A Robbins-Monro procedure for estimation in semiparametric regression models

This paper is devoted to the parametric estimation of a shift together with the nonparametric estimation of a regression function in a semiparametric regression model. We implement a very efficient and easy to handle Robbins-Monro procedure. On the one hand, we propose a stochastic algorithm similar to that of Robbins-Monro in order to estimate the shift parameter. A preliminary evaluation of the regression function is not necessary to estimate the shift parameter. On the other hand, we make use of a recursive Nadaraya-Watson estimator for the estimation of the regression function. This kernel estimator takes into account the previous estimation of the shift parameter. We establish the almost sure convergence for both Robbins-Monro and Nadaraya--Watson estimators. The asymptotic normality of our estimates is also provided. Finally, we illustrate our semiparametric estimation procedure on simulated and real data.Comment: Published in at http://dx.doi.org/10.1214/12-AOS969 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Les prises d'information dans les activités professionnelles : des éléments à prendre en compte en formation.

We propose to provide lines for thought regarding gathering of information by professionals, and the importance of their inclusion in training situations. This paper results from two researches in professional didactics: the first one, focuses on the activity of farmers who use chipped ground to fertilize their soil, the second one, focuses on the use of a Computer Numerical Control Machine in professional situation and training situation. We show that information gathering is both source and product of the professionals' representations for action. We propose theoretical and methodological proposals concerning the gathering of information. Finally, we show that focusing on the gathering of information is useful to analyze the activity in professional situation, the activity in training situation, and the relationship between these two situations.Nous proposons une réflexion autour des prises d'information effectuées par les professionnels, et de l'importance de leur prise en compte dans les situations de formation. Notre propos découle de deux recherches issues de la didactique professionnelle : une recherche porte sur l'activité d'agriculteurs qui utilisent du bois broyé pour fertiliser leur sol, l'autre recherche porte sur l'utilisation d'une Machine Outil à Commande Numérique en contexte professionnel et en contexte de formation. Après avoir montré que les prises d'information des professionnels sont à la fois sources et produits de leurs représentations pour l'action, nous avançons des propositions théoriques et méthodologiques concernant l'étude des prises d'information. Nous montrons également qu'une focalisation sur les prises d'information permet d'analyser l'activité en situation professionnelle, l'activité en situation de formation, mais également l'articulation entre ces deux situations

Des références pour des pratiques de formation

Ce travail de recherche s’intéresse aux rapports entre le contexte professionnel et le contexte de la formation technologique supérieure lors du développement d’un simulateur de machine-outil.Le cadre conceptuel présente le contexte de la formation technologique supérieure et articule des concepts didactiques, tels que la transposition et les références dans la constitution des situations de formation. Dans cette perspective, une analyse de l’ancrage épistémologique des savoirs pratiques est présentée, à travers la spécificité disciplinaire et le rapport de ces savoirs à la pratique professionnelle. Concernant cette transposition pour la formation deux références dans la modélisation des savoirs sont explorées : les situations professionnelles et les savoirs issus de la recherche scientifique.La méthodologie est portée par le choix de contenus d’enseignement, à travers deux entretiens avec deux professeurs et deux concepteurs du simulateur et ensuite par l’analyse de l’élaboration de contenus d’enseignement (les « savoirs à enseigner »). La méthodologie utilisée mobilise certains outils développés au sein de la didactique professionnelle : l’analyse du contexte professionnel et la structure conceptuelle de la situation. Les résultats exposés permettent de comprendre les modalités de transposition effectuées à travers la simulation informatique et annoncent des possibles voies d’exploitation qui donnent continuité à ce travail.This research focuses on the relations between professional context and higher technological education context during the development of a machine tool simulator. The conceptual framework outlines the context of higher technological education and articulates the didactical concepts, such as the transposition and the references in the composition of educational situations. In this perspective, an analysis of the epistemological roots of practical knowledge is presented, through the specific disciplinary action and the relationship of such knowledge with professional practice. The methodology is driven by the choice of learning content, through two interviews with two teachers and two simulator designers and then by analysing the development of teaching content (the “knowledge to teach”) in two cases. The adopted methodology involves a number of tools developed within professional education: professional contexts analysis and the situation’s conceptual structure. The results presented provide an understanding of the transpositional process through computer simulation and introduce some possible ways of operating that give continuity to this work.Este trabajo de investigación estudia las relaciones entre le contexto profesional y el contexto de la formación tecnológica superior que se dan en le marco del desarrollo de un simulador de maquina-herramienta. El marco conceptual presenta el contexto de la formación tecnológica superior y articula conceptos didácticos como la transposición y las referencias en la constitución de situaciones de formación. En esta perspectiva, presentamos un análisis del anclaje epistemológico de los saberes prácticos, a través de la especificidad disciplinar y la relación entre esos saberes y la practica profesional. Acerca de esta transposición para la formación, se exploraron dos referencias de la modelización de los saberes : las situaciones profesionales y los saberes desde la investigación científica. La metodología esta guiada por la elección de los contenidos de la enseñanza, por medio de dos entrevistas con dos profesores y con dos diseñadores de simuladores, y luego por el análisis de la elaboración de contenidos pedagógicos (“los saberes que se enseñan”). La metodología utilizada moviliza ciertas herramientas desarrolladas en el seno de la didáctica profesional : el análisis del contexto profesional y de la estructura conceptual de la situación. Los resultados expuestos permiten comprender las modalidades de transposición efectuadas a través de la simulación informática y anuncian posibles vías de tratamiento, que serian la continuidad de este trabajo

