In a distribution system, sparse reliable samples and inconsistent fault characteristics always appear in the dataset of neural network fault detection models because of high impedance fault (HIF) and system structural changes. In this paper, we present an algorithm called Generative Adversarial Networks (GAN) based on the Reptile Algorithm (GANRA) for generating fault data and propose an evolution strategy based on GANRA to assist the fault detection of neural networks. First, the GANRA generates enough high-quality analogous fault data to solve a shortage of realistic fault data for the fault detection model’s training. Second, an evolution strategy is proposed to help the GANRA improve the fault detection neural network’s accuracy and generalization by searching for GAN’s initial parameters. Finally, Convolutional Neural Network (CNN) is considered as the identification fault model in simulation experiments to verify the validity of the evolution strategy and the GANRA under the HIF environment. The results show that the GANRA can optimize the initial parameters of GAN and effectively reduce the calculation time, the sample size, and the number of learning iterations needed for dataset generation in the new grid structures.
Objectives: The osteogenic potential of periodontal ligament stem cells (PDLSCs) is crucial for periodontal tissue regeneration. Prolonged and excessive oxidative stress (OS) impairs the osteogenic function of PDLSCs. Recently, Semaphorin 3A (Sema3A) has been reported to have multiple roles in bone protection. This study aimed to investigate the protective effect of Sema3A on the osteogenic differentiation of PDLSCs under OS conditions induced by hydrogen peroxide (H2O2). Methods: PDLSCs were subjected to H2O2 treatment to induce OS. The OS indices in PDLSCs were evaluated by analyzing levels of reactive oxygen species (ROS), cell viability, and expression of antioxidant factors using relevant assay kits. A small molecule inhibitor, XAV-939, was employed to block the Wnt/β-catenin pathway. Osteogenic differentiation was assessed using alkaline phosphatase (ALP) activity staining and Alizarin Red S (ARS) staining for mineralized nodules. Expression levels of osteogenic gene markers and β-catenin were determined via real-time quantitative polymerase chain reaction (RT-qPCR) or western blot (WB) analysis. Results: The stimulation of H2O2 induced OS in PDLSCs, resulting in a downregulation of Sema3A expression and a decrease in osteogenic markers, including ALP activity, mineralized nodule formation, and the expression of osteogenic genes (RUNX2 and ALP). However, the application of recombinant human Sema3A (rhSema3A) counteracted H2O2-induced OS and restored these osteogenic markers in PDLSCs under OS induced by H2O2. Mechanistic studies revealed that these effects were associated with an upregulation of β-catenin levels. Moreover, inhibiting β-- catenin expression compromised the protective effect of Sema3A on osteogenesis in PDLSCs under OS. Conclusion: Sema3A exerts a protective effect against H2O2-induced OS and activates the Wnt/β-- catenin pathway to restore osteogenic differentiation impaired by OS in PDLSCs.
Abstract A large current ripple may arise in the finite control set model‐free predictive current control (FCS‐MFPCC) strategy because only one voltage vector can be applied during the whole control period. Therefore, an improved three‐vector‐based model‐free predictive current control (MFPCC) strategy to improve the current tracking performance is proposed by increasing the number of the applied voltage vector. Based on the extreme existence theorem for the function of two variables, the optimal voltage vector can be synthesized. Compared with the one‐vector‐based FCS‐model‐based predicted current control (FCS‐MBPCC) and two‐vector‐based FCS‐MBPCC in the time and frequency domains, the maximum tracking error is decreased by 42.17% and 48.58%, and the total harmonic distortion is decreased by 40.97% and 37.56%, respectively. Besides, compared with the previous three‐vector‐based strategy, the computational time of the proposed strategy is reduced from 57.6 to 45.89 , which is reduced by 20.33%. Furthermore, the switching frequency of the proposed method can be decreased by 70.3% compared with the deadbeat MFPCC. The experimental results in the time and frequency domains demonstrate that the proposed three‐vector‐based MFPCC can not only improve the current tracking performance but also improve robustness against parameter mismatches.
Various forms of calcium in 12 species of shrub of Leguminosae used as feed in Yunnan were isolated and Abstracted, and the content of each form of calcium was determined by atomic Absorption spectrophotometry. The results showed that the available calcium rates of eight tree species are over 29% in 12 tree species. The inorganic calcium content of Indigoferia tinctoria is more than 3 000mg/kg in 12 tree species, and they might be used as tree species which could supplement feed with calcium.
