5,790 research outputs found
COCO_TS Dataset: Pixel-level Annotations Based on Weak Supervision for Scene Text Segmentation
The absence of large scale datasets with pixel-level supervisions is a
significant obstacle for the training of deep convolutional networks for scene
text segmentation. For this reason, synthetic data generation is normally
employed to enlarge the training dataset. Nonetheless, synthetic data cannot
reproduce the complexity and variability of natural images. In this paper, a
weakly supervised learning approach is used to reduce the shift between
training on real and synthetic data. Pixel-level supervisions for a text
detection dataset (i.e. where only bounding-box annotations are available) are
generated. In particular, the COCO-Text-Segmentation (COCO_TS) dataset, which
provides pixel-level supervisions for the COCO-Text dataset, is created and
released. The generated annotations are used to train a deep convolutional
neural network for semantic segmentation. Experiments show that the proposed
dataset can be used instead of synthetic data, allowing us to use only a
fraction of the training samples and significantly improving the performances
A conserved BDNF, glutamate- and GABA-enriched gene module related to human depression identified by coexpression meta-analysis and DNA variant genome-wide association studies
Large scale gene expression (transcriptome) analysis and genome-wide association studies (GWAS) for single nucleotide polymorphisms have generated a considerable amount of gene- and disease-related information, but heterogeneity and various sources of noise have limited the discovery of disease mechanisms. As systematic dataset integration is becoming essential, we developed methods and performed meta-clustering of gene coexpression links in 11 transcriptome studies from postmortem brains of human subjects with major depressive disorder (MDD) and non-psychiatric control subjects. We next sought enrichment in the top 50 meta-analyzed coexpression modules for genes otherwise identified by GWAS for various sets of disorders. One coexpression module of 88 genes was consistently and significantly associated with GWAS for MDD, other neuropsychiatric disorders and brain functions, and for medical illnesses with elevated clinical risk of depression, but not for other diseases. In support of the superior discriminative power of this novel approach, we observed no significant enrichment for GWAS-related genes in coexpression modules extracted from single studies or in meta-modules using gene expression data from non-psychiatric control subjects. Genes in the identified module encode proteins implicated in neuronal signaling and structure, including glutamate metabotropic receptors (GRM1, GRM7), GABA receptors (GABRA2, GABRA4), and neurotrophic and development-related proteins [BDNF, reelin (RELN), Ephrin receptors (EPHA3, EPHA5)]. These results are consistent with the current understanding of molecular mechanisms of MDD and provide a set of putative interacting molecular partners, potentially reflecting components of a functional module across cells and biological pathways that are synchronously recruited in MDD, other brain disorders and MDD-related illnesses. Collectively, this study demonstrates the importance of integrating transcriptome data, gene coexpression modules and GWAS results for providing novel and complementary approaches to investigate the molecular pathology of MDD and other complex brain disorders. © 2014 Chang et al
Online video streaming for human tracking based on weighted resampling particle filter
© 2018 The Authors. Published by Elsevier Ltd. This paper proposes a weighted resampling method for particle filter which is applied for human tracking on active camera. The proposed system consists of three major parts which are human detection, human tracking, and camera control. The codebook matching algorithm is used for extracting human region in human detection system, and the particle filter algorithm estimates the position of the human in every input image. The proposed system in this paper selects the particles with highly weighted value in resampling, because it provides higher accurate tracking features. Moreover, a proportional-integral-derivative controller (PID controller) controls the active camera by minimizing difference between center of image and the position of object obtained from particle filter. The proposed system also converts the position difference into pan-tilt speed to drive the active camera and keep the human in the field of view (FOV) camera. The intensity of image changes overtime while tracking human therefore the proposed system uses the Gaussian mixture model (GMM) to update the human feature model. As regards, the temporal occlusion problem is solved by feature similarity and the resampling particles. Also, the particle filter estimates the position of human in every input frames, thus the active camera drives smoothly. The robustness of the accurate tracking of the proposed system can be seen in the experimental results
Algorithms for outerplanar graph roots and graph roots of pathwidth at most 2
Deciding whether a given graph has a square root is a classical problem that
has been studied extensively both from graph theoretic and from algorithmic
perspectives. The problem is NP-complete in general, and consequently
substantial effort has been dedicated to deciding whether a given graph has a
square root that belongs to a particular graph class. There are both
polynomial-time solvable and NP-complete cases, depending on the graph class.
