In this paper we prove a posteriori L2(L2) and L∞(H−1) residual based error estimates for a finite element method for the one-dimensional time dependent coupling equations of two scalar conservation laws. The underlying discretization scheme is Characteristic Galerkin method which is the particular variant of the Streamline diffusion finite element method for δ = 0. Our estimate contains certai...

We evaluate a parallel Schur preconditioner for large systems of equations arising from a finite element discretization of the Navier-Stokes equations with streamline diffusion. The performance of the method is assessed on a biomedical problem involving oscillatory flow in a human abdominal bifurcation. Fast access to flow conditions in this location might support physicians in quicker decision...

The tractability and integrity of fiber tracts within an edema, and the functional roles of long-range fiber tracts during language processing are discussed controversially. We studied the dorsal and ventral language fiber tracts of patients initially presenting with a peritumoral edema in both their pre-and postoperative states. Here, we report preliminary results of three patients. Diffusion ...

Previous attempts to involve doctors and nurses with Healthcare organisation Information Technology initiatives have often proved futile. Often this has been because Healthcare professionals do not perceive any direct benefit for them at the point of care. Traditional, static implementations of Clinical Information Systems have been driven by Hospital Administration in an attempt to reduce cost...

The discrete convection-diffusion equations obtained from streamline diffusion finite element discretization are solved on both uniform meshes and adaptive meshes. Estimates of error reduction rates for both geometric multigrid (GMG) and algebraic multigrid (AMG) are established on uniform rectangular meshes for a model problem. Our analysis shows that GMG with line Gauss-Seidel smoothing and b...

In the subway station fires, the most immediate threat to passengers’ life is not the direct exposure to fire, but the smoke inhalation because it contains hot air and toxic gases. Theoretical analysis and CFD simulations are applied to analyze the various possible ventilation model and obtain the optimization of ventilation mode in the subway station fires. According to the structure character...

OBJECTIVE Up to now, fiber tractography in the clinical routine is mostly based on diffusion tensor imaging (DTI). However, there are known drawbacks in the resolution of crossing or kissing fibers and in the vicinity of a tumor or edema. These restrictions can be overcome by tractography based on High Angular Resolution Diffusion Imaging (HARDI) which in turn requires larger numbers of gradien...

Diffusion tensor imaging (DTI) allows investigating white matter structures in vivo which is of great interest for various applications in neuroanatomy and neurosurgery. In order to reconstruct white matter tracts from DTI data, fiber tracking approaches are used which are commonly based on streamline propagation techniques. In order to provide more reliable tracking results, local regularizati...

Obtaining accurate solutions for convection–diffusion equations is challenging due to the presence of layers when convection dominates the diffusion. To solve this problem, we design an adaptive meshing algorithm which optimizes the alignment of anisotropic meshes with the numerical solution. Three main ingredients are used. First, the streamline upwind Petrov–Galerkin method is used to produce...

Diffusion tensor imaging allows investigating white matter structures in vivo which is of particular interest for neurosurgery. A promising approach for the reconstruction of neural pathways are streamline based techniques commonly referred to as fiber tracking. However, due to the diverging nature of tract systems, the density of streamlines varies over the domain without control resulting in ...