The Cost of Cochlear Implantation: A Review of Methodological Considerations

Objectives. Cost studies can provide useful guidance, so long as they adhere to accepted methodology. Cochlear implants (CIs) are electronic devices introduced surgically into the inner ear. It is a relevant example to review cost study analyses because of its costliness. The aim of this study was to review relevant published cost studies of CI to analyze the method used. Methods. First, we described the key points of cost study methodology. Cost studies relating to CI were systematically reviewed, focussing on an analysis of the different methods used. Results. The methods, data sources, and estimated cost categories in each study varied widely. The paper showed that cost studies adopted significantly different approaches to estimate costs of CI, reflecting a lack of consensus on the methodology of cost studies. Conclusion. To increase its credibility, closer agreement among researchers on the methodological principles of cost studies would be desirable

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tile only ( 1 85-110 dB HL, 250-500 Hz). In the remaining 7 cases, residual hearing was maintained up to at least 6 months after operation with minor changes. Insertion depth angles in these cases ranged from 285 to 420°. For these subjects, the mean preoperative score for words presented at 65 dB SPL was 22%. Mean postoperative scores were 56% for CI alone, and 68% for CI plus ipsilateral hearing aid (p ! 0.05, paired t). For sentences presented in multitalker babble noise at 5 dB SNR, mean scores were 61% CI alone, and 75% CI+IpsiHA (p ! 0.01, paired t). Conclusions: Hearing was conserved during surgery and over time in 70% of conventional candidates implanted with the Nucleus 24 Contour Advance CI who had significant levels of preoperative low-frequency residual hearing ( ^ 60 dB HL). These conventional candidates for CI also benefited from improved speech recognition in noise when using combined ipsilateral electrical and acoustic stimulation

Development and evaluation of the modiolar research array – multi-centre collaborative study in human temporal bones

OBJECTIVE: Multi-centre collaborative study to develop and refine the design of a prototype thin perimodiolar cochlear implant electrode array and to assess feasibility for use in human subjects. STUDY DESIGN: Multi-centre temporal bone insertion studies. MATERIALS AND METHODS: The modiolar research array (MRA) is a thin pre-curved electrode that is held straight for initial insertion with an external sheath rather than an internal stylet. Between November 2006 and February 2009, six iterations of electrode design were studied in 21 separate insertion studies in which 140 electrode insertions were performed in 85 human temporal bones by 12 surgeons. These studies aimed at addressing four fundamental questions related to the electrode concept, being: (1) Could a sheath result in additional intra-cochlear trauma? (2) Could a sheath accommodate variations in cochlea size and anatomies? (3) Could a sheath be inserted via the round window? and (4) Could a sheath be safely removed once the electrode had been inserted? These questions were investigated within these studies using a number of evaluation techniques, including X-ray and microfluoroscopy, acrylic fixation and temporal bone histologic sectioning, temporal bone microdissection of cochlear structures with electrode visualization, rotational tomography, and insertion force analysis. RESULTS: Frequent examples of electrode rotation and tip fold-over were demonstrated with the initial designs. This was typically caused by excessive curvature of the electrode tip, and also difficulty in handling of the electrode and sheath. The degree of tip curvature was progressively relaxed in subsequent versions with a corresponding reduction in the frequency of tip fold-over. Modifications to the sheath facilitated electrode insertion and sheath removal. Insertion studies with the final MRA design demonstrated minimal trauma, excellent perimodiolar placement, and very small electrode dimensions within scala tympani. Force measurements in temporal bones demonstrated negligible force on cochlear structures with angular insertion depths of between 390 and 450°. CONCLUSION: The MRA is a novel, very thin perimodiolar prototype electrode array that has been developed using a systematic collaborative approach. The different evaluation techniques employed by the investigators contributed to the early identification of issues and generation of solutions. Regarding the four fundamental questions related to the electrode concept, the studies demonstrated that (1) the sheath did not result in additional intra-cochlear trauma; (2) the sheath could accommodate variations in cochlea size and anatomies; (3) the sheath was more successfully inserted via a cochleostomy than via the round window; and (4) the sheath could be safely removed once the electrode had been inserted

