Article
Acoustics
Peter Risby Andersen, Gyeong-Tae Lee, Daniel Gert Nielsen, Junghwan Kook, Vicente Cutanda Henriquez, Niels Aage, Yong-Hwa Park
Summary: This work focuses on the shape optimization and experimental validation of an acoustic lens for compact loudspeakers, such as those used in speakerphones. The optimization uses a combined lumped parameter and boundary element method model with a free form deformation geometry parameterization. The optimized design is 3D printed and characterized experimentally to verify its frequency response. The results show good agreement between measurements and simulations, although some shortcomings of the model assumptions are revealed.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Computer Science, Interdisciplinary Applications
Ahmad H. Bokhari, Abbas Mousavi, Bin Niu, Eddie Wadbro
Summary: The study investigates the design of a passive acoustic device using topology optimization to achieve one-way flow of sound waves. By maximizing wave propagation in one direction and minimizing it in the reverse, the optimized waveguide transmits over 99.8% of power from left to right and less than 0.3% in the opposite direction for planar incoming waves in a specific frequency range.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2021)
Article
Acoustics
Zhaoxi Li, Rong Guo, Dongdong Chen, Chunlong Fei, Xiao Yang, Di Li, Chenxi Zheng, Jun Chen, Runcong Wu, Wei Feng, Zhuo Xu, Yintang Yang
Summary: An efficient optimization design method of acoustic liquid lens (ALL) using the particle swarm optimization (PSO) algorithm was developed to effectively control acoustic pattern. By optimizing the design parameters of ALL, the desired performance parameters of acoustic pattern were achieved as verified by simulation and experiments.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2021)
Article
Automation & Control Systems
Frederic Magoules, Thi Phuong Kieu Nguyen, Pascal Omnes, Anna Rozanova-Pierrat
Summary: The study focuses on finding the optimal shape of a noise absorbing wall to dissipate the acoustical energy of a sound wave. The well-posedness of the frequency model with specific boundaries is proven and an admissible class of Lipschitz boundaries is introduced to minimize the acoustic energy by incorporating Radon measures.
SIAM JOURNAL ON CONTROL AND OPTIMIZATION
(2021)
Article
Chemistry, Multidisciplinary
Lingling Wu, Zirui Zhai, Xinguang Zhao, Xiaoyong Tian, Dichen Li, Qianxuan Wang, Hanqing Jiang
Summary: This study introduces a modular design method to create acoustic metamaterials based on nested Helmholtz resonators for low-frequency sound attenuation, utilizing finite element methods and genetic algorithms. The optimized acoustic metamaterials demonstrate noise attenuation properties in both simulated and experimental results, showing potential for practical sound attenuation applications in industries by considering different environments and constraints.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Engineering, Marine
Mikhail Lytaev
Summary: This paper aims to improve the computational efficiency of numerical methods for the one-way Helmholtz Equation in a heterogeneous underwater environment. The finite-difference rational Pade approximation of the propagation operator is used, with artificial computational parameters being the grid cell sizes and reference sound speed. An optimized method for automatically determining the artificial computational parameters is proposed, taking into account any propagation angle and arbitrary variations in refractive index. Numerical simulation results confirm the adequacy and efficiency of the proposed approach. Automating the selection process of the computational parameters eliminates human errors and prevents excessive consumption of computational resources.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Mathematics, Applied
Varun Hiremath, Jose E. Roman
Summary: Closed combustion devices like gas turbines and rockets are prone to thermoacoustic instabilities. Design engineers in the industry need tools to accurately identify and remove instabilities early in the design cycle. In this work, the authors focus on the Helmholtz wave equation based solver, which is found to be relatively fast and accurate, and propose the use of specialized algorithms implemented in SLEPc for efficient computation of eigenvalues of nonlinear eigenvalue problems in the acoustic modes analysis.
APPLIED MATHEMATICS AND COMPUTATION
(2023)
Article
Engineering, Electrical & Electronic
Zhezheng Zhu, Wangnan Chen, Lingmeng Yang, Chengchen Gao, Yilong Hao, Zhenchuan Yang
Summary: This paper presents a two-dimensional acoustic horn packaged with a two-dimensional acoustic particle velocity sensor (APVS). The particle velocity amplification factor of the horn is analyzed theoretically and experimentally, and the experimental results show good agreement with the theoretical expectations. The model takes into account the gain attenuation at low frequency and the influence of chip assembly deviation, which greatly affects the package gain due to the large changes in particle velocity distribution in the boundary layer.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Physics, Multidisciplinary
Hongjun Liu, Ying Zheng, Yu Lu, Qianlong Kang, Kai Guo, Zhongyi Guo
Summary: The study presents highly efficient transmitted acoustic focusing lenses based on the Helmholtz resonator (HR) metasurface, demonstrating superior focusing performances and broad bandwidth. Investigating the effects of different parameters, off-axis focusing and spherical wave focusing lenses are demonstrated, as well as a wideband acoustic lens is designed and achieved.
