scholarly journals Performance Analysis of Metalenses Based on Three Kinds of Phase Compensation Techniques

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2091
Author(s):  
Peiyao Lu ◽  
Changda Zhou ◽  
Zhen Mou ◽  
Danhua Liu ◽  
Shuyun Teng
Keyword(s):  
Performance Analysis ◽  
Geometric Phase ◽  
Polarization Dependence ◽  
Phase Delay ◽  
Optical Performance ◽  
Phase Compensation ◽  
Practical Applications ◽  
The Cross ◽  
Structure Complexity ◽  
Working Efficiency

The phase delays introduced by anisotropic nanounits include propagation phase delay, resonant phase delay and geometric phase delay. Various phase devices can be formed based on the metasurfaces consisting of anisotropic nanounits and the phase devices of the same kind function have different performances because of different working modes. In this paper, metalenses and vortex metalenses are chosen as examples to compare the optical performance of metasurface phase devices based on three kinds of phase compensation techniques. We design separately three kinds of metalenses and vortex metalenses using the cross nanoholes, L-shaped nanohole and V-shaped nanoholes and simulate numerically their intensity and phase distributions. Additionally, the results show the differences among these elements in structure complexity, polarization dependence, working efficiency and phase uniformity. The comparison for three kinds of metalenses clearly shows the merits of different phase compensation techniques and this work must be helpful for expanding the practical applications of metasurfaces.

Flexoelectric effect induced in an anisotropic bar with cubic symmetry under torsion

2019 ◽  
Vol 25 (3) ◽  
pp. 820-837
Author(s):  
AR El Dhaba ◽  
ME Gabr
Keyword(s):  
Cross Section ◽  
Gradient Elasticity ◽  
Strain Gradient Elasticity ◽  
Cubic Symmetry ◽  
Rectangular Shape ◽  
Practical Applications ◽  
Flexoelectric Effect ◽  
The Cross ◽  
Gradient Elasticity Theory ◽  
Physical Quantities

In this article, we study the flexoelectricity induced in a prismatic anisotropic bar due to torsion. The simplified strain gradient elasticity theory is considered in this study. The bar is uniform, that is, any cross-section of the bar has a rectangular shape with cubic internal structure symmetry. The traction and higher traction forces effect on the deflection and spontaneous polarization of the bar with different boundary conditions are also discussed. The induced wedge forces are also considered during this study. The magnesium oxide (MgO) physical quantities values are chosen to present a numerical example as one of the practical applications of the problem. The results are discussed and introduced graphically. The most interesting finding in this study is the wedge force directions. When the displacements inside the cross-section of the bar are uniformly distributed, the resultant wedge forces have the same inclination with the cross-section boundary. Meanwhile, if the displacement is not uniformly distributed, the wedge force inclinations with the cross-section boundary are not equal.

Assessment of cross-laminated timber panels by the state-space approach

2019 ◽  
Vol 22 (11) ◽  
pp. 2375-2391
Author(s):  
Asad S Albostami ◽  
Zhangjian Wu ◽  
Lee S Cunningham
Keyword(s):  
State Space ◽  
Three Dimensional ◽  
The State ◽  
Composite Panel ◽  
State Space Approach ◽  
Cross Laminated Timber ◽  
Practical Applications ◽  
The Cross ◽  
Analytical Approaches ◽  
Space Approach

In this article, cross-laminated timber panels are investigated as a novel engineering application of the state-space approach. As cross-laminated timber is a laminated composite panel, the three-dimensional analytical method provided by the state-space approach offers the potential for improved accuracy over existing common approaches to the analysis of cross-laminated timber. Before focusing on the specific application to cross-laminated timber, the general theory of the state-space approach is outlined. The method is then applied to describe the behaviour of a number of cross-laminated timber panel configurations previously examined experimentally and analytically. In order to demonstrate the capability of the state-space approach in this application, the results are compared with those from various two-dimensional and three-dimensional analytical approaches and finite element modelling briefly. With a view to design, different failure criteria are explored to assess the ultimate strength of the cross-laminated timber panels. The state-space approach demonstrates its superior capability in capturing the nonlinear distribution of the elastic stresses through the thickness of the cross-laminated timber panels over a range of span-to-thickness ratios common in practical applications.

scholarly journals A dynamic model of classifier competence based on the local fuzzy confusion matrix and the random reference classifier

2016 ◽  
Vol 26 (1) ◽  
pp. 175-189 ◽  
Author(s):  
Pawel Trajdos ◽  
Marek Kurzynski
Keyword(s):  
Classification Accuracy ◽  
Confusion Matrix ◽  
Dynamic Mode ◽  
Static Mode ◽  
Feedback Information ◽  
Practical Applications ◽  
Storage Complexity ◽  
The Cross ◽  
Validation Set ◽  
Ensemble Systems

