The wave propagation in a circular metal waveguide with a central cylindrical dielectric rod and coaxial layer of absorbing liquid have been studied at the frequency range 5-30 GHz. Owing to the ...absorbing liquid the operating frequencies range can be extended up to centimeter wavelength range. This fact takes place because of the two-layered waveguide with absorbing liquid does not have fixed cutoff frequencies for waveguide modes. It has been found abnormally low attenuation coefficients of electromagnetic waves HE11 in the centimeter wavelength range at certain frequencies and values of thickness of the absorbing liquid. The sensitivity of the method of complex permittivity determination of absorbing liquid using a thin liquid layer increases in comparison with a thick layer.
The paper presents several variations of fuzzy extractors to generate cryptographic keys and password based on parameters of keystroke dynamics. A series of simulation experiments was run to estimate ...the efficiency of these methods, the best parameters of fuzzy extractors were found. The best result was: FRR=0.061, FAR=0.023 with a key length 192 bits.
The chaotic properties of the frequency spectrum of layered microwave spherical and cylindrical cavity resonators are studied analytically, numerically, and experimentally. The physical objects ...selected for the study of the chaotic spectral properties were quasi-optical microwave resonators of spherical (cylindrical) geometries that contain metal and(or) dielectric inserts in the form of a sphere (cylinder). With increasing the radius of the insert, the resonance frequencies shift towards smaller values, and the additional resonances appear which cannot be identified by the same oscillation indices. The symmetric (integrable) spherical (cylindrical) resonant structures with an inner sphere (disk) show correlation factors close to zero, whereas non-integrable structures where the inner sphere (disk) is placed asymmetrically demonstrate correlation factors C(1) > 0.2 in absolute value. A transition between such states may occur within a narrow range of the structure's eccentricity. The distributions of the inter-line intervals are studied in dependency on the mean separation between the eigenfrequencies.
