Jari A. Toivanen

Works (11)

Updated: July 5th, 2023 15:57

2019 journal article

A PARALLEL DOMAIN DECOMPOSITION METHOD FOR THE HELMHOLTZ EQUATION IN LAYERED MEDIA

SIAM JOURNAL ON SCIENTIFIC COMPUTING, 41(5), C505–C521.

By: E. Heikkola*, K. Ito* & J. Toivanen*

author keywords: Helmholtz equation; domain decomposition method; preconditioned iterative method; ultrasonic tomography; geological survey
topics (OpenAlex): Electromagnetic Simulation and Numerical Methods; Advanced Numerical Methods in Computational Mathematics; Numerical methods in engineering
TL;DR: An efficient domain decomposition method and its parallel implementation for the solution of the Helmholtz equation in three-dimensional layered media are considered. (via Semantic Scholar)
Source: Web Of Science
Added: November 25, 2019

2009 journal article

LAGRANGE MULTIPLIER APPROACH WITH OPTIMIZED FINITE DIFFERENCE STENCILS FOR PRICING AMERICAN OPTIONS UNDER STOCHASTIC VOLATILITY

SIAM JOURNAL ON SCIENTIFIC COMPUTING, 31(4), 2646–2664.

By: K. Ito* & J. Toivanen*

author keywords: American option pricing; stochastic volatility model; linear complementarity problem; finite difference method; quadratic programming; multigrid method; Lagrange method; penalty method
topics (OpenAlex): Stochastic processes and financial applications; Capital Investment and Risk Analysis; Financial Risk and Volatility Modeling
TL;DR: The deterministic numerical valuation of American options under Heston's stochastic volatility model is considered and a Lagrange approach is used to treat the linear complementarity problems. (via Semantic Scholar)
UN Sustainable Development Goals Color Wheel
UN Sustainable Development Goal Categories
Source: Web Of Science
Added: August 6, 2018

2008 journal article

A domain decomposition solver for acoustic scattering by elastic objects in layered media

JOURNAL OF COMPUTATIONAL PHYSICS, 227(19), 8685–8698.

By: K. Ito n, Z. Qiao n & J. Toivanen n

author keywords: fast Helmholtz solver; scattering from elastic targets; domain decomposition preconditioner
topics (OpenAlex): Geophysical Methods and Applications; Electromagnetic Simulation and Numerical Methods; Electromagnetic Scattering and Analysis
TL;DR: An improved finite element discretization based on trilinear basis functions leading to fourth-order phase accuracy is described, which demonstrates capability to evaluate the scattered field with hundreds of wavelengths. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2007 article

A fast iterative solver for scattering by elastic objects in layered media

APPLIED NUMERICAL MATHEMATICS, Vol. 57, pp. 811–820.

By: K. Ito n & J. Toivanen n

topics (OpenAlex): Geophysical Methods and Applications; Electromagnetic Scattering and Analysis; Electromagnetic Simulation and Numerical Methods
TL;DR: A fast iterative solver for computing time-harmonic acoustic waves scattered by an elastic object in layered media using a domain decomposition preconditioner in the iterative solution of the resulting system of linear equations. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2007 journal article

An adaptive evolutionary algorithm with intelligent mutation local searchers for designing multidrug therapies for HIV

APPLIED INTELLIGENCE, 27(3), 219–235.

By: F. Neri *, J. Toivanen* & R. Makinen *

topics (OpenAlex): HIV Research and Treatment; HIV/AIDS drug development and treatment; Immune Cell Function and Interaction
TL;DR: The results show that the therapies designed by the AEA lead to a “healthy” state faster than with the other methods, and the statistical analysis confirms the computational effectiveness of the algorithm. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2007 journal article

Solution of time-independent Schrodinger equation by the imaginary time propagation method

JOURNAL OF COMPUTATIONAL PHYSICS, 221(1), 148–157.

