This paper explores the relationship between the debt ratio of Brazilian football clubs and several potential determinants, both financial and sports-related. Our explanatory variables are Current Ratio, Return on Assets, Score Percentage, Size, 12 Biggest Clubs, Access (to specific championships, e.g. Libertadores da América), Division, Title (won at time t) and Relegated (at time t). Data was collected from several publicly available channels and our sample was mostly decided according to this availability. The time range adopted was 2010-2013. The model employed was Generalized Estimating Equation. Our results suggest that debt ratios are more associated with their popularity or their participation in the highest division of its main championship rather than titles held, access to different competitions or relegation to lower levels. We believe that our findings may be useful for both practitioners, who might know the impact of their sports-related choices in their clubs' debts, and policymakers, that could prepare differentiated policies for specific groups (e.g divisions).
The generalized frequency division multiplexing transmission technique (GFDM), is being discussed as a candidate waveform for the fifth generation wireless communication system (5G). Since it only uses one cyclic prefix (CP) per group of symbols instead of one CP per symbol, the GFDM technique is more spectrally efficient than the traditional OFDM systems. In this work we propose a low complexity detection scheme for GFDM where a matched filter (MF) detection is used in conjunction with the parallel interference cancellation technique (PIC). In addition to reducing the complexity of the receiver, the proposed scheme incorporates a strategy to dynamically limit the number of iterations of the PIC. Performance results are presented in terms of information symbol error rate (SER).
Resumo-Este artigo examina a detecção eficiente de sinais em sistemas de comunicação de banda ultra-larga baseados no padrão IEEE std 802.15.4a. Considera-se inicialmente a estrutura do receptor ótimo e, a partir de alterações neste receptor, um receptor modificado é apresentado. As condições de otimalidade deste novo receptor são cuidadosamente examinadas. O receptor modificado utiliza como filtro de detecção um filtro casado ao código efetivo do usuário de interesse e apresenta bom desempenho mesmo em ambientes com interferência de múltiplo acesso. Dois métodos distintos para estimar o código efetivo são propostos: um método assistido e um método às cegas. Destes dois métodos destacamos o método às cegas, pois tem baixa complexidade computacional quando comparado à maioria dos métodos de detecção às cegas com supressão de interferência, que requerem a inversão de matrizes com dimensão elevada. Resultados de simulação computacional ilustram o desempenho do receptor modificado equipado com os métodos de estimação propostos para este sistema de comunicação.
Resumo-Os sistemas de transmissão em blocos, permitem a transmissão de N símbolos de forma simultânea, seja em modulação de portadoraúnica ou multiportadora. A recepçãó otima, no sentido de máxima verossimilhança em canais com multipercursos apresenta um custo computacional elevado de A N , onde Aé a ordem da constelação (A = 2 para BPSK). Para evitar este alto custo computacionalé usual fazer a detecção símbolo a símbolo após a equalização. Neste trabalhoé proposto um receptor com detecção por grupos que apresenta um bom compromisso entre complexidade computacional e desempenho em termos de taxa de erro médio de bit.
Palavras-Chave-OFDM, sistemas de portadoraúnica, detecção por grupos, detecção MLAbstract-Block transmission system, allows transmissions of N symbols simultaneously, with single carrier or multi-carrier modulation. Maximum likelihood optimal reception in multipath channels have a high computational cost of A N , where A is the constellation order (A = 2 for BPSK). To avoid this cost is usual to make symbol by symbol detection after equalization. In this work we propose a receiver with group detection having a good trade of between computation complexity and bit error rate performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.