203 research outputs found
Artificial Neural Network Symbol Estimator With Enhanced Robustness to Nonlinear Phase Noise
This letter reports a novel approach for nonlinear phase noise mitigation, based on artificial neural networks (ANNs) tailored to classification applications and a pre-processing stage of feature engineering. Starting with a set of proof-of-concept simulations, we verify that the proposed system can achieve optimal performance for the additive white Gaussian noise (AWGN) channel. Then, considering a dispersion-less channel with strong nonlinear phase noise (NLPN) distortion, we demonstrate a Q-factor increase of 0.4dB, comparing with standard carrier-phase estimation (CPE) followed by minimum distance detection. Finally, simulating the propagation of 64Gbaud PM-16QAM over standard single mode fiber (SSMF), we verify that the ANN-based solution is effective on wavelength-division multiplexing (WDM) transmission conditions, enabling to increase the maximum signal reach by approximately 1 fiber span over the legacy CPE-enabled NLPN compensation
Intense violet–blue emission and paramagnetism of nanocrystalline Gd3+ doped ZnO ceramics
Nanocrystalline Zn1-xGdxO (x = 0, 0.02, 0.04, 0.06, and 0.08) ceramics were synthesized by ball milling and subsequent solid-state reaction. The transmission electron microscopy (TEM) micrograph of as synthesized samples revealed the formation of crystallites with an average diameter of 60 nm, and the selected area electron diffraction (SAED) pattern confirmed the formation of wurtzite structure. A red shift in the band gap was observed with increasing Gd3+ concentration. The photoluminescence of nanocrystalline Gd3+ doped ZnO exhibited a strong violet–blue emission. Concentration dependence of the emission intensity of Gd3+ in ZnO was studied, and the critical concentration was found to be 4 mol% of Gd3+. The Gd3+ doped ZnO exhibited paramagnetic behavior at room temperature, and the magnetic moment increased with Gd3+ concentration
Desvio fonológico e alterações práxicas orofaciais e do sistema estomatognático
OBJETIVO: verificar, bem como relacionar entre si, o desempenho de crianças com Desvio Fonológico e com Desenvolvimento Fonológico TÃpico na avaliação do Sistema Estomatognático e em testes de habilidades práxicas orofaciais avaliando suas habilidades práxicas orofaciais. MÉTODOS: amostra constituiu-se de 50 sujeitos, com idades entre quatro e oito anos, com Desvio Fonológico e com Desenvolvimento Fonológico TÃpico. Avaliou-se a fonologia por meio do instrumento Avaliação Fonológica da Criança e a gravidade do desvio por meio do Percentual de Consoantes Corretas. Posteriormente, aplicou-se a Avaliação do sistema estomatongático e o The Orofacial Praxis Test, para avaliar as habilidades práxicas orofaciais. Os dados foram tabulados e submetidos a tratamento estatÃstico, considerando-se p<0,05. RESULTADOS: com relação ao sistema estomatongático, observou-se diferença estatÃstica entre os grupos apenas nas tarefas de assobio, contração e vibração de lábios e de lÃngua, apresentando desempenho inferior as crianças com Desvio Fonológico. O mesmo foi observado quanto à postura de lÃngua na sucção. As médias obtidas nas tarefas de habilidades práxicas orofaciais realizadas após Imitação foram melhores que após Solicitação Verbal, para todas as idades. Ainda, as crianças com menor idade apresentaram mais alterações que as crianças maiores, da mesma forma que as crianças com Desvio Fonológico apresentaram mais dificuldades que aquelas sem alterações de fala. CONCLUSÃO: as crianças com Desvio Fonológico apresentaram mais alterações do sistema estomatognático e das habilidades práxicas orofaciais que aquelas com Desenvolvimento Fonológico TÃpico, havendo melhora no desempenho com o avanço da idade e encontrando-se estas alterações relacionadas com as alterações de fala
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Naturopathic Care for Anxiety: A Randomized Controlled Trial ISRCTN78958974
BACKGROUND: Anxiety is a serious personal health condition and represents a substantial burden to overall quality of life. Additionally anxiety disorders represent a significant cost to the health care system as well as employers through benefits coverage and days missed due to incapacity. This study sought to explore the effectiveness of naturopathic care on anxiety symptoms using a randomized trial. METHODS: Employees with moderate to severe anxiety of longer than 6 weeks duration were randomized based on age and gender to receive naturopathic care (NC) (n = 41) or standardized psychotherapy intervention (PT) (n = 40) over a period of 12 weeks. Blinding of investigators and participants during randomization and allocation was maintained. Participants in the NC group received dietary counseling, deep breathing relaxation techniques, a standard multi-vitamin, and the herbal medicine, ashwagandha (Withania somnifera) (300 mg b.i.d. standardized to 1.5% with anolides, prepared from root). The PT intervention received psychotherapy, and matched deep breathing relaxation techniques, and placebo. The primary outcome measure was the Beck Anxiety Inventory (BAI) and secondary outcome measures included the Short Form 36 (SF-36), Fatigue Symptom Inventory (FSI), and Measure Yourself Medical Outcomes Profile (MY-MOP) to measure anxiety, mental health, and quality of life respectively. Participants were blinded to the placebo-controlled intervention. RESULTS: Seventy-five participants (93%) were followed for 8 or more weeks on the trial. Final BAI scores decreased by 56.5% (p<0.0001) in the NC group and 30.5% (p<0.0001) in the PT group. BAI group scores were significantly decreased in the NC group compared to PT group (p = 0.003). Significant differences between groups were also observed in mental health, concentration, fatigue, social functioning, vitality, and overall quality of life with the NC group exhibiting greater clinical benefit. No serious adverse reactions were observed in either group. RELEVANCE: Many patients seek alternatives and/or complementary care to conventional anxiety treatments. To date, no study has evaluated the potential of a naturopathic treatment protocol to effectively treat anxiety. Knowledge of the efficacy, safety or risk of natural health products, and naturopathic treatments is important for physicians and the public in order to make informed decisions. INTERPRETATION: Both NC and PT led to significant improvements in patients' anxiety. Group comparison demonstrated a significant decrease in anxiety levels in the NC group over the PT group. Significant improvements in secondary quality of life measures were also observed in the NC group as compared to PT. The whole system of naturopathic care for anxiety needs to be investigated further including a closer examination of the individual components within the context of their additive effect. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN78958974
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