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This paper deals with the analysis of the number of tourists travelling to the Canary Islands by means of using different seasonal statistical models. Deterministic and stochastic seasonality is considered. For the latter case, we employ seasonal unit roots and seasonally fractionally integrated models. As a final approach, we also employ a model with possibly different orders of integration at zero and the seasonal frequencies. All these models are compared in terms of their forecasting ability in an out‐of‐sample experiment. The results in the paper show that a simple deterministic model with seasonal dummy variables and AR(1) disturbances produce better results than other approaches based on seasonal fractional and integer differentiation over short horizons. However, increasing the time horizon, the results cannot distinguish between the model based on seasonal dummies and another using fractional integration at zero and the seasonal frequencies. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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The implication of corporate bankruptcy prediction is important to financial institutions when making lending decisions. In related studies, many bankruptcy prediction models have been developed based on some machine‐learning techniques. This paper presents a meta‐learning framework, which is composed of two‐level classifiers for bankruptcy prediction. The first‐level multiple classifiers perform the data reduction task by filtering out unrepresentative training data. Then, the outputs of the first‐level classifiers are utilized to create the second‐level single (meta) classifier. The experiments are based on five related datasets and the results show that the proposed meta‐learning framework provides higher prediction accuracy rates and lower type I/II errors when compared with the stacked generalization classifier and other three widely developed baselines, such as neural networks, decision trees, and logistic regression. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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The problem of prediction in time series using nonparametric functional techniques is considered. An extension of the local linear method to regression with functional explanatory variable is proposed. This forecasting method is compared with the functional Nadaraya–Watson method and with finite‐dimensional nonparametric predictors for several real‐time series. Prediction intervals based on the bootstrap and conditional distribution estimation for those nonparametric methods are also compared. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
46.
Standard measures of prices are often contaminated by transitory shocks. This has prompted economists to suggest the use of measures of underlying inflation to formulate monetary policy and assist in forecasting observed inflation. Recent work has concentrated on modelling large data sets using factor models. In this paper we estimate factors from data sets of disaggregated price indices for European countries. We then assess the forecasting ability of these factor estimates against other measures of underlying inflation built from more traditional methods. The power to forecast headline inflation over horizons of 12 to 18 months is adopted as a valid criterion to assess forecasting. Empirical results for the five largest euro area countries, as well as for the euro area itself, are presented. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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R. W. Trottier Jr E. Moore J. McMillan N. Evans 《Cellular and molecular life sciences : CMLS》1977,33(5):639-640
Summary The intensity of the hyperthermic response in rats promoted by subplantar injection of 1 mg of carrageenin is directly related to the irritant properties of the type of carrageenin. The overall pyretic response is more dramatic in female rats than in male rats. Subtle changes in the time-course hyperthermic profiles are seen after hormonal modifications.This work was supported by NIH, MBS research grant No. RR08111. 相似文献
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H Alexandre 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(16):1215-1217
Alpha-Methylornithine, an inhibitor of the synthesis of putrescine does not affect the cleavage of Mouse eggs, cultured in vitro from the 2-cell stage, before blastocyst formation, whereas methylglyoxal-Bis (guanylhydrazone), an inhibitor of the syntheses of spermidine and spermine induces the embryos to become quiescent at about the 8-cell stage; resumption of their development, after transfer to fresh medium, is followed by a delay in cavitation. These results may be related to the biological clock theory for primary differentiation. 相似文献
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