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Coherent soliton propagation through doped optical fibers: cloning, breakup, and soliton interactions Anais da ABC (AABC)
CAVALCANTI,SOLANGE B.; FONSECA,EDUARDO J. DA S.; CAETANO,DILSON P.; HICKMANN,JANDIR M..
The simultaneous propagation of two optical pulses through a doped nonlinear dispersive medium modelled by a resonant three-level system was investigated numerically, within the framework of a pair of coupled extended nonlinear Schrödinger equations. These included the contribution of the dopant resonances whose dynamics is governed by Bloch equations. In this work, we review the interesting possibilities on the manipulation of fields such as cloning, breakup and soliton interactions, that the combination of coherent population trapping with nonlinear dispersive media offers.
Tipo: Info:eu-repo/semantics/article Palavras-chave: Soliton; Quantum coherence; Nonlinearity; Cloning.
Ano: 2001 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000200005
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Price Transmission and Adjustment in the Ethiopian Coffee Market AgEcon
Alemu, Zerihun Gudeta; Worako, Tadesse Kumma.
This study focused on the interrelationships among producer, auction and world prices. In so doing, it criticized previous studies and extended technique developed by Hansen (1999) to handle inferential biases occurring as a result of specification errors. The following results were found: unidirectional transmission of shocks from the world price to the auction price and then to the producer price; asymmetries in price transmissions and adjustments in the auction market; weak interrelationship between producer and world prices causing producer price to be less responsive to changes in the world prices. In general, results imply that coffee growers’ benefit little from positive changes in the world price compared with participants in the auction markets....
Tipo: Conference Paper or Presentation Palavras-chave: Coffee; Ethiopia; Threshold vector error correction models; Nonlinearity; Demand and Price Analysis.
Ano: 2009 URL: http://purl.umn.edu/51085
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Nonlinearity in the Return to Education AgEcon
Trostel, Philip A..
This study estimates marginal rates of return to investment in schooling in 12 countries. Significant systematic nonlinearity in the marginal rate of return is found. In particular, the marginal rate of return is increasing significantly at low levels of education, and decreasing significantly at high levels of education. This may help explain why estimates of the return to schooling are often considerably higher when instrumenting for education.
Tipo: Journal Article Palavras-chave: Return to education; Nonlinearity; Instrumental variables; I20; J24.
Ano: 2005 URL: http://purl.umn.edu/37550
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Sample Size and Robustness of Inferences from Logistic Regression in the Presence of Nonlinearity and Multicollinearity AgEcon
Bergtold, Jason S.; Yeager, Elizabeth A.; Featherstone, Allen M..
The logistic regression models has been widely used in the social and natural sciences and results from studies using this model can have significant impact. Thus, confidence in the reliability of inferences drawn from these models is essential. The robustness of such inferences is dependent on sample size. The purpose of this study is to examine the impact of sample size on the mean estimated bias and efficiency of parameter estimation and inference for the logistic regression model. A number of simulations are conducted examining the impact of sample size, nonlinear predictors, and multicollinearity on substantive inferences (e.g. odds ratios, marginal effects) and goodness of fit (e.g. pseudo-R2, predictability) of logistic regression models. Findings...
Tipo: Conference Paper or Presentation Palavras-chave: Logistic Regression Model; Multicollinearity; Nonlinearity; Robustness; Small Sample Bias; Research Methods/ Statistical Methods.
Ano: 2011 URL: http://purl.umn.edu/103771
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Price Transmission Asymmetries and Nonlinearities in the International Coffee Supply Chain AgEcon
Lee, Jun; Gomez, Miguel I..
We examine two distinct and important dimensions (e.g. symmetry vs. asymmetry and linearity vs. nonlinearity) of price transmission from international to retail coffee prices in France, Germany and the United States. We show that ignoring these two features of the price transmission process may lead to misleading impact assessments resulting from the elimination of International Coffee Agreement (ICA) in 1990. Our results confirm the presence of threshold effects in both periods (ICA and post ICA) in all three countries. Our estimates show that, in the long-run, the speed of adjustment toward equilibrium becomes faster during the post-ICA period in France and Germany. Our results suggest that, for these two countries, changes in international prices did...
Tipo: Conference Paper or Presentation Palavras-chave: Threshold; Nonlinearity; Asymmetric Price Transmission; Roasted Coffee; Germany; United States; France; Error Correction Model; Demand and Price Analysis; International Relations/Trade; C32; Q17.
Ano: 2011 URL: http://purl.umn.edu/104024
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Superior Forecasts of the U.S. Unemployment Rate Using a Nonparametric Method AgEcon
Golan, Amos; Perloff, Jeffrey M..
We use a nonlinear, nonparametric method to forecast the unemployment rates. We compare these forecasts to several linear and nonlinear parametric methods based on the work of Montgomery et al. (1998) and Carruth et al. (1998). Our main result is that, due to the nonlinearity in the data generating process, the nonparametric method outperforms many other wellknown models, even when these models use more information. This result holds for forecasts based on quarterly and on monthly data.
Tipo: Working or Discussion Paper Palavras-chave: Embedding dimension; Nonlinearity; Nonparametric; Unemployment rate; Labor and Human Capital.
Ano: 2002 URL: http://purl.umn.edu/25060
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