Robust predictive control based on the Meixner-like model     

Safa Maraoui  Abdelkader Krifa  Kais Bouzrara 《Journal of The Franklin Institute》2019,356(12):6226-6254

This paper is devoted to the issue of a robust predictive control for linear discrete-time systems by using Meixner-like model. The Meixner-like functions are an extension of Laguerre functions and convenient when the system has a slow start or delay. To ensure the reduction of the parameter number in the Meixner-like model, the optimization of parameters characterizing the Meixner-like functions is proposed. This proposed robust predictive control copes with physical constraints and geometrical constraints due to parameter uncertainties, which are estimated by using the Unknown But Bounded Error (UBBE) approach, and leads to the min-max optimization problem.  相似文献   

Arabic texts analysis for topic modeling evaluation     

Abderrezak Brahmi  Ahmed Ech-Cherif  Abdelkader Benyettou 《Information Retrieval》2012,15(1):33-53

Significant progress has been made in information retrieval covering text semantic indexing and multilingual analysis. However, developments in Arabic information retrieval did not follow the extraordinary growth of Arabic usage in the Web during the ten last years. In the tasks relating to semantic analysis, it is preferable to directly deal with texts in their original language. Studies on topic models, which provide a good way to automatically deal with semantic embedded in texts, are not complete enough to assess the effectiveness of the approach on Arabic texts. This paper investigates several text stemming methods for Arabic topic modeling. A new lemma-based stemmer is described and applied to newspaper articles. The Latent Dirichlet Allocation model is used to extract latent topics from three Arabic real-world corpora. For supervised classification in the topics space, experiments show an improvement when comparing to classification in the full words space or with root-based stemming approach. In addition, topic modeling with lemma-based stemming allows us to discover interesting subjects in the press articles published during the 2007–2009 period.  相似文献   

A method for determining generators’ shares in loads, line flows and losses     

S. Abdelkader 《Journal of The Franklin Institute》2007,344(8):1063-1074

This paper presents a new method for calculating the individual generators’ shares in line flows, line losses and loads. The method is described and illustrated on active power flows, but it can be applied in the same way to reactive power flows.Starting from a power flow solution, the line flow matrix is formed. This matrix is used for identifying node types, tracing the power flow from generators downstream to loads, and to determine generators’ participation factors to lines and loads. Neither exhaustive search nor matrix inversion is required. Hence, the method is claimed to be the least computationally demanding amongst all of the similar methods.  相似文献   

The myth of literacy relapse: Literacy retention among Moroccan primary school leavers     

Daniel A. Wagner  Jennifer E. Spratt  Gary D. Klein  Abdelkader Essaki 《International Journal of Educational Development》1989,9(4)

The issue of literacy retention is central to the educational policy concerning of most developing countries. It has been variously suggested that 4–6 years of primary education may serve as an inoculation against ‘relapse’ into illiteracy in the Third World. This paper reports on one of the first longitudinal studies designed to address this question, by investigating the nature of literacy and cognitive retention in a sample of 72 adolescents two years following fifth grade departure from primary school in Morocco. The present study found that these school leavers, when reassessed two years later, showed a significant increase in performance in first literacy (Arabic), modest gains in second literacy (French), no change in cognitive skills, and a decrement in math skill. Furthermore, urban leavers gained more literacy than rural leavers, and girls more than boys. The present findings do not support the hypothesis of literacy ‘relapse’ or loss of academic/cognitive skills after five grades of primary schooling. It was also found that girls retained more academic skills than boys, but were much less likely to be employed, a finding which calls into question certain claims about the impact of schooled knowledge and literacy on employment in developing countries.  相似文献