- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Uniformity-modeled Magnetic Resonance Electrical Properties Tomography for Nasopharyngeal Carcinoma
摘要： A new numerical technique to solve nonlinear systems of initial value problems for nonlinear first-order differential equations (ODEs) that model genetic networks in systems biology is developed. This technique is based on finding local Galerkin approximations on each sub-interval at a given time grid of points using piecewise hat functions. Comparing the numerical solution of the new method for a single nonlinear ODE with an exact solution shows that this method gives accurate solutions with relative error 1.88 × 10?11 for a time step 1 × 10?6. This new method is compared with the adaptive Runge Kutta (ARK) method for solving systems of ODEs, and the results are comparable for a time step 2 × 10?4. It is shown that the relative error of the Galerkin method decreases approximately linearly with the log of the number of hat functions used. Unlike the ARK method, this new method has the potential to be parallelizable and to be useful for solving biological problems involving large genetic networks. An NSF commissioned video illustrating how systems biology helps us understand that a fundamental process in cells is included.
关键词： hat function,Galerkin method,systems biology,ordinary differential equation,finite element method,toggle switch,Newton–Raphson method,Biological clock
更新于2025-09-19 17:13:59
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Electromagnetic Wave Absorbers (Detailed Theories and Applications) || Basic Theory of Computer Analysis
摘要： One of the reasons that a wide variety of EM-wave absorber analyses came to be possible recently is the remarkable progress of modeling and computer simulation technologies. In addition, in actual computer simulation technologies, a number of theoretical analysis methods and means are compounded and systemized. In this chapter, in order to deepen the basic understanding of computer simulation analysis of EM-wave absorbers, the finite-difference time-domain (FDTD) method and finite element (FE) method are explained in detail, including their fundamental principles.
关键词： EM-wave absorbers,FDTD method,Maxwell's equations,Finite element method,Computer simulation
更新于2025-09-19 17:13:59
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A data-driven framework to predict the morphology of interfacial Cu6Sn5 IMC in SAC/Cu system during laser soldering
摘要： A data-driven approach combining together the experimental laser soldering, finite element analysis and machine learning, has been utilized to predict the morphology of interfacial intermetallic compound (IMC) in Sn-xAg-yCu/Cu (SAC/Cu) system. Six types of SAC solders with varying weight proportion of Ag and Cu, have been processed with fiber laser at different magnitudes of power (30-50 W) and scan speed (10-240 mm/min), and the resultant IMC morphologies characterized through scanning electron microscope are categorized as prismatic and scalloped ones. For the different alloy composition and laser parameters, finite element method (FEM) is employed to compute the transient distribution of temperature at the interface of solder and substrates. The FEM-generated datasets are supplied to a neural network that predicts the IMC morphology through the quantified values of temperature dependent Jackson parameter (αJ). The numerical value of αJ predicted from neural network is validated with experimental IMC morphologies. The critical scan speed for the morphology transition between prismatic and scalloped IMC is estimated for each solder composition at a given power. Sn-0.7Cu having the largest critical scan speed at 30 W and Sn-3.5Ag alloy having the largest critical scan speed at input power values of 40 W and 50 W, thus possessing the greatest likelihood of forming prismatic interfacial IMC during laser soldering, can be inferred as most suitable SAC solders in applications exposed to shear loads.
关键词： Neural network,Intermetallic compound,Lead-free solders,Finite element method (FEM),Laser parameters,Morphology
更新于2025-09-19 17:13:59
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A wave-based optimization approach of curved joints for improved defect detection in waveguide assemblies
摘要： A wave-based numerical approach is proposed for the detection of defects in waveguide assemblies with curved joints. Within this framework, the wave finite element (WFE) method is used. It provides an efficient numerical means for computing waves in one-dimensional periodic structures (waveguides), and assessing the reflection and transmission coefficients of waves around defects and curved joints. A so-called apparent reflection matrix of the defects, which takes into account the influence of the joints on the reflected signals recorded at some measurement point at the beginning of a waveguide assembly, is proposed. This appears to be the relevant criterion for detecting defects. As it turns out, an optimization procedure for the design of curved joints can be proposed to magnify the amplitude of the reflected signals issued from defects. Numerical experiments are carried out on 2D waveguide assemblies, with one or two curved joints which are parameterized with respect to their radius and angle of curvature. Optimized values of these parameters can be found which magnify the reflected signals issued from several kinds of defects. Time response simulations are finally undertaken to highlight the relevance of the proposed approach.
