3,820 research outputs found

    DEFormer: DCT-driven Enhancement Transformer for Low-light Image and Dark Vision

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    The goal of low-light image enhancement is to restore the color and details of the image and is of great significance for high-level visual tasks in autonomous driving. However, it is difficult to restore the lost details in the dark area by relying only on the RGB domain. In this paper we introduce frequency as a new clue into the network and propose a novel DCT-driven enhancement transformer (DEFormer). First, we propose a learnable frequency branch (LFB) for frequency enhancement contains DCT processing and curvature-based frequency enhancement (CFE). CFE calculates the curvature of each channel to represent the detail richness of different frequency bands, then we divides the frequency features, which focuses on frequency bands with richer textures. In addition, we propose a cross domain fusion (CDF) for reducing the differences between the RGB domain and the frequency domain. We also adopt DEFormer as a preprocessing in dark detection, DEFormer effectively improves the performance of the detector, bringing 2.1% and 3.4% improvement in ExDark and DARK FACE datasets on mAP respectively.Comment: submit to ICRA202

    Differential vascular cell adhesion molecule-1 expression and superoxide production in simulated microgravity rat vasculature

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    Exposure to microgravity leads to orthostatic intolerance in astronauts and differential vascular structural and functional adaptations have been implicated in its occurrence. The present study tended to clarify the characteristics of vascular inflammation and oxidative stress in hindlimb unweighting (HU) rat vasculature. Male Sprague-Dawley rats were randomly divided into control (CON) and hindlimb unweighting (HU) groups. Three weeks later, immunohistochemistry was used to localize the expression of vascular cell adhesion molecule-1 (VCAM-1) and laser scanning confocal microscope were used to detect superoxide production. Immunohistochemical results revealed positive staining of VCAM-1 on endothelial cells in HU rat basilar and carotid arteries compared with CON, but not in abdominal aorta and femoral arteries. Meanwhile, HU increased O2·- levels in all the layers of basilar and carotid arteries from HU rat but not in abdominal aorta and femoral arteries from HU rat. These data suggested that differential expression of VCAM-1 and O2- production were concomitant with the vascular adaptations to simulated microgravity and whether they participate in vascular structure and function remodeling merits further investigation

    Vremenski razlučeni fotoluminescentni spektri legure (AlxGa1−x)0.51In0.49P (x = 0.29)

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    Measurements of time-resolved photoluminescence (TRPL) spectra were made in a study of the optical properties of partially ordered quaternary (AlxGa1-x)0.51In0.49P (x=0.29) alloy. Both excitation-wavelength dependence of lifetime and excitation-intensity dependence of lifetime show a wide distribution of carriers. In TRPL spectra measured at 300 K, a blue-shift of photoluminescence (PL) peaks in (AlxGa1-x)0.51In0.49P is observed. The phenomenon is in agreement with the Z-shaped temperature dependence of the PL peak. Possible origins of the blue-shift and Z-shaped behaviour of PL peak are presented.Načinili smo vremenski-razlučena (VR) mjerenja fotoluminescentnih (FL) spektara radi istraživanja optičkih svojstava djelomično sređene četverokomponentne legure (AlxGa1−x)0.51In0.49P (x = 0.29). Obje ovisnosti vremena života, uzbuda – valna duljina i uzbuda – intenzitet pokazuju široku raspodjelu nositelja. VR FL spektri (AlxGa1−x)0.51In0.49P na 300 K pokazuju plavi pomak fotoluminescentnih linija. Ta je pojava u skladu s temperaturnom ovisnošću FL vrha u vidu slova Z. Raspravljaju se mogući uzroci plavog pomaka i Z-ovisnosti FL vrha

    Vremenski razlučeni fotoluminescentni spektri legure (AlxGa1−x)0.51In0.49P (x = 0.29)

