Simplified Metrics Calculation for Soft Bit Detection in DVB-T2

The constellation rotation and cyclic quadrature component delay (RQD) technique has been adopted in the second generation terrestrial digital video broadcasting (DVB-T2) standard. It improves the system performance under severe propagation conditions, but introduces serious complexity problems in the hardware implementation of the detection process. In this paper, we present a simplified scheme that greatly reduces the complexity of the demapper by simplifying the soft bit metrics computation having a negligible overall system performance loss

Towards a systematic design of isotropic bulk magnetic metamaterials using the cubic point groups of symmetry

In this paper a systematic approach to the design of bulk isotropic magnetic metamaterials is presented. The role of the symmetries of both the constitutive element and the lattice are analyzed. For this purpose it is assumed that the metamaterial is composed by cubic SRR resonators, arranged in a cubic lattice. The minimum symmetries needed to ensure an isotropic behavior are analyzed, and some particular configurations are proposed. Besides, an equivalent circuit model is proposed for the considered cubic SRR resonators. Experiments are carried out in order to validate the proposed theory. We hope that this analysis will pave the way to the design of bulk metamaterials with strong isotropic magnetic response, including negative permeability and left-handed metamaterials.Comment: Submitted to Physical Review B, 23 page

Camel genetic resources conservation through tourism: A key sociocultural approach of camelback leisure riding

Camels are exotic elements, which can be comprised within adventure travel companies promoting ecotourism activities. Such recreations contribute to sustainable livelihoods for local communities and educational empowerment towards nature and its conservation. At present, some local camel breeds’ survival reduces to this animal-based leisure industry and its reliability to perform and promote customized services accurately. By conducting an on-site questionnaire to customers participating in camelback riding tours, we assessed the motivational factors affecting participation, satisfaction, and loyalty in this tourism segment that may have made it socially differentiated. The sixfold combination of staff performance, culture geography, diverse and humane close interaction, camel behavior and performance, sociotemporal context, and positive previous experience involves the elemental dimensions that explain customer satisfaction and return intention probability within this entertainment business. Customer knowledge is essential for stakeholders to build personalized riding experiences and align profits with environmental sustainability and biodiversity mainstream concerns into their everyday operations. In turn, domestic camel tourist rides could be managed as a viable path to nature conservation by helping endangered local breeds to avoid their functional devaluation and potential extinction

Unified Homogenization Theory for Magnetoinductive and Electromagnetic Waves in Split Ring Metamaterials

A unified homogenization procedure for split ring metamaterials taking into account time and spatial dispersion is introduced. The procedure is based on two coupled systems of equations. The first one comes from an approximation of the metamaterial as a cubic arrangement of coupled LC circuits, giving the relation between currents and local magnetic field. The second equation comes from macroscopic Maxwell equations, and gives the relation between the macroscopic magnetic field and the average magnetization of the metamaterial. It is shown that electromagnetic and magnetoinductive waves propagating in the metamaterial are obtained from this analysis. Therefore, the proposed time and spatially dispersive permeability accounts for the characterization of the complete spectrum of waves of the metamaterial. Finally, it is shown that the proposed theory is in good quantitative and qualitative agreement with full wave simulations.Comment: 4 pages, 3 figure

De novo reefs: Fish habitat provision by oyster aquaculture varies with farming method

Aquaculture industries have the capacity to produce positive ecosystem service benefits, such as the provision of habitat to wild animals. Oyster cultivation is the oldest and largest aquaculture industry in south-eastern Australia. Oyster spat are grown to marketable size in rack-and-rail (‘racks’) or longline-and-basket (‘baskets’) configurations, which add structure to estuarine waters. This study assessed: (1) how the fish communities associated with oyster farms vary with production method; (2) how communities of fish utilise oyster infrastructure, as compared to adjacent natural habitats; and (3) whether oyster infrastructure can serve as de facto oyster reefs by supporting similar fish communities. Remote underwater video surveys, conducted during summer and winter of 2 study years, revealed that fish observations and species richness were generally greater for rack than basket cultivation. Both types of oyster farms supported at least as many species of fish as adjacent natural habitats, including oyster reef, seagrass, mangrove and bare sediment. Fish communities were, in general, most similar between racks and baskets and most dissimilar between racks and bare sediments. Oyster farms supported species of fish otherwise limited to habitats with wild oysters, and unique harvested fish species were observed more frequently at racks. Fish use of oyster-growing infrastructure for foraging and shelter mirrored use of natural biogenic habitats. Overall, this study suggests that the oyster aquaculture infrastructure can support fish communities with species composition similar to those of natural biogenic habitats, although this service is dependent on farming method. Ecosystem services provided by aquaculture should be considered in estuarine habitat enhancement, conservation and restoration