Ischemia depresses tissue excitability more rapidly in the ventricular epicardium than in the endocardium. We hypothesized that this would provide the substrate for transmural reentry originating in the epicardium. We mapped transmural conduction in isolated and perfused wedges taken from canine left ventricles during global ischemia while pacing alternately between the epicardium and endocardi...

A study of the mechanism by which disturbances can cause tripping between steady-flow regular and Mach reflection in the dual-solution domain is presented. Computational results indicate that the disturbance shock created as a result of the impact of dense particles on one of the shock-generating wedges can cause transition from regular to Mach reflection. The disturbance shock may also be gene...

The shape of a liquid surface bounded by an acute or obtuse wedge is considered by using classical analysis methods. For acute wedges the two principal curvatures are of the order of the (fixed) mean curvature. But for obtuse wedges, the principal curvatures both diverge as the vertex is approached. The power-law divergence becomes stronger with increasing opening angle. Possible implications o...

Shock waves are steep wavefronts that are fundamental in nature, especially in high-speed fluid flows. When a shock hits an obstacle, or a flying body meets a shock, shock reflection/diffraction phenomena occur. In this paper, we show how several long-standing shock reflection/diffraction problems can be formulated as free boundary problems, discuss some recent progress in developing mathematic...

Identifying communities plays a central role in understanding the structure of large networks. As practitioners analyze progressively larger networks, it becomes increasingly important to understand the computational complexity of candidate algorithms. We examine the complexity of the link clustering algorithm (Ahn et al., 2010) for overlapping community detection. We provide new, tight bounds ...

The interface between two wedges can be treated as a displacement discontinuity characterized by elastic stiffnesses. By representing the boundary between the two quarter-spaces as a displacement discontinuity, coupled wedge waves were determined theoretically to be dispersive and to depend on the specific stiffness of the non-welded contact between the two wedges. Laboratory experiments on iso...

Magnetic slot wedges are often used to improve starting performance of large induction motors. In this paper we have investigated – through simulation – the effects of the wedges on the performance characteristics of the motor and core losses under no load condition. Both analytical and hybrid two-dimensional field-circuit models have been used. In order to reliably establish the parameters of ...

The subject of the study is a wedge pair under impact constant forces. In article, an equation for equilibrium state derived and reaction forces are determined. Research methods based on classical laws theoretical mechanics to derive analytical method determining force constraints. equations were by addition, constraints A mathematical expression axisymmetric was obtained which generalizes form...

The floodlight illumination problem asks whether there exists a one-to-one placement of n floodlights illuminating infinite wedges of angles α1, . . . , αn at n sites p1, . . . , pn in a plane such that a given infinite wedge W of angle θ located at point q is completely illuminated by the floodlights. We prove that this problem is NP-hard, closing an open problem from 2001 [6]. In fact, we sho...