Ultrasonic fault diagnosis has emerged as a promising technique for gear fault detection, owing to its capability to capture modulated high-frequency transients induced by incipient or localized defects. However, its ...
Ultrasonic fault diagnosis has emerged as a promising technique for gear fault detection, owing to its capability to capture modulated high-frequency transients induced by incipient or localized defects. However, its practical application is constrained by the requirement for extremely high sampling rates. Heterodyne downconversion offers a potential solution by translating ultrasonic spectral components to lower frequencies, though its effectiveness in preserving diagnostic features remains insufficiently validated. This study conducts a theoretical analysis of the influence of heterodyne downconversion on ultrasonic signal characteristics and proposes an optimized heterodyne-based ultrasonic acquisition system with enhanced charge amplification and frequency conversion circuits. Experimental evaluations using a gear fault test platform demonstrate that the downconverted signals preserve the envelope spectral features of the original ultrasonic signals. Furthermore, comparative analyses indicate that the proposed method achieves superior fault detection sensitivity compared to conventional vibration-based techniques, particularly under high rotational speeds. These findings validate the feasibility and diagnostic advantages of the proposed heterodyne-based approach for efficient and accurate ultrasonic condition monitoring.
Optical coherence tomography (OCT) is a label-free, non-invasive imaging technique that is widely used in the diagnosis of various ophthalmic diseases. The diagnostic information related to these diseases is embodied ...
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ISBN:
(纸本)9781665415897;9781665446839
Optical coherence tomography (OCT) is a label-free, non-invasive imaging technique that is widely used in the diagnosis of various ophthalmic diseases. The diagnostic information related to these diseases is embodied in the texture and geometric features of the OCT scans, which are used by the retinal experts for interpretation and classification. However, due to the large number of OCT scans obtained every day, doctors and hospital staff are unable to meaningfully examine the potential retinal pathological conditions (RPCs), resulting in unexpected delays in the diagnosis and treatment of RPCs. In this paper, we propose an automated deep recurrent residual inception network, RRI-Net, for the classification of retinal OCT scans into diagnostically relevant classes, including healthy, age-related macular degeneration (AMD), diabetic macular edema (DME) and choroidal neovascularization (CNV). The proposed RRI-Net employs residual connections with cascaded multi-kernel convolutions to provide optimal training and classification results. In addition, we conducted extensive training of RRI-Net using 108,312 OCT scans, and tested the performance of the proposed framework over 1,000 OCT scans. The results show that RRI-Net achieves 98.8% accuracy in multi-class classification problem between healthy, AMD, DME and CNV, with 97.6% true positive rate and 99.2% true negative rate, outperforming other state-of-the-art methods.
This paper concentrates on the control problem of a class of fractional order nonlinear systems. A new adaptive backstepping sliding mode control is proposed, which inherits both the advantages of backstepping and sli...
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This paper concentrates on the control problem of a class of fractional order nonlinear systems. A new adaptive backstepping sliding mode control is proposed, which inherits both the advantages of backstepping and sliding mode ***, a fractional order sliding mode disturbance observer is proposed to estimate unknown external disturbances. Meanwhile, RBF neural network is adopted to approximate unknown nonlinear terms. Finally, an illustrative simulation result based on a practical fractional order permanent magnet synchronous motor model is presented to verify the validity of proposed controller.
Diagnostic pathology, which is the basis and gold standard of cancer diagnosis, provides essential information on the prognosis of the disease and vital evidence for clinical treatment. However, pathological diagnosis...
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ISBN:
(纸本)9781665429825
Diagnostic pathology, which is the basis and gold standard of cancer diagnosis, provides essential information on the prognosis of the disease and vital evidence for clinical treatment. However, pathological diagnosis is subjective, and differences in observation and diagnosis between pathologists are common. This phenomenon is more evident in hospitals with insufficient medical resources. Deep learning (DL) can be used to identify and classify structures in digital pathology. In order to solve the above difficulties, in this work, we propose a DL framework for generating pathological diagnosis by analyzing histopathological images of renal cell carcinoma. A deep neural network is trained on a large high-quality annotated dataset for accurate tumor area detection, subtyping, and grading. The results show that our framework has achieved pathologist-level accuracy in diagnosis, can generate pathology reports with tumor indicators, and provide pathologists with interpretable auxiliary diagnoses
—We study how to secure distributed filters for linear time-invariant systems with bounded noise under false-data injection attacks. A malicious attacker is able to arbitrarily manipulate the observations for a time-...
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The poor voltage regulation capability of traditional switched-capacitor converters (SCCs) is one severe disadvantage that limits the applicable fields. In this paper, one of the diodes in the five common step-up SCCs...
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ISBN:
(数字)9781728153018
ISBN:
(纸本)9781728153025
The poor voltage regulation capability of traditional switched-capacitor converters (SCCs) is one severe disadvantage that limits the applicable fields. In this paper, one of the diodes in the five common step-up SCCs - Ladder, Dickson, Fibonacci, Series-parallel, Voltage Doubler- is replaced by a filter inductor. As a result, the new formed switched-capacitor-based (SC-based) hybrid converters attain the wide and continuous voltage regulation capability. Different replaced diode positions lead to different characteristics, so a brief comparison of voltage gain is given. The added inductor may conduct reverse current and thus deteriorate the efficiency, so a boundary map is derived to avoid such region. A hybrid converter based on the 3X Ladder SCC was built to verify the analysis.
Privacy preserving in distributed control is getting more attention, and differential privacy (DP) is the common tool to protect data privacy, in which additive noise is applied in the algorithm function. However, DP ...
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To meet the demand for designing efficient neural networks with appropriate trade-offs between model performance (e.g., classification accuracy) and computational complexity, the differentiable neural architecture dis...
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