We propose an efficient numerical algorithm for computing deformations of ‘very’ soft tissues (such as the brain, liver, kidney etc.), with applications to real-time surgical simulation. The algorithm is based on the finite element method using the total Lagrangian formulation, where stresses and strains are measured with respect to the original configuration. This choice allows for pre-computi...

Although explicit and implicit knowledge of language learners are essential to theoretical and pedagogical debates in second language acquisition (SLA), little research has addressed the effects of instructional interventions on the two knowledge types (R. Ellis, 2005).This study examined the relative effectiveness of explicit and implicit types of form-focused instruction (FFI) on the acquisit...

The geometric constraint enforcement using Lagrange Multipliers is one of the popular methods to control the behavior and trajectories of dynamically simulated entities. Therefore, effective and efficient enforcement and proper integration of the geometric constraints is the key to a successful constraint management. This paper describes the formulation and integration of geometric constraints ...

Abstract. In this paper, we revisit the reverse-time imaging procedure. We discuss an inverse scattering transform derived from reverse-time migration (RTM), and establish its relation with generalized Radon transform inversion. In the process, the explicit evaluation of the so-called normal operator is avoided, at the cost of introducing other pseudodifferential operator factors. Using techniq...

In this paper higher order implicit Runge-Kutta schemes are applied to fluid-structure interaction (FSI) simulations. A staggered approach with a structural predictor is applied to an FSI problem. The equations governing the dynamics of the structure are integrated in time by the Explicit Single Diagonal Implicit Runge-Kutta (ESDIRK) schemes and the arbitrary high order finite volume scheme is ...

Historically, time-split schemes for numerically integrating the nonhydrostatic compressible equations of motion have not formally conserved mass and other first-order flux quantities. In this paper, split-explicit integration techniques are developed that numerically conserve these properties by integrating prognostic equations for conserved quantities represented in flux form. These procedure...

We consider the problem of integration of the initial value problem of the rotational rigid body dynamics. We are motivated by a very practical problem: time integration of the equations of motion of drill bits as they cut through rock. The drill bit geometry is fully three-dimensional, as is the surface of the rock to be cut, and the force laws of cutting, scraping, impacts, and persistent con...

Abstract This paper studies fully discrete finite element approximations to the Navier–Stokes equations using inf-sup stable elements and grad-div stabilization. For time integration, two implicit–explicit second-order backward differentiation formulae (BDF2) schemes are applied. In both, Laplacian is implicit while nonlinear term explicit, in first one, semiimplicit, second one. The stabilizat...

The optimization of some W-methods [7] for the time integration of time-dependent PDEs in several spatial variables is considered. In [2, Theorem 1] several three-parametric families of three-stage W-methods for the integration of IVPs in ODEs were studied. Besides, the optimization of several specific methods for PDEs when the Approximate Matrix Factorization Splitting (AMF) [3, 4] is used to ...