This note is a contribution to the application of generalized inverse of homomorphisms of modules in ring(module)theory.Using the{1}-and{2}-inverses of homomorphisms of modules,we characterize a class of rings and an ...This note is a contribution to the application of generalized inverse of homomorphisms of modules in ring(module)theory.Using the{1}-and{2}-inverses of homomorphisms of modules,we characterize a class of rings and an important class of modules respectively.展开更多
This paper looks at forecasting daily exchange rates for the United Kingdom, European Union, and China. Here, the authors evaluate the forecasting performance of neural networks （NN）, vector singular spectrum analys...This paper looks at forecasting daily exchange rates for the United Kingdom, European Union, and China. Here, the authors evaluate the forecasting performance of neural networks （NN）, vector singular spectrum analysis （VSSA）, and recurrent singular spectrum analysis （RSSA） for fore casting exchange rates in these countries. The authors find statistically significant evidence based on the RMSE, that both VSSA and RSSA models outperform NN at forecasting the highly unpredictable exchange rates for China. However, the authors find no evidence to suggest any difference between the forecasting accuracy of the three models for UK and EU exchange rates.展开更多
文摘This note is a contribution to the application of generalized inverse of homomorphisms of modules in ring(module)theory.Using the{1}-and{2}-inverses of homomorphisms of modules,we characterize a class of rings and an important class of modules respectively.
基金supported by a grant from Payame Noor University,Tehran-Iran
文摘This paper looks at forecasting daily exchange rates for the United Kingdom, European Union, and China. Here, the authors evaluate the forecasting performance of neural networks （NN）, vector singular spectrum analysis （VSSA）, and recurrent singular spectrum analysis （RSSA） for fore casting exchange rates in these countries. The authors find statistically significant evidence based on the RMSE, that both VSSA and RSSA models outperform NN at forecasting the highly unpredictable exchange rates for China. However, the authors find no evidence to suggest any difference between the forecasting accuracy of the three models for UK and EU exchange rates.
