Adaptive Bayesian decision feedback equalizer for dispersive mobile radio channels

The paper investigates adaptive equalization of time dispersive mobile ratio fading channels and develops a robust high performance Bayesian decision feedback equalizer (DFE). The characteristics and implementation aspects of this Bayesian DFE are analyzed, and its performance is compared with those of the conventional symbol or fractional spaced DFE and the maximum likelihood sequence estimator (MLSE). In terms of computational complexity, the adaptive Bayesian DFE is slightly more complex than the conventional DFE but is much simpler than the adaptive MLSE. In terms of error rate in symbol detection, the adaptive Bayesian DFE outperforms the conventional DFE dramatically. Moreover, for severely fading multipath channels, the adaptive MLSE exhibits significant degradation from the theoretical optimal performance and becomes inferior to the adaptive Bayesian DFE

Fluxes and distribution of dissolved iron in the eastern (sub-) tropical North Atlantic Ocean

Aeolian dust transport from the Saharan/Sahel desert regions is considered the dominant external input of iron (Fe) to the surface waters of the eastern (sub-) tropical North Atlantic Ocean. To test this hypothesis, we investigated the sources of dissolved Fe (DFe) and quantified DFe fluxes to the surface ocean in this region. In winter 2008, surface water DFe concentrations varied between <0.1 nM and 0.37 nM, with an average of 0.13 ± 0.07 nM DFe (n = 194). A strong correlation between mixed layer averaged concentrations of dissolved aluminum (DAl), a proxy for dust input, and DFe indicated dust as a source of DFe to the surface ocean. The importance of Aeolian nutrient input was further confirmed by an increase of 0.1 nM DFe and 0.05 ?M phosphate during a repeat transect before and after a dust event. An exponential decrease of DFe with increasing distance from the African continent, suggested that continental shelf waters were a source of DFe to the northern part of our study area. Relatively high Fe:C ratios of up to 3 × 10?5 (C derived from apparent oxygen utilization (AOU)) indicated an external source of Fe to these African continental shelf waters. Below the wind mixed layer along 12°N, enhanced DFe concentrations (>1.5 nM) correlated positively with apparent oxygen utilization (AOU) and showed the importance of organic matter remineralization as an DFe source. As a consequence, vertical diffusive mixing formed an important Fe flux to the surface ocean in this region, even surpassing that of a major dust event

Educational advantage and employability of UK university graduates

In the UK, the majority of university students specialise and study just one subject at bachelor degree level, commonly known in the UK as a single honours degree. However, nearly all British universities will permit students if they wish to study two or even three subjects, so-called joint or combined honours degrees, internationally known as a double major. The purpose of this paper is to explore whether educational advantage, measured by the “Participation of Local Areas” (POLAR) classification, correlated with rates of graduate destinations for joint and single honours graduates. This study focused particularly on Russell Group and Post-92 Universities. The authors analysed the complete data set provided from the Higher Education Statistics Agency Destination of Leavers from the Higher Education survey, and combined this with data from the POLAR4 quintiles, which aggregate geographical regions across the UK based on the proportion of its young people that participate in higher education. The data were analysed to establish whether there was a difference in the highly skilled graduate employability of the joint honours students, focusing particularly on Russell Group and Post-92 Universities, in order to build on previous published work. Single honours and joint honours graduates from higher participation POLAR4 quintiles were more likely to be in a highly skilled destination. However at both the Russell Group and the Post-92 universities, respectively, there was no trend towards a smaller highly skilled destinations gap between the honours types for the higher quintiles. For the highest POLAR4 quintile, the proportion of joint honours graduates was substantially higher at the Russell Group than at Post-92 universities. Furthermore, in any quintile, there were proportionately more joint honours graduates from the Russell Group, compared with single honours graduates, and increasingly so the higher the quintile. This study focused on joint honours degrees in the UK where the two or three principal subjects fall into different Joint Academic Coding System (JACS) subject areas, i.e. the two or three subjects are necessarily diverse rather than academically cognate. This excluded the class of joint honours degrees where the principal subjects lie within the same JACS subject area, i.e. they may be closer academically, although still taught by different academic teams. However, the overall proportion of joint honours graduates identified using the classification was in line with the UCAS (2017) data on national rates of combined studies acceptances. All Russell Group graduates, irrespective of their POLAR4 quintile, were far more likely to be in a highly skilled destination than single or joint honours graduates of Post-92 universities. Even the lowest quintile graduates of the Russell Group had greater rates of highly skilled destination than the highest quintile from Post-92 universities, for both single and joint honours graduates. This demonstrated the positive impact that graduating from the Russell Group confers on both single and joint honours graduates. This study could not explain the much smaller gap in the highly skilled destinations between single honours and joint honours graduates found in the Russell Group, compared with the Post-92. Why do a higher proportion of joint honours graduates hail form the upper POLAR4 quintiles, the Russell Group joint honours graduates were more disproportionately from the upper POLAR4 quintiles and the joint honours upper POLAR4 quintiles represented such a larger proportion of the Russell Group overall undergraduate population? Other student characteristics such as tariff on entry, subjects studied, gender, age and ethnicity might all contribute to this finding. This study demonstrated that, averaged across all universities in the UK, there was a trend for both single honours and joint honours graduates from higher participation POLAR4 quintiles to be more likely to be in a highly skilled destination, i.e. the more educationally advantaged, were more likely to be in a highly skilled destination, as a proportion of the total from each honours type. This accorded with HESA (2018b) data, but expanded those findings to include direct consideration of joint honours graduates.N/