ANNALEN DER PHYSIK
(2021)
Article
Astronomy & Astrophysics
J. Rolla, A. Machtay, A. Patton, W. Banzhaf, A. Connolly, R. Debolt, L. Deer, E. Fahimi, E. Ferstle, P. Kuzma, C. Pfendner, B. Sipe, K. Staats, S. A. Wissel
Summary: The Genetically Evolved NEutrino Telescopes for Improved Sensitivity project aims to optimize detectors in physics using genetic algorithm for improved sensitivity. The initial results show that the evolved antenna design improves the sensitivity of in-ice neutrino detectors by 11% compared to the baseline experiment. Future work will focus on increasing the computational efficiency of the genetic algorithm and enhancing the complexity and fitness of the antenna designs.
Article
Physics, Applied
Chengfu Gu, Zengtao Yang, Hua Wang
Summary: This paper proposes an acoustic lens design method based on a simulated annealing particle swarm algorithm to overcome the shortcomings of traditional forward and inverse iterative algorithms when dealing with sharp plane with abrupt changes in sound field distribution. The feasibility and effectiveness of this method are verified through designing a lens with a flat-top sound pressure distribution, providing a more widely applicable approach in acoustic lens design.
APPLIED PHYSICS LETTERS
(2021)
Article
Mathematics
Antonios Charalambopoulos, Leonidas Gergidis, Eleftheria Vassilopoulou
Summary: In this study, a novel stochastic method is developed to address the time-reduced inverse scattering problem governed by the Helmholtz equation. Stochastic representations of the scattering field are constructed based on stochastic analysis, providing an alternative approach to solve the direct and inverse scattering problem locally. Two different schemes are proposed for the reconstruction from far field and near field data, respectively.
Article
Engineering, Multidisciplinary
Raquel Mattoso, Antonio A. Novotny
Summary: This work focuses on pointwise antennas design in hyperthermia treatment to selectively heat a specified target using optimal current densities. The methodology involves solving the steady-state heat equation and Helmholtz problem, minimizing an objective functional, and using sensitivities to devise antenna design algorithms. Numerical experiments demonstrate the capability of the proposed methodology to selectively heat the target up to the desired temperature.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Acoustics
Qiang Gui, You Zhou, Wei Li, Yingbin Chai
Summary: In this study, a three-node linear triangular element with linear interpolation cover functions was used to solve two-dimensional acoustic radiation problems, which effectively alleviated pollution errors and increased convergence rate by enriching the original approximation space with cover functions. Additionally, the Dirichlet-to-Neumann mapping technique was applied to truncate infinite problem domains and satisfy Sommerfeld radiation conditions at infinity, demonstrating the effectiveness of the numerical tool for acoustic radiation problems.
Article
Acoustics
Mehran Afshari, Behrooz Arezoo
Summary: This article discusses the characteristics of a well-designed horn, proposing an optimal design procedure for wide blade horns using Genetic Algorithm and constraint handling method. The results show a high amplitude uniformity, slightly higher longitudinal natural frequency, acceptable frequency separation and gain ratio, and a safe maximum stress level. Simulation and experimental results are in good agreement.
Article
Thermodynamics
Clio Saglietti, Philipp Schlatter, Eddie Wadbro, Martin Berggren, Dan S. Henningson
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2018)
Article
Forestry
Ahmad Hosseini, Ola Lindroos, Eddie Wadbro
CANADIAN JOURNAL OF FOREST RESEARCH
(2019)
Article
Computer Science, Interdisciplinary Applications
Bin Niu, Eddie Wadbro
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2019)
Article
Computer Science, Interdisciplinary Applications
Eddie Wadbro, Daniel Noreland
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2019)
Article
Engineering, Multidisciplinary
Quoc Khanh Nguyen, Stefano Serra-Capizzano, Eddie Wadbro
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2020)
Article
Engineering, Multidisciplinary
Eddie Wadbro, Bin Niu
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2019)
Article
Engineering, Electrical & Electronic
Emadeldeen Hassan, Benedict Scheiner, Fabian Michler, Martin Berggren, Eddie Wadbro, Franz Roehrl, Stefan Zorn, Robert Weigel, Fabian Lurz
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2020)
Article
Engineering, Multidisciplinary
Juan C. Araujo, Eddie Wadbro
Summary: In this project, shape optimization of a dielectric scatterer for efficient directional routing of light is considered. A numerical optimization strategy combined with sensitivity analysis is used to design shapes with high scattering efficiencies.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2021)
Article
Mathematics
Martin Berggren, Linus Hagg
Summary: Finite element methods and Hilbert-space theory for partial differential equations rely on variational formulations, but there is a sharp disparity between established well-posedness theories for systems of Friedrichs type and the successful discontinuous Galerkin methods developed for such systems. In an attempt to address this dichotomy, we present well-posed variational formulations for boundary and initial-boundary-value problems of Friedrichs type through specific examples of increasing complexity. These variational forms are generalizations of those used for discontinuous Galerkin methods, incorporating inhomogeneous boundary and initial conditions weakly through integrals.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2021)
Article
Mathematics, Applied
Quoc Khanh Nguyen, Stefano Serra-Capizzano, Cristina Tablino-Possio, Eddie Wadbro
Summary: This article presents a method for optimizing topology by improving the efficiency of solving linear systems through spectral analysis and multigrid methods, leading to excellent numerical results.