Consensus Statement on Bone Conduction Devices and Active Middle Ear Implants in Conductive and Mixed Hearing Loss

Nowadays, several options are available to treat patients with conductive or mixed hearing loss. Whenever surgical intervention is not possible or contra-indicated, and amplification by a conventional hearing device (e.g., behind-the-ear device) is not feasible, then implantable hearing devices are an indispensable next option. Implantable bone-conduction devices and middle-ear implants have advantages but also limitations concerning complexity/invasiveness of the surgery, medical complications, and effectiveness. To counsel the patient, the clinician should have a good overview of the options with regard to safety and reliability as well as unequivocal technical performance data. The present consensus document is the outcome of an extensive iterative process including ENT specialists, audiologists, health-policy scientists, and representatives/technicians of the main companies in this field. This document should provide a first framework for procedures and technical characterization to enhance effective communication between these stakeholders, improving health care

Apprentissage technologique, un simulateur comme outil d’évaluation des compétences

L’article présente une tentative d’innovation en formation technologique d’un simulateur de machine outil à commande numérique. Il s’agit évaluer les effets de cette formation afin d’optimiser aussi bien le processus technique que de formation. Le travail est mené par une équipe multidisciplinaire de chercheurs en génie mécanique et en sciences de l’éducation. Le point de départ est la question des compétences traitée en contexte de formation technologique sous l’angle des activités. Les premiers résultats sont présentés et analysés, ouvrant des perspectives de recherche prometteuses.This article presents an attempt at technological innovation of a digitally controlled machine-tool simulator. It is concerned with the effects of this training in order to optimize not only the technical process but also the training. The work has been carried out by a team of researchers in mechanical engineering and educational science. The starting point is the question of skills, dealt with in the context of technological training from the point of view of the activities. The initial results are presented and analyzed, which opens up a promising field of research.O artigo apresenta uma tentativa de inovação em formação tecnológica de um simulador de máquina, utensílio com mecanismo de comando numérico. Trata-se de avaliar os efeitos desta formação a fim de optimizar quer o processo técnico, quer o de formação. O trabalho é conduzido por uma equipa multidisciplinar de investigadores em engenharia mecânica e em ciências da educação. O ponto de partida é a questão das competências tratada em contexto de formação tecnológica do ponto de vista das actividades. Os primeiros resultados são apresentados e analisados, abrindo perspectivas de investigação promissoras

Professionnalisation et représentation socioprofessionnelle

This paper aims at studying the process of the mobilization of the representation of their future job for training engineers. It attempts to show how this process can influence the investment in the training and, conversely how the training knowledge contributes to the evolution and the transformation of these representations. We propose the concept of socioprofessional representation and we describe it in its organizing principles in order to account for this representational process which plays an essential role in the professionalization. This modeling, illustrated by research work concerning several engineering schools reveals some new emerging knowledge thus asserting the role of Social and Human Sciences in professionalizing training.Le présent article vise à étudier le processus de mobilisation des représentations de leur futur métier de la part d'élèves ingénieurs en formation. Il veut montrer comment ce processus va conditionner l'investissement en formation, et à l'inverse comment les savoirs de formation participent à l'évolution, à la transformation des représentations. Nous proposons le concept de représentation socioprofessionnelle, et nous le décrivons dans ses principes organisateurs pour rendre compte de ce processus représentationnel qui va jouer un rôle essentiel dans la professionnalisation. Cette modélisation, illustrée par des travaux concernant plusieurs écoles d'ingénieurs, fait apparaître de nouveaux savoirs émergents en formation affirmant ainsi la place des Sciences de l'homme et de la société dans les formations professionnalisantes.Fraysse Bernard. Professionnalisation et représentation socioprofessionnelle. In: Recherche & Formation, N°29, 1998. Les sciences humaines et sociales dans la formation des ingénieurs, sous la direction de Odette Bardel-Denonain et Marie-Laure Chaix. pp. 127-141