2,088 research outputs found
Long properly colored cycles in edge colored complete graphs
Let denote a complete graph on vertices whose edges are
colored in an arbitrary way. Let denote the
maximum number of edges of the same color incident with a vertex of
. A properly colored cycle (path) in is a cycle (path)
in which adjacent edges have distinct colors. B. Bollob\'{a}s and P. Erd\"{o}s
(1976) proposed the following conjecture: if , then contains a properly
colored Hamiltonian cycle. Li, Wang and Zhou proved that if
, then
contains a properly colored cycle of length at least . In this paper, we improve the bound to .Comment: 8 page
Vision-based Real-Time Aerial Object Localization and Tracking for UAV Sensing System
The paper focuses on the problem of vision-based obstacle detection and
tracking for unmanned aerial vehicle navigation. A real-time object
localization and tracking strategy from monocular image sequences is developed
by effectively integrating the object detection and tracking into a dynamic
Kalman model. At the detection stage, the object of interest is automatically
detected and localized from a saliency map computed via the image background
connectivity cue at each frame; at the tracking stage, a Kalman filter is
employed to provide a coarse prediction of the object state, which is further
refined via a local detector incorporating the saliency map and the temporal
information between two consecutive frames. Compared to existing methods, the
proposed approach does not require any manual initialization for tracking, runs
much faster than the state-of-the-art trackers of its kind, and achieves
competitive tracking performance on a large number of image sequences.
Extensive experiments demonstrate the effectiveness and superior performance of
the proposed approach.Comment: 8 pages, 7 figure
An Efficient Approach for Polyps Detection in Endoscopic Videos Based on Faster R-CNN
Polyp has long been considered as one of the major etiologies to colorectal
cancer which is a fatal disease around the world, thus early detection and
recognition of polyps plays a crucial role in clinical routines. Accurate
diagnoses of polyps through endoscopes operated by physicians becomes a
challenging task not only due to the varying expertise of physicians, but also
the inherent nature of endoscopic inspections. To facilitate this process,
computer-aid techniques that emphasize fully-conventional image processing and
novel machine learning enhanced approaches have been dedicatedly designed for
polyp detection in endoscopic videos or images. Among all proposed algorithms,
deep learning based methods take the lead in terms of multiple metrics in
evolutions for algorithmic performance. In this work, a highly effective model,
namely the faster region-based convolutional neural network (Faster R-CNN) is
implemented for polyp detection. In comparison with the reported results of the
state-of-the-art approaches on polyps detection, extensive experiments
demonstrate that the Faster R-CNN achieves very competing results, and it is an
efficient approach for clinical practice.Comment: 6 pages, 10 figures,2018 International Conference on Pattern
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BPGrad: Towards Global Optimality in Deep Learning via Branch and Pruning
Understanding the global optimality in deep learning (DL) has been attracting
more and more attention recently. Conventional DL solvers, however, have not
been developed intentionally to seek for such global optimality. In this paper
we propose a novel approximation algorithm, BPGrad, towards optimizing deep
models globally via branch and pruning. Our BPGrad algorithm is based on the
assumption of Lipschitz continuity in DL, and as a result it can adaptively
determine the step size for current gradient given the history of previous
updates, wherein theoretically no smaller steps can achieve the global
optimality. We prove that, by repeating such branch-and-pruning procedure, we
can locate the global optimality within finite iterations. Empirically an
efficient solver based on BPGrad for DL is proposed as well, and it outperforms
conventional DL solvers such as Adagrad, Adadelta, RMSProp, and Adam in the
tasks of object recognition, detection, and segmentation
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