33,469 research outputs found

    Occlusion-Robust MVO: Multimotion Estimation Through Occlusion Via Motion Closure

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    Visual motion estimation is an integral and well-studied challenge in autonomous navigation. Recent work has focused on addressing multimotion estimation, which is especially challenging in highly dynamic environments. Such environments not only comprise multiple, complex motions but also tend to exhibit significant occlusion. Previous work in object tracking focuses on maintaining the integrity of object tracks but usually relies on specific appearance-based descriptors or constrained motion models. These approaches are very effective in specific applications but do not generalize to the full multimotion estimation problem. This paper presents a pipeline for estimating multiple motions, including the camera egomotion, in the presence of occlusions. This approach uses an expressive motion prior to estimate the SE (3) trajectory of every motion in the scene, even during temporary occlusions, and identify the reappearance of motions through motion closure. The performance of this occlusion-robust multimotion visual odometry (MVO) pipeline is evaluated on real-world data and the Oxford Multimotion Dataset.Comment: To appear at the 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). An earlier version of this work first appeared at the Long-term Human Motion Planning Workshop (ICRA 2019). 8 pages, 5 figures. Video available at https://www.youtube.com/watch?v=o_N71AA6FR

    Reference Pricing of Pharmaceuticals for Medicare: Evidence from Germany, the Netherlands and New Zealand

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    This paper describes three prototypical systems of therapeutic reference pricing (RP) for pharmaceuticals -- Germany, the Netherlands, and New Zealand -- and examines their effects on the availability of new drugs, reimbursement levels, manufacturer prices and out-of-pocket surcharges to patients. RP for pharmaceuticals is not simply analogous to a defined contribution approach to subsidizing insurance coverage. Although a major purpose of RP is to stimulate competition, theory suggests that this is unlikely and this is confirmed by the empirical evidence. Other effects of RP differ across countries in predictable ways, reflecting each country's system design and other cost control policies. New Zealand's RP system has reduced reimbursement and limited the availability of new drugs, particularly more expensive drugs. Compared to these three countries, if RP were applied in the US, it would likely have a more negative effect on prices of on-patent products, due to the more competitive US generic market, and a more negative effect on R&D and on the future supply of new drugs, due to the much larger US share of global pharmaceutical sales.

    Chiral effective field theory beyond the power-counting regime

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    Novel techniques are presented, which identify the chiral power-counting regime (PCR), and realize the existence of an intrinsic energy scale embedded in lattice QCD results that extend outside the PCR. The nucleon mass is considered as a benchmark for illustrating this new approach. Using finite-range regularization, an optimal regularization scale can be extracted from lattice simulation results by analyzing the renormalization of the low energy coefficients. The optimal scale allows a description of lattice simulation results that extend beyond the PCR by quantifying and thus handling any scheme-dependence. Preliminary results for the nucleon magnetic moment are also examined, and a consistent optimal regularization scale is obtained. This indicates the existence of an intrinsic scale corresponding to the finite size of the source of the pion cloud.Comment: 6 pages, 4 figures, conferenc

    Near-field coupling of gold plasmonic antennas for sub-100 nm magneto-thermal microscopy

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    The development of spintronic technology with increasingly dense, high-speed, and complex devices will be accelerated by accessible microscopy techniques capable of probing magnetic phenomena on picosecond time scales and at deeply sub-micron length scales. A recently developed time-resolved magneto-thermal microscope provides a path towards this goal if it is augmented with a picosecond, nanoscale heat source. We theoretically study adiabatic nanofocusing and near-field heat induction using conical gold plasmonic antennas to generate sub-100 nm thermal gradients for time-resolved magneto-thermal imaging. Finite element calculations of antenna-sample interactions reveal focused electromagnetic loss profiles that are either peaked directly under the antenna or are annular, depending on the sample's conductivity, the antenna's apex radius, and the tip-sample separation. We find that the thermal gradient is confined to 40 nm to 60 nm full width at half maximum for realistic ranges of sample conductivity and apex radius. To mitigate this variation, which is undesirable for microscopy, we investigate the use of a platinum capping layer on top of the sample as a thermal transduction layer to produce heat uniformly across different sample materials. After determining the optimal capping layer thickness, we simulate the evolution of the thermal gradient in the underlying sample layer, and find that the temporal width is below 10 ps. These results lay a theoretical foundation for nanoscale, time-resolved magneto-thermal imaging.Comment: 24 pages including Supporting Information, 6 figures in the main text, 4 supporting figure
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