In this paper, we present an edge detection method based on wavelet transform and Hessian matrix of image at each pixel. Many methods which based on wavelet transform, use wavelet transform to approximate the gradient of image and detect edges by searching the modulus maximum of gradient vectors. In our scheme, we use wavelet transform to approximate Hessian matrix of image at each pixel, too. ...

The main objective of this paper is to present a wavelet-based procedure to characterize principle features of a special class of motions called pulse-like ground motions. Initially, continues wavelet transform (CWT) which has been known as a powerful technique both in earthquake engineering and seismology field is applied easily in automated detecting of strong pulse of earthquakes. In this pr...

this paper presents a new coding method for image compression based on jpeg2000 and contourlet transform. jpeg2000 standard is a common standard that uses discrete wavelet transform (dwt) in the compression process. the main problems of dwt are failure to detect curved edges in image and its shortage representation of the ridge and furrow patterns which cause deficiency and block artifacts rema...

A (complex) Enriques surface is a projective smooth connected algebraic surface Y over C with H(Y,OY ) = H (Y,OY ) = (0), (Ω 2 Y ) ⊗ 2 ≃ OY but Ω 2 Y 6≃ OY ([CF]). In this note we give a short proof of the fact that the coarse moduli space of complex Enriques surfaces is quasi-affine. This was first shown by Borcherds [B] using the denominator function of a generalized Kac-Moody superalgebra (t...

For a quasidifferentiable function f defined on R 2 , it is proved, in the sense of Demyanov and Rubinov, that the following assertion [∂f (x),∂f (x)]∈Df (x) (∂f (x) + ∂f (x)), [∂f (x),∂f (x)]∈Df (x) (∂f (x) − ∂f (x)) ∈ Df (x) in this paper, where Df (x) denotes the set of all quasidifferentials of f at x. It is shown that this way can be viewed as an approach to determining or choosing a repre...

HS 2325+8205 is a long-period eclipsing dwarf nova with an orbital period above the gap (Porb>3 h) and reported to be Z Cam-type nova. Based on photometry of Transiting Exoplanet Survey Satellite (TESS), light variation quasi-periodic oscillation (QPOs) are studied. Using Continuous Wavelet Transform (CWT), Lomb-Scargle Periodogram (LSP), sine fitting methods, we find for first time that there ...

ABSTRACT We report the detection of quasi-periodic oscillations (QPOs) in radio light curves at 4.8, 8, and 14.5 GHz blazar OT 081, by means Weighted Wavelet Z-transform (WWZ) Lomb–Scargle periodogram (LSP) methods. The LSP diagrams time-averaged WWZ powers demonstrate several significant claims QPOs above 4? confidence level: ?850 ?1500 d 4.8-GHz curve, ?850, ?1120, ?1540 8-GHz ?1130 14.5-GHz ...

We have analyzed cortical and subcortical field recordings from spatially distinct neural circuits in order to support the hypothesis that spatially distinct brain locations display correlated ictal activity during epileptic seizures. Field recordings have been obtained from cortex (CTX), anterior thalamic nuclei (AN), posterior thalamus (PT) and hippocampus (HPC) during pentylenetetrazol (PTZ)...

modern world revolutions have created some instruments known as ‎quasi-negotiable instruments which are different from negotiable ones, ‎despite having some similarities to them. commercial custom recognizes ‎them as quasi-negotiable instruments. the principle is that we don’t ‎need new legal regime for this new category because they are right in ‎personam when they are created and rights in re...

The construction of generalized continuous wavelet transforms on locally compact abelian groups A from quasi-regular representations of a semidirect product group G = A ⋊ H acting on L(A) requires the existence of a square-integrable function whose Plancherel transform satisfies Calderón-type resolution of the identity. The question then arises under what conditions such square-integrable funct...