Time Delay Induced Death in Coupled Limit Cycle Oscillators

We investigate the dynamical behaviour of two limit cycle oscillators that interact with each other via time delayed coupling and find that time delay can lead to amplitude death of the oscillators even if they have the same frequency. We demonstrate that this novel regime of amplitude "death" also exists for large collections of coupled identical oscillators and provide quantitative measures of this death region in the parameter space of coupling strength and time delay. Its implication for certain biological and physical applications is also pointed out.Comment: 4 aps formatted revtex pages; 3 figures; to be published in Phys. Rev. Let

A Review on Edge Detection Algorithms in Digital Image Processing Applications

Edge detection is one of the major step in Image segmentation, image enhancement, image detection and recognition applications. The main goal of edge detection is that to localize the variation in the intensity of an image to identify the phenomena of physical properties which produced by the capturing device. An edge might be characterized as a set of neighborhood pixels that forms a boundary between two different regions. Detecting the edges is an essential technique for segmenting the image in to various regions based on their discontinuity in the pixels. Edge detection has very important applications in image processing and computer vison. It is broadly used technique and quick feature extraction technique hence used in various feature extraction and feature detection techniques. There exists several methods in the literature for edge detection such as Canny, Prewitt, Sobel, Maar Hildrith, Robert etc. In this paper we have studied and compared Prewitt, Sobel, and Canny detection operators. Our experimental study shows that the canny operator is giving better results for different kinds of images and has numerous advantages than the other operators such as the nature of adaptive, works better for noisy images and providing the sharp edges with low probability of false detection edges

Neutral Larkin--Ovchinnikov--Fulde--Ferrell state and chromomagnetic instability in two-flavor dense QCD

In two-flavor dense quark matter, we describe the dynamics in the single plane wave Larkin--Ovchinnikov--Fulde--Ferrell (LOFF) state satisfying the color and electric neutrality conditions. We find that because the neutral LOFF state itself suffers from a chromomagnetic instability in the whole region where it coexists with the (gapped/gapless) two-flavor superconducting (2SC/g2SC) phases, it cannot cure this instability in those phases. This is unlike the recently revealed gluonic phase which seems to be able to resolve this problem.Comment: Revtex4, 5 pages, 3 figures, clarifications added, to appear in Phys.Rev.Let

Collective excitations, instabilities, and ground state in dense quark matter

We study the spectrum of light plasmons in the (gapped and gapless) two-flavor color superconducting phases and its connection with the chromomagnetic instabilities and the structure of the ground state. It is revealed that the chromomagnetic instabilities in the 4-7th and 8th gluonic channels correspond to two very different plasmon spectra. These spectra lead us to the unequivocal conclusion about the existence of gluonic condensates (some of which can be spatially inhomogeneous) in the ground state. We also argue that spatially inhomogeneous gluonic condensates should exist in the three-flavor quark matter with the values of the mass of strange quark corresponding to the gapless color-flavor locked state.Comment: Revtex, 5 pages, 4 figures, two figures and clarifications added, to appear in PRD (Rapid Communications