3,992 research outputs found

    Online Bearing Remaining Useful Life Prediction Based on a Novel Degradation Indicator and Convolutional Neural Networks

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    In industrial applications, nearly half the failures of motors are caused by the degradation of rolling element bearings (REBs). Therefore, accurately estimating the remaining useful life (RUL) for REBs are of crucial importance to ensure the reliability and safety of mechanical systems. To tackle this challenge, model-based approaches are often limited by the complexity of mathematical modeling. Conventional data-driven approaches, on the other hand, require massive efforts to extract the degradation features and construct health index. In this paper, a novel online data-driven framework is proposed to exploit the adoption of deep convolutional neural networks (CNN) in predicting the RUL of bearings. More concretely, the raw vibrations of training bearings are first processed using the Hilbert-Huang transform (HHT) and a novel nonlinear degradation indicator is constructed as the label for learning. The CNN is then employed to identify the hidden pattern between the extracted degradation indicator and the vibration of training bearings, which makes it possible to estimate the degradation of the test bearings automatically. Finally, testing bearings' RULs are predicted by using a ϵ\epsilon-support vector regression model. The superior performance of the proposed RUL estimation framework, compared with the state-of-the-art approaches, is demonstrated through the experimental results. The generality of the proposed CNN model is also validated by transferring to bearings undergoing different operating conditions

    Principles and Practices Report on Online Enrichment and Extension for the Gifted and Talented

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    Based on analysis of the individual characteristics and needs of gifted and talented students, this report gives a brief discussion of the attributes of online enrichment and extension to support quick learners. A conceptual framework for the structure and processes of good online enrichment and extension will also be explained. Key words: attributes; online enrichment and extension; the gifted and talented Résumé: Basé sur les analyses des caractères individuels et des besoins des étudiants doués et talentueux, ce rapport nous donne une discussion brève sur les attributs de l’enrichissement et de l’extension en ligne en tant qu’un support pour les débutants rapides. Le cadre conceptuel pour la structure et les processus de l’enrichissement et de l’extension en lighe sera également expliqué dans cet article . Mots-Clés: attributs; enrishissement et extension en ligne; les doués et les talentueu

    3D-GOI: 3D GAN Omni-Inversion for Multifaceted and Multi-object Editing

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    The current GAN inversion methods typically can only edit the appearance and shape of a single object and background while overlooking spatial information. In this work, we propose a 3D editing framework, 3D-GOI, to enable multifaceted editing of affine information (scale, translation, and rotation) on multiple objects. 3D-GOI realizes the complex editing function by inverting the abundance of attribute codes (object shape/appearance/scale/rotation/translation, background shape/appearance, and camera pose) controlled by GIRAFFE, a renowned 3D GAN. Accurately inverting all the codes is challenging, 3D-GOI solves this challenge following three main steps. First, we segment the objects and the background in a multi-object image. Second, we use a custom Neural Inversion Encoder to obtain coarse codes of each object. Finally, we use a round-robin optimization algorithm to get precise codes to reconstruct the image. To the best of our knowledge, 3D-GOI is the first framework to enable multifaceted editing on multiple objects. Both qualitative and quantitative experiments demonstrate that 3D-GOI holds immense potential for flexible, multifaceted editing in complex multi-object scenes

    Dietary Lipoic Acid Influences Antioxidant Capability and Oxidative Status of Broilers

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    The effects of lipoic acid (LA) on the antioxidant status of broilers were investigated. Birds (1 day old) were randomly assigned to four groups and fed corn-soybean diets supplemented with 0, 100, 200, 300 mg/kg LA, respectively. The feeding program included a starter diet from 1 to 21 days of age and a grower diet from 22 to 42 days of age. Serum, liver and muscle samples were collected at 42 days of age. For antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in serum, liver and breast muscle significantly increased in chickens fed with LA. The concentration of malondiadehyde (MDA), an indicator of lipid peroxidation, was significantly lower in serum, liver and leg muscle in birds that received LA than in the control group. Treatments with LA significantly increased glutathione (GSH) content in liver and increased α-tocopherol content in leg muscle as compared to the control. These results indicate that dietary supplementation with 300 mg/kg LA may enhance antioxidant capability and depress oxidative stress in broilers

    Nomogram prediction model for the risk of intracranial hemorrhagic transformation after intravenous thrombolysis in patients with acute ischemic stroke

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    BackgroundHemorrhagic transformation (HT) after intravenous thrombolysis (IVT) might worsen the clinical outcomes, and a reliable predictive system is needed to identify the risk of hemorrhagic transformation after IVT.MethodsRetrospective collection of patients with acute cerebral infarction treated with intravenous thrombolysis in our hospital from 2018 to 2022. 197 patients were included in the research study. Multivariate logistic regression analysis was used to screen the factors in the predictive nomogram. The performance of nomogram was assessed on the area under the receiver operating characteristic curve (AUC-ROC), calibration plots and decision curve analysis (DCA).ResultsA total of 197 patients were recruited, of whom 24 (12.1%) developed HT. In multivariate logistic regression model National Institute of Health Stroke Scale (NIHSS) (OR, 1.362; 95% CI, 1.161–1.652; p = 0.001), N-terminal pro-brain natriuretic peptide (NT-pro BNP) (OR, 1.012; 95% CI, 1.004–1.020; p = 0.003), neutrophil to lymphocyte ratio (NLR) (OR, 3.430; 95% CI, 2.082–6.262; p < 0.001), systolic blood pressure (SBP) (OR, 1.039; 95% CI, 1.009–1.075; p = 0.016) were the independent predictors of HT which were used to generate nomogram. The nomogram showed good discrimination due to AUC-ROC values. Calibration plot showed good calibration. DCA showed that nomogram is clinically useful.ConclusionNomogram consisting of NIHSS, NT-pro BNP, NLR, SBP scores predict the risk of HT in AIS patients treated with IVT
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