Inference of the Distribution of Selection Coefficients for New Nonsynonymous Mutations Using Large Samples.

The distribution of fitness effects (DFE) has considerable importance in population genetics. To date, estimates of the DFE come from studies using a small number of individuals. Thus, estimates of the proportion of moderately to strongly deleterious new mutations may be unreliable because such variants are unlikely to be segregating in the data. Additionally, the true functional form of the DFE is unknown, and estimates of the DFE differ significantly between studies. Here we present a flexible and computationally tractable method, called Fit∂a∂i, to estimate the DFE of new mutations using the site frequency spectrum from a large number of individuals. We apply our approach to the frequency spectrum of 1300 Europeans from the Exome Sequencing Project ESP6400 data set, 1298 Danes from the LuCamp data set, and 432 Europeans from the 1000 Genomes Project to estimate the DFE of deleterious nonsynonymous mutations. We infer significantly fewer (0.38-0.84 fold) strongly deleterious mutations with selection coefficient |s| > 0.01 and more (1.24-1.43 fold) weakly deleterious mutations with selection coefficient |s| < 0.001 compared to previous estimates. Furthermore, a DFE that is a mixture distribution of a point mass at neutrality plus a gamma distribution fits better than a gamma distribution in two of the three data sets. Our results suggest that nearly neutral forces play a larger role in human evolution than previously thought

Adaptive MBER space-time DFE assisted multiuser detection for SDMA systems

In this contribution we propose a space-time decision feedback equalization (ST-DFE) assisted multiuser detection (MUD) scheme for multiple antenna aided space division multiple access systems. A minimum bit error rate (MBER) design is invoked for the MUD, which is shown to be capable of improving the achievable bit error rate performance over that of the minimum mean square error (MMSE) design. An adaptive MBER ST-DFE-MUD is proposed using the least bit error rate algorithm, which is demonstrated to consistently outperform the least mean square (LMS) algorithm, while achieving a lower computational complexity than the LMS algorithm for the binary signalling scheme. Simulation results demonstrate that theMBER ST-DFE-MUD is more robust to channel estimation errors as well as to error propagation imposed by decision feedback errors, compared to the MMSE ST-DFE-MUD

Influenced of Fe buffer thickness on the crystalline quality and the transport properties of Fe/Ba(Fe1-xCox)2As2 bilayers

The implementation of an Fe buffer layer is a promising way to obtain epitaxial growth of Co-doped BaFe2As2 (Ba-122). However, the crystalline quality and the superconducting properties of Co-doped Ba-122 are influenced by the Fe buffer layer thickness, dFe. The well-textured growth of the Fe/Ba-122 bilayer with dFe = 15 nm results in a high Jc of 0.45 MAcm$^{-2}$ at 12 K in self-field, whereas a low Jc value of 61000 Acm$^{-2}$ is recorded for the bilayer with dFe = 4 nm at the corresponding reduced temperature due to the presence of grain boundaries

Effect of increased CO₂ and iron levels on the marine plankton food web during a mesocosm experiment

A mesocosm experiment was carried out in the Raunefjord (Norway) during 25 days, to investigate the interactive effects of increased CO2 and iron availability on the plankton community. The seawater carbonate system in the mesocosms was manipulated to achieve two different CO2 levels, corresponding to the present (390 ppmv, LC) and to levels predicted for year 2100 (900 ppmv, HC), in combination with ambient and increased dissolved Fe (dFe) concentrations in a full factorial design. We observed a shift in the plankton community structure, initially dominated by picoeukaryotes and small nanoeukaryotes, changing to an Emiliania huxleyi dominated bloom. E. huxleyi and Synechococcus were the most sensitive organisms to changes in CO2 and Fe levels, being negatively affected by increased CO2 and favoured by high dFe levels. Picoeukaryotes, large nanoplankton, viruses and ciliates abundances were not affected by changes in CO2 or dFe levels. Bacterial abundance showed a significant positive response to high CO2 but it was unaffected by dFe. Total mesozooplankton abundances did not change significantly. The relevance of these results within the global change scenario will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech