In this paper, we propose a representation of the face image based on the phase of the 2-D Fourier transform of the image to overcome the adverse effect of illumination. The phase of the Fourier transform preserves the locations of the edges of a given face image. The main problem in the use of the phase spectrum is the need for unwrapping of the phase. The problem of unwrapping is avoided by c...

We analytically derive the spectrum of gravitational waves due to magneto-hydrodynamical turbulence generated by bubble collisions in a first-order phase transition. In contrast to previous studies, we take into account the fact that turbulence and magnetic fields act as sources of gravitational waves for many Hubble times after the phase transition is completed. This modifies the gravitational...

We extend the notion of phase locking to the case of chaotic oscillators. Different definitions of the phase are discussed, and the phase dynamics of a single self-sustained chaotic oscillator subjected to external force is investigated. We describe regimes where the amplitude of the oscillator remains chaotic and the phase is synchronized by the external force. This effect is demonstrated for ...

Viewers can recognize the gist of a scene (i.e., its holistic semantic representation, such as its category) in less time than a single fixation, and backward masking has traditionally been employed as a means to determine that time course. The masks used in those paradigms are often characterized by either specific amplitude spectra only, or amplitude and phase spectra-defined structural prope...

It was shown that the structure and particle size of zirconia nanoparticles has been controlled through the homogeneous precipitation process by using templates. Hexamine as the template led to ZrO2 nanoparticles with tetragonal structure, whereas coffee extract favored monoclinic structures. Field Emission Scanning electron microscopy (FeSEM), Transmission electron microscopy (TEM) measurement...

This study is devoted to the investigation of Josephson phase qubit spectrum considering anharmonic current-phase relation junction. The change in energy difference qubits based on single-band/multiband junctions also analyzed. It was shown that presence term and frustration effects junction electrodes leads changing effective plasma frequencies different cases results an spectrum.

-This paper develops a novel spectrum enhancement method to simplify the spectrum representation. It uses a forward synchronous transform to convert three phase current signals into the two current signals in the synchronous reference frame. The spectrum obtained by applying Fast Fourier Transform (FFT) to one of the transformed current signals is then maximized by varying the initial phase in ...

The phase transition for turbulent diffusion, reported by Avellaneda and Majda [Avellaneda, M. & Majda, A. J. (1994) Philos. Trans. R. Soc. London A 346, 205-233, and several earlier papers], is traced to a modeling assumption in which the energy spectrum of the turbulent fluid is singularly dependent on the viscosity in the inertial range. Phenomenological models of turbulence and intermittenc...

conclusions propofol and alfentanil combination can be considered as a treatment approach in the attack phase of cluster headache. introduction cluster headache is a severe hemifacial pain with concomitant symptoms such as lacrimation, conjunctival congestion, and nasal discharge. peripheral (to be a spectrum of trigeminal autonomic cephalgia) and central (hypothalamus) disorders have been sugg...