The Extended-window Channel Estimator For Iterative Channel-and-symbol Estimation

The application of the expectation-maximization (EM) algorithm to channel estimation results in a well-known iterative channel-and-symbol estimator (ICSE). The EM-ICSE iterates between a symbol estimator based on the forward-backward recursion (BCJR equalizer) and a channel estimator, and may provide approximate maximum-likelihood blind or semiblind channel estimates. Nevertheless, the EM-ICSE has high complexity, and it is prone to misconvergence. In this paper, we propose the extended-window (EW) estimator, a novel channel estimator for ICSE that can be used with any soft-output symbol estimator. Therefore, the symbol estimator may be chosen according to performance or complexity specifications. We show that the EW-ICSE, an ICSE that uses the EW estimator and the BCJR equalizer, is less complex and less susceptible to misconvergence than the EM-ICSE. Simulation results reveal that the EW-ICSE may converge faster than the EM-ICSE. © 2005 Hindawi Publishing Corporation.200529299Barry, J.R., Lee, E.A., Messerschmitt, D.G., (2003) Digital Communications, , Kluwer Academic Publishers, Norwell, Mass, USA, 3rd editionAyadi, J., De Carvalho, E., Slock, D.T.M., Blind and semi-blind maximum likelihood methods for FIR multichannel identification (1998) Proc. IEEE International Conference on Acoustics, Speech, Signal Processing (ICASSP'98), 6, pp. 3185-3188. , Seattle, Wash, USA, MayFeder, M., Catipovic, J.A., Algorithms for joint channel estimation and data recovery-application to equalization in underwater communications (1991) IEEE J. Oceanic Eng., 16 (1), pp. 42-55Kaleh, G.K., Vallet, R., Joint parameter estimation and symbol detection for linear or nonlinear unknown channels (1994) IEEE Trans. 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Areas Commun., 19 (9), pp. 1729-1743Lopes, R.R., Barry, J.R., Exploiting error-control coding in blind channel estimation (2001) IEEE Global Communications Conference (GLOBECOM'01), 2, pp. 1317-1321. , San Antonio, Tex, USA, NovemberKrishnamurthy, V., Moore, J.B., On-line estimation of hidden Markov model parameters based on the Kullback-Leibler information measure (1993) IEEE Trans. Signal Processing, 41 (8), pp. 2557-2573White, L.B., Perreau, S., Duhamel, P., Reduced computation blind equalization for FIR channel input Markov models (1995) IEEE International Conference on Communications (ICC'95), 2, pp. 993-997. , Seattle, Wash, USA, JuneShao, M., Nikias, C.L., An ML/MMSE estimation approach to blind equalization (1994) Proc. IEEE International Conference on Acoustics, Speech, Signal Processing (ICASSP'94), 4, pp. 569-572. , Adelaide, SA, Australia, AprilCirpan, H.A., Tsatsanis, M.K., Stochastic maximum likelihood methods for semi-blind channel estimation (1998) IEEE Signal Processing Lett., 5 (1), pp. 21-24Paris, B.-P., Self-adaptive maximum-likelihood sequence estimation (1993) IEEE Global Communications Conference (GLOBECOM'93), 4, pp. 92-96. , Houston, Tex, USA, November-DecemberBaum, L.E., Petrie, T., Soules, G., Weiss, N., A maximization technique occurring in the statistical analysis of probabilistic functions of Markov chains (1970) Annals of Mathematics Statistics, 41 (1), pp. 164-171Dempster, A.P., Laird, N.M., Rubin, D.B., Maximum likelihood from incomplete data via the em algorithm (1977) Journal of the Royal Statistics Society, 39 (1), pp. 1-38Bahl, L.R., Cocke, J., Jelinek, F., Raviv, J., Optimal decoding of linear codes for minimizing symbol error rate (1974) IEEE Trans. Inform. 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Commun., 50 (5), pp. 754-767Lopes, R.R., Barry, J.R., Soft-output decision-feedback equalization with a priori information (2003) IEEE Global Communications Conference (GLOBECOM'03), 3, pp. 1705-1709. , San Francisco, Calif, USA, DecemberPoor, H.V., (1994) An Introduction to Signal Detection and Estimation, , Springer-Verlag, New York, NY, USA, 2nd editionMontemayor, C.A., Flikkema, P.G., Near-optimum iterative estimation of dispersive multipath channels (1998) IEEE 48th Vehicular Technology Conference (VTC'98), 3, pp. 2246-2250. , Ottawa, ON, Canada, MaySandell, M., Luschi, C., Strauch, P., Yan, R., Iterative channel estimation using soft decision feedback (1998) IEEE Global Communications Conference (GLOBECOM'98), 6, pp. 3728-3733. , Sydney, NSW, Australia, Novembe

