adapts to the most likely user navigation path
and that it minimizes distortion variations that can be very disturbing for
users in traditional navigation systems
Where Is Earth Science? Mining for Opportunities in Chemistry, Physics, and Biology
The Earth sciences are newly marginalized in Kâ12 classrooms. With few high schools offering Earth science courses, studentsâ exposure to the Earth sciences relies on the teacherâs ability to incorporate Earth science material into a biology, chemistry, or physics course. âG.E.T. (Geoscience Experiences for Teachers) in the Fieldâ is an exploratory program funded by the National Science Foundation aimed to increase teachersâ geoscience interest and content knowledge. Participant teachers (n = 7) included nonâEarth science teachers from underrepresented groups and/or high schools with a high percentage of students from underrepresented groups. A variety of quantitative and qualitative measures assessed changes in teachersâ readiness and propensity for incorporating geoscience concepts into their current curricula. Findings are compelling, though these results are based on a small sample of teachers. In light of current politics, where Earth science is largely disregarded, professional development workshops like this one can help science teachers become knowledgeable enough to incorporate and expand on geosciences connections in biology, chemistry, and physics
Trophic interactions of the freshwater jellyfish Craspedacusta sowerbii
The predatory impact and the trophic role of the freshwater jellyfish, Craspedacusta sowerbii, was studied using microcosm and enclosure experiments as well as a 3-year pond survey. The results showed a significant decrease of small herbivorous crustaceans, i.e. Bosmina longirostris and juvenile cyclopoid copepods, in the medusa treatments of the microcosms and the enclosure experiments. Chlorophyll concentrations in the enclosure experiment were significantly increased in the medusa treatment, suggesting that C. sowerbii may cause cascading effects in the food chain. A comparison of daily zooplankton losses during the pond survey caused by medusae and fish (roach, Rutilus rutilus), and their food selectivities suggest food separation of these two predators and reveal a strong negative impact of medusae on the copepod pond community. In the case of a jellyfish bloom, our results show that both food chains can co-occur in lakes because of a weak interaction between these top predators, fish and jellyfish, with simultaneous impacts on the zooplankton structur
Constitutional Limitations on State-Imposed Continuing Competency Requirements for Licensed Professionals
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