Planning and dynamic spectrum management in heterogeneous mobile networks with QoE optimization

The radio and network planning and optimisation are continuous processes that do not end after the network has been launched. To achieve the best trade-offs, especially between quality and costs, operators make use of several coverage and capacity enhancement methods. The research from this thesis proposes methods such as the implementation of cell zooming and Relay Stations (RSs) with dynamic sleep modes and Carrier Aggregation (CA) for coverage and capacity enhancements. Initially, a survey is presented on ubiquitous mesh networks implementation scenarios and an updated characterization of requirements for services and applications is proposed. The performance targets for the key parameters, delay, delay variation, information loss and throughput have been addressed for all types of services. Furthermore, with the increased competition, mobile operator’s success does not only depend on how good the offered Quality of Service (QoS) is, but also if it meets the end user’s expectations, i.e., Quality of Experience (QoE). In this context, a model for the mapping between QoS parameters and QoE has been proposed for multimedia traffic. The planning and optimization of fixed Worldwide Interoperability for Microwave Access (WiMAX) networks with RSs in conjunction with cell zooming has been addressed. The challenging case of a propagation measurement-based scenario in the hilly region of Covilhã has been considered. A cost/revenue function has been developed by taking into account the cost of building and maintaining the infrastructure with the use of RSs. This part of the work also investigates the energy efficiency and economic implications of the use of power saving modes for RSs in conjunction with cell zooming. Assuming that the RSs can be switched-off or zoomed out to zero in periods when the traffic exchange is low, such as nights and weekends, it has been shown that energy consumption may be reduced whereas cellular coverage and capacity, as well as economic performance may be improved. An integrated Common Radio Resource Management (iCRRM) entity is proposed that implements inter-band CA by performing scheduling between two Long Term Evolution – Advanced (LTE-A) Component Carriers (CCs). Considering the bandwidths available in Portugal, the 800 MHz and 2.6 GHz CCs have been considered whilst mobile video traffic is addressed. Through extensive simulations it has been found that the proposed multi-band schedulers overcome the capacity of LTE systems without CA. Result shown a clear improvement of the QoS, QoE and economic trade-off with CA

Diversity of the arthropod fauna in organically grown garlic intercropped with fodder radish.

The cultivation of garlic faces several problems, which include pest attack, and the diversification of habitat through intercropping with attractive plants comes up as a method to pest management. The objective of this research was to verify the effect of the association of garlic with fodder radish on richness, abundance and diversity of arthropods under organic production system in Lavras, MG, Brazil. The treatments were composed of garlic in monoculture and garlic in association with fodder radish, in plots of 40 garlic plants, intercropped or not with two lines of fodder radish. Weekly, 25 samples were collected for a period of 10 weeks (n=250). Species accumulation curves, species richness, abundance, and diversity index were determined, and T or Mann-Whitney tests were used for analysis. The 250 samples collected were sufficient to register the majority of species present in garlic. Richness and abundance were higher in diversified garlic whereas diversity was higher in monoculture. Diversified system increased the overall richness of phytophagous species and parasitoids. The abundance of T. tabaci decreased, while increased the presence of A. fabae, demonstrating that the association was potentially beneficent to the culture. The possible reasons for these results are discussed, and future works should focus in the ecological mechanisms involved in crop diversification of organic garlic

Geographical and seasonal distributions of the seedeaters Sporophila bouvreuil and Sporophila pileata (aves: Emberizidae)

