On Lorentz dynamics : From group actions to warped products via homogeneous spaces

We show a geometric rigidity of isometric actions of non compact (semisimple) Lie groups on Lorentz manifolds. Namely, we show that the manifold has a warped product structure of a Lorentz manifold with constant curvature by a Riemannian manifold

Actions of noncompact semisimple groups on Lorentz manifolds

The above title is the same, but with "semisimple" instead of "simple," as that of a notice by N. Kowalsky. There, she announced many theorems on the subject of actions of simple Lie groups preserving a Lorentz structure. Unfortunately, she published proofs for essentially only half of the announced results before her premature death. Here, using a different, geometric approach, we generalize her results to the semisimple case, and give proofs of all her announced results.Comment: 25 pp, to appear in Geometric and Functional Analysis sharpened thm 1.9 to give global description of actions in all cases; added section 8 on structure of orbits of Riemannian type and how Riemannian and Lorentzian orbits meet around degenerate set; many minor corrections and improvements thanks to referee's comment

Handwritten Character Recognition Based on the Specificity and the Singularity of the Arabic Language

A good Arabic handwritten recognition system must consider the characteristics of Arabic letters which can be explicit such as the presence of diacritics or implicit such as the baseline information (a virtual line on which cursive text are aligned and/join). In order to find an adequate method of features extraction, we have taken into consideration the nature of the Arabic characters. The paper investigate two methods based on two different visions: one describes the image in terms of the distribution of pixels, and the other describes it in terms of local patterns. Spatial Distribution of Pixels (SDP) is used according to the first vision; whereas Local Binary Patterns (LBP) are used for the second one. Tested on the Arabic portion of the Isolated Farsi Handwritten Character Database (IFHCDB) and using neural networks as a classifier, SDP achieve a recognition rate around 94% while LBP achieve a recognition rate of about 96%

Multi-agent Systems for Arabic Handwriting Recognition

This paper aims to give a presentation of the PhD defended by Boulid Youssef on December 26th, 2016 at University Ibn Tofail, entitled “Arabic handwritten recognition in an offline mode”. The adopted approach is realized under the multi agent paradigm. The dissertation was held in Faculty of Science Kénitra in a publicly open presentation. After the presentation, Boulid was awarded with the highest grade (Très honorable avec félicitations de jury)

Detection of Text Lines of Handwritten Arabic Manuscripts using Markov Decision Processes

In a character recognition systems, the segmentation phase is critical since the accuracy of the recognition depend strongly on it. In this paper we present an approach based on Markov Decision Processes to extract text lines from binary images of Arabic handwritten documents. The proposed approach detects the connected components belonging to the same line by making use of knowledge about features and arrangement of those components. The initial results show that the system is promising for extracting Arabic handwritten lines

Conceptual Architecture for Agent-Based Modelling of Supplier Selection Conducted by a Supply Chain Dyad

Within the fourth stage of industrialization, artificial intelligence and in particular the multi-agent systems paradigm is highly adopted. Within the agent approach, the industrial resources are defined as intelligent agents that negotiate with each other to implement dynamic reconfiguration and reach agility and higher customer satisfaction. In this paper a smart configuration of the agent-based system for multi-product dyadic supplier selection is proposed. The objective is to select suppliers for multiple products simultaneously in a vertical collaboration context while involving the customer of the purchasing company and considering its preferences. Negotiation experiments are conducted for initial validation of the proposed conceptual architecture

Service oriented centered e-health solution for monitoring and preventing chronic diseases

The modern and continuously changing lifestyles in almost all parts of the world resulted in an increase in the incidence of chronic diseases (CDs). To reduce risks associated with chronic diseases, health professionals are studying various clinical solutions. As a result of recent advances in sensing technology, wireless communications, and distributed communication, the monitoring of patients\u27 health condition and the elaboration of prevention plans are considered the most promising solutions for the treatment of chronic diseases. In this paper, we propose a novel framework for monitoring chronic diseases and tracking their vital signs. The framework relies on the service orientation concepts and standards to integrate various subsystems. Monitoring of subjects\u27 health condition, using various sensors and wireless devices, aims to proactively detect any risk of chronic diseases. The system will allow generating and customizing preventive plans dynamically according to the subject\u27s health profile and context while considering many impelling parameters. As a proof of concept of our monitoring and tracking schemes, we have considered a case study for which we have collected and analyzed preliminary data

An Extender Kalman Filter-based Induction Machines Faults Detection

This paper deals with the detection and localization of electrical drives faults, especially those containing induction machines. First, the context of the study is presented and an Extended Kalman Filter is described for induction machines fault detection. Then the modeling procedure under faulty conditions is shown, and the machine diagnosis methods are developed. The proposed diagnosis approach requires only little experimental data, and more importantly it provides efficient simulation tools that allow characterizing faulty behavior.Fault detection uses signal processing techniques in known operating phases (fixed speed), considering and locating malfunctions