Mohamed E. Lalami, Hala Rifaï, Samer Mohammed, Walid Hassani, Georges Fried and Yacine Amirat
– The purpose of this paper is the control of lower limb orthosis acting at the knee joint level for a passive rehabilitation purpose.
Abstract
Purpose
The purpose of this paper is the control of lower limb orthosis acting at the knee joint level for a passive rehabilitation purpose.
Design/methodology/approach
A control law, based on a saturated proportional derivative controller, is proposed in order to drive the shank-foot-orthosis system along a desired trajectory.
Findings
The proposed control law is tested in real time using the orthosis EICOSI of the LISSI-Laboratory. The experiments show that the proposed control law is capable of providing satisfactory trajectory tracking performance given only the knee joint angle measurement. Moreover, the control law is robust with respect to external disturbances.
Originality/value
Robust control of an actuated lower limb orthosis.
Details
Keywords
Robert C. Moussetis, Ali Abu Rahma and George Nakos
This paper examined the relationships between national culture and strategic behavior in the banking industry in Jordan and U.S. The study first developed a strategic posture and…
Abstract
This paper examined the relationships between national culture and strategic behavior in the banking industry in Jordan and U.S. The study first developed a strategic posture and secondly a cultural profile for the top management of the research domain. The strategic posture suggested the readiness for strategic response from managers. The degree of readiness was correlated with the constructed cultural profile of the managers and financial performance of the banks. The study found significant relationships between certain national cultural strategic characteristics, (risk propensity, time orientation, and openness to change, uncertainty avoidance and managerial perception of control over the environment) strategic behavior and financial performance.
Details
Keywords
The purpose of this study is to investigate the volatility and forecast accuracy of the Islamic stock market for the period 1999–2017. This period is characterized by the…
Abstract
Purpose
The purpose of this study is to investigate the volatility and forecast accuracy of the Islamic stock market for the period 1999–2017. This period is characterized by the occurrence of several economic and political events such as the September 11, 2001, terrorist attack and the 2007–2008 global financial crisis.
Design/methodology/approach
This study constructs a new hybrid generalized autoregressive conditional heteroskedasticity (GARCH)-type model based on an artificial neural network (ANN). This model is applied to the daily Dow Jones Islamic Market World Index during the period June 1999–January 2017.
Findings
The in-sample results show that the volatility of the Islamic stock market can be better described by the fractionally integrated asymmetric power ARCH (FIAPARCH) approach that takes into account asymmetry and long memory features. Considering the out-of-sample analysis, this paper has applied a hybrid forecasting model, which combines the FIAPARCH approach and the ANN. Empirical results reveal that the proposed hybrid model (FIAPARCH-ANN) outperforms all other single models such as GARCH, fractional integrated GARCH and FIAPARCH in terms of all performance criteria used in the study.
Practical implications
The results have some implications for Islamic investors, portfolio managers and policymakers. These implications are related to the optimal portfolio diversification decision, the hedging strategy choice and the risk management analysis.
Originality/value
The paper develops a new framework that combines an ANN and FIAPARCH model that introduces two important features of time series, namely, asymmetry and long memory.