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS
(2022)
Article
Computer Science, Artificial Intelligence
Ahmad Hosseini, Eddie Wadbro
Summary: Efficient management is built on transport networks, but uncertainty in the operating environment complicates the establishment of an optimum transport network design. This study addresses an uncertain TND problem using uncertain programming and GRASP to develop an optimization framework and propose a solution technique.
EXPERT SYSTEMS WITH APPLICATIONS
(2022)
Article
Engineering, Multidisciplinary
Harrison Nobis, Philipp Schlatter, Eddie Wadbro, Martin Berggren, Dan S. Henningson
Summary: This study applies topology optimization to laminar-turbulent transition for the first time and finds that a spatially inhomogeneous SuperHydrophobic Surface (SHS) can significantly delay transition by inhibiting the growth of secondary instability modes. Designs have been discovered with comparable mean transition time and lower variance by optimizing over an ensemble of streamwise phase-shifted perturbations.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Mathematics, Interdisciplinary Applications
Quoc Khanh Nguyen, Stefano Serra-Capizzano, Cristina Tablino-Possio, Eddie Wadbro
Summary: The paper discusses material distribution methods for topology optimization by casting the governing equation as an extended domain problem. It utilizes the finite element method to approximate the equations, and presents a spectral analysis of the coefficient matrices for an optimal multigrid method in three spatial dimensions. Selected numerical examples are provided to illustrate the theoretical findings in connection with the linearly elastic problem.
MATHEMATICAL AND COMPUTATIONAL APPLICATIONS
(2022)
Article
Computer Science, Information Systems
Noor Badariah Asan, Emadeldeen Hassan, Mauricio David Perez, Laya Joseph, Martin Berggren, Thiemo Voigt, Robin Augustine
Summary: This study conducted numerical modeling and experimental validation of signal path loss at 5.8 GHz using fat-intrabody communication technology. By investigating various configurations of fat tissue thickness, antenna polarizations, and locations, the communication performance was comprehensively characterized. Additionally, the study discussed the impact of different tissue models on communication in real-world scenarios.
Article
Mathematics, Applied
M. S. Bruzon, T. M. Garrido, R. de la Rosa
Summary: We study a family of generalized Zakharov-Kuznetsov modified equal width equations in (2+1)-dimensions involving an arbitrary function and three parameters. By using the Lie group theory, we classify the Lie point symmetries of these equations and obtain exact solutions. We also show that this family of equations admits local low-order multipliers and derive all local low-order conservation laws through the multiplier approach.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Dohee Jung, Changbum Chun
Summary: The paper presents a general approach to enhance the Pade iterations for computing the matrix sign function by selecting an arbitrary three-point family of methods based on weight functions. The approach leads to a multi-parameter family of iterations and allows for the discovery of new methods. Convergence and stability analysis as well as numerical experiments confirm the improved performance of the new methods.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Abhishek Yadav, Amit Setia, M. Thamban Nair
Summary: In this paper, we propose a Galerkin's residual-based numerical scheme for solving a system of Cauchy-type singular integral equations using Chebyshev polynomials. We prove the well-posedness of the system and derive a theoretical error bound and convergence order. The numerical examples validate the theoretical results.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Fernando Chacon-Gomez, M. Eugenia Cornejo, Jesus Medina, Eloisa Ramirez-Poussa
Summary: The use of decision rules allows for reliable extraction of information and inference of conclusions from relational databases, but the concepts of decision algorithms need to be extended in fuzzy environments.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Ilhame Amirali, Gabil M. Amiraliyev
Summary: This paper considers the one-dimensional initial-boundary problem for a pseudoparabolic equation with a time delay. To solve this problem numerically, a higher-order difference method is constructed and the error estimate for its solution is obtained. Based on the method of energy estimates, the fully discrete scheme is shown to be convergent of order four in space and of order two in time. The given numerical results illustrate the convergence and effectiveness of the numerical method.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Tong-tong Shang, Guo-ji Tang, Wen-sheng Jia
Summary: The goal of this paper is to investigate a class of linear complementarity problems over tensor-spaces, denoted by TLCP, which is an extension of the classical linear complementarity problem. First, two classes of structured tensors over tensor-spaces (i.e., T-R tensor and T-RO tensor) are introduced and some equivalent characterizations are discussed. Then, the lower bound and upper bound of the solutions in the sense of the infinity norm of the TLCP are obtained when the problem has a solution.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Fabio Difonzo, Pawel Przybylowicz, Yue Wu
