Uncertainty Theories Based Iris Recognition System

The performance and robustness of the iris-based recognition systems still suffer from imperfection in the biometric information. This paper makes an attempt to address these imperfections and deals with important problem for real system. We proposed a new method for iris recognition system based on uncertainty theories to treat imperfection iris feature. Several factors cause different types of degradation in iris data such as the poor quality of the acquired pictures, the partial occlusion of the iris region due to light spots, or lenses, eyeglasses, hair or eyelids, and adverse illumination and/or contrast. All of these factors are open problems in the field of iris recognition and affect the performance of iris segmentation, its feature extraction or decision making process, and appear as imperfections in the extracted iris feature. The aim of our experiments is to model the variability and ambiguity in the iris data with the uncertainty theories. This paper illustrates the importance of the use of this theory for modeling or/and treating encountered imperfections. Several comparative experiments are conducted on two subsets of the CASIA-V4 iris image database namely Interval and Synthetic. Compared to a typical iris recognition system relying on the uncertainty theories, experimental results show that our proposed model improves the iris recognition system in terms of Equal Error Rates (EER), Area Under the receiver operating characteristics Curve (AUC) and Accuracy Recognition Rate (ARR) statistics

Indoor/outdoor navigation system based on possibilistic traversable area segmentation for visually impaired people

Autonomous collision avoidance for visually impaired people requires a specific processing for an accurate definition of traversable area. Processing of a real time image sequence for traversable area segmentation is quite mandatory. Low cost systems suggest use of poor quality cameras. However, real time low cost camera suffers from great variability of traversable area appearance at indoor as well as outdoor environments. Taking into account ambiguity affecting object and traversable area appearance induced by reflections, illumination variations, occlusions (, etc...), an accurate segmentation of traversable area in such conditions remains a challenge. Moreover, indoor and outdoor environments add additional variability to traversable areas. In this paper, we present a real-time approach for fast traversable area segmentation from image sequence recorded by a low-cost monocular camera for navigation system. Taking into account all kinds of variability in the image, we apply possibility theory for modeling information ambiguity. An efficient way of updating the traversable area model in each environment condition is to consider traversable area samples from the same processed image for building its possibility maps. Then fusing these maps allows making a fair model definition of the traversable area. Performance of the proposed system was evaluated on public databases, with indoor and outdoor environments. Experimental results show that this method is challenging leading to higher segmentation rates

High level production and purification of human interferon α2b in high cell density culture of Pichia pastoris.

Human interferon α2b gene was cloned in the methylotrophic yeast Pichia pastoris under the control of the AOX1 methanol inducible promoter. To optimise the volumetric productivity, we performed different fed-batch studies in a 5-L bioreactor. We demonstrated that hIFNα2b was highly sensitive to proteases activity during high cell density culture. The target protein was totally degraded 20 h after the start of methanol feeding. Replacement of culture medium with fresh medium after glycerol fed-batch culture mode as well as medium enrichment with casamino acids at 0.1% and EDTA at 10 mM, had significantly improved hIFNα2b expression and prevented its proteolysis. Moreover, to further improve hIFNα2b production, three different methanol fed-batch strategies had been assayed in high cell density culture. The optimal strategy resulted in a production level of 600 mg/l while residual methanol level was maintained below 2 g/l. Clarification of culture supernatant through a 0.1 μm hollow fiber cartridge showed that almost 95% of the target protein was retained within the retentate. Triton X-100 or NaCl addition to the culture harvest before microfiltration had improved the recovery yield of this step. rhIFNα2b was further purified by cation exchange on Sepharose SP resin followed by gel permeation on Sephacryl S-100. The overall yield of the process was equal to 30% (180 mg/l). The biological activity of the purified protein based on the antiviral activity test was 1.5 × 108 IU/mg. The optimised process has a great potential for large scale production of fully functional hIFNα2b.pre-print3123 K

Association analysis of polymorphisms in EGFR, HER2, ESR1 and THRA genes with coronary artery diseases

