The design and development of a proximity fed dualband microstrip patch antenna based on David fractal geometry are presented. David fractal microstrip antenna offers good performance in the 1.754 1.816 GHz and 3.37 3.415 GHz bands and is suitable for GSM 1800, WiMAX applications. The use of David fractal geometry offers miniaturization of the antenna structure. The proposed first iteration fra...

The existing recognition methods of radiation source signal are extremely sensitive to the change of signal-to-noise ratio (SNR). In order to solve this problem, in this paper, it proposes a radar signal recognition method based on fractal box dimension and neural network under the condition of unstable SNR. Firstly, it extracts box counting dimension features of four different radiation source...

Fractal analysis was applied to study the trends of EEG signals in the hypnotic condition. The subjects were 19 psychiatric outpatients. Hypnotizability was measured with the Hypnotic Induction Profile (HIP). Fifty-four sets of EEG data were analyzed by detrended fluctuation analysis (DFA), a well-established fractal analysis technique. The scaling exponents, which are the results of fractal an...

The convergence of fractal operator F used in image compression is investigated by analysis of block innuence graph and pixel innuence graph. The graph stability condition in block innuence graph implies eventual contractivity condition which is suucient for the operator iteration convergence. The graph stability condition in pixel innuence graph appears to be suucient and necessary for converg...

This paper presents the design of rectangular, fractal Microstrip patch antenna and their backscattering reduction. These antennas have been designed on εr = 4.3, h = 1.53 mm substrate with rectangular patch dimension 36.08 x 29.6 mm and its 2 iterative fractal patch. The experimental resonant frequency of 2 iterative fractal patch is observed 2.11 GHz in comparison to rectangular patch 2.42 GH...

Material components for the nuclear fusion and the advanced nuclear fi ssion reactors are exposed to high levels of radiation energy, high temperature, and high thermo-mechanical stresses. Radiation damage is inherently a multiscale phenomenon, with interactions encompassing time scales from femto-seconds to years and length scales from subnanometer to meters. In this study, multiscale modeling...

Rapid fluctuation with a frequency dependence of 1/f (with α≃ 1−2) is characteristic of radiation from black-hole objects. Its origin remains poorly understood. We examine the three-dimensional magnetohydrodynamical (MHD) simulation data, finding that a magnetized accretion disk exhibits both 1/f fluctuation (with α≃2) and a fractal magnetic structure (with the fractal dimension of D∼1.9). The ...

Peculiarities of the spatial behaviour of the dislocation lines resulting from scattering of coherent radiation from random and fractal rough surfaces are studied. The technique of optical correlation is proposed for diagnostics of phase singularities in a complex speckle field by comparing the correlation lengths of amplitude and intensity of the local fields. It is shown that the dislocation ...

A new ultawideband circular fractal antenna with notched-band characteristics is presented. A notched-band characteristic is achieved by employing a U-shape slot in 50 Ω feed lines. The ultra-wideband impedance matching and compact size have been obtained by using CPW-feed technique and the fractal concept. The measured result of proposed fractal antenna exhibits the ultra wideband characterist...