Many species in the genus Sporophila are migratory. Migration patterns, while poorly studied, may be influenced by seed production which can be very seasonal in some regions. The distribution of S. bouvreuil extends from the Amazon and Suriname south through a large part of the open regions of Brazil. Sporophila pileata, on the other hand, is found in southeastern and southern Brazil as well as Argentina and Paraguay. Both of these species migrate, but their movement patterns are poorly known. To better understand the geographical and the seasonal distributions of S. bouvreuil and S. pileata, we grouped the records into two categories: the breeding season (September to March) and the putative migration season (April to August). We found two areas of sympatry between S. bouvreuil and S. pileata in the Brazilian states of Minas Gerais and São Paulo. For S. bouvreuil we suggest that populations that breed in the Amazon migrate to the Cerrado or Caatinga, where they will encounter resident populations of the same species. These resident populations may take part in short distance migrations. Sporophila pileata, on the other hand, occur in the Cerrado and open areas within the Atlantic Forest and it is not yet possible to determine migratory tendencies or destinations in the non-breeding season.Muitos representantes do gênero Sporophila são migratórios. Estes movimentos são pouco estudados e podem ser determinados por fatores como a produção de gramíneas, que podem ser altamente sazonais em algumas regiões. A distribuição de Sporophila bouvreuil se estende desde a região amazônica e Suriname passando pelas áreas abertas de boa parte do Brasil, enquanto que S. pileata distribui-se pelo sul e sudeste do Brasil, além da Argentina e Paraguai. Os movimentos migratórios destas duas espécies são pouco conhecidos e há evidências de que algumas populações podem ser residentes durante todo o ano. Com o objetivo de definir a distribuição geográfica e sazonal de S. bouvreuil e S. pileata, os registros foram agrupados em dois tipos, um durante o período reprodutivo (setembro a março) e outro durante os meses de abril a agosto, quando supostamente estas espécies podem migrar. Foram identificadas duas áreas de simpatria entre S. bouvreuil e S. pileata, nos estados de Minas Gerais e São Paulo. Para S. bouvreuil sugere-se que as populações que reproduzem na Amazônia se deslocam para o Cerrado ou a Caatinga, onde se encontram com as populações residentes nestes biomas. As populações desta diagonal seca se reproduzem nestes domínios e provavelmente realizam apenas migrações de curta distância. Na Mata Atlântica parte das populações são residentes, permanecendo neste bioma durante todo o ano. As populações de S. pileata que ocorrem no Cerrado e nas áreas abertas da Mata Atlântica se reproduzem nos seus respectivos biomas, mas não foi possível identificar as possíveis áreas de invernagem para esta espécie

The inversion of the spatial lag operator in binary choice models: Fast computation and a closed formula approximation

This paper presents a new method to approximate the inverse of the spatial lag operator, used in the estimation of spatial lag models for binary dependent variables. The related matrix operations are approximated as well. Closed formulas for the elements of the approximated matrices are deduced. A GMM estimator is also presented. This estimator is a variant of Klier and McMillen’s iterative GMM estimator. The approximated matrices are used in the gradients of the new iterative GMM procedure. Monte Carlo experiments suggest that the proposed approximation is accurate and allows to significantly reduce the computational complexity, and consequently the computational time, associated with the estimation of spatial binary choice models, especially for the case where the spatial weighting matrix is large and dense. Also, the simulation experiments suggest that the proposed iterative GMM estimator performs well in terms of bias and root mean square error and exhibits a minimum trade-off between computational time and unbiasedness within a class of spatial GMM estimators. Finally, the new iterative GMM estimator is applied to the analysis of competitiveness in the U.S. Metropolitan Statistical Areas. A new definition for binary competitiveness is introduced. The estimation of spatial and environmental effects are addressed as central issues.info:eu-repo/semantics/publishedVersio

The inversion of the spatial lag operator in binary choice models : fast computation and a closed formula approximation

This paper presents a new method to approximate the inverse of the spatial lag operator matrix, used in the estimation of a spatial lag model with a binary dependent variable. The method is based on an approximation of the high order terms of the inverse series expansion. The proposed method is also applied to approximate other complex matrix operations and closed formulas for the elements of the approximated matrices are deduced. The approximated matrices are used in the gradients of a variant of Klier and McMillen's full GMM estimator, allowing to reduce the overall computational complexity of the estimation procedure. Monte Carlo experiments show that the new estimator performs well in terms of bias and root mean square error and exhibits a minimum trade-off between time and unbiasedness within a class of spatial GMM estimators. The new estimator is also applied to the analysis of competitiveness in the Metropolitan Statistical Areas of the United States of America. A new de_nition of binary competitiveness is proposed. Estimation of the spatial dependence parameter and the environmental effects are addressed as central issues.info:eu-repo/semantics/publishedVersio

MORPHOLOGICAL VARIATION AND TAXONOMY OF LEPIDOCOLAPTES ANGUSTIROSTRIS (VIEILLOT, 1818) (PASSERIFORMES: DENDROCOLAPTIDAE)

