In this paper we propose a technique for softwareimplementation of Edge detection which serves as a preprocessing step for many image processing algorithms such as image enhancement, image segmentation, tracking and image and video coding. The Edge Detection is one of the key stages in image processing and object recognition. Edge detection is a basic operation in image processing, it refers to...

We study the small dispersion limit for the Korteweg-de Vries (KdV) equation ut + 6uux + ǫ uxxx = 0 in a critical scaling regime where x approaches the trailing edge of the region where the KdV solution shows oscillatory behavior. Using the Riemann-Hilbert approach, we obtain an asymptotic expansion for the KdV solution in a double scaling limit, which shows that the oscillations degenerate to ...

In the framework of the four dimensional heterotic superstring with free world-sheet fermions and using all constraints due to the conformal and superconformal symmetries (Virasoro and super-Virasoro algebras), the two dimensional current algebra, the global reparametrization (modular) invariance and the autoduality of the fermion charge lattice we study the rank eight/sixteen Grand Unified Str...

Here we analyse aeroelastic devices in the wings of a steppe eagle Aquila nipalensis during manoeuvres. Chaotic deflections of the upperwing coverts observed using video cameras carried by the bird (50 frames s(-1)) indicate trailing-edge separation but attached flow near the leading edge during flapping and gust response, and completely stalled flows upon landing. The underwing coverts deflect...

The evolution of a gust front to bore to solitary wave transition, and comprehensive information on the evolving nocturnal boundary layer (NBL) associated with this change, are described with analysis of radar and profiler measurements. The observations were obtained on 21 June 2002 in the Oklahoma panhandle during the International H2O Project. The evolution of this system, from a strong bore ...

Insect wings are flexible. For rigid wings lift enhancing unsteady aerodynamics mechanisms, such as delayed stall via leading-edge vortices (LEVs), wake-capture, and rotational forces, characterize the lift generation of a hovering insect. We have uncovered a novel mechanism that fruit fly size insects can utilize to further increase the lift by adjusting its wing shape passively: A pair of a L...

For a fixed integer m, we consider edge colorings of complete graphs which contain no properly edge colored cycle Cm as a subgraph. Within colorings free of these subgraphs, we establish a global structure by bounding the number of colors that can induce a spanning and connected subgraph. In the case of small cycles, namely C4, C5, and C6, we show that our bounds are sharp.

Low-temperature photoluminescence-excitation spectra are studied in an n-type modulation-doped T-shaped single quantum wire with a gate to tune electron densities. With a nondegenerate one-dimensional (1D) electron gas, the band-edge absorption exhibits a sharp peak structure induced by the 1D density of states. When the dense 1D electron gas is degenerate at a low temperature, we observe a Fer...

In a graph G, we say a cycle C : v1, v2, . . . , vk, v1 is chorded if its vertices induce an additional edge (chord) which is not an edge of the cycle. The cycle C is doubly chorded if there are at least two such chords. In this paper we show a sharp degree sum condition that implies the existence of k vertex disjoint doubly chorded cycles in a graph. © 2015 Elsevier B.V. All rights reserved.

Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In or...