Background: Research in the genetic basis of coronary artery diseases (CAD) has identified some genes and pathways associated with diseases that would not be considered to underlie conventional risk factors. Among these genes there are the EGFR (epidermal growth factor receptor) receptor family genes and the regulation factor genes (such as thyroid hormone receptor a (THRA) and estrogen receptor a (ESR1)).Aim: In this study we investigated the relation between 4 polymorphisms within EGFR, HER2 (human epidermal growth factor receptor 2), ESR1 and THRA genes and CAD.Subjects and methods: The association analysis was performed with 151 healthy individuals and 151 CAD patients documented by angiography.Results: No significant difference was found in the allelic and genotypic frequency distribution of the four variants studied between the control and patient groups. We have also investigated the relationship of these polymorphic sites with clinical and biochemical parameters such as smoking habit, diabetes mellitus, hypertension, dyslipidemia, CAD severity, glucose, triglyceride, total cholesterol and urea levels. The EGFR and THRA variants were associated with glycemia and triglyceride levels, respectively. Also a significant correlation was found between the ESR1 polymorphism and the levels of urea and triglyceride.Conclusion: Our results suggest the absence of any significant association between the four polymorphisms analyzed and CAD risk as well as disease severity

Étude du flambage des plaques composites

Nous étudions dans ce travail le comportement des plaques composites spécialement orthotropes en compression plane, dans le domaine élastique. Cette étude est effectuée en développant un programme d'éléments finis qui utilise des éléments rectangulaires à quatres noeuds et à six degrés de libertés par noeuds. Le programme ainsi développé est utilisé pour étudier l'influence de quelques paramètres sur la stabilité et le comportement post critique des plaques composites spécialement orthotropes. Nous avons ensuite examiné les plaques testées expérimentalement par Hoa et al

Étude du flambage des plaques composites

Nous étudions dans ce travail le comportement des plaques composites spécialement orthotropes en compression plane, dans le domaine élastique. Cette étude est effectuée en développant un programme d'éléments finis qui utilise des éléments rectangulaires à quatres noeuds et à six degrés de libertés par noeuds. Le programme ainsi développé est utilisé pour étudier l'influence de quelques paramètres sur la stabilité et le comportement post critique des plaques composites spécialement orthotropes. Nous avons ensuite examiné les plaques testées expérimentalement par Hoa et al

Kohn–Vogelius formulation and topological sensitivity analysis based method for solving geometric inverse problems

In this paper, we propose an alternative approach combining the advantages of the Kohn–Vogelius formulation and the topological sensitivity analysis method for solving geometric inverse problems. The Kohn–Vogelius formulation can rephrase the geometric inverse problem into a shape optimization one minimizing an energy-like function. The sensitivity analysis gives the leading term of the energy-like function variation with respect to the presence of a small geometry perturbation inside the computational domain. The obtained theoretical results lead to build a fast and accurate numerical reconstruction algorithm. The efficiency and accuracy of the proposed algorithm are illustrated by some numerical results

Probability-Possibility Theories Based Iris Biometric Recognition System

The performance and robustness of the iris-based recognition systems still suffer from imperfection in the biometric information. This paper makes an attempt to address these imperfections and deals with important problem for real system. We proposed a new method for iris recognition system based on uncertainty theories to treat imperfection iris feature. Several factors cause different types of degradation in iris data such as the poor quality of the acquired pictures, the partial occlusion of the iris region due to light spots, or lenses, eyeglasses, hair or eyelids, and adverse illumination and/or contrast. All of these factors are open problems in the field of iris recognition and affect the performance of iris segmentation, its feature extraction or decision making process, and appear as imperfections in the extracted iris feature. The aim of our experiments is to model the variability and ambiguity in the iris data with the uncertainty theories. This paper illustrates the importance of the use of this theory for modeling or/and treating encountered imperfections. Several comparative experiments are conducted on two subsets of the CASIA-V4 iris image database namely Interval and Synthetic. Compared to a typical iris recognition system relying on the uncertainty theories, experimental results show that our proposed model improves the iris recognition system in terms of Equal Error Rates (EER), Area Under the receiver operating characteristics Curve (AUC) and Accuracy Recognition Rate (ARR) statistics

Optimisation de forme des structures hyperélastiques incompressibles et anisotropes

Dans ce travail, nous nous sommes intéressés à l’optimisation de forme des structures dont le comportement est hyperélastique incompressible et anisotrope. La fonction énergie est décomposée en une composante isotrope et une composante anisotrope. L’approche décrite dans cet article est le calcul exact de la sensibilité pour les éléments solides en utilisant un matériau à comportement hyperélastique. La résolution du problème mécanique est faite par la méthode des éléments-finis en utilisant un algorithme d’optimisation appelé SQP (Sequential Quadratic Programming). Le critère d’optimisation (fonction objectif à minimiser) est défini à partir du critère de Von Mises avec une limitation de conservation du volume. Les variables d’optimisation sont les coordonnées des points de contrôle avec une paramétrisation par les courbes de B-splines. La faisabilité de la méthode développée est validée par un exemple numérique avec une comparaison du calcul de la sensibilité par la méthode des différences finies