Emergência E Estabelecimento De Espécies Nativas E Exóticas Em Solos De Campos Convertidos E Nativos Remanescentes Do Planalto - Sul Do Brasil

Native grasslands in the Campos de Cima da Serra, Brazil, are being converted at speed for exotic tree plantations and cropland. The impact of modified and novel soil conditions on the establishment of native grassland species is unknown; establishment of non-native species, deliberately or accidentally introduced, could be favoured. In a common garden composed of fully randomized replicate samples of soils collected from remnant grassland, former cropland and pine plantations, we tested emergence and establishment of five cold-season species: Native low-tussock grass Piptochaetium montevidense (Spreng.) Parodi; native legume Trifolium riograndense Burkart; naturalized low-tussock grass Vulpia bromoides (L.) Gray; low-tussock grass Holcus lanatus L., cultivated and naturalized in Brazil; and a cultivar of non-native Trifolium repens. Other than expected, soil type and species*soil type interactions had no significant effect on seedling emergence after 132 days in the field. Species effect on seedling emergence, however, was highly significant. Vulpia bromoides emergence was significantly highest in all soil types. Holcus lanatus and Trifolium riograndense both achieved second highest emergence rates and did not differ significantly from each other. Lowest overall emergence rates were found in the non-native clover cultivar. Lab germination tests failed for Piptochaetium, although it showed reasonable emergence in the field. Good performance of the native clover is encouraging for future grassland restoration, but the value of highly germinable Vulpia as a forage remains to be tested. Holcus tolerates a wide range of soil conditions and its life history traits may promote naturalization, or even invasiveness. Native grasslands of the region should be monitored for this species. Studies like these, but set up on a larger geographical scale and with a wider array of native species, will be essential in developing ecological restoration methods for southern Brazilian grasslands. © 2017, Universidade Estadual de Campinas UNICAMP. All rights reserved.17

Statistical properties of detrended fluctuation analysis

The main goal of this work is to consider the detrended fluctuation analysis (DFA), proposed by Peng et al. [Mosaic organization of DNA nucleotides, Phys. Rev. E. 49(5) (1994), 1685–1689]. This is a wellknown method for analysing the long-range dependence in non-stationary time series. Here we describe the DFA method and we prove its consistency and its exact distribution, based on the usual i.i.d. assumption, as an estimator for the fractional parameter d. In the literature it is well established that the nucleotide sequences present long-range dependence property. In this work, we analyse the long dependence property in view of the autoregressive moving average fractionally integrated ARFIMA(p, d, q) processes through the analysis of four nucleotide sequences. For estimating the fractional parameter d we consider the semiparametric regression method based on the periodogram function, in both classical and robust versions; the semiparametric R/S(n) method, proposed by Hurst [Long term storage in reservoirs, Trans. Am. Soc. Civil Eng. 116 (1986), 770–779] and the maximum likelihood method (see [R. Fox and M.S. Taqqu, Large-sample properties of parameter estimates for strongly dependent stationary Gaussian time series, Ann. Statist. 14 (1986), 517–532]), by considering the approximation suggested by Whittle [Hypothesis Testing in Time Series Analysis (1953), Hafner, New York]..info:eu-repo/semantics/publishedVersio

α-stable laws for noncoding regions in DNA sequences

In this work, we analyze the long-range dependence parameter for a nucleotide sequence in several different transformations. The long-range dependence parameter is estimated by the approximated maximum likelihood method, by a novel estimator based on the spectral envelope theory, by a regression method based on the periodogram function, and also by the detrended fluctuation analysis method. We study the length distribution of coding and noncoding regions for all Homo sapiens chromosomes available from the European Bioinformatics Institute. The parameter of the tail rate decay is estimated by the Hill estimator αˆ. We show that the tail rate decay is greater than 2 for coding regions, while for almost all noncoding regions it is less than 2.info:eu-repo/semantics/publishedVersio

Apoio Em Rede: A Rede Humaniza Sus Conectando Possibilidades No Ciberespaço

This paper presents the HUmanizaSUS Network (Rede HumanizaSUS) as a virtual environment connecting practices and knowledge about SUS (Brazilian National Health System), conveying the support function in a network. Based on the theoretical framework of Collective Intelligence, we present some dimensions of support experienced on Rede HumanizaSUS as a network intervention technology for strengthening the virtual environment of SUS or CiberespaSUS. © 2016, Fundacao UNI Botucatu/UNESP. All rights reserved.205733734