Abstract Nowadays, multiclassifier systems (MCSs) are being widely applied in various machine learning problems and in many different domains. Over the last two decades, a variety of ensemble systems have been developed, but there is still room for improvement. This paper focuses on developing competence and interclass cross-competence measures which can be applied as a method for classifiers combination. The cross-competence measure allows an ensemble to harness pieces of information obtained from incompetent classifiers instead of removing them from the ensemble. The cross-competence measure originally determined on the basis of a validation set (static mode) can be further easily updated using additional feedback information on correct/incorrect classification during the recognition process (dynamic mode). The analysis of computational and storage complexity of the proposed method is presented. The performance of the MCS with the proposed cross-competence function was experimentally compared against five reference MCSs and one reference MCS for static and dynamic modes, respectively. Results for the static mode show that the proposed technique is comparable with the reference methods in terms of classification accuracy. For the dynamic mode, the system developed achieves the highest classification accuracy, demonstrating the potential of the MCS for practical applications when feedback information is available.

scholarly journals The Design of Educational Simulator for Noise and Filter Types in Image Processing

2018 ◽  
Vol 1 (1) ◽  
pp. 25-30
Author(s):  
Fahri Vatansever ◽  
Nedim Aktan Yalcin
Keyword(s):  
Image Processing ◽  
Performance Analysis ◽  
Theoretical Knowledge ◽  
Comparative Performance ◽  
Signal And Image Processing ◽  
Practical Applications ◽  
Interactive Applications

Noise and filtering noise are basic topics in the field of signal and image processing. In this study, an interactive simulator is designed for comprehension of related topics and to be reinforced theoretical knowledge with practical applications by students which have educated in these fields. Knowledge about noise and filtering in the field of image processing is easily, quickly and effectively gained to students with the simulator which includes many noise (Gaussian, Gamma, Rayleigh etc.) and filter (mean, median, min, max etc.) types, presents theoretical topics (explanations, mathematical statements, examples, etc.) about them visually, allows realizing of interactive applications (parameter and type changes etc.) and creates singular and comparative performance analysis.

scholarly journals Design, Simulation, and Performance Analysis of an INS/GPS System using Parallel Kalman Filters Structure

2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Tran Duc-Tan ◽  
Paul Fortier ◽  
Huu-Tue Huynh
Keyword(s):  
Performance Analysis ◽  
Kalman Filtering ◽  
Inertial Navigation System ◽  
Moving Objects ◽  
Practical Applications ◽  
System A ◽  
Mems Technology ◽  
Filtering Technique ◽  
And Performance ◽  
Gps System

Thanks to the strong growth of MEMS technology, the Inertial Navigation System (INS) is widely applied to navigation and guidance of moving objects. However, there exist errors in the inertial sensor’s signals that cause unacceptable drifts. To minimize these effects on the INS system, a GPS is usually employed simultaneously with an INS in order to increase the dimension of the system; the desired parameters are estimated by Kalman filtering technique applied to the enlarged system. In this paper, we present the design, simulation and performance analysis of an INS/GPS system using two parallel Kaman filters in order to increase the accuracy of the parameter estimation process. The results show that this system could be efficiently brought to practical applications.

An Inverse Design Method of Buckling-Guided Assembly for Ribbon-Type 3D Structures

2019 ◽  
Vol 87 (3) ◽  
Author(s):  
Zheng Xu ◽  
Zhichao Fan ◽  
Yanyang Zi ◽  
Yihui Zhang ◽  
Yonggang Huang
Keyword(s):  
Cross Section ◽  
3D Structure ◽  
Experimental Studies ◽  
Functional Materials ◽  
Optimization Method ◽  
Inverse Design ◽  
Torsional Angle ◽  
3D Structures ◽  
Practical Applications ◽  
The Cross

Abstract Mechanically guided three-dimensional (3D) assembly based on the controlled buckling of pre-designed 2D thin-film precursors provides deterministic routes to complex 3D mesostructures in diverse functional materials, with access to a broad range of material types and length scales. Existing mechanics studies on this topic mainly focus on the forward problem that aims at predicting the configurations of assembled 3D structures, especially ribbon-shaped structures, given the configuration of initial 2D precursor and loading magnitude. The inverse design problem that maps the target 3D structure onto an unknown 2D precursor in the context of a prescribed loading method is essential for practical applications, but remains a challenge. This paper proposes a systematic optimization method to solve the inverse design of ribbon-type 3D geometries assembled through the buckling-guided approach. In addition to the torsional angle of the cross section, this method introduces the non-uniform width distribution of the initial ribbon structure and the loading mode as additional design variables, which can significantly enhance the optimization accuracy for reproducing the desired 3D centroid line of the target ribbon. Extension of this method allows the inverse design of entire 3D ribbon configurations with specific geometries, taking into account both the centroid line and the torsion for the cross section. Computational and experimental studies over a variety of elaborate examples, encompassing both the single-ribbon and ribbon-framework structures, demonstrate the effectiveness and applicability of the developed method.

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