Diffusion tensor imaging (DTI) is a recent magnetic resonance (MR) technique that provides comprehensive information about water diffusivity. Since diffusivity correlates with tissue structure at the microscopic level DTI reveals fibrous structures such as white matter (WM) pathways in the field of neurosurgery. WM tracts are thereby of major interest and the ability to distinguish between diff...

The analysis and visualization of flows is a central problem in visualization. Topology based methods have gained increasing interest in recent years. This article describes a method for the detection of closed streamlines in flows. It is based on a special treatment of cases where a streamline reenters a cell to prevent infinite cycling during streamline calculation. The algorithm checks for p...

abstract weirs are the most common structures for discharge measurement in engineering research. streamline curvature, non hydrostatic pressure distribution on weir and nappe adherence to the weir lead to differences between calculated and measured discharges. thus discharge coefficient, which is the ratio of real and theoretic discharges, is usually less than unity. in circular weirs the press...

Streamline tracing on irregular grids requires reliable interpolation of velocity fields. We propose a new method for direct streamline tracing on polygon and polytope cells. While some numerical methods provide a basis function that can be used for interpolation, other methods provide only the fluxes at the faces of the elements. We introduce the concept of full field and raw field methods. Fu...

This work introduces a novel streamline seeding technique based on dual streamlines that are orthogonal to the vector field, instead of tangential. The greedy algorithm presented here produces a net of orthogonal streamlines that is iteratively refined resulting in good domain coverage and a high degree of continuity and uniformity. The algorithm is easy to implement and efficient, and it natur...

A software tool for the prediction of the aero-thermodynamic environments of conceptual aerospace configurations is presented. The vehicle geometry is defined using unstructured, triangulated surface meshes. For subsonic Mach numbers a fast, unstructured, multi-pole panel code is coupled with a streamline tracing formulation to define the viscous surface solution. For supersonic and hypersonic ...

in this study the land surface in western half of hyper-arid lut desert, in south east of iran, which is covered by yardangs, a worldwide typical landform for aeolian erosion, were classified by self organizing maps (som) method. in the first step by using digital elevation model with 10 m resolution and matlab software, 22 morphometric parameters were calculated based on derivative of the surf...

Abstract OBJECTIVES The actual underlying mechanisms of acute type A aortic dissection (AAAD) are not well understood. present study aimed to elucidate the mechanism AAAD using computational fluid dynamics (CFD) analysis. METHODS We performed CFD analysis patient-specific computed tomography imaging in 3 healthy control cases and patients with AAAD. From images, we made a model or pre-dissectio...