Lepidocolaptes angustirostris habita principalmente regiões abertas como a Caatinga, o Cerrado e o Chaco. Oito subespécies são atualmente reconhecidas, baseadas em padrões da plumagem e distribuição geográfica. Uma análise morfológica e uma revisão taxonômica nunca foram realizadas nesta espécie. O objetivo deste estudo é desenvolver uma revisão taxonômica de L. angustirostris utiliazndo caracteres morfométricos e de plumagem, e análises de modelagem (GLM) foram feitas para identificar variáveis ambientais que possam explicar esta variação. Os resultados indicam que as diferentes populações de L. angustirostris que habitam as áreas abertas da Caatinga, Cerrado e Chaco (mais as populações amazônicas) não têm um nível significativo de diferenciação mofológica e nem de plumagem para serem consideradas como táxons válidos. Nas análises do GLM, duas variáveis climáticas explicaram a variação geográfica no táxon, a sazonalidade térmica e a precipitação no trimestre mais quente. As leis ecogeográficas de Bergmann e Gloger podem ser aplicadas para explicar esta variação, assim como a lei de Allen, esta de forma mais restrita. Assim, as populações do arapaçu-do-cerrado tendem a ser maiores ao sul da distribuição. A proposta apresentada aqui é de manter o status taxonômico de L. angustirostris como uma espécie única, sem qualquer outro táxon subordinado. Apesar do polimorfismo identificado nos padrões da plumagem, o elevado nível de intergradação e a baixa resolução dos limites geográficos entre as populações não suportam a divisão deste táxon.Lepidocolaptes angustirostris is a South American woodcreeper that inhabits predominantly open lowlands such as the Cerrado, Chaco and Caatinga. Eight subspecies are currently recognized based on plumage patterns and geographical distribution. However, a more detailed morphological analysis and taxonomic revision have not been done in this species. The objective of this study was to conduct a taxonomic revision of L. angustirostris using morphometrical and plumage character, and a Generalized Linear Models analyzes (GLM) were elaborated to identify environmental variables that could account for this variation. We found a high level of intergradation among all named populations. The principal component analyzes show certain levels of morphological differentiation among the taxa, with a first component formed by bill characters (bill length, exposed and total culmen), and a second one that includes the bill width and the tarsus-metatarsus length. In the GLM analyzes, two climatic variables explain the geographical variation in the taxon, temperature seasonality and precipitation of warmest quarter. The ecogeographic rules of Bergmann and Gloger can be applied to this variation, and, more narrowly, the Allen's rule. Thus, the populations of the Narrow-billed Woodcreeper tend to be larger to the south of the distribution. We propose here that L. angustirostris is a single species, with no subordinate taxa. Any evidence analyzed here did not support the taxonomic validity of the proposed subspecies in the taxon. Despite colour-polymorphism identified in the plumage patterns, the high level of intergradation and the poor resolution of geographical boundaries did not support the splitting of this species

Repeated divergent selection on pigmentation genes in a rapid finch radiation

Instances of recent and rapid speciation are suitable for associating phenotypes with their causal genotypes, especially if gene flow homogenizes areas of the genome that are not under divergent selection. We study a rapid radiation of nine sympatric bird species known as capuchino seedeaters, which are differentiated in sexually selected characters of male plumage and song. We sequenced the genomes of a phenotypically diverse set of species to search for differentiated genomic regions. Capuchinos show differences in a small proportion of their genomes, yet selection has acted independently on the same targets in different members of this radiation. Many divergent regions contain genes involved in the melanogenesis pathway, with the strongest signal originating from putative regulatory regions. Selection has acted on these same genomic regions in different lineages, likely shaping the evolution of cis-regulatory elements, which control how more conserved genes are expressed and thereby generate diversity in classically sexually selected traits.Fil: Campagna, Leonardo. Cornell University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Repenning, Márcio. Pontificia Universidade Católica do Rio Grande do Sul. Museu de Ciências e Tecnologia; BrasilFil: Silveira, Luís Fábio. Universidade de Sao Paulo; BrasilFil: Fontana, Carla Suertegaray. Pontificia Universidade Católica do Rio Grande do Sul; BrasilFil: Tubaro, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lovette, Irby. Cornell University; Estados Unido