- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Kiev (2018.4.24-2018.4.26)] 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Harmonic Balance Method and Effective Magnetization Curves in Finite Element Analysis of Eddy-Current Losses
摘要： A nonlinear model of the magnetic field in a conductive ferromagnetic medium is presented. The model based on the simultaneous use of the harmonic balance method and the finite element method. The case of a magnetic field excitation by an alternating current source is considered. The values of eddy current losses are compared, determined using the presented method as well as by applying the monoharmonic approach using the normal magnetization curve and the curves obtained from it, by means of two energy methods.
关键词： finite element method,ferromagnetic,conductive medium,eddy current losses,harmonic balance method
更新于2025-09-10 09:29:36
-
[Institution of Engineering and Technology 2015 IET International Conference on Biomedical Image and Signal Processing (ICBISP 2015) - Beijing, China (19 Nov. 2015)] 2015 IET International Conference on Biomedical Image and Signal Processing (ICBISP 2015) - Iterative reconstruction for bioluminescence tomography based on an adaptive region shrinking strategy
摘要： The main challenge of bioluminescence tomography (BLT) is the ill-posed, non-unique nature of the inverse problem. To get reliable reconstruction, permissible source region is a commonly used a priori knowledge in the inverse procedure. In this paper, to accurately reveal 3D distribution of bioluminescent sources from limited boundary measurement, we propose an iterative reconstruction method incorporating adaptive algebraic reconstruction technique (AART) and adaptively shrinking permissible source region. AART algorithm is applied to get the solution without permissible region. Base on the distribution of the solution, we calculate the expectation and the covariance matrix and then derive the parameters for determining a cuboid-shaped region. Simulation experiments on a 3D digital mouse and an in vivo experiment are conducted to validate the feasibility and evaluate the performance of the proposed reconstruction method. The reconstructed results demonstrate the shrinking strategy is helpful for improving the stability of inverse algorithm.
关键词： iterative reconstruction method,finite element method,inverse problems,bioluminescence tomography
更新于2025-09-10 09:29:36
-
Tri-core photonic crystal fiber based refractive index dual sensor for salinity and temperature detection
摘要： This article discusses the tri-core photonic crystal microstructure fiber for the process of simultaneous sensing for salinity and temperature of water substances. This kind of microstructure is preferred in many sensing application to scale the detection process in micrometer range. In this novel sensor, the sensitivity is calculated through coupling mechanism by tracking wavelength shift of various concentrations of salinity and temperature using finite element method. The sensible samples are in liquid and are infiltrated into the framed hollow cavity. Based on the coupling principle between silica substrate and the analyte material, the sense of the salt as well as temperature is obtained. Finally, it is noted that sensitivity of the salt level in water as 5404.9 nm/RIU for x polarization direction and 5674 nm/RIU for y polarization direction have been calculated with the temperature sensitivity of 4 nm/(cid:1)C in the same water substances.
关键词： photonic crystal fiber,finite element method,sensitivity and coupling mechanism
更新于2025-09-10 09:29:36
-
The Elastic Property of Bulk Silicon Nanomaterials through an Atomic Simulation Method
摘要： This paper reports a systematic study on the elastic property of bulk silicon nanomaterials using the atomic finite element method. The Tersoff-Brenner potential is used to describe the interaction between silicon atoms, and the atomic finite element method is constructed in a computational scheme similar to the continuum finite element method. Young’s modulus and Poisson ratio are calculated for [100], [110], and [111] silicon nanowires that are treated as three-dimensional structures. It is found that the nanowire possesses the lowest Young’s modulus along the [100] direction, while the [110] nanowire has the highest value with the same radius. The bending deformation of [100] silicon nanowire is also modeled, and the bending stiffness is calculated.
关键词： atomic finite element method,silicon nanowires,Poisson ratio,elastic property,bending stiffness,Young’s modulus
更新于2025-09-10 09:29:36
-
Designing Anisotropic, Inhomogeneous Metamaterial Devices Through Optimization
摘要： A method for designing multi-input, multi-output metamaterial devices is presented. The devices are 2D anisotropic, inhomogeneous media. The design technique consists of a custom FEM solver coupled to a constrained, nonlinear minimization algorithm. The design method has advantages over existing metamaterial design methods such as transformation optics, in that material constraints can be imposed and multi-input, multi-output functionality allowed. Transformation optics devices only achieve multi-input, multi-output functionality through geometrical symmetry. The gradient-based optimization method employed in the metamaterial design process is fast given that an analytic expression for the gradient of the cost function can be written. The proposed technique is demonstrated through the design of two beamforming devices. A commercial full-wave solver is used to validate the design approach. The constitutive parameters of these 2D designs can be implemented using printed-circuit board metamaterials, such as tensor transmission-line metamaterials.
