345 research outputs found
Entropy solutions to the Dirichlet problem for nonlinear diffusion equations with conservative noise
Motivated by porous medium equations with randomly perturbed velocity field,
this paper considers a class of nonlinear degenerate diffusion equations with
nonlinear conservative noise in bounded domains. The existence, uniqueness and
-stability of non-negative entropy solutions under the homogeneous
Dirichlet boundary condition are proved. The approach combines Kruzhkov's
doubling variables technique with a revised strong entropy condition that is
automatically satisfied by the solutions of approximate equations.Comment: 33 page
Cross-Model Conjunctive Queries over Relation and Tree-structured Data
Conjunctive queries are the most basic and central class of database queries. With the continued growth of demands to manage and process the massive volume of different types of data, there is little research to study the conjunctive queries between relation and tree data. In this paper, we study Cross-Model Conjunctive Queries (CMCQs) over relation and tree-structured data (XML and JSON). To efficiently process CMCQs with bounded intermediate results we first encode tree nodes with position information. With tree node original label values and encoded position values, it allows our proposed algorithm CMJoin to join relations and tree data simultaneously, avoiding massive intermediate results. CMJoin achieves worst-case optimality in terms of the total result of label values and encoded position values. Experimental results demonstrate the efficiency and scalability of the proposed techniques to answer a CMCQ in terms of running time and intermediate result size.Peer reviewe
Wound Segmentation with Dynamic Illumination Correction and Dual-view Semantic Fusion
Wound image segmentation is a critical component for the clinical diagnosis
and in-time treatment of wounds. Recently, deep learning has become the
mainstream methodology for wound image segmentation. However, the
pre-processing of the wound image, such as the illumination correction, is
required before the training phase as the performance can be greatly improved.
The correction procedure and the training of deep models are independent of
each other, which leads to sub-optimal segmentation performance as the fixed
illumination correction may not be suitable for all images. To address
aforementioned issues, an end-to-end dual-view segmentation approach was
proposed in this paper, by incorporating a learn-able illumination correction
module into the deep segmentation models. The parameters of the module can be
learned and updated during the training stage automatically, while the
dual-view fusion can fully employ the features from both the raw images and the
enhanced ones. To demonstrate the effectiveness and robustness of the proposed
framework, the extensive experiments are conducted on the benchmark datasets.
The encouraging results suggest that our framework can significantly improve
the segmentation performance, compared to the state-of-the-art methods
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