Research ArticleOpen accessIn the abstractReduced Order Models of a Current Source Inverter Induction Motor DriveIbrahim K. Al-AbbasProblem Statement: The current source inverter induction motor (CSI-IM) drive was widely used in various industries. The main disadvantage of this drive was nonlinearity and complexity. This work was done to develop a simple drive systems models. Approach: The MATLAB/SIMULINK software was used for system modeling. Three reduced models were developed by choosing specific frame, neglecting stator transients and ignoring … …American Journal of Engineering and Applied Sciences, Vol. 2, Issue 1 · 31 Mar 2009 · 7,865 accessesView PDFCite
Research ArticleOpen accessIn the abstractModelling and Forecasting Volatility of Returns on the Ghana Stock Exchange Using Garch ModelsFrimpong Joseph Magnus, Oteng-Abayie Eric FosuThis paper models and forecasts volatility (conditional variance) on the Ghana Stock Exchange using a random walk (RW), GARCH(1,1), EGARCH(1,1), and TGARCH(1,1) models. The unique ‘three days a week’ Databank Stock Index (DSI) was used to study the dynamics of the Ghana stock market volatility over a 10-year period. The competing volatility models were estimated and their specification and forecast … …American Journal of Applied Sciences, Vol. 3, Issue 10 · 31 Oct 2006 · 7,551 accessesView PDFCite