Results 81 to 90 of about 3,669,023 (333)

Generalized Kirchhoff approximation for Helmholtz equation [PDF]

, 2014
We give integral formulas to approximate solutions of Dirichlet and Neumann problems for Helmholtz equation at high frequencies. These approximations are valid in the complementary of a union of convex compact obstacles.
Cuvelier, François
core   +1 more source

Exact nonparaxial beams of the scalar Helmholtz equation [PDF]

, 2003
It is shown that three-dimensional nonparaxial beams are described by the oblate spheroidal exact solutions of the Helmholtz equation. For the first time, their beam behaviour is investigated and their corresponding parameters are defined. Using the fact
Cao, Chavez-Cerda, Ciattoni, Deschamps, Gustavo Rodríguez-Morales, Kraus, Landesman, Lax, Lekner, Saari, Sabino Chávez-Cerda, Seshadri, Sheppard, Shin, Ulanowski   +14 more
core   +1 more source

Air‐Pressure–Actuated Vibroacoustic Metamaterial With Tunable Bandgap: Design, Modeling, and Characterization

Advanced Engineering Materials, EarlyView.
This article presents the design, modeling, and characterization of air‐pressure–actuated programmable vibroacoustic metamaterials (PVAMM). The study focuses on leveraging air pressure to dynamically tune resonance frequencies for effective noise attenuation.
William Kaal, Michael M. Becker, Sarah C. L. Fischer   +2 more
wiley   +1 more source

Numerical solution to the Complex 2D Helmholtz Equation based on Finite Volume Method with Impedance Boundary Conditions

Open Physics, 2016
In this paper, the numerical solution to the Helmholtz equation with impedance boundary condition, based on the Finite volume method, is discussed. We used the Robin boundary condition using exterior points.
Handlovičová Angela, Riečanová Izabela   +1 more
doaj   +1 more source

Empirical estimation of the eigenmodes of macroscale cortical dynamics: Reconciling neural field eigenmodes and resting-state networks

NeuroImage: Reports, 2022
Neural field theories successfully describe normal, awake mesoscale to macroscale brain activity using linearized partial differential equations that involve a Laplacian operator.
James A. Henderson, Kevin M. Aquino, P.A. Robinson   +2 more
doaj   +1 more source

Tailoring Functional Properties of Ti–Ni–Cu Shape Memory Alloy Thin Films for MEMS Actuators

Advanced Engineering Materials, EarlyView.
A comprehensive study of critical parameters required to develop well‐performing Ti–Ni–Cu thin film shape memory alloy microactuators is provided. Materials science and device integration aspects are integrated by addressing structural and physical relationships using complementary characterization techniques as well as a practical fabrication solution
Elaheh Akbarnejad, Aleksander Kostka, Gowtham Arivanandhan, Yujiao Li, Alan Savan, Manfred Kohl, Alfred Ludwig   +6 more
wiley   +1 more source

Limiting absorption principle for the dissipative Helmholtz equation [PDF]

, 2009
Adapting Mourre's commutator method to the dissipative setting, we prove a limiting absorption principle for a class of abstract dissipative operators.
Amrein W., Benamou J.-D., Benamou J.-D., Cycon H.L., Engel K.J., Gérard C., Hörmander L., Jensen A., Jensen A., Jensen A., Julien Royer, Martinez A., Nagy S., Reed M., Reed M., Robert D., Robert D., Wang X.P., Wang X.P., Wang X.P., Wang X.P.   +20 more
core   +6 more sources

A Topology Optimization Framework for the Inverse Design of Nonlinear Mechanical Metamaterials

Advanced Engineering Materials, EarlyView.
This work uses topology optimization to design unit cells for mechanical metamaterials with a prescribed nonlinear stress–strain response. The framework adds contact and postbuckling modeling to synthesize microstructures for three highly nonlinear responses, including pseudoductile behavior, monostable with snap‐through buckling, and bistable ...
Charlie Aveline, Matthew Santer, Robert Hewson   +2 more
wiley   +1 more source

Resonance in Bottles with Different Shapes

International Scholastic Journal of Science, 2012
The Helmholtz Resonance equation derived in the 1800’s describes the nature of resonance in narrow-necked vessels, known as Helmholtz Resonators.
Amy Elliott
doaj  

Stable determination of polyhedral interfaces from boundary data for the Helmholtz equation [PDF]

, 2014
We study an inverse boundary value problem for the Helmholtz equation using the Dirichlet-to-Neumann map as the data. We consider piecewise constant wavespeeds on an unknown tetrahedral partition and prove a Lipschitz stability estimate in terms of the ...
Beretta, Elena, de Hoop, Maarten V., Francini, Elisa, Vessella, Sergio   +3 more
core   +2 more sources