Contour fitting in image segmentation guarantees the closedness of the segment boundary at any stage of the approximation, thus preserving an important global property of the segment. A contour fitting scheme consists of strategies to modify the contour and to optimize the current approximation. For the purpose of contour modification a two-dimensional adaptation of a geometrically deformable m...

‎in this paper‎, ‎we consider an inverse boundary value problem for two-dimensional heat equation in an annular domain‎. ‎this problem consists of determining the temperature on the interior boundary curve from the cauchy data (boundary temperature and heat flux) on the exterior boundary curve‎. ‎to this end‎, ‎the boundary integral equation method is used‎. ‎since the resulting system of linea...

We present a method for unsupervised boundary classification by producing and analyzing intensity profiles. Each profile is created by sampling an ellipsoidal neighborhood of voxels oriented along the image gradient. The profile is analyzed via non-linear optimization to find the best fitting cumulative Gaussian. The parameters of the cumulative Gaussian parameterize the boundary directly yield...

Building boundary lines are important spatial features that characterize the topographic maps and three-dimensional (3D) city models. Airborne LiDAR Point clouds provide adequate 3D spatial information for building boundary mapping. However, information of boundary features contained in point clouds is implicit. This study focuses on developing an automatic algorithm of building boundary line e...

Optimality studies and studies of decision-making in monkeys have been used to support a model in which the decision boundaries used to evaluate evidence collapse over time. This article investigates whether a diffusion model with collapsing boundaries provides a better account of human data than a model with fixed boundaries. We compared the models using data from four new numerosity discrimin...

Morphology of individual microcalcifications is an important clinical factor in microcalcification clusters diagnosis. Accurate segmentation remains a difficult task due to microcalcifications small size, low contrast, fuzzy nature and low distinguishability from surrounding tissue. A novel application of active rays (polar transformed active contours) on B-spline wavelet representation is empl...

Morphology of individual microcalcifications is an important clinical factor in microcalcification clusters diagnosis. Accurate segmentation remains a difficult task due to microcalcifications small size, low contrast, fuzzy nature and low distinguishability from surrounding tissue. A novel application of active rays (polar transformed active contours) on B-spline wavelet representation is empl...

We present a local exponential fitting hybridized mixed finiteelement method for convection-diffusion problem on a bounded domain with mixed Dirichlet Neuman boundary conditions. With a new technique that interpretes the algebraic system after static condensation as a bilinear form acting on certain lifting operators we prove an a priori error estimate on the Lagrange multipliers that requires ...

When computing a partial differential equation, it is often necessary to introduce artificial boundaries. Here we explain a systematic method to obtain boundary conditions for the wave equation in one dimension, fitting to the discretization scheme and stable. Moreover, we give error estimates on the reflected part.

The receptivity of a hypersonic boundary layer to three-dimensional wall perturbations is investigated in this paper by numerical simulations. The work is motivated by Tumin’s [1] theoretical analysis on the receptivity of compressible boundary layers to three-dimensional wall perturbations with the help of the biorthogonal eigenfunction system. Specifically, receptivity processes of a Mach 5.9...