The predecessor of China Optics was China Optics and Applied Optics Digest, which was founded in 1985. At that time, it was the only retrieval journal in the field of optics in China. At the end of 2008, China Optics and Applied Optics Digest was renamed
Maneuvering target tracking of Unmanned Aerial Vehicle(UAV) in cluttered environments is a challenging issue owing to the unknown motion intention of the target and the complex moving environments. As the complexity of the environment increases, stable and secure target tracking is increasingly difficult to guarantee. To address the issue, this paper proposes a stable quadrotor tracking solution. The proposed solution contains two parts: target motion prediction and tracking path searching. The target motion prediction method predicts the future target motion based on the obtained target observations while considering observation noise and prediction errors. The tracking path searching method utilizes a sampling-based search method, using the homotopy of paths to ensure that the tracking path and the target position are in the same space. Finally, simulations, real-world experiments and statistical analysis verify the correctness and effectiveness of the proposed approach.
In this work, the parasitic capacitance of the V-GAA transistor structure was successfully extracted, which suffer from the different pillar size in SADP process. Such as pillar height and width. Based on the range of λ from 0.85 to 1.15, the variation of gate around capacitance with the pillar height and width is less than 1.6% and more than 15%, respectively. In addition, the pillar width is the main factor affecting the coupling capacitance of V-GAA array structure. This provides fundamental research for further device study of V-GAA in the far technology node.
In this paper, we describe a novel fully-actuated hexarotor with tilted fixed rotors and its controller for trajectory tracking and preparing for aerial contact-based inspection operations. Unlike conventional quadcopters or hexarotors, this fully-actuated hexarotor has the ability to move in any direction, making it suitable as a flying platform for aerial contact-based inspection robots. We model the dynamics of the hexarotor using the Newton-Euler equations, and design various attitude generation methods and a control algorithm for different scenarios. To validate the feasibility of the algorithm, we conduct simulation experiments using MATLAB and Simulink to evaluate its performance. We conduct trajectory tracking experiments, where the hexarotor is able to effectively move to the desired target points and effectively track different desired trajectories. The experimental results demonstrate the effectiveness and accuracy of the proposed control algorithm for the fully-actuated hexarotor.
Aerial transportation technology is the lifeline of air disaster rescue. In this article, a robust adaptive tracking control scheme using backstepping sliding mode techniques is proposed for a quadrotor-based aerial transportation system with a cable-suspended payload in disaster rescue, where the payload is ensured to be driven to predefined trajectories in the presence of strong coupling, uncertainties, and external disturbances. The quadrotor and the payload are modeled as a rigid body and a point mass, respectively, and the two coupling terms between the virtual input of the payload position loop and the payload attitude error as well as between the input force and the quadrotor attitude error are analyzed owing to the underactuated of the quadrotor-based transportation system. Then, adaptive backstepping sliding mode control strategies are designed for the position and swing dynamics of the payload to guarantee payload trajectory tracking, and an observer-based geometric attitude control method is presented for the quadrotor attitude dynamics to ensure the global attitude stability of the system, where prior information about disturbances is not required. The closed-loop stability of the whole system is strictly proven. Finally, real-world experiments are conducted to verify the feasibility and robustness of the proposed control scheme. Note to Practitioners —The motivation of this article is to investigate a robust and adaptive control tracking scheme for aerial transportation systems with a cable-suspended payload in disaster rescue. In most of the existing aerial transportation control schemes with a cable-suspended payload, the payload is driven to follow a desired trajectory while only considering the coupling effect between the aerial platform and the payload. However, in practical disaster rescue applications, the aerial transportation system is inevitably affected by strong coupling, uncertainties, and external disturbances. Meanwhile, to the authors’ best knowledge, there exist few studies that investigate payload following issues while considering strong coupling, uncertainties, and external disturbances simultaneously. Therefore, this article proposes a robust and adaptive tracking control scheme using backstepping sliding mode techniques for a quadrotor-based aerial transportation system with a cable-suspended payload to ensure the stable and accurate payload following control under strong coupling, uncertainties, and external disturbances, where prior information about disturbances is not required under the proposed scheme. The closed-loop stability of the whole system is strictly and mathematically analyzed as well as real-world experiments provide promising results. Moreover, the proposed scheme provides a more realistic setup for autonomous aerial transportation with cable-suspended supplies in disaster rescue.
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