121 research outputs found

    The use of Artificial Neural Networks to adjust and robustness study of experience tables of maintenance in disability

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    Pricing and, more important, reserving "life / death" and "disability" risks are strictly defined by the regulation, which imposes particular constraints on the technical rate and the laws of occurrence or maintenance. However, the assessment of portfolios reserving differs from the standard one proposed by the BCAC. Insurance companies are increasingly forced toseek the construction of experience tables to manage these risks, especially since it is unrealistic today to expect offset losses by financial products. Traditional adjustment methods, in actuarial literature, usually used to smooth the recovery curve rate estimated usually by the robust Adjusted Kaplan‐Meier estimator, induce a model error due a boundary bias. The available data are usually sparse and poor quality on the border. Thus a boundary bias is due to weight allocation by the fixed symmetric argument outside the support of the gross curve, when smoothing close to the boundary is carried out. The objective of this work is the use of Artificial Neural Networks (ANN) for adjustment and smoothing experience tables of maintenance in disability applied to a two cycles real set data. The artificial neural networks are parametric nonlinear models able to play an "universal approximator" role achieving a local and global approximation. Two architectures networks are particularly suited to model and smooth gross output rates: Feedforward Neural Networks (FNN) and Radial Basis Functions (RBF) Networks. The robustness of the ANN globally and especially at the edge of curve can be also studied. Graphical tests are used to compare output surfaces rates obtained by neural networks with those obtained by Whittaker‐Henderson framework

    Actuator fault detection and isolation for robot manipulator using higher order sliding mode observers

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    Fault detection and isolation (FDI) approach for actuator faults on a robot manipulator using a model-based FDI fault, which can occur on a specific component of the system. To detect actuator faults, higher order sliding mode Unknown Input Observers (UIO) are proposed to make analytical redundancy. The observers input laws are designed according to the so-called Super-Twisting Second Order Sliding Mode Control (SOSMC) approach and they are proved to be capable of guaranteeing the exponential convergence of the fault estimate to the actual fault signal. The proposed approach is verified in simulation on a robot manipulator

    Fault-tolerant control with high-order sliding mode for manipulator robot

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    The safety of manipulators systems is receiving a lot of attention these days. Faults have the ability to carry out harmful activities that harm equipment, the environment, or persons. As a result, it is critical to detect and diagnose problems as soon as possible, as well as to incorporate fault tolerance to avoid performance deterioration and harmful circumstances. Robust sensor fault detection and isolation (FDI) as well as fault-tolerant control (FTC) for a robotic system are discussed in this work. The goal of this research is to create an FDI method that uses a super-twisting third-order sliding mode (STW-TOSM) observer to estimate residual signals. A suggested system based on a higher-order sliding mode (HOSM) observer/controller approaches is used to accomplish this. In comparison to an active FTC technique, the test results demonstrate high level of performance. Finally, simulation results illustrate the efficacy of the presented techniques

    Impacto do Trauma Relacional Precoce nos Processos Psíquicos em Famílias Vulneráveis: Implicações para o Tratamento de Crianças e Famílias

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    Numerous works and clinical research conducted in various institutions have cast fresh light on the notion of trauma and have contributed to the emergence of the concept of early relational trauma. Early relational trauma is a form of trauma rendered complex by the multiplicity of its sources and its modes of expression. Its main features are often attachment and acting-out disturbances. In families where such trauma occurs, links could sometimes be perverted and form a narcissistic configuration. This mode of functioning, organized around negativity, impacts the plurality of psychic processes and interferes with the treatment approaches of multidisciplinary teams. In order to promote a multifocal approach to care tailored to differences in situations, educational and socio-judicial practitioners.Inúmeros trabalhos e pesquisas clínicas realizados em diversas instituições trouxeram à luz a noção de trauma e contribuíram para o surgimento do conceito de trauma relacional precoce. O trauma relacional precoce é uma forma de trauma complexo pela multiplicidade de suas fontes e seus modos de expressão. Suas principais características são frequentemente distúrbios de apego e atuação. Nas famílias onde ocorre tal trauma que às vezes pode ser pervertido em configurações narcísicas, esse modo de funcionamento organizado em torno da negatividade impacta a pluralidade do psíquico e interfere nas abordagens de tratamento das equipes multidisciplinares. Para promover uma abordagem multifocal de cuidados adaptados às diferenças de situações, profissionais de educação e sócio judiciais

    Étude comparative des performances en production de quelques générations de Solanum tuberosum consommées au Maroc