关键词： defect detection,wave finite element method,optimization,curved joints,scattering matrix
更新于2025-09-19 17:13:59
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[IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Electromagnetic FPCB micromirror scanning laser rangefinder
摘要： Since several years, the number of total hip arthroplasty revision surgeries is substantially growing. One of the main reasons for this procedure to become necessary is the loosening or damage of the prothesis, which is facilitated by bone necrosis at the implant–bone interface. Electrostimulation is one promising technique, which can accelerate the growth of bone cells and, therefore, enhance the anchorage of the implant to the bone. We present computational models of an electrostimulative total hip revision system to enhance bone regeneration. In this study, the influence of uncertainty in the conductivity of bone tissue on the electric field strength and the beneficial stimulation volume for an optimized electrode geometry and arrangement is investigated. The generalized polynomial chaos technique is used to quantify the uncertainty in the stimulation volumes with respect to the uncertain conductivity of cancellous bone, bone marrow, and bone substitute, which is used to fill defective areas. The results suggest that the overall beneficial stimulation areas are only slightly sensitive to the uncertainty in conductivity of bone tissue. However, in the proximity of tissue boundaries, larger uncertainties, especially in the transition between beneficial and understimulation areas, can be expected.
关键词： Electrical stimulation,finite-element method,multiobjective optimization,uncertainty quantification,total hip arthroplasty (THA) revision
更新于2025-09-19 17:13:59
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Gold Nanoearbuds: Seed-Mediated Synthesis and the Emergence of Three Plasmonic Peaks
摘要： We demonstrate the first successful synthesis of reasonably monodisperse and single crystalline gold nano-earbuds (Au NEBs) using a binary surfactant mixture of cetyltrimethylammonium chloride (CTAC) and benzyldimethylhexadecylammonium chloride (BDAC) in a seed-mediated growth method. We have focused on the key chemical parameters behind the formation and growth of Au NEBs to result in tunable dimensions (lengths 37-77 nm; widths 4-6 nm and aspect ratios 7-19), as a consequence of which the longitudinal surface plasmon resonance (LSPR) peak could be tuned beyond 1200 nm. The achievement of LSPR beyond 1200 nm while maintaining the dimension well below 100 nm is a challenging accomplishment in the realm of 1D Au nanostructures. This earbud-like morphology additionally exhibits three plasmonic peaks, rather uncommon for 1D nanostructure, which were analyzed theoretically based on finite element method. The new resonance peak of Au NEB was assigned as an additional longitudinal mode intensified by the bulbous ends as well as the high-aspect ratio, thereby providing conclusive evidence that it is indeed a new morphology.
关键词： Au nano-earbud,Seed-mediated growth,Surface plasmon resonance,1D nanostructure,3D finite element method
更新于2025-09-19 17:13:59
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Ultra-High Refractive Index Sensing Structure Based on a Metal-Insulator-Metal Waveguide-Coupled T-Shape Cavity with Metal Nanorod Defects
摘要： An ultra-high plasmonic refractive index sensing structure composed of a metal–insulator–metal (MIM) waveguide coupled to a T-shape cavity and several metal nanorod defects is proposed and investigated by using finite element method. The designed plasmonic MIM waveguide can constitute a cavity resonance zone and the metal nanorod defects can effectively trap the light in the T-shape cavity. The results reveal that both the size of defects in wider rectangular cavity and the length of narrower rectangular cavity are primary factors increasing the sensitivity performance. The sensitivity can achieve as high as 8280 nm/RIU (RIU denotes the refractive index unit), which is the highest sensitivity reported in plasmonic MIM waveguide-based sensors to our knowledge. In addition, the proposed structure can also serve as a temperature sensor with temperature sensitivity as high as 3.30 nm/°C. The designed structure with simplicity and ease of fabrication can be applied in sensitivity nanometer scale refractive index sensor and may potentially be used in optical on-chip nanosensor.