关键词： transformation electromagnetics,optimization,metamaterials,Beamformer,finite-element method
更新于2025-09-10 09:29:36
-
Finite Element Modellingand Simulations of Piezoelectric Actuators Responses with Uncertainty Quantification
摘要： Piezoelectric structures are widely used in engineering designs including sensors, actuators, and energy-harvesting devices. In this paper, we present the development of a three-dimensional finite element model for simulations of piezoelectric actuators and quantification of their responses under uncertain parameter inputs. The implementation of the finite element model is based on standard nodal approach extended for piezoelectric materials using three-dimensional tetrahedral and hexahedral elements. To account for electrical-mechanical coupling in piezoelectric materials, an additional degree of freedom for electrical potential is added to each node in those elements together with their usual mechanical displacement unknowns. The development was validated with analytical and experimental data for a range of problems from a single-layer piezoelectric beam to multiple layer beams in unimorph and bimorph arrangement. A more detailed analysis is conducted for a unimorph composite plate actuator with different design parameters. Uncertainty quantification was also performed to evaluate the sensitivity of the responses of the piezoelectric composite plate with an uncertain input of material properties. This sheds light on understanding the variations in reported responses of the device; at the same time, providing extra confidence to the numerical model.
关键词： finite element method,uncertainty quantification,piezoelectric materials,unimorph actuator,energy harvesting,PZT
更新于2025-09-10 09:29:36
-
D-shaped PCF sensor based on SPR for the detection of carcinogenic agents in food and cosmetics
摘要： D-Shaped PCF sensor working on the principle of Surface Plasmon Resonance is scrutinized in our work by Finite element method. Indium titanium oxide (ITO) is coated over the flat surface of the sensor and over it the analyte is placed which enhances the excitation of Plasmon in the intermediate surface which is the major part in sensing. In our work we have achieved the maximal spectral sensitivity of 50000 nm/RIU accompanied by high resolution 4x10-4 RIU, and also maximum amplitude sensitivity of 1266.67 RIU?1. We have numerically investigated the SPR sensing performance by considering the diameter of the core which can be optimized by varying the air-hole diameter and also the proposed model enables the feasibility of D-shaped PCF structure with very high sensitivity near IR region. Among the proposed SPR sensors, our sensor achieved the highest sensitivity range and it can be used for various chemical and bio-sensing applications.
关键词： D shaped PCF,Amplitude Sensitivity,Surface Plasmon Resonance,Finite element method,Bio Sensor
更新于2025-09-10 09:29:36
-
Enhanced sensitivity of hemoglobin sensor using dual-core photonic crystal fiber
摘要： A Hemoglobin (Hb) biosensor based on dual-core photonic crystal fiber is proposed and analyzed. In this paper, the effective refractive index dependency on the Hb concentration within a blood sample is utilized in obtaining the transmission spectrum variation. The results are calculated using full vectorial finite element method. Through this study, the effect of the structure geometrical parameters on the sensor performance is optimized to maximize the sensor sensitivity. The numerical results show a sensitivity of 8.013 nm/g/dL for the X-polarized mode at 3.7 cm fiber length and 7.68 nm/g/dL for the Y-polarized mode at 3.2 cm fiber length of the proposed sensor.
关键词： Coupling length,Finite element method,Transmission spectrum,Dual-core photonic crystal fiber,Hemoglobin concentration
更新于2025-09-10 09:29:36
-
Band Gap Optimization Design of Photonic Crystals Material
摘要： The photonic crystal has a fundamental characteristic - photonic band gap, which can prevent light to spread in the crystals. This paper studies the width variation of band gaps of two-dimension square lattice photonic crystals by changing the geometrical shape of the unit cells' inner medium column. Using the finite element method, we conduct numerical experiments on MATLAB 2012a and COMSOL 3.5. By shortening the radius in vertical axis and rotating the medium column, we design a new unit cell, with a 0.3*3.85e-7 vertical radius and a 15 degree deviation to the horizontal axis. The new cell has a gap 1.51 percent wider than the circle medium structure in TE gap and creates a 0.0124 wide TM gap. Besides, the experiment shows the first TM gap is partially overlapped by the second TE gap in gap pictures. This is helpful to format the absolute photonic band gaps and provides favorable theoretical basis for designing photonic communication material.
关键词： band gap,photonic crystals,finite element method,MATLAB,COMSOL
更新于2025-09-10 09:29:36
-
[IEEE 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Kiev (2018.4.24-2018.4.26)] 2018 IEEE 38th International Conference on Electronics and Nanotechnology (ELNANO) - Efficient Geometry of Surface Plasmon Resonance Based Fiber Optic Sensor
摘要： The efficient structure for optical fiber based surface Plasmon resonance sensor has been investigated. The sensor structure is based on removing the cladding of a multimode optical fiber and replacing it with thin film of gold. The incident light inside the fiber will excite surface plasmons which will be resulted in the absorption in specific wavelengths. The absorption behavior is dependent on the dielectric constants at the vicinity of the metallic thin film. Based on the amount of removed cladding and deposition regions on the core structure of the fiber, different configurations can be considered. Based on the computational analysis, we have studied performance of sensor for three different configurations. Our method of study is based on solving wave equation in different sensor geometry and calculating absorption for different available modes using Finite Element Method in COMSOL environment. The results of our study show that, the optimum configuration of sensor considering wavelength sensitivity is for a fiber which half of core and cladding has been removed and the gold thin film is deposited on its surface.
关键词： Refractive Index Sensor,Surface Plasmon Resonance,SPR Fiber,Fiber Based Sensor,Finite Element Method,COMSOL
更新于2025-09-10 09:29:36