    Get PDF
    Measurements of time-resolved photoluminescence (TRPL) spectra were made in a study of the optical properties of partially ordered quaternary (AlxGa1-x)0.51In0.49P (x=0.29) alloy. Both excitation-wavelength dependence of lifetime and excitation-intensity dependence of lifetime show a wide distribution of carriers. In TRPL spectra measured at 300 K, a blue-shift of photoluminescence (PL) peaks in (AlxGa1-x)0.51In0.49P is observed. The phenomenon is in agreement with the Z-shaped temperature dependence of the PL peak. Possible origins of the blue-shift and Z-shaped behaviour of PL peak are presented.Načinili smo vremenski-razlučena (VR) mjerenja fotoluminescentnih (FL) spektara radi istraživanja optičkih svojstava djelomično sređene četverokomponentne legure (AlxGa1−x)0.51In0.49P (x = 0.29). Obje ovisnosti vremena života, uzbuda – valna duljina i uzbuda – intenzitet pokazuju široku raspodjelu nositelja. VR FL spektri (AlxGa1−x)0.51In0.49P na 300 K pokazuju plavi pomak fotoluminescentnih linija. Ta je pojava u skladu s temperaturnom ovisnošću FL vrha u vidu slova Z. Raspravljaju se mogući uzroci plavog pomaka i Z-ovisnosti FL vrha

    Serum metabolic signatures for acute pulmonary embolism identified by untargeted metabolomics

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    Background and aimsThe important metabolic features of acute pulmonary embolism (APE) risk stratification and their underlying biological basis remain elusive. Our study aims to develop early diagnostic models and classification models by analyzing the plasma metabolic profile of patients with APE.Materials and methodsSerum samples were collected from 68 subjects, including 19 patients with confirmed APE, 35 patients with confirmed NSTEMI, and 14 healthy individuals. A comprehensive metabolic assessment was performed using ultra-performance liquid chromatography-mass spectrometry based on an untargeted metabolomics approach. In addition, an integrated machine learning strategy based on LASSO and logistic regression was used for feature selection and model building.ResultsThe metabolic profiles of patients with acute pulmonary embolism and NSTEMI is significantly altered relative to that of healthy individuals. KEGG pathway enrichment analysis revealed differential metabolites between acute pulmonary embolism and healthy individuals mainly involving glycerophosphate shuttle, riboflavin metabolism, and glycerolipid metabolism. A panel of biomarkers was defined to distinguish acute pulmonary embolism, NSTEMI, and healthy individuals with an area under the receiver operating characteristic curve exceeding 0.9 and higher than that of D-dimers.ConclusionThis study contributes to a better understanding of the pathogenesis of APE and facilitates the discovery of new therapeutic targets. The metabolite panel can be used as a potential non-invasive diagnostic and risk stratification tool for APE

    Mask-free OVIS: Open-Vocabulary Instance Segmentation without Manual Mask Annotations

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    Existing instance segmentation models learn task-specific information using manual mask annotations from base (training) categories. These mask annotations require tremendous human effort, limiting the scalability to annotate novel (new) categories. To alleviate this problem, Open-Vocabulary (OV) methods leverage large-scale image-caption pairs and vision-language models to learn novel categories. In summary, an OV method learns task-specific information using strong supervision from base annotations and novel category information using weak supervision from image-captions pairs. This difference between strong and weak supervision leads to overfitting on base categories, resulting in poor generalization towards novel categories. In this work, we overcome this issue by learning both base and novel categories from pseudo-mask annotations generated by the vision-language model in a weakly supervised manner using our proposed Mask-free OVIS pipeline. Our method automatically generates pseudo-mask annotations by leveraging the localization ability of a pre-trained vision-language model for objects present in image-caption pairs. The generated pseudo-mask annotations are then used to supervise an instance segmentation model, freeing the entire pipeline from any labour-expensive instance-level annotations and overfitting. Our extensive experiments show that our method trained with just pseudo-masks significantly improves the mAP scores on the MS-COCO dataset and OpenImages dataset compared to the recent state-of-the-art methods trained with manual masks. Codes and models are provided in https://vibashan.github.io/ovis-web/.Comment: Accepted to CVPR 2023. Project site: https://vibashan.github.io/ovis-web

    Concepts, Structure and Developments of High-Reliability Cyber-Physical Fusion Based Coordinated Planning for Distribution System

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    Coordinated control is imperative for the distribution network with the integration of wind power, photovoltaic system, and energy storage system. Meanwhile, the advanced automation terminal, intelligent control technology, and information communication technologies have greatly promoted the informatization of distribution networks which also increase the correlation between the physical system (primary system) and the cyber system (secondary system). Hence, it is critical to comprehensively coordinate the planning of the cyber-physical system for building a highly reliable power grid. This work summarizes a series of challenges brought by the highly coupled cyber-physical system, such as the primary and secondary collaborated planning models and solution algorithms. Then, the reliability assessment theories of cyber-physical systems and their application in distribution network planning models are introduced. Finally, three development directions of distribution network planning in the future are proposed, considering primary and secondary system coordinated planning
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