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    La qualité des tubercules de différentes générations de pomme de terre issues de la variété française Désirée est étudiée par différentes méthodes statistiques. Quelque soit la génération, la germination de tubercules est contrôlée par la température, l’humidité relative et l’hydratation des tubercules. Une corrélation positive existe entre le calibre, le poids des tubercules et la formation des germes; cette dernière est réduite à partir de la 3ème génération probablement à cause d’une différenciation excessive des cellules composant les tubercules et de leur manque en réserves énergétiques. Aucune différence significative n’est décelée entre les trois premières générations qui se sont montrées homogènes pour les calibres, les poids, la différenciation des cellules et leur teneur en grains d’amidon. Au-delà de la 3ème génération des différences notables entre les tubercules sont observées et la production est réduite. Toutes les générations sont sensibles au stress hydrique, mais ce sont les générations âgées qui sont les plus vulnérables à un manque d’eau et à une attaque par les micro-organismes

    Conception d’un Nouveau Mécanisme Aléatoirement Dynamique Optimisé pour le Chiffrement Basé Chaos d’Images

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    Le traitement de message par message permet de réaliser une cryptanalyse fondée sur l’exploitation du contexte général de l’échange. Dans cet article, pour annuler cette vulnérabilité, nous introduisons un nouveau système cryptographique basé chaos pour le chiffrement des images numériques, son fonctionnement est aléatoirement dynamique fondé sur l'utilisation simultanée de plusieurs attracteurs chaotiques. L’étude expérimentale prouve que ce nouveau système produit un cryptage avec un très bon compromis entre sécurité et rapidité en plus il évite que deux messages aient le même chiffré

    BIG HEALTH DATA: A SYSTEMATIC MAPPING STUDY

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    The Big Data, a result of the digital revolution, offers several opportunities in the field of health. Indeed, appliances and applications permanently connected to humans and the global digitalization of medical documents produce a vast health data: "Big Health Data". This data is the subject of several projects in the world given the opportunities offered to optimize this area. This paper focuses on quantifying the production of scientific articles about Big Health Data research and the most investigated Big Health Data topics. It also presents a mapping of countries producing articles about this subject. In remote sensing using real time categories, we aimed to quantify articles dealing with “big data architectures”, technologies and data sources used. A systematic mapping study was conducted with a set of seven research questions by investigating articles from two digital libraries: Scopus and Springer. The study concern articles published in 2017 and the first half of 2018. The results are illustrated by diagrams answering each question from which a set of recommendations are concluded in this area of research. The study shows that this Data is used the most in studies of oncology. Statistics show that while remote sensing and monitoring is a hot topic, real-time use is not as interesting. It was found that there’s a lack in studies interested in big data technologies used in real time remote sensing in the field of health. In conclusion, we recommend more focus on research area treating architecture in remote sensing real time Big Health Data systems combined with geolocation

    A phase 1b clinical trial to determine the safety, tolerability and immunogenicity of simian adenovirus and poxvirus vectored vaccines against Mycobacterium avium complex subspecies in patients with active Crohn's disease

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    BACKGROUND: Crohn's Disease (CD) is a chronic, debilitating condition hypothesised to be associated with Mycobacterium avium ssp paratuberculosis (MAP) infection. It is the causative pathogen of the granulomatous inflammatory enteritis in ruminants, Johne's Disease. A developing treatment approach is utilising heterologous prime-boost viral vectored vaccines. We report a Phase 1b dose-escalation trial to determine the safety, tolerability and immunogenicity of candidate recombinant ChAdOx2 and MVA vectored vaccines against MAP in patients with CD.METHODS: 28 patients with mild to moderate CD, aged 18-50, were randomly allocated into 5 groups. Group 1 and 2 were vaccinated with ChAdOx2 HAV, Groups 3 and 4 with MVA HAV and Group 5 with both vaccines in a prime-boost regimen. A 112-day follow-up period assessed safety and tolerability by recording adverse events (AEs) and serious adverse events (SAEs). Secondary objectives of immunogenicity were assessed by ELISpot (enzyme-linked immunosorbent spot) and clinical response by Crohn's Disease Activity Index (CDAI) and Simple Endoscopic Score for Crohn's Disease (SES-CD).FINDINGS: 28 participants received either a single dose of ChAdOx2 HAV (n = 12), a single dose of MVA HAV (n = 6) or a prime dose of ChAdOx2 HAV (n = 10) followed by an MVA HAV (n = 9) boost. Solicited AEs were 196 in all participants, one AE was graded as severe but resolved within 24 h. The majority of solicited AEs were graded as mild (149/196; 76%, 95% CI 69%-82%) or moderate (45/196; 23%, 95% CI 17%-29%). ELISpot responses increased in Groups 1 and 2 and significantly more after boosting with MVA HAV.INTERPRETATION: Candidate vaccines ChAdOx2 HAV and MVA HAV were safe, well-tolerated and immunogenic in patients with active CD. A heterologous prime-boost schedule induces a T cell-mediated immune response. Further studies are required to determine the efficacy and optimal regime of the vaccines.FUNDING: HAV Vaccines Limited funded the trial and acted as trial sponsor. The Sponsor was involved in protocol development, trial conduct, including data monitoring and analysis, and the preparation of this manuscript in line with the Medicines for Human Use (Clinical Trials) Regulations 2004 and amendments.</p
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