Summary: This paper focuses on the existence, uniqueness, and approximation of solutions of delay differential equations (DDEs) with Caratheodory type right-hand side functions. It presents the construction of the randomized Euler scheme for DDEs and investigates its error. Furthermore, the paper reports the results of numerical experiments.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Priyanka Roy, Geetanjali Panda, Dong Qiu
Summary: In this article, a gradient based descent line search scheme is proposed for solving interval optimization problems under generalized Hukuhara differentiability. The innovation and importance of these concepts are presented from practical and computational perspectives. The necessary condition for existence of critical point is presented in inclusion form of interval-valued gradient. Suitable efficient descent direction is chosen based on the monotonic property of the interval-valued function and specific interval ordering. Mathematical convergence of the scheme is proved under the assumption of Inexact line search. The theoretical developments are implemented with a set of interval test problems in different dimensions. A possible application in finance is provided and solved by the proposed scheme.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Zhongqian Wang, Changqing Ye, Eric T. Chung
Summary: In this paper, the constrained energy minimizing generalized multiscale finite element method (CEM-GMsFEM) with mixed boundary conditions for elasticity equations in high contrast media is developed. The method offers advantages such as independence of target region's contrast from precision and significant impact of oversampling domain sizes on numerical accuracy. Furthermore, this is the first proof of convergence of CEM-GMsFEM with mixed boundary conditions for elasticity equations. Numerical experiments demonstrate the method's performance.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Samaneh Soradi-Zeid, Maryam Alipour
Summary: The Laguerre polynomials are a new set of basic functions used to solve a specific class of optimal control problems specified by integro-differential equations, namely IOCP. The corresponding operational matrices of derivatives are calculated to extend the solution of the problem in terms of Laguerre polynomials. By considering the basis functions and using the collocation method, the IOCP is simplified into solving a system of nonlinear algebraic equations. The proposed method has been proven to have an error bound and convergence analysis for the approximate optimal value of the performance index. Finally, examples are provided to demonstrate the validity and applicability of this technique.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Almudena P. Marquez, Maria L. Gandarias, Stephen C. Anco
Summary: A generalization of the KP equation involving higher-order dispersion is studied. The Lie point symmetries and conservation laws of the equation are obtained using Noether's theorem and the introduction of a potential. Sech-type line wave solutions are found and their features, including dark solitary waves on varying backgrounds, are discussed.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Susanne Saminger-Platz, Anna Kolesarova, Adam Seliga, Radko Mesiar, Erich Peter Klement
Summary: In this article, we study real functions defined on the unit square satisfying basic properties and explore the conditions for generating bivariate copulas using parameterized transformations and other constructions.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Lulu Tian, Nattaporn Chuenjarern, Hui Guo, Yang Yang
Summary: In this paper, a new local discontinuous Galerkin (LDG) algorithm is proposed to solve the incompressible Euler equation in two dimensions on overlapping meshes. The algorithm solves the vorticity, velocity field, and potential function on different meshes. The method employs overlapping meshes to ensure continuity of velocity along the interfaces of the primitive meshes, allowing for the application of upwind fluxes. The article introduces two sufficient conditions to maintain the maximum principle of vorticity.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Cheng Wang, Jilu Wang, Steven M. Wise, Zeyu Xia, Liwei Xu
Summary: In this paper, a temporally second-order accurate numerical scheme for the Cahn-Hilliard-Magnetohydrodynamics system of equations is proposed and analyzed. The scheme utilizes a modified Crank-Nicolson-type approximation for time discretization and a mixed finite element method for spatial discretization. The modified Crank-Nicolson approximation allows for mass conservation and energy stability analysis. Error estimates are derived for the phase field, velocity, and magnetic fields, and numerical examples are presented to validate the proposed scheme's theoretical results.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
Article
Mathematics, Applied
Mingyu He, Wenyuan Liao
Summary: This paper presents a numerical method for solving reaction-diffusion equations in spatially heterogeneous domains, which are commonly used to model biological applications. The method utilizes a fourth-order compact alternative directional implicit scheme based on Pade approximation-based operator splitting techniques. Stability analysis shows that the method is unconditionally stable, and numerical examples demonstrate its high efficiency and high order accuracy in both space and time.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2024)