关键词： T-shape cavity,nanorod defects,temperature sensor,finite element method,refractive index sensor,metal–insulator–metal,plasmonics,sensitivity
更新于2025-09-19 17:13:59
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Estimation of temperature-dependent yield strength and modulus of elasticity during laser bending
摘要： In this work, an inverse method is developed to estimate the temperature-dependent value of yield strength (Y) and modulus of elasticity (E) of the material during a laser bending process. The method requires measurement of bend angle of the laser scanned workpiece. The inverse model uses the bend angle computed by a direct model. The temperature-dependent Y and E are inversely estimated by minimizing the difference between actual and direct model predicted bend angles. The validation of the proposed method is demonstrated with the help of two examples. For this purpose, inversely estimated values of E and Y are used to predict bend angles for various processing conditions and predicted values are compared with actual values. In examples, actual data has been obtained from a detailed FEM simulation in lieu of shop floor experiments. Later on, the proposed method is also validated by performing shop floor experiments for AH36 steel.
关键词： Inverse technique,Finite element method,Yield strength,Laser bending,Modulus of elasticity
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - PV Degradation a?? Mounting & Temperature
摘要： In this paper, a solution to the double curl equation with generalized Coulomb gauge is proposed based on the vectorial representation of the magnetic vector potential. Traditional Coulomb gauge is applied to remove the null space of the curl operator and hence the uniqueness of the solution is guaranteed. However, as the divergence operator cannot act on edge elements (curl-conforming) directly, the magnetic vector potential is represented by nodal elements, which is too restrictive, since both the tangential continuity and the normal continuity are required. Inspired by the mapping of Whitney forms by mathematical operators and Hodge (star) operators, the divergence of the magnetic vector potential, as a whole, can be approximated by Whitney elements. Hence, the magnetic vector potential can be expanded by the edge elements, where its vectorial nature is retained and only the tangential continuity is required. Finally, the original equation can be rewritten in a generalized form and solved in a more natural and accurate way using finite-element method.
关键词： Whitney forms,generalized Coulomb gauge,Finite-element method (FEM),magnetostatic
更新于2025-09-19 17:13:59
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[IEEE 2019 21st International Middle East Power Systems Conference (MEPCON) - Cairo, Egypt (2019.12.17-2019.12.19)] 2019 21st International Middle East Power Systems Conference (MEPCON) - Optimal Allocation of Reactive Power Compensation in a Distribution Network with Photovoltaic System Integration
摘要： Since several years, the number of total hip arthroplasty revision surgeries is substantially growing. One of the main reasons for this procedure to become necessary is the loosening or damage of the prothesis, which is facilitated by bone necrosis at the implant–bone interface. Electrostimulation is one promising technique, which can accelerate the growth of bone cells and, therefore, enhance the anchorage of the implant to the bone. We present computational models of an electrostimulative total hip revision system to enhance bone regeneration. In this study, the influence of uncertainty in the conductivity of bone tissue on the electric field strength and the beneficial stimulation volume for an optimized electrode geometry and arrangement is investigated. The generalized polynomial chaos technique is used to quantify the uncertainty in the stimulation volumes with respect to the uncertain conductivity of cancellous bone, bone marrow, and bone substitute, which is used to fill defective areas. The results suggest that the overall beneficial stimulation areas are only slightly sensitive to the uncertainty in conductivity of bone tissue. However, in the proximity of tissue boundaries, larger uncertainties, especially in the transition between beneficial and understimulation areas, can be expected.
关键词： Electrical stimulation,finite-element method,multiobjective optimization,uncertainty quantification,total hip arthroplasty (THA) revision
更新于2025-09-19 17:13:59