By: L. Lehtovaara*, J. Toivanen n & J. Eloranta *

author keywords: imaginary time propagation; Schrodinger equation; Lanczos method; operator-splitting
topics (OpenAlex): Electromagnetic Simulation and Numerical Methods; Numerical methods for differential equations; Matrix Theory and Algorithms
TL;DR: The results show that the ITP method has better scaling with respect to matrix size as compared to the implicitly restarted Lanczos method. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2006 journal article

A state-dependent Riccati equation-based estimator approach for HIV feedback control

OPTIMAL CONTROL APPLICATIONS & METHODS, 27(2), 93–121.

By: H. Banks n, H. Kwon *, J. Toivanen n & H. Tran n 

author keywords: multidrug therapies; feedback control; estimator; HIV model; SDRE
topics (OpenAlex): Immune Cell Function and Interaction; Mathematical and Theoretical Epidemiology and Ecology Models; HIV Research and Treatment
TL;DR: By anticipation of and response to the disease progression, the dynamic multidrug strategy reduces the viral load, increases the CD4+ T‐cell count and improves the immune response. (via Semantic Scholar)
UN Sustainable Development Goals Color Wheel
UN Sustainable Development Goal Categories
3. Good Health and Well-being (Web of Science; OpenAlex)
Sources: Web Of Science, NC State University Libraries
Added: August 6, 2018

2006 journal article

Determination of interrogating frequencies to maximize electromagnetic backscatter from objects with material coatings

Communications in Computational Physics, 1(2), 362–382.

By: H. Banks, K. Ito & J. Toivanen

Source: NC State University Libraries
Added: August 6, 2018

2006 journal article

Material surface design to counter electromagnetic interrogation of targets

SIAM JOURNAL ON APPLIED MATHEMATICS, 66(3), 1027–1049.

By: H. Banks*, K. Ito*, G. Kepler* & J. Toivanen*

author keywords: electromagnetic; inverse scattering; attenuation
topics (OpenAlex): Electromagnetic Scattering and Analysis; Electromagnetic Simulation and Numerical Methods
TL;DR: F Fresnel's law for the reflectance index is extended to the electromagnetic propagation in anisotropic composite layers of ferromagnetic and electronic devices and is used to demonstrate feasibility of control of reflections. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2006 journal article

Preconditioned iterative methods on sparse subspaces

APPLIED MATHEMATICS LETTERS, 19(11), 1191–1197.

By: K. Ito n & J. Toivanen n

author keywords: subspace iteration; preconditioning; Krylov subspace method; domain decomposition method; fictitious domain method; interface problem
topics (OpenAlex): Advanced Numerical Methods in Computational Mathematics; Electromagnetic Scattering and Analysis; Matrix Theory and Algorithms
TL;DR: This work considers the iterative solution of a discretized partial differential equation on this sparse subspace of a domain decomposition method and a fictitious domain method, where the subspace corresponds a small neighborhood of an interface. (via Semantic Scholar)
Source: Web Of Science
Added: August 6, 2018

2005 journal article

A multigrid preconditioner and automatic differentiation for non-equilibrium radiation diffusion problems

JOURNAL OF COMPUTATIONAL PHYSICS, 207(1), 354–374.

By: R. Glowinski* & J. Toivanen n

author keywords: non-equilibrium radiation diffusion; multigrid method; preconditioning; Newton-Krylov method; automatic differentiation
topics (OpenAlex): Advanced Numerical Methods in Computational Mathematics; Computational Fluid Dynamics and Aerodynamics; Numerical methods for differential equations
TL;DR: This work describes the computation of the Jacobian matrix for Newton's method using automatic differentiation based on the operator overloading in Fortran 90 and proposes a simple multigrid preconditioner applied directly to the coupled linearized problems. (via Semantic Scholar)
UN Sustainable Development Goals Color Wheel
UN Sustainable Development Goal Categories
7. Affordable and Clean Energy (OpenAlex)
Source: Web Of Science
Added: August 6, 2018

Citation Index includes data from a number of different sources. If you have questions about the sources of data in the Citation Index or need a set of data which is free to re-distribute, please contact us.

Certain data included herein are derived from the Web of Science© and InCites© (2025) of Clarivate Analytics. All rights reserved. You may not copy or re-distribute this material in whole or in part without the prior written consent of Clarivate Analytics.