AUTOMATIC ACTIVE CONTOURS PROPAGATION IN A SEQUENCE OF MEDICAL IMAGES

In this paper we present a new algorithm to track an organ in a sequence of medical images in order to achieve a 3D reconstruction. The automatic method that we propose allows the tracking of the external contour of the anatomical organ in all the sequence from one contour initialized by the user on the first image. The required operations for our tracking method are the region-based active contours segmentation. The objects localization with dynamic prediction of displacements is based on the level-set functions and the definition of the region of interest for the robust local estimation of the image model. An application of this method is the 3D reconstruction of abdominal aorta.

A Displacement-Focused Seismic Design of Mixed Building Systems

A postulated prediction of displacements in ductile reinforced concrete building systems is based on a redefinition of basic structural properties. Contrary to the ability of traditional techniques, the proposed approach permits displacement limits, relevant to ductile mixed systems, i.e., those with markedly differing components, to be established before details, such as strengths, are addressed. This should lead to significant benefits at the stage of preliminary design. Acceptable displacement limits, associated with currently introduced direct displacement-based seismic design strategies, can be readily and simply established. Similarly, limits of displacement ductility demands on components and the system, associated with current force-based approaches, can be estimated already as part of the preliminary design.