Carlo Tomasi Any m n matrix of rank r transforms the unit sphere in Rn into an r-dimensional hyperellipsoid in Rm. For instance, the rank-2 matrix A = 1 p2 264 p3 p3 3 3 1 1 375 (1) transforms the unit circle on the plane into an ellipse embedded in three-dimensional space. Figure 1 shows the map y = Ax : Two diametrically opposite points on the unit circle are mapped into the two endpoints of ...

In this report, I present a novel algorithm to detect and track the head regions in a normal human walking sequence. The algorithm also classifies each head orientation for the detected head regions. The main assumption for the algorithm is: Head is always located at an extreme position of the body image and there is a noticeable difference between the head and shoulders in the input images. Th...

It is suggested recently that most of halo coronal mass ejections (CMEs) may be formed by an ice cream cone-like shell of dense CME electrons. We improve our cone model (Zhao, Plunkett and Liu, 2002) to include the contribution of the top surface of the ice cream part as well as the cone part to the shape of the halo CMEs. It is found that for an ice cream cone with a half sphere sitting on the...

Human arm viscoelasticity is important in stabilizing posture, movement, and in interacting with objects. Viscoelastic spatial characteristics are usually indexed by the size, shape, and orientation of a hand stiffness ellipse. It is well known that arm posture is a dominant factor in determining the properties of the stiffness ellipse. However, it is still unclear how much joint stiffness can ...

This thesis proposes an improved interactive brain tumor segmentation method based on graph cuts, which is an efficient global optimization framework for image segmentation, and star shape, which is a general segmentation shape prior with minimal user assistance. Our improvements lie in volume ballooning, compactness measure and inclusion constraints. Volume ballooning is incorporated to help t...

This paper proposes the use of a particle filter combined with color, depth information and shape features as an efficient and effective way to deal with tracking a head on the basis of image stream coming from a mobile stereovision camera. The head is modeled in the 2D image domain by an ellipse. The color distribution within interior of the ellipse is represented by a color histogram. The col...

We present optical and neutral hydrogen observations of the central ∼2 kpc in NGC 4151, and examine the distribution and kinematics of neutral hydrogen in the vicinity of the optical circumnuclear dust ‘ellipse’. The V-I colour map, derived from broad-band images obtained using TAURUS II in imaging mode, shows clearly the red arcs which delineate the 11′′ × 18′′ dust ellipse detected previously...

Objectives To evaluate the abdominal visceral fat area (VFA), we developed novel ultrasonographic (US) methods for estimating. Methods 100 male volunteers were recruited, and their VFA was calculated by two novel US methods, the triangle method and the ellipse method. The VFA calculated by these methods was compared with the VFA calculated by CT. Results Both the VFA calculated by the trian...