A Long Time Gone: Post-conflict Rural Property Restitution under Customary Law

Mass displacement of people due to violence poses a unique set of challenges for property restitution when people return to their homes after a long absence. This is particularly evident in rural areas where the dominant form of land holding is customary tenure. Violence-induced displacement, unlike voluntary migration, challenges both customary and public legaladministrative structures. The lack of written documentation of customary holdings and the importance of the support of community leaders means that incorporating returnees back into a community can be easier for those who choose to return, while reclaiming property without physical return is nearly impossible. This article seeks to make three contributions: 1) to note the diversity of return processes after long displacements in terms of timing and demographics; 2) to demonstrate that the nature of the claims people can make on customary tenure systems is at odds with international legal norms on property restitution after displacement; and 3) to introduce a set of observations and questions on how conflict can change customary law. The article is based on fieldwork conducted in Uganda, Liberia and Timor-Leste, all countries with extended displacement

VALIDAÇÃO E APLICAÇÃO DE MÉTODO PARA ANÁLISE DE PESTICIDAS EM ÁGUA PARA CONSUMO HUMANO DE DOURADOS (MS) POR CLAE/UV E CG/DTE

O uso inadequado de pesticidas na agricultura tem sido apontado como fonte de risco para a saúde humana e para o ambiente. Considerando que os recursos hídricos são os principais destinos desses compostos após a aplicação, este trabalho apresenta a otimização e validação de dois métodos analíticos simples e eficientes para a determinação de pesticidas em águas superficiais e subterrâneas. Foram selecionados os pesticidas mais aplicados no município de Dourados, (Mato Grosso – Brasil) com intensa atividade agrícola. Efetuou-se a pré-concentração por extração em fase sólida com cartucho C18 (500 mg) e eluição com metanol para as amostras analisadas por cromatografia a líquido de alta eficiência com detector espectrofotométrico na região do ultravioleta (CLAE/UV) (2,4-D e 2,4-DCF) e com acetato de etila:diclorometano (1:1, v/v) para as analisadas por cromatografia a gás com detector termiônico específico (CG/DTE) (atrazina, DIA, DEA, trifluralina e parationa metílica). Os métodos apresentaram exatidão (76-107%) e precisão (<12%) satisfatórias para as substâncias nos níveis de fortificação selecionados, exceto para DIA (<51%), assim como para o estudo de estabilidade dos pesticidas (-20ºC por até 21 dias). Os limites de quantificação dos métodos (0,22 - 0,48 µg L-1) estão de acordo com a legislação brasileira vigente para pesticidas em água. Embora somente o 2,4-D tenha sido detectado em dois pontos de coleta no período estudado, alerta-se para a necessidade de avaliação sistemática da presença de pesticidas em água para consumo humano, particularmente, em regiões com intensa atividade agrícola. Tal monitoramento pode fornecer subsídios para políticas públicas ambientais

Higher derivative correction to Kaluza-Klein black hole solution

We investigate the attractor mechanism in Kaluza-Klein black hole solution in the presence of higher derivative terms. In particular, we discuss the attractor behavior of static black holes by using the effective potential approach as well as entropy function formalism. We consider different higher derivative terms with a general coupling to moduli field. For the $R^2$ theory, we use effective potential approach, looking for solutions which are analytic near the horizon and show that they exist and enjoy the attractor behavior. The attractor point is determined by extremization of the modified effective potential at the horizon. We study the effect of the general higher derivative corrections of $R^n$ terms. Using the entropy function we define the modified effective potential and we find the conditions to have the attractor solution. In particular for a single charged Kaluza-Klein black hole solution we show that higher derivative correction dresses the naked singularity for an appropriate coupling, and we can find the attractor solution.Comment: 25 pages, 2 figures, JHEP sty

On exact solutions for quintessential (inflationary) cosmological models with exponential potentials

We first study dark energy models with a minimally-coupled scalar field and exponential potentials, admitting exact solutions for the cosmological equations: actually, it turns out that for this class of potentials the Einstein field equations exhibit alternative Lagrangians, and are completely integrable and separable (i.e. it is possible to integrate the system analytically, at least by quadratures). We analyze such solutions, especially discussing when they are compatible with a late time quintessential expansion of the universe. As a further issue, we discuss how such quintessential scalar fields can be connected to the inflationary phase, building up, for this class of potentials, a quintessential inflationary scenario: actually, it turns out that the transition from inflation toward late-time exponential quintessential tail admits a kination period, which is an indispensable ingredient of this kind of theoretical models. All such considerations have also been done by including radiation into the model.Comment: Revtex4, 10 figure