Bojan B. Guzina
University of Minnesota
Asymptotic expansionPhysicsTopologyGeologyEngineeringMathematical analysisInverse problemInverse scattering problemBoundary value problemGeotechnical engineeringMaterials scienceModulusSensitivity (control systems)AcousticsGeometryTopological derivativeAcoustic radiation forceMathematicsHomogenization (chemistry)Structural engineering
127Publications
22H-index
1,668Citations
Publications 118
Newest
#1Bojan B. Guzina (UMN: University of Minnesota)H-Index: 22
#2Marc Bonnet (IRIA: French Institute for Research in Computer Science and Automation)H-Index: 21
Abstract We consider the effective wave motion, at spectral singularities such as corners of the Brillouin zone and Dirac points, in periodic continua intercepted by compliant interfaces that pertain to e.g. masonry and fractured materials. We assume the Bloch-wave form of the scalar wave equation (describing anti-plane shear waves) as a point of departure, and we seek an asymptotic expansion about a reference point in the wavenumber-frequency space – deploying wavenumber separation as the pertu...
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#1Othman Oudghiri-Idrissi (UMN: University of Minnesota)H-Index: 2
#2Bojan B. Guzina (UMN: University of Minnesota)H-Index: 22
Last. Shixu Meng (CAS: Chinese Academy of Sciences)H-Index: 8
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We consider homogenization of the scalar wave equation in periodic media at finite wavenumbers and frequencies, with the focus on continua characterized by: (a) arbitrary Bravais lattice in \mathbb{R}^d d\!\geqslant\!2 and (b) exclusions i.e. "voids" that are subject to homogenous (Neumann or Dirichlet) boundary conditions. Making use of the Bloch wave expansion, we pursue this goal via asymptotic ansatz featuring the "spectral distance" from a given wavenumber-eigenfrequency pair (within ...
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#1Alan A. S. Amad (Swansea University)H-Index: 3
Last. Bojan B. Guzina (UMN: University of Minnesota)H-Index: 22
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Abstract In this work, we propose a full-waveform technique for the spatial reconstruction and characterization of (micro-) seismic events via joint source location and moment tensor inversion. The approach is formulated in the frequency domain, and it allows for the simultaneous inversion of multiple point-like events. In the core of the proposed methodology is a grid search for the source locations that encapsulates the optimality condition on the respective moment tensors. The developments ca...
1 CitationsSource
The focus of our work is dispersive, second-order effective model describing the low-frequency wave motion in heterogeneous (e.g.~functionally-graded) media endowed with periodic microstructure. For this class of quasi-periodic medium variations, we pursue homogenization of the scalar wave equation in \mathbb{R}^d d\geqslant 1within the framework of multiple scales expansion. When either d=1or d=2 this model problem bears direct relevance to the description of (anti-plane) shear wave...
#1Danial P. Shahraki (UMN: University of Minnesota)
#2Viksit Kumar (Mayo Clinic)H-Index: 11
Last. Mostafa Fatemi (Mayo Clinic)H-Index: 35
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Abstract C-Elastography (CE) is a new ultrasound technique that locally maps the non-linear elasticity of soft tissue using low-frequency (150–250 Hz) shear waves generated by the acoustic radiation force (ARF). CE is based on a recent finding that the magnitude of the ARF in an isotropic tissue-like solid is related linearly to a third-order modulus of elasticity, C, which is responsible for the coupling between deviatoric and volumetric constitutive behaviors. The main objective of the work de...
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#1Rémi Cornaggia (AMU: Aix-Marseille University)H-Index: 3
#2Bojan B. Guzina (UMN: University of Minnesota)H-Index: 22
Abstract We consider the homogenized boundary and transmission conditions governing the mean-field approximations of 1D waves in finite periodic media within the framework of two-scale analysis. We establish the homogenization ansatz (up to the second order of approximation), for both types of problems, by obtaining the relevant boundary correctors and exposing the enriched boundary and transmission conditions as those of Robin type. Rigorous asymptotic analysis is performed for boundary conditi...
6 CitationsSource
#2Bojan B. GuzinaH-Index: 22
Last. Joseph F. LabuzH-Index: 32
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#1Shixu Meng (UM: University of Michigan)H-Index: 8
#2Othman Oudghiri-Idrissi (UMN: University of Minnesota)H-Index: 2
Last. Bojan B. Guzina (UMN: University of Minnesota)H-Index: 22
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We pursue a low-wavenumber, second-order homogenized solution of the time-harmonic wave equation in periodic media with a source term whose frequency resides inside a band gap. Considering the wave motion in an unbounded medium \mathbb{R}^d(d\geqslant1, we first use the Bloch transform to formulate an equivalent variational problem in a bounded domain. By investigating the source term's projection onto certain periodic functions, the second-order model can then be derived via asymptotic ex...
2 Citations
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We study the homogenization of a transmission problem arising in the scattering theory for bounded inhomogeneities with periodic coefficient in the lower-order term of the Helmholtz equation. The s...
6 CitationsSource