Re-design of a given antenna structure for various substrates is a practically important issue yet non trivial, particularly for wideband and ultra-wideband antennas. In this work, a technique for expedited redesign of ultra-wideband antennas for various substrates is presented. The proposed approach is based on inverse surrogate modeling with the scaling model constructed for several reference designs that are optimized for selected values of the substrate permittivity. The surrogate is set up at the level of coarse-discretization EM simulation model of the antenna and, subsequently, corrected to provide prediction at the high-fidelity EM model level. The dimensions of the antenna scaled to any substrate permittivity within the region of validity of the surrogate are obtained instantly, without any additional EM simulation necessary. The proposed approach is demonstrated using an ultra-wideband monopole with the permittivity scaling range from 2.2 to 4.5. Numerical validation is supported by physical measurements of the fabricated prototypes of the re-designed antennas.

The paper deals with the problem of bias randomization in evaluation of the measuring instrument capability. The bias plays a significant role in assessment of the measuring instrument quality. Because the measurement uncertainty is a comfortable parameter for evaluation in metrology, the bias may be treated as a component of the uncertainty associated with the measuring instrument. The basic method for calculation of the uncertainty in modern metrology is propagation of distributions. Any component of the uncertainty budget should be expressed as a distribution. Usually, in the case of a systematic effect being a bias, the rectangular distribution is assumed. In the paper an alternative randomization method using the Flatten-Gaussian distribution is proposed.

The infection of black rockcod, Notothenia coriiceps, with digeneans in Admiralty Bay (South Shetland Islands ) within three months, from November 2007 to January 2008, is compared with the infection in the same three months in 1978/79, based on the examination of twenty fish collected in each month. Digenea found in 1978/1979 season were more numerous, and more diverse. Only five digenean species, Macvicaria georgiana , Neolebouria antarctica , Lepidapedon garrardi , Genolinea bowersi and Lecithaster macrocotyle , were recorded during both investigations, whereas three species, Neolepidapedon trematomi , Elytro− phalloides oatesi and Gonocerca phycidis , only in 1978/79. M. georgiana was the dominant species in 1978/79 and sub−dominant in 2007/08. Other digeneans were found in N. coriiceps in 2007/08 invariably together with M. georgiana. G. bowersi was the sub−dominant species in 1978/79 and the most common species in 2007/2008. Infections with Digenea belonging to other species were much less intense. Of the three rare or common species in 1978/79, the two, L. garrardi and L. macrocotyle , occurred in both seasons, whereas E. oatesi occurred only in 1978/79. Three remaining species were sporadic or absent. The overall results therefore demonstrated that infections with almost all digenean species were less strong in 2007/08 than three decades earlier, in 1978/79. Only data on M. georgiana , G. bowersi and L. g arrardi were statistically significant (p <0.05). Data on the occurrence of 14 species of Digenea in N. coriiceps from South Shetland Islands, South Orkney Islands, South Georgia, Argentine Is − lands, Melchior Islands, Adelie Land and Heard Island are given.