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 $(r+1) \nmid n$ 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 $(r+1) \nmid n$. 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 $(n,k,d,r,\delta)$ 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 $(n,k,d,r,\delta)$ 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

Everyone Wanted Carnations That Year

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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 K–12 classrooms. With few high schools offering Earth science courses, students’ exposure to the Earth sciences relies on the teacher’s ability to incorporate Earth science material into a biology, chemistry, or physics course. “G.E.T. (Geoscience Experiences for Teachers) in the Field” is an exploratory program funded by the National Science Foundation aimed to increase teachers’ geoscience interest and content knowledge. Participant teachers (n = 7) included non–Earth 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 teachers’ 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