Metamaterials are composite materials whose material properties(acoustic, electrical, magnetic, or optical, etc.) are determined by their constitutive structural materials, especially the unit cells. The development o...Metamaterials are composite materials whose material properties(acoustic, electrical, magnetic, or optical, etc.) are determined by their constitutive structural materials, especially the unit cells. The development of metamaterials continues to redefine the boundaries of materials science. In the field of electromagnetic research and beyond, these materials offer excellent design flexibility with their customized properties and their tunability under external stimuli. In this paper, we first provide a literature review of metamaterials with a focus on the technology and its evolution. We then discuss steps in the industrialization process and share our own experience.展开更多
We discuss blending sensor scheduling strategies with particle filtering (PF) methods to deal with the prob-lem of tracking a ‘smart’ target, that is, a target being able to be aware it is being tracked and act in a...We discuss blending sensor scheduling strategies with particle filtering (PF) methods to deal with the prob-lem of tracking a ‘smart’ target, that is, a target being able to be aware it is being tracked and act in a manner that makes the future track more difficult. We concern here how to accurately track the target with a care on concealing the observer to a possible extent. We propose a PF method, which is tailored to mix a sensor scheduling technique, called covariance control, within its framework. A Rao-blackwellised unscented Kal-man filter (UKF) is used to produce proposal distributions for the PF method, making it more robust and computationally efficient. We show that the proposed method can balance the tracking filter performance with the observer’s concealment.展开更多
We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at s...We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder.展开更多
Metamaterial design,encompassing both microstructure topology selection and geometric parameter optimization,constitutes a high-dimensional optimization problem,with computationally expensive and time-consuming design...Metamaterial design,encompassing both microstructure topology selection and geometric parameter optimization,constitutes a high-dimensional optimization problem,with computationally expensive and time-consuming design evaluations.Bayesian optimization(BO)offers a promising approach for black-box optimization involved in various material designs,and this work presents several advanced techniques to adapt BO to address the challenges associated with metamaterial design.First,variational autoencoders(VAEs)are employed for efficient dimensionality reduction,mapping complex,high-dimensional metamaterial microstructures into a compact latent space.Second,mutual information maximization is incorporated into the VAE to enhance the quality of the learned latent space,ensuring that the most relevant features for optimization are retained.Third,trust region-based Bayesian optimization(TuRBO)dynamically adjusts local search regions,ensuring stability and convergence in high-dimensional spaces.The proposed techniques are well incorporated with conventional Gaussian processes(GP)-based BO framework.We applied the proposed method for the design of electromagnetic metamaterial microstructures.Experimental results show that we achieve a significantly high probability of finding the ground-truth topology types and their geometric parameters,leading to high accuracy in matching the design target.Moreover,our approach demonstrates significant time efficiency compared with traditional design methods.展开更多
基金supported by Guangdong Innovative Research Team Program (2009010005)
文摘Metamaterials are composite materials whose material properties(acoustic, electrical, magnetic, or optical, etc.) are determined by their constitutive structural materials, especially the unit cells. The development of metamaterials continues to redefine the boundaries of materials science. In the field of electromagnetic research and beyond, these materials offer excellent design flexibility with their customized properties and their tunability under external stimuli. In this paper, we first provide a literature review of metamaterials with a focus on the technology and its evolution. We then discuss steps in the industrialization process and share our own experience.
文摘We discuss blending sensor scheduling strategies with particle filtering (PF) methods to deal with the prob-lem of tracking a ‘smart’ target, that is, a target being able to be aware it is being tracked and act in a manner that makes the future track more difficult. We concern here how to accurately track the target with a care on concealing the observer to a possible extent. We propose a PF method, which is tailored to mix a sensor scheduling technique, called covariance control, within its framework. A Rao-blackwellised unscented Kal-man filter (UKF) is used to produce proposal distributions for the PF method, making it more robust and computationally efficient. We show that the proposed method can balance the tracking filter performance with the observer’s concealment.
文摘We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder.
基金supported by the National Key R&D Program of China No.2021YFB3802103Open Project of the State Key Laboratory of Metamaterial Electromagnetic Modulation Technology:“Research on Optimization Algorithms for Antenna Wideband Matching Network Parameters”.
文摘Metamaterial design,encompassing both microstructure topology selection and geometric parameter optimization,constitutes a high-dimensional optimization problem,with computationally expensive and time-consuming design evaluations.Bayesian optimization(BO)offers a promising approach for black-box optimization involved in various material designs,and this work presents several advanced techniques to adapt BO to address the challenges associated with metamaterial design.First,variational autoencoders(VAEs)are employed for efficient dimensionality reduction,mapping complex,high-dimensional metamaterial microstructures into a compact latent space.Second,mutual information maximization is incorporated into the VAE to enhance the quality of the learned latent space,ensuring that the most relevant features for optimization are retained.Third,trust region-based Bayesian optimization(TuRBO)dynamically adjusts local search regions,ensuring stability and convergence in high-dimensional spaces.The proposed techniques are well incorporated with conventional Gaussian processes(GP)-based BO framework.We applied the proposed method for the design of electromagnetic metamaterial microstructures.Experimental results show that we achieve a significantly high probability of finding the ground-truth topology types and their geometric parameters,leading to high accuracy in matching the design target.Moreover,our approach demonstrates significant time efficiency compared with traditional design methods.