We contribute with new results in this direction. Given an arbitrary input
graph G, we give polynomial-time algorithms to decide whether G has an
outerplanar square root, and whether G has a square root that is of pathwidth
at most 2
OneGAN: Simultaneous Unsupervised Learning of Conditional Image Generation, Foreground Segmentation, and Fine-Grained Clustering
We present a method for simultaneously learning, in an unsupervised manner,
(i) a conditional image generator, (ii) foreground extraction and segmentation,
(iii) clustering into a two-level class hierarchy, and (iv) object removal and
background completion, all done without any use of annotation. The method
combines a Generative Adversarial Network and a Variational Auto-Encoder, with
multiple encoders, generators and discriminators, and benefits from solving all
tasks at once. The input to the training scheme is a varied collection of
unlabeled images from the same domain, as well as a set of background images
without a foreground object. In addition, the image generator can mix the
background from one image, with a foreground that is conditioned either on that
of a second image or on the index of a desired cluster. The method obtains
state of the art results in comparison to the literature methods, when compared
to the current state of the art in each of the tasks.Comment: To be published in the European Conference on Computer Vision (ECCV)
202
Life cycle assessment of a biogas system for cassava processing to close the loop in the water-waste-energy-food nexus in Brazil
Biogas, generated from anaerobic digester (AD), has been one of the promising sources of renewable energy. To manage the organic waste from small cassava industry in Brazil, a waste-water-energy-food nexus (WWEF) system is proposed, combining AD and co-generation or combined heat and power (CHP) plants. However, the environmental impacts and benefits of this system are yet not known. By using Life Cycle Assessment (LCA) method, environmental impacts of three scenarios are assessed, i.e. business-as-usual (base), improved business-as-usual and WWEF closed-loop. Functional unit (FU) in this study is defined as generating 1 kg cassava starch/flour. Global warming potential (GWP), cumulative energy demand (CED), freshwater eutrophication potential (FEP), terrestrial acidification potential (TAP) and water depletion potential (WDP) are selected. Landfilling cassava waste, power use for cassava starch and flour production, and emissions from fertilizer application are identified as environmental hotspots for business-as-usual case, suggesting making decisions on these aspects when dealing with environmental impacts. By using cassava waste to recover energy and nutrients for Brazilian rural family farming, the WWEF system is identified as the best environment-friendly scenario with lowest environmental impacts for the selected impact categories. The impact savings of the closed-loop scenario for GWP are over 90%, while over 50% of emissions for other selected impact categories, except FEP (lower than 10%), are saved compared to the business-as-usual and improved scenarios. Sensitivity analysis reinforces the results. Overall, this study provides a view on the potential of using cassava waste for the WWEF closed-loop system in Brazil, suggesting that the proposed WWEF closed-loop system is feasible and beneficial for small industries from the environmental perspective
Efficient degradation of triclosan by aluminium acetylacetonate doped polymeric carbon nitride photocatalyst under visible light
Triclosan (TCS), as a typical toxic and harmful micro-pollutant, has been frequently detected in various water bodies, and its threat to the aquatic environment has raised significant concerns. In this study, aluminium acetylacetonate doped polymeric carbon nitride photocatalysts (PCN-AA) were synthesized to investigate the degradation properties of TCS under simulated visible light. The results showed that the best ratio material PCN-AA30 (k = 0.0529 min-1) can degrade 99.29 % of TCS in 90 min, which is 2.45 times the degradation of the original polymeric carbon nitride material PCN-AA0 (k = 0.0216 min-1). The degradation process of TCS presented different rules under the changing conditions of catalyst dosage, initial concentration of TCS, pH, common inorganic anions and natural organic matter in water. The results of radicals quencher experiment showed that ·O2- played the most important role in the photocatalytic degradation in the reaction system. This study also identified 10 degradation products of TCS using UPLC-Q-TOF technology and proposed the possible degradation pathways. In addition, the acute biotoxicity of PCN-AA materials were tested by luminescent bacteria method, indicating that the safety of PCN-AA was relatively high. These results demonstrated that the polymeric carbon nitride material doped with aluminium acetylacetonate is a promising catalyst for the degradation of micro-pollutants in water under visible light
Controlling Style and Semantics in Weakly-Supervised Image Generation
We propose a weakly-supervised approach for conditional image generation of
complex scenes where a user has fine control over objects appearing in the
scene. We exploit sparse semantic maps to control object shapes and classes, as
well as textual descriptions or attributes to control both local and global
style. In order to condition our model on textual descriptions, we introduce a
semantic attention module whose computational cost is independent of the image
resolution. To further augment the controllability of the scene, we propose a
two-step generation scheme that decomposes background and foreground. The label
maps used to train our model are produced by a large-vocabulary object
detector, which enables access to unlabeled data and provides structured
instance information. In such a setting, we report better FID scores compared
to fully-supervised settings where the model is trained on ground-truth
semantic maps. We also showcase the ability of our model to manipulate a scene
on complex datasets such as COCO and Visual Genome.Comment: European Conference on Computer Vision (ECCV) 2020, Spotlight. Code
at https://github.com/dariopavllo/style-semantic
Genomic Expansion of Magnetotactic Bacteria Reveals an Early Common Origin of Magnetotaxis with Lineage-specific Evolution
The origin and evolution of magnetoreception, which in diverse prokaryotes and protozoa is known as magnetotaxis and enables these microorganisms to detect Earth’s magnetic field for orientation and navigation, is not well understood in evolutionary biology. The only known prokaryotes capable of sensing the geomagnetic field are magnetotactic bacteria (MTB), motile microorganisms that biomineralize intracellular, membrane-bounded magnetic single-domain crystals of either magnetite (Fe3O4) or greigite (Fe3S4) called magnetosomes. Magnetosomes are responsible for magnetotaxis in MTB. Here we report the first large-scale metagenomic survey of MTB from both northern and southern hemispheres combined with 28 genomes from uncultivated MTB. These genomes expand greatly the coverage of MTB in the Proteobacteria, Nitrospirae, and Omnitrophica phyla, and provide the first genomic evidence of MTB belonging to the Zetaproteobacteria and “Candidatus Lambdaproteobacteria” classes. The gene content and organization of magnetosome gene clusters, which are physically grouped genes that encode proteins for magnetosome biosynthesis and organization, are more conserved within phylogenetically similar groups than between different taxonomic lineages. Moreover, the phylogenies of core magnetosome proteins form monophyletic clades. Together, these results suggest a common ancient origin of iron-based (Fe3O4 and Fe3S4) magnetotaxis in the domain Bacteria that underwent lineage-specific evolution, shedding new light on the origin and evolution of biomineralization and magnetotaxis, and expanding significantly the phylogenomic representation of MTB
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