A5012516851- Electromagnetic Scattering and Analysis
- Electromagnetic Simulation and Numerical Methods
- Numerical methods in engineering
- Ultrasound Imaging and Elastography
- Ultrasonics and Acoustic Wave Propagation
- Ultrasound and Hyperthermia Applications
- Electromagnetic Compatibility and Measurements
- Acoustic Wave Phenomena Research
- Microwave Imaging and Scattering Analysis
- Underwater Acoustics Research
- Meteorological Phenomena and Simulations
- Geology and Paleoclimatology Research
- Climate variability and models
- Advanced Computational Techniques in Science and Engineering
- Numerical methods for differential equations
- Ultrasound and Cavitation Phenomena
- Matrix Theory and Algorithms
- Electrostatics and Colloid Interactions
- Numerical methods in inverse problems
- Advanced Numerical Methods in Computational Mathematics
- Isotope Analysis in Ecology
- Atmospheric and Environmental Gas Dynamics
- Geological and Tectonic Studies in Latin America
- Cavitation Phenomena in Pumps
- Soil Geostatistics and Mapping
Pontificia Universidad Católica de Chile
2016-2025
University of Cambridge
2021
University College London
2015-2021
Netherlands Aerospace Centre
2011-2015
Delft University of Technology
2010-2015
Netherlands Leprosy Relief
2012-2013
Computational models of acoustic wave propagation are frequently used in transcranial ultrasound therapy, for example, to calculate the intracranial pressure field or phase delays correct skull distortions. To allow intercomparison between different modeling tools and techniques by community, an international working group was convened formulate a set numerical benchmarks. Here, these benchmarks presented, along with results. Nine increasing geometric complexity defined. These include...
Abstract Many applications in Earth sciences require spatial prediction, that is, obtaining a continuous scalar field from set of discrete data points on the Earth's surface. Such include model‐data comparisons and derivation fields as input for system models. The advantage kriging an interpolation method is it provides predictions with confidence intervals sets irregularly distributed space. However, theory non‐Euclidean domains such oblate spheroids (e.g., surface) poorly developed,...
Acoustic cavitation threshold charts are used to map between acoustic parameters (mainly intensity and frequency) different regimes of cavitation. The two main transient cavitation, where a bubble collapses, stable undergoes periodic oscillations without collapse. strongly depend on the physical model compute dynamics algorithm for classifying threshold. differences modeling approaches become especially noticeable resonant bubbles when sonication result in large-amplitude oscillations. This...
High-intensity focused ultrasound (HIFU) techniques are promising modalities for the non-invasive treatment of cancer. For HIFU therapies of, e.g., liver cancer, one main challenges is accurate focusing acoustic field inside a ribcage. Computational methods can play an important role in patient-specific planning these transcostal treatments. This requires modeling scattering at ribcages. The use boundary element method (BEM) effective approach this purpose because only boundaries ribs have...
In recent years there have been tremendous advances in the theoretical understanding of boundary integral equations for Maxwell problems. particular, stable dual pairing discretisation spaces developed that allow robust formulations preconditioned electric field, magnetic field and combined equations. Within BEM++ element library we implementations these frameworks an intuitive formulation typical within a few lines code. The basis developments is efficient Calder\'on identities together...
Abstract The Poisson‐Boltzmann equation offers an efficient way to study electrostatics in molecular settings. Its numerical solution with the boundary element method is widely used, as complicated surface accurately represented by mesh, and point charges are accounted for explicitly. In fact, there several well‐known integral formulations available literature. This work presents a generalized expression of representation implicit solvent model, giving rise new forms compute electrostatic...
Increasing the number of closely packed air bubbles immersed in water changes frequency Minnaert resonance. The collective interactions between a small ensemble are primarily same phase, causing them to radiate spherically symmetric field that peaks at lower than resonance for single bubble. In contrast, large periodic arrays include further apart half wavelength such resonances have oscillating opposite phases, ultimately creating fundamental higher single-bubble This work investigates...
A key parameter in the design of integral equation methods for transient electromagnetic scattering is definition temporal basis functions. The choice functions has a profound impact on efficiency and accuracy numerical scheme. This paper presents framework with predefined varying smoothness properties. well-known shifted Lagrange naturally fit this framework. New spline will be derived that have same interpolation as added advantage being smooth. Numerical experiments show positive...
The acoustic resonances of radiatively damped air bubbles in water near reflecting boundaries are investigated by representing the bubble and its image two a full space, ensonified incident fields. Results obtained using an analytic monopole theory compared with those coupled spherical harmonic technique boundary element method. Near rigid boundary, resonance frequency is reduced, response characteristics determined predominant monopolar character individual motion, small changes peak...
Ship simulators are used for training purposes and therefore have to calculate realistic wave patterns around the moving ship in real time. We consider a model that is based on variational Boussinesq formulation, which results set of partial differential equations. Discretization these equations gives large system linear equations, has be solved each time-step. The requirement real-time simulations necessitates fast solver. In this paper we study combination Relaxed Incomplete Cholesky...
Transient electromagnetic scattering phenomena can effectively be simulated with time domain integral equation methods. The stability and accuracy of the marching on in scheme is usually established exact evaluation radiation fields. Due to singularities their analytical expressions, straightforward finite precision arithmetic jeopardize Computational experiments confirm this show that it even lead late-time instability numerical model. Hence, a reformulation necessary remove singular...
Police agencies expend considerable effort to anticipate future incidences of criminal behaviour. Since a large proportion crimes are committed by small group individuals, preventive measures often targeted on prolific offenders. There is long-standing expectation that new technologies can improve the accurate identification crime patterns. Here, we explore big data technology and design machine learning algorithm for forecasting repeated arrests. The forecasts based administrative provided...
A key parameter in the design of integral equation methods for transient electromagnetic scattering is choice temporal basis functions. Newly constructed functions have to meet requirements on accuracy, smoothness and efficiency, while requirement bandlimitedness dropped nonlinear case. An analysis interpolation accuracy will justify widespread use shifted Lagrange functions, because these optimal but introduce non-smoothness calculated fields. Alternatively, a novel spline function proposed...
The boundary element method (BEM) is an efficient numerical for simulating harmonic wave propagation. It uses integral formulations of the Helmholtz equation at interfaces piecewise homogeneous domains. discretisation its weak formulation leads to a dense system linear equations, which typically solved with iterative such as GMRES. application BEM propagation through large-scale geometries only feasible when compression and preconditioning techniques reduce computational footprint....
Computational methods are widely used in the engineering community for analysis of electromagnetic scattering phenomena. To achieve robustness required industrial application numerical scheme has to be provably stable. The existing stability proof space-time Galerkin will augmented such that it can more popular marching-on-in-time scheme. These extensions lead a stable is easy implement marching methods.
The aim of this thesis is to design a computational method that can be used in modern stealth technology. In particular, the should capable simulate scattering ultra-wideband radar signals for military aircraft constructed with ferromagnetic absorbent materials. A full-wave boundary element has been chosen because its efficiency electromagnetic electrically large structures. time-domain wideband simulated single run. Moreover, future use nonlinear constitutive equations materials requires...
Paleoclimatic measurements serve to understand geophysical processes and evaluate climate model performances. However, their spatial coverage is generally sparse unevenly distributed across the globe. Statistical interpolation methods are prevalent techniques grid such data, but these purely data-driven approaches sometimes produce results that incoherent with our knowledge of physical world. Physics-Informed Neural Networks (PINNs) follow an innovative approach data analysis modeling...
The growth of gated communities and the omnipresence video surveillance have changed urban life considerably in last decades. Especially cities governed by neoliberal public policies widespread fear crime, residents search for security, social status, shared services fortified enclaves where cameras watch everybody who enters their premises. These developments are not restricted to private space, affluent neighborhoods megacities eager adopt a wide range technology protect citizens. Eight...