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On-chip visible comb generation covering from 720 to 840 nm is demonstrated in AlN-on-sapphire microring resonators. Broadband frequency conversion of near-infrared Kerr comb into visible region is achieved in slightly phase-mismatched condition.
Coexistence of stimulated Raman scattering and four-wave mixing is observed in high quality factor AlN-on-sapphire microring resonators, which facilitates broadband Kerr frequency comb generation covering from 1.2 to 2.2 μm along with strong Raman lines.
Failures exist ubiquitously in physical actuators, which usually are uncertain in time, pattern, and value. This effect would deteriorate system tracking performance, and even trigger instability. In this paper, we consider the problem of compensating for actuator failures by proposing a fuzzy control scheme for stochastic nonlinear systems. Comparison with existing research on stochastic nonlinear...
A vibration controller based on wavelet neural network (WNN) is designed for jacket-type offshore platforms with time delay. The offshore platform is regarded as a single-degree-of-freedom (SDOF) system while wave forces are irregular disturbances, and we can rebuild them in the context of Morison equation and wave theory. To reduce the vibration, a WNN vibration controller is designed based on a...
Wind as the one of typical renewable energy are widely used in the world. Traditional energy storage system (ESS) involved wind power dispatch plan is merely focus on the wind power fluctuation suppression. However, with wind generation participate in the deregulated electricity power market, the way to improve the wind farm financial income is became another major task, which is as crucial as the...
Based on analysis of sources of the noise of switched reluctance motor (SRM), the paper puts forward methods to reduce noise in terms of torque ripple and phase change from the point of control view. In the low speed stage, phase current closed-loop segmented according to the sine and cosine curve, maintain a constant torque to reduce the torque ripple. Put forward soft turn-off method at the time...
Accurately modeling the dynamic behavior of a lithium-ion battery is one of the major themes for researches on state of charge (SOC) estimation. A large number of experiments were performed at different discharge rates and operating temperatures for three compact lithium-ion batteries aiming at determining the relationship of open circuit voltage (OCV) with SOC. The curve of OCV-SOC is approximated...
This paper first analyzes the mechanism of vibration noise and torque ripple of the switched reluctance motor, and then studies methods of reducing torque ripple and noise reduction according to the principle. In order to reduce the noise, two-step phase conduction is proposed when motor starts. Meanwhile, each phase of the shutoff in advance will be replaced by reducing duty ratio slowly. In order...
This paper considers the problem of global practical tracking by output-feedback for a class of planar nonlinear systems with unknown control coefficients. Compared with the closely related works, the key point of the paper is that it is only required the sign information but not the upper and lower bounds of unknown control coefficients are known a prior. Motivated by our recent works, by combining...
This paper proposes a three-phase six-inductor double-switch PFC circuit which is suitable for high frequency UPS application. This PFC circuit not only achieves high power factor correction in grid-connected mode of UPS, but also improves bus voltage in battery mode of UPS. This new PFC removes the independent boost design in common UPS and the whole cost can be reduced. The topology structure and...
A step-up control method is proposed to solve the problem of the normalized voltage gain less than 1 when the bi-directional LLC resonant converter works in backward mode. This step-up control method turns on rectifier switches to help resonant components recover their energy and improves the normalized voltage gain to 2. Working principle of the bidirectional LLC resonant converter is introduced...
This paper designs a vibration controller based on back propagation neural network (BPNN) for jacket-type offshore platforms with time delay. The offshore structure is simplified into a single-degree-of-freedom (SDOF) system and transformed into a non-delay model. With an system designed to describe wave forces in the context of Morison equation and wave theory, the original vibration control is formulated...
This paper designs a vibration controller based on back propagation (BP) neural network for jacket-type offshore platforms with time delay. With an exosystem designed, we can describe the irregular wave forces in the context of Morison equation and wave theory. The original vibration control can be seen as an optimal control problem. This linear discrete-time system is affected by wave forces as external...
Hyperspectral remote sensing technology can acquire nearly continuous spectrum information and rich sea ice image information, thus providing an important means of sea ice detection. However, the correlation and redundancy among hyperspectral bands reduce the accuracy of traditional sea ice detection methods. Based on the spectral characteristics of sea ice, this study presents an improved similarity...
Sensor model is required to build the relationship between the three-dimensional (3D) object space and two-dimensional (2D) image space of high resolution satellite imagery (HRSI). However, each satellite sensor has its own imaging system with different physical sensor model, which increases the difficulty of geometric integration of heterogeneous images with different sensor models. Therefore, it...
This paper studies the cluster consensus problem of heterogeneous linear multi-agent systems under fixed directed topology. Compared to existing results for cluster consensus problems, dynamics of all agents are allowed to be nonidentical, which promotes the application of the results. A state-feedback control protocol with a dynamic compensator is proposed to solve the problem. Output regulation...
In this paper, a novel effective method based on Scale-invariant feature transform in Imagery to realize Target tracking, where the discriminating process is improved through Image Matching Processing. It is the first time that the problem of tracking in Imaging processing, contrasted with traditional methods in data processing. It can track target for clutter. Simulation results show that the proposed...
This paper addresses the problem of track initiation for multi-target in different motion forms and in complicated clutter background. The method proposed combines the traditional logic-based method and convolution neural network. The logic-based method is used mainly to generate a set of track proposals, which is computed by the convolution neural network to extract features in data domain. In this...
The enormous amount of sampling raw data makes difficulties in storage and transmission for multi-channel SAR-GMTI system. In this paper we present a STAP-based GMTI approach using a small amount of multichannel SAR raw data. The SAR raw data is firstly sampled in the azimuth direction sparsely. Secondly, STAP processing method is adopted to eliminate the clutter returns in slow time domain. Finally,...
In order to improve the utilization rate of power equipment and service life, reduce the economic loss of the power grid and overcome the shortcomings of traditional threshold determination methods, this paper proposed a power equipment fault diagnosis method based on fuzzy multilayer support vector machines. The new method mines equipment feature information by the fuzzy